Merge tag 'scmi-updates-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux into arm/drivers

ARM SCMI updates for v5.13

The major and big addition this time is to support modularisation of
individual SCMI protocols thus enabling to add support for vendors'
custom SCMI protocol. This changes the interface provided by the SCMI
driver to all the users of SCMI and hence involved changes in various
other subsystem SCMI drivers. The change has been split with a bit of
transient code to preserve bisectability and avoiding one big patch bomb
changing all the users.

This also includes SCMI IIO driver(pulled from IIO tree) and support for
per-cpu DVFS.

* tag 'scmi-updates-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux: (41 commits)
  firmware: arm_scmi: Add dynamic scmi devices creation
  firmware: arm_scmi: Add protocol modularization support
  firmware: arm_scmi: Rename non devres notify_ops
  firmware: arm_scmi: Make notify_priv really private
  firmware: arm_scmi: Cleanup events registration transient code
  firmware: arm_scmi: Cleanup unused core transfer helper wrappers
  firmware: arm_scmi: Cleanup legacy protocol init code
  firmware: arm_scmi: Make references to handle const
  firmware: arm_scmi: Remove legacy scmi_voltage_ops protocol interface
  regulator: scmi: Port driver to the new scmi_voltage_proto_ops interface
  firmware: arm_scmi: Port voltage protocol to new protocols interface
  firmware: arm_scmi: Port systempower protocol to new protocols interface
  firmware: arm_scmi: Remove legacy scmi_sensor_ops protocol interface
  iio/scmi: Port driver to the new scmi_sensor_proto_ops interface
  hwmon: (scmi) port driver to the new scmi_sensor_proto_ops interface
  firmware: arm_scmi: Port sensor protocol to new protocols interface
  firmware: arm_scmi: Remove legacy scmi_reset_ops protocol interface
  reset: reset-scmi: Port driver to the new scmi_reset_proto_ops interface
  firmware: arm_scmi: Port reset protocol to new protocols interface
  firmware: arm_scmi: Remove legacy scmi_clk_ops protocol interface
  ...

Link: https://lore.kernel.org/r/20210331100657.ilu63i4swnr3zp4e@bogus
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

14 files changed, 1879 insertions, 780 deletions

diff --git a/drivers/firmware/arm_scmi/base.c b/drivers/firmware/arm_scmi/base.c
index 017e5d8bd869..de416f9e7921 100644
--- a/drivers/firmware/arm_scmi/base.c
+++ b/drivers/firmware/arm_scmi/base.c
@@ -2,11 +2,12 @@
 /*
  * System Control and Management Interface (SCMI) Base Protocol
  *
- * Copyright (C) 2018 ARM Ltd.
+ * Copyright (C) 2018-2021 ARM Ltd.
  */
 
 #define pr_fmt(fmt) "SCMI Notifications BASE - " fmt
 
+#include <linux/module.h>
 #include <linux/scmi_protocol.h>
 
 #include "common.h"
@@ -50,30 +51,30 @@ struct scmi_base_error_notify_payld {
  * scmi_base_attributes_get() - gets the implementation details
  *	that are associated with the base protocol.
  *
- * @handle: SCMI entity handle
+ * @ph: SCMI protocol handle
  *
  * Return: 0 on success, else appropriate SCMI error.
  */
-static int scmi_base_attributes_get(const struct scmi_handle *handle)
+static int scmi_base_attributes_get(const struct scmi_protocol_handle *ph)
 {
 	int ret;
 	struct scmi_xfer *t;
 	struct scmi_msg_resp_base_attributes *attr_info;
-	struct scmi_revision_info *rev = handle->version;
+	struct scmi_revision_info *rev = ph->get_priv(ph);
 
-	ret = scmi_xfer_get_init(handle, PROTOCOL_ATTRIBUTES,
-				 SCMI_PROTOCOL_BASE, 0, sizeof(*attr_info), &t);
+	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES,
+				      0, sizeof(*attr_info), &t);
 	if (ret)
 		return ret;
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 	if (!ret) {
 		attr_info = t->rx.buf;
 		rev->num_protocols = attr_info->num_protocols;
 		rev->num_agents = attr_info->num_agents;
 	}
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 
 	return ret;
 }
@@ -81,19 +82,20 @@ static int scmi_base_attributes_get(const struct scmi_handle *handle)
 /**
  * scmi_base_vendor_id_get() - gets vendor/subvendor identifier ASCII string.
  *
- * @handle: SCMI entity handle
+ * @ph: SCMI protocol handle
  * @sub_vendor: specify true if sub-vendor ID is needed
  *
  * Return: 0 on success, else appropriate SCMI error.
  */
 static int
-scmi_base_vendor_id_get(const struct scmi_handle *handle, bool sub_vendor)
+scmi_base_vendor_id_get(const struct scmi_protocol_handle *ph, bool sub_vendor)
 {
 	u8 cmd;
 	int ret, size;
 	char *vendor_id;
 	struct scmi_xfer *t;
-	struct scmi_revision_info *rev = handle->version;
+	struct scmi_revision_info *rev = ph->get_priv(ph);
+
 
 	if (sub_vendor) {
 		cmd = BASE_DISCOVER_SUB_VENDOR;
@@ -105,15 +107,15 @@ scmi_base_vendor_id_get(const struct scmi_handle *handle, bool sub_vendor)
 		size = ARRAY_SIZE(rev->vendor_id);
 	}
 
-	ret = scmi_xfer_get_init(handle, cmd, SCMI_PROTOCOL_BASE, 0, size, &t);
+	ret = ph->xops->xfer_get_init(ph, cmd, 0, size, &t);
 	if (ret)
 		return ret;
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 	if (!ret)
 		memcpy(vendor_id, t->rx.buf, size);
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 
 	return ret;
 }
@@ -123,30 +125,30 @@ scmi_base_vendor_id_get(const struct scmi_handle *handle, bool sub_vendor)
  *	implementation 32-bit version. The format of the version number is
  *	vendor-specific
  *
- * @handle: SCMI entity handle
+ * @ph: SCMI protocol handle
  *
  * Return: 0 on success, else appropriate SCMI error.
  */
 static int
-scmi_base_implementation_version_get(const struct scmi_handle *handle)
+scmi_base_implementation_version_get(const struct scmi_protocol_handle *ph)
 {
 	int ret;
 	__le32 *impl_ver;
 	struct scmi_xfer *t;
-	struct scmi_revision_info *rev = handle->version;
+	struct scmi_revision_info *rev = ph->get_priv(ph);
 
-	ret = scmi_xfer_get_init(handle, BASE_DISCOVER_IMPLEMENT_VERSION,
-				 SCMI_PROTOCOL_BASE, 0, sizeof(*impl_ver), &t);
+	ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_IMPLEMENT_VERSION,
+				      0, sizeof(*impl_ver), &t);
 	if (ret)
 		return ret;
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 	if (!ret) {
 		impl_ver = t->rx.buf;
 		rev->impl_ver = le32_to_cpu(*impl_ver);
 	}
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 
 	return ret;
 }
@@ -155,23 +157,24 @@ scmi_base_implementation_version_get(const struct scmi_handle *handle)
  * scmi_base_implementation_list_get() - gets the list of protocols it is
  *	OSPM is allowed to access
  *
- * @handle: SCMI entity handle
+ * @ph: SCMI protocol handle
  * @protocols_imp: pointer to hold the list of protocol identifiers
  *
  * Return: 0 on success, else appropriate SCMI error.
  */
-static int scmi_base_implementation_list_get(const struct scmi_handle *handle,
-					     u8 *protocols_imp)
+static int
+scmi_base_implementation_list_get(const struct scmi_protocol_handle *ph,
+				  u8 *protocols_imp)
 {
 	u8 *list;
 	int ret, loop;
 	struct scmi_xfer *t;
 	__le32 *num_skip, *num_ret;
 	u32 tot_num_ret = 0, loop_num_ret;
-	struct device *dev = handle->dev;
+	struct device *dev = ph->dev;
 
-	ret = scmi_xfer_get_init(handle, BASE_DISCOVER_LIST_PROTOCOLS,
-				 SCMI_PROTOCOL_BASE, sizeof(*num_skip), 0, &t);
+	ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_LIST_PROTOCOLS,
+				      sizeof(*num_skip), 0, &t);
 	if (ret)
 		return ret;
 
@@ -183,7 +186,7 @@ static int scmi_base_implementation_list_get(const struct scmi_handle *handle,
 		/* Set the number of protocols to be skipped/already read */
 		*num_skip = cpu_to_le32(tot_num_ret);
 
-		ret = scmi_do_xfer(handle, t);
+		ret = ph->xops->do_xfer(ph, t);
 		if (ret)
 			break;
 
@@ -198,10 +201,10 @@ static int scmi_base_implementation_list_get(const struct scmi_handle *handle,
 
 		tot_num_ret += loop_num_ret;
 
-		scmi_reset_rx_to_maxsz(handle, t);
+		ph->xops->reset_rx_to_maxsz(ph, t);
 	} while (loop_num_ret);
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 
 	return ret;
 }
@@ -209,7 +212,7 @@ static int scmi_base_implementation_list_get(const struct scmi_handle *handle,
 /**
  * scmi_base_discover_agent_get() - discover the name of an agent
  *
- * @handle: SCMI entity handle
+ * @ph: SCMI protocol handle
  * @id: Agent identifier
  * @name: Agent identifier ASCII string
  *
@@ -218,63 +221,63 @@ static int scmi_base_implementation_list_get(const struct scmi_handle *handle,
  *
  * Return: 0 on success, else appropriate SCMI error.
  */
-static int scmi_base_discover_agent_get(const struct scmi_handle *handle,
+static int scmi_base_discover_agent_get(const struct scmi_protocol_handle *ph,
 					int id, char *name)
 {
 	int ret;
 	struct scmi_xfer *t;
 
-	ret = scmi_xfer_get_init(handle, BASE_DISCOVER_AGENT,
-				 SCMI_PROTOCOL_BASE, sizeof(__le32),
-				 SCMI_MAX_STR_SIZE, &t);
+	ret = ph->xops->xfer_get_init(ph, BASE_DISCOVER_AGENT,
+				      sizeof(__le32), SCMI_MAX_STR_SIZE, &t);
 	if (ret)
 		return ret;
 
 	put_unaligned_le32(id, t->tx.buf);
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 	if (!ret)
 		strlcpy(name, t->rx.buf, SCMI_MAX_STR_SIZE);
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 
 	return ret;
 }
 
-static int scmi_base_error_notify(const struct scmi_handle *handle, bool enable)
+static int scmi_base_error_notify(const struct scmi_protocol_handle *ph,
+				  bool enable)
 {
 	int ret;
 	u32 evt_cntl = enable ? BASE_TP_NOTIFY_ALL : 0;
 	struct scmi_xfer *t;
 	struct scmi_msg_base_error_notify *cfg;
 
-	ret = scmi_xfer_get_init(handle, BASE_NOTIFY_ERRORS,
-				 SCMI_PROTOCOL_BASE, sizeof(*cfg), 0, &t);
+	ret = ph->xops->xfer_get_init(ph, BASE_NOTIFY_ERRORS,
+				      sizeof(*cfg), 0, &t);
 	if (ret)
 		return ret;
 
 	cfg = t->tx.buf;
 	cfg->event_control = cpu_to_le32(evt_cntl);
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
-static int scmi_base_set_notify_enabled(const struct scmi_handle *handle,
+static int scmi_base_set_notify_enabled(const struct scmi_protocol_handle *ph,
 					u8 evt_id, u32 src_id, bool enable)
 {
 	int ret;
 
-	ret = scmi_base_error_notify(handle, enable);
+	ret = scmi_base_error_notify(ph, enable);
 	if (ret)
 		pr_debug("FAIL_ENABLED - evt[%X] ret:%d\n", evt_id, ret);
 
 	return ret;
 }
 
-static void *scmi_base_fill_custom_report(const struct scmi_handle *handle,
+static void *scmi_base_fill_custom_report(const struct scmi_protocol_handle *ph,
 					  u8 evt_id, ktime_t timestamp,
 					  const void *payld, size_t payld_sz,
 					  void *report, u32 *src_id)
@@ -318,17 +321,24 @@ static const struct scmi_event_ops base_event_ops = {
 	.fill_custom_report = scmi_base_fill_custom_report,
 };
 
-int scmi_base_protocol_init(struct scmi_handle *h)
+static const struct scmi_protocol_events base_protocol_events = {
+	.queue_sz = 4 * SCMI_PROTO_QUEUE_SZ,
+	.ops = &base_event_ops,
+	.evts = base_events,
+	.num_events = ARRAY_SIZE(base_events),
+	.num_sources = SCMI_BASE_NUM_SOURCES,
+};
+
+static int scmi_base_protocol_init(const struct scmi_protocol_handle *ph)
 {
 	int id, ret;
 	u8 *prot_imp;
 	u32 version;
 	char name[SCMI_MAX_STR_SIZE];
-	const struct scmi_handle *handle = h;
-	struct device *dev = handle->dev;
-	struct scmi_revision_info *rev = handle->version;
+	struct device *dev = ph->dev;
+	struct scmi_revision_info *rev = scmi_revision_area_get(ph);
 
-	ret = scmi_version_get(handle, SCMI_PROTOCOL_BASE, &version);
+	ret = ph->xops->version_get(ph, &version);
 	if (ret)
 		return ret;
 
@@ -338,13 +348,15 @@ int scmi_base_protocol_init(struct scmi_handle *h)
 
 	rev->major_ver = PROTOCOL_REV_MAJOR(version),
 	rev->minor_ver = PROTOCOL_REV_MINOR(version);
+	ph->set_priv(ph, rev);
+
+	scmi_base_attributes_get(ph);
+	scmi_base_vendor_id_get(ph, false);
+	scmi_base_vendor_id_get(ph, true);
+	scmi_base_implementation_version_get(ph);
+	scmi_base_implementation_list_get(ph, prot_imp);
 
-	scmi_base_attributes_get(handle);
-	scmi_base_vendor_id_get(handle, false);
-	scmi_base_vendor_id_get(handle, true);
-	scmi_base_implementation_version_get(handle);
-	scmi_base_implementation_list_get(handle, prot_imp);
-	scmi_setup_protocol_implemented(handle, prot_imp);
+	scmi_setup_protocol_implemented(ph, prot_imp);
 
 	dev_info(dev, "SCMI Protocol v%d.%d '%s:%s' Firmware version 0x%x\n",
 		 rev->major_ver, rev->minor_ver, rev->vendor_id,
@@ -352,16 +364,20 @@ int scmi_base_protocol_init(struct scmi_handle *h)
 	dev_dbg(dev, "Found %d protocol(s) %d agent(s)\n", rev->num_protocols,
 		rev->num_agents);
 
-	scmi_register_protocol_events(handle, SCMI_PROTOCOL_BASE,
-				      (4 * SCMI_PROTO_QUEUE_SZ),
-				      &base_event_ops, base_events,
-				      ARRAY_SIZE(base_events),
-				      SCMI_BASE_NUM_SOURCES);
-
 	for (id = 0; id < rev->num_agents; id++) {
-		scmi_base_discover_agent_get(handle, id, name);
+		scmi_base_discover_agent_get(ph, id, name);
 		dev_dbg(dev, "Agent %d: %s\n", id, name);
 	}
 
 	return 0;
 }
+
+static const struct scmi_protocol scmi_base = {
+	.id = SCMI_PROTOCOL_BASE,
+	.owner = NULL,
+	.instance_init = &scmi_base_protocol_init,
+	.ops = NULL,
+	.events = &base_protocol_events,
+};
+
+DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(base, scmi_base)
diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index 1377ec76a45d..784cf0027da3 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -2,7 +2,7 @@
 /*
  * System Control and Management Interface (SCMI) Message Protocol bus layer
  *
- * Copyright (C) 2018 ARM Ltd.
+ * Copyright (C) 2018-2021 ARM Ltd.
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -51,18 +51,53 @@ static int scmi_dev_match(struct device *dev, struct device_driver *drv)
 	return 0;
 }
 
-static int scmi_protocol_init(int protocol_id, struct scmi_handle *handle)
+static int scmi_match_by_id_table(struct device *dev, void *data)
 {
-	scmi_prot_init_fn_t fn = idr_find(&scmi_protocols, protocol_id);
+	struct scmi_device *sdev = to_scmi_dev(dev);
+	struct scmi_device_id *id_table = data;
 
-	if (unlikely(!fn))
-		return -EINVAL;
-	return fn(handle);
+	return sdev->protocol_id == id_table->protocol_id &&
+		!strcmp(sdev->name, id_table->name);
 }
 
-static int scmi_protocol_dummy_init(struct scmi_handle *handle)
+struct scmi_device *scmi_child_dev_find(struct device *parent,
+					int prot_id, const char *name)
 {
-	return 0;
+	struct scmi_device_id id_table;
+	struct device *dev;
+
+	id_table.protocol_id = prot_id;
+	id_table.name = name;
+
+	dev = device_find_child(parent, &id_table, scmi_match_by_id_table);
+	if (!dev)
+		return NULL;
+
+	return to_scmi_dev(dev);
+}
+
+const struct scmi_protocol *scmi_protocol_get(int protocol_id)
+{
+	const struct scmi_protocol *proto;
+
+	proto = idr_find(&scmi_protocols, protocol_id);
+	if (!proto || !try_module_get(proto->owner)) {
+		pr_warn("SCMI Protocol 0x%x not found!\n", protocol_id);
+		return NULL;
+	}
+
+	pr_debug("Found SCMI Protocol 0x%x\n", protocol_id);
+
+	return proto;
+}
+
+void scmi_protocol_put(int protocol_id)
+{
+	const struct scmi_protocol *proto;
+
+	proto = idr_find(&scmi_protocols, protocol_id);
+	if (proto)
+		module_put(proto->owner);
 }
 
 static int scmi_dev_probe(struct device *dev)
@@ -70,7 +105,6 @@ static int scmi_dev_probe(struct device *dev)
 	struct scmi_driver *scmi_drv = to_scmi_driver(dev->driver);
 	struct scmi_device *scmi_dev = to_scmi_dev(dev);
 	const struct scmi_device_id *id;
-	int ret;
 
 	id = scmi_dev_match_id(scmi_dev, scmi_drv);
 	if (!id)
@@ -79,14 +113,6 @@ static int scmi_dev_probe(struct device *dev)
 	if (!scmi_dev->handle)
 		return -EPROBE_DEFER;
 
-	ret = scmi_protocol_init(scmi_dev->protocol_id, scmi_dev->handle);
-	if (ret)
-		return ret;
-
-	/* Skip protocol initialisation for additional devices */
-	idr_replace(&scmi_protocols, &scmi_protocol_dummy_init,
-		    scmi_dev->protocol_id);
-
 	return scmi_drv->probe(scmi_dev);
 }
 
@@ -113,6 +139,10 @@ int scmi_driver_register(struct scmi_driver *driver, struct module *owner,
 {
 	int retval;
 
+	retval = scmi_protocol_device_request(driver->id_table);
+	if (retval)
+		return retval;
+
 	driver->driver.bus = &scmi_bus_type;
 	driver->driver.name = driver->name;
 	driver->driver.owner = owner;
@@ -129,6 +159,7 @@ EXPORT_SYMBOL_GPL(scmi_driver_register);
 void scmi_driver_unregister(struct scmi_driver *driver)
 {
 	driver_unregister(&driver->driver);
+	scmi_protocol_device_unrequest(driver->id_table);
 }
 EXPORT_SYMBOL_GPL(scmi_driver_unregister);
 
@@ -194,26 +225,45 @@ void scmi_set_handle(struct scmi_device *scmi_dev)
 	scmi_dev->handle = scmi_handle_get(&scmi_dev->dev);
 }
 
-int scmi_protocol_register(int protocol_id, scmi_prot_init_fn_t fn)
+int scmi_protocol_register(const struct scmi_protocol *proto)
 {
 	int ret;
 
+	if (!proto) {
+		pr_err("invalid protocol\n");
+		return -EINVAL;
+	}
+
+	if (!proto->instance_init) {
+		pr_err("missing init for protocol 0x%x\n", proto->id);
+		return -EINVAL;
+	}
+
 	spin_lock(&protocol_lock);
-	ret = idr_alloc(&scmi_protocols, fn, protocol_id, protocol_id + 1,
-			GFP_ATOMIC);
+	ret = idr_alloc(&scmi_protocols, (void *)proto,
+			proto->id, proto->id + 1, GFP_ATOMIC);
 	spin_unlock(&protocol_lock);
-	if (ret != protocol_id)
-		pr_err("unable to allocate SCMI idr slot, err %d\n", ret);
+	if (ret != proto->id) {
+		pr_err("unable to allocate SCMI idr slot for 0x%x - err %d\n",
+		       proto->id, ret);
+		return ret;
+	}
 
-	return ret;
+	pr_debug("Registered SCMI Protocol 0x%x\n", proto->id);
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(scmi_protocol_register);
 
-void scmi_protocol_unregister(int protocol_id)
+void scmi_protocol_unregister(const struct scmi_protocol *proto)
 {
 	spin_lock(&protocol_lock);
-	idr_remove(&scmi_protocols, protocol_id);
+	idr_remove(&scmi_protocols, proto->id);
 	spin_unlock(&protocol_lock);
+
+	pr_debug("Unregistered SCMI Protocol 0x%x\n", proto->id);
+
+	return;
 }
 EXPORT_SYMBOL_GPL(scmi_protocol_unregister);
 
diff --git a/drivers/firmware/arm_scmi/clock.c b/drivers/firmware/arm_scmi/clock.c
index 4645677d86f1..35b56c8ba0c0 100644
--- a/drivers/firmware/arm_scmi/clock.c
+++ b/drivers/firmware/arm_scmi/clock.c
@@ -2,9 +2,10 @@
 /*
  * System Control and Management Interface (SCMI) Clock Protocol
  *
- * Copyright (C) 2018 ARM Ltd.
+ * Copyright (C) 2018-2021 ARM Ltd.
  */
 
+#include <linux/module.h>
 #include <linux/sort.h>
 
 #include "common.h"
@@ -74,52 +75,53 @@ struct clock_info {
 	struct scmi_clock_info *clk;
 };
 
-static int scmi_clock_protocol_attributes_get(const struct scmi_handle *handle,
-					      struct clock_info *ci)
+static int
+scmi_clock_protocol_attributes_get(const struct scmi_protocol_handle *ph,
+				   struct clock_info *ci)
 {
 	int ret;
 	struct scmi_xfer *t;
 	struct scmi_msg_resp_clock_protocol_attributes *attr;
 
-	ret = scmi_xfer_get_init(handle, PROTOCOL_ATTRIBUTES,
-				 SCMI_PROTOCOL_CLOCK, 0, sizeof(*attr), &t);
+	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES,
+				      0, sizeof(*attr), &t);
 	if (ret)
 		return ret;
 
 	attr = t->rx.buf;
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 	if (!ret) {
 		ci->num_clocks = le16_to_cpu(attr->num_clocks);
 		ci->max_async_req = attr->max_async_req;
 	}
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
-static int scmi_clock_attributes_get(const struct scmi_handle *handle,
+static int scmi_clock_attributes_get(const struct scmi_protocol_handle *ph,
 				     u32 clk_id, struct scmi_clock_info *clk)
 {
 	int ret;
 	struct scmi_xfer *t;
 	struct scmi_msg_resp_clock_attributes *attr;
 
-	ret = scmi_xfer_get_init(handle, CLOCK_ATTRIBUTES, SCMI_PROTOCOL_CLOCK,
-				 sizeof(clk_id), sizeof(*attr), &t);
+	ret = ph->xops->xfer_get_init(ph, CLOCK_ATTRIBUTES,
+				      sizeof(clk_id), sizeof(*attr), &t);
 	if (ret)
 		return ret;
 
 	put_unaligned_le32(clk_id, t->tx.buf);
 	attr = t->rx.buf;
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 	if (!ret)
 		strlcpy(clk->name, attr->name, SCMI_MAX_STR_SIZE);
 	else
 		clk->name[0] = '\0';
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
@@ -136,7 +138,7 @@ static int rate_cmp_func(const void *_r1, const void *_r2)
 }
 
 static int
-scmi_clock_describe_rates_get(const struct scmi_handle *handle, u32 clk_id,
+scmi_clock_describe_rates_get(const struct scmi_protocol_handle *ph, u32 clk_id,
 			      struct scmi_clock_info *clk)
 {
 	u64 *rate = NULL;
@@ -148,8 +150,8 @@ scmi_clock_describe_rates_get(const struct scmi_handle *handle, u32 clk_id,
 	struct scmi_msg_clock_describe_rates *clk_desc;
 	struct scmi_msg_resp_clock_describe_rates *rlist;
 
-	ret = scmi_xfer_get_init(handle, CLOCK_DESCRIBE_RATES,
-				 SCMI_PROTOCOL_CLOCK, sizeof(*clk_desc), 0, &t);
+	ret = ph->xops->xfer_get_init(ph, CLOCK_DESCRIBE_RATES,
+				      sizeof(*clk_desc), 0, &t);
 	if (ret)
 		return ret;
 
@@ -161,7 +163,7 @@ scmi_clock_describe_rates_get(const struct scmi_handle *handle, u32 clk_id,
 		/* Set the number of rates to be skipped/already read */
 		clk_desc->rate_index = cpu_to_le32(tot_rate_cnt);
 
-		ret = scmi_do_xfer(handle, t);
+		ret = ph->xops->do_xfer(ph, t);
 		if (ret)
 			goto err;
 
@@ -171,7 +173,7 @@ scmi_clock_describe_rates_get(const struct scmi_handle *handle, u32 clk_id,
 		num_returned = NUM_RETURNED(rates_flag);
 
 		if (tot_rate_cnt + num_returned > SCMI_MAX_NUM_RATES) {
-			dev_err(handle->dev, "No. of rates > MAX_NUM_RATES");
+			dev_err(ph->dev, "No. of rates > MAX_NUM_RATES");
 			break;
 		}
 
@@ -179,7 +181,7 @@ scmi_clock_describe_rates_get(const struct scmi_handle *handle, u32 clk_id,
 			clk->range.min_rate = RATE_TO_U64(rlist->rate[0]);
 			clk->range.max_rate = RATE_TO_U64(rlist->rate[1]);
 			clk->range.step_size = RATE_TO_U64(rlist->rate[2]);
-			dev_dbg(handle->dev, "Min %llu Max %llu Step %llu Hz\n",
+			dev_dbg(ph->dev, "Min %llu Max %llu Step %llu Hz\n",
 				clk->range.min_rate, clk->range.max_rate,
 				clk->range.step_size);
 			break;
@@ -188,12 +190,12 @@ scmi_clock_describe_rates_get(const struct scmi_handle *handle, u32 clk_id,
 		rate = &clk->list.rates[tot_rate_cnt];
 		for (cnt = 0; cnt < num_returned; cnt++, rate++) {
 			*rate = RATE_TO_U64(rlist->rate[cnt]);
-			dev_dbg(handle->dev, "Rate %llu Hz\n", *rate);
+			dev_dbg(ph->dev, "Rate %llu Hz\n", *rate);
 		}
 
 		tot_rate_cnt += num_returned;
 
-		scmi_reset_rx_to_maxsz(handle, t);
+		ph->xops->reset_rx_to_maxsz(ph, t);
 		/*
 		 * check for both returned and remaining to avoid infinite
 		 * loop due to buggy firmware
@@ -208,42 +210,42 @@ scmi_clock_describe_rates_get(const struct scmi_handle *handle, u32 clk_id,
 	clk->rate_discrete = rate_discrete;
 
 err:
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
 static int
-scmi_clock_rate_get(const struct scmi_handle *handle, u32 clk_id, u64 *value)
+scmi_clock_rate_get(const struct scmi_protocol_handle *ph,
+		    u32 clk_id, u64 *value)
 {
 	int ret;
 	struct scmi_xfer *t;
 
-	ret = scmi_xfer_get_init(handle, CLOCK_RATE_GET, SCMI_PROTOCOL_CLOCK,
-				 sizeof(__le32), sizeof(u64), &t);
+	ret = ph->xops->xfer_get_init(ph, CLOCK_RATE_GET,
+				      sizeof(__le32), sizeof(u64), &t);
 	if (ret)
 		return ret;
 
 	put_unaligned_le32(clk_id, t->tx.buf);
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 	if (!ret)
 		*value = get_unaligned_le64(t->rx.buf);
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
-static int scmi_clock_rate_set(const struct scmi_handle *handle, u32 clk_id,
-			       u64 rate)
+static int scmi_clock_rate_set(const struct scmi_protocol_handle *ph,
+			       u32 clk_id, u64 rate)
 {
 	int ret;
 	u32 flags = 0;
 	struct scmi_xfer *t;
 	struct scmi_clock_set_rate *cfg;
-	struct clock_info *ci = handle->clk_priv;
+	struct clock_info *ci = ph->get_priv(ph);
 
-	ret = scmi_xfer_get_init(handle, CLOCK_RATE_SET, SCMI_PROTOCOL_CLOCK,
-				 sizeof(*cfg), 0, &t);
+	ret = ph->xops->xfer_get_init(ph, CLOCK_RATE_SET, sizeof(*cfg), 0, &t);
 	if (ret)
 		return ret;
 
@@ -258,26 +260,27 @@ static int scmi_clock_rate_set(const struct scmi_handle *handle, u32 clk_id,
 	cfg->value_high = cpu_to_le32(rate >> 32);
 
 	if (flags & CLOCK_SET_ASYNC)
-		ret = scmi_do_xfer_with_response(handle, t);
+		ret = ph->xops->do_xfer_with_response(ph, t);
 	else
-		ret = scmi_do_xfer(handle, t);
+		ret = ph->xops->do_xfer(ph, t);
 
 	if (ci->max_async_req)
 		atomic_dec(&ci->cur_async_req);
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
 static int
-scmi_clock_config_set(const struct scmi_handle *handle, u32 clk_id, u32 config)
+scmi_clock_config_set(const struct scmi_protocol_handle *ph, u32 clk_id,
+		      u32 config)
 {
 	int ret;
 	struct scmi_xfer *t;
 	struct scmi_clock_set_config *cfg;
 
-	ret = scmi_xfer_get_init(handle, CLOCK_CONFIG_SET, SCMI_PROTOCOL_CLOCK,
-				 sizeof(*cfg), 0, &t);
+	ret = ph->xops->xfer_get_init(ph, CLOCK_CONFIG_SET,
+				      sizeof(*cfg), 0, &t);
 	if (ret)
 		return ret;
 
@@ -285,33 +288,33 @@ scmi_clock_config_set(const struct scmi_handle *handle, u32 clk_id, u32 config)
 	cfg->id = cpu_to_le32(clk_id);
 	cfg->attributes = cpu_to_le32(config);
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
-static int scmi_clock_enable(const struct scmi_handle *handle, u32 clk_id)
+static int scmi_clock_enable(const struct scmi_protocol_handle *ph, u32 clk_id)
 {
-	return scmi_clock_config_set(handle, clk_id, CLOCK_ENABLE);
+	return scmi_clock_config_set(ph, clk_id, CLOCK_ENABLE);
 }
 
-static int scmi_clock_disable(const struct scmi_handle *handle, u32 clk_id)
+static int scmi_clock_disable(const struct scmi_protocol_handle *ph, u32 clk_id)
 {
-	return scmi_clock_config_set(handle, clk_id, 0);
+	return scmi_clock_config_set(ph, clk_id, 0);
 }
 
-static int scmi_clock_count_get(const struct scmi_handle *handle)
+static int scmi_clock_count_get(const struct scmi_protocol_handle *ph)
 {
-	struct clock_info *ci = handle->clk_priv;
+	struct clock_info *ci = ph->get_priv(ph);
 
 	return ci->num_clocks;
 }
 
 static const struct scmi_clock_info *
-scmi_clock_info_get(const struct scmi_handle *handle, u32 clk_id)
+scmi_clock_info_get(const struct scmi_protocol_handle *ph, u32 clk_id)
 {
-	struct clock_info *ci = handle->clk_priv;
+	struct clock_info *ci = ph->get_priv(ph);
 	struct scmi_clock_info *clk = ci->clk + clk_id;
 
 	if (!clk->name[0])
@@ -320,7 +323,7 @@ scmi_clock_info_get(const struct scmi_handle *handle, u32 clk_id)
 	return clk;
 }
 
-static const struct scmi_clk_ops clk_ops = {
+static const struct scmi_clk_proto_ops clk_proto_ops = {
 	.count_get = scmi_clock_count_get,
 	.info_get = scmi_clock_info_get,
 	.rate_get = scmi_clock_rate_get,
@@ -329,24 +332,24 @@ static const struct scmi_clk_ops clk_ops = {
 	.disable = scmi_clock_disable,
 };
 
-static int scmi_clock_protocol_init(struct scmi_handle *handle)
+static int scmi_clock_protocol_init(const struct scmi_protocol_handle *ph)
 {
 	u32 version;
 	int clkid, ret;
 	struct clock_info *cinfo;
 
-	scmi_version_get(handle, SCMI_PROTOCOL_CLOCK, &version);
+	ph->xops->version_get(ph, &version);
 
-	dev_dbg(handle->dev, "Clock Version %d.%d\n",
+	dev_dbg(ph->dev, "Clock Version %d.%d\n",
 		PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
 
-	cinfo = devm_kzalloc(handle->dev, sizeof(*cinfo), GFP_KERNEL);
+	cinfo = devm_kzalloc(ph->dev, sizeof(*cinfo), GFP_KERNEL);
 	if (!cinfo)
 		return -ENOMEM;
 
-	scmi_clock_protocol_attributes_get(handle, cinfo);
+	scmi_clock_protocol_attributes_get(ph, cinfo);
 
-	cinfo->clk = devm_kcalloc(handle->dev, cinfo->num_clocks,
+	cinfo->clk = devm_kcalloc(ph->dev, cinfo->num_clocks,
 				  sizeof(*cinfo->clk), GFP_KERNEL);
 	if (!cinfo->clk)
 		return -ENOMEM;
@@ -354,16 +357,20 @@ static int scmi_clock_protocol_init(struct scmi_handle *handle)
 	for (clkid = 0; clkid < cinfo->num_clocks; clkid++) {
 		struct scmi_clock_info *clk = cinfo->clk + clkid;
 
-		ret = scmi_clock_attributes_get(handle, clkid, clk);
+		ret = scmi_clock_attributes_get(ph, clkid, clk);
 		if (!ret)
-			scmi_clock_describe_rates_get(handle, clkid, clk);
+			scmi_clock_describe_rates_get(ph, clkid, clk);
 	}
 
 	cinfo->version = version;
-	handle->clk_ops = &clk_ops;
-	handle->clk_priv = cinfo;
-
-	return 0;
+	return ph->set_priv(ph, cinfo);
 }
 
-DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(SCMI_PROTOCOL_CLOCK, clock)
+static const struct scmi_protocol scmi_clock = {
+	.id = SCMI_PROTOCOL_CLOCK,
+	.owner = THIS_MODULE,
+	.instance_init = &scmi_clock_protocol_init,
+	.ops = &clk_proto_ops,
+};
+
+DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(clock, scmi_clock)
diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index c0fb45e7c3e8..228bf4a71d23 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -4,7 +4,7 @@
  * driver common header file containing some definitions, structures
  * and function prototypes used in all the different SCMI protocols.
  *
- * Copyright (C) 2018 ARM Ltd.
+ * Copyright (C) 2018-2021 ARM Ltd.
  */
 #ifndef _SCMI_COMMON_H
 #define _SCMI_COMMON_H
@@ -14,11 +14,14 @@
 #include <linux/device.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/scmi_protocol.h>
 #include <linux/types.h>
 
 #include <asm/unaligned.h>
 
+#include "notify.h"
+
 #define PROTOCOL_REV_MINOR_MASK	GENMASK(15, 0)
 #define PROTOCOL_REV_MAJOR_MASK	GENMASK(31, 16)
 #define PROTOCOL_REV_MAJOR(x)	(u16)(FIELD_GET(PROTOCOL_REV_MAJOR_MASK, (x)))
@@ -141,22 +144,92 @@ struct scmi_xfer {
 	struct completion *async_done;
 };
 
-void scmi_xfer_put(const struct scmi_handle *h, struct scmi_xfer *xfer);
-int scmi_do_xfer(const struct scmi_handle *h, struct scmi_xfer *xfer);
-int scmi_do_xfer_with_response(const struct scmi_handle *h,
-			       struct scmi_xfer *xfer);
-int scmi_xfer_get_init(const struct scmi_handle *h, u8 msg_id, u8 prot_id,
-		       size_t tx_size, size_t rx_size, struct scmi_xfer **p);
-void scmi_reset_rx_to_maxsz(const struct scmi_handle *handle,
-			    struct scmi_xfer *xfer);
+struct scmi_xfer_ops;
+
+/**
+ * struct scmi_protocol_handle  - Reference to an initialized protocol instance
+ *
+ * @dev: A reference to the associated SCMI instance device (handle->dev).
+ * @xops: A reference to a struct holding refs to the core xfer operations that
+ *	  can be used by the protocol implementation to generate SCMI messages.
+ * @set_priv: A method to set protocol private data for this instance.
+ * @get_priv: A method to get protocol private data previously set.
+ *
+ * This structure represents a protocol initialized against specific SCMI
+ * instance and it will be used as follows:
+ * - as a parameter fed from the core to the protocol initialization code so
+ *   that it can access the core xfer operations to build and generate SCMI
+ *   messages exclusively for the specific underlying protocol instance.
+ * - as an opaque handle fed by an SCMI driver user when it tries to access
+ *   this protocol through its own protocol operations.
+ *   In this case this handle will be returned as an opaque object together
+ *   with the related protocol operations when the SCMI driver tries to access
+ *   the protocol.
+ */
+struct scmi_protocol_handle {
+	struct device *dev;
+	const struct scmi_xfer_ops *xops;
+	int (*set_priv)(const struct scmi_protocol_handle *ph, void *priv);
+	void *(*get_priv)(const struct scmi_protocol_handle *ph);
+};
+
+/**
+ * struct scmi_xfer_ops  - References to the core SCMI xfer operations.
+ * @version_get: Get this version protocol.
+ * @xfer_get_init: Initialize one struct xfer if any xfer slot is free.
+ * @reset_rx_to_maxsz: Reset rx size to max transport size.
+ * @do_xfer: Do the SCMI transfer.
+ * @do_xfer_with_response: Do the SCMI transfer waiting for a response.
+ * @xfer_put: Free the xfer slot.
+ *
+ * Note that all this operations expect a protocol handle as first parameter;
+ * they then internally use it to infer the underlying protocol number: this
+ * way is not possible for a protocol implementation to forge messages for
+ * another protocol.
+ */
+struct scmi_xfer_ops {
+	int (*version_get)(const struct scmi_protocol_handle *ph, u32 *version);
+	int (*xfer_get_init)(const struct scmi_protocol_handle *ph, u8 msg_id,
+			     size_t tx_size, size_t rx_size,
+			     struct scmi_xfer **p);
+	void (*reset_rx_to_maxsz)(const struct scmi_protocol_handle *ph,
+				  struct scmi_xfer *xfer);
+	int (*do_xfer)(const struct scmi_protocol_handle *ph,
+		       struct scmi_xfer *xfer);
+	int (*do_xfer_with_response)(const struct scmi_protocol_handle *ph,
+				     struct scmi_xfer *xfer);
+	void (*xfer_put)(const struct scmi_protocol_handle *ph,
+			 struct scmi_xfer *xfer);
+};
+
+struct scmi_revision_info *
+scmi_revision_area_get(const struct scmi_protocol_handle *ph);
 int scmi_handle_put(const struct scmi_handle *handle);
 struct scmi_handle *scmi_handle_get(struct device *dev);
 void scmi_set_handle(struct scmi_device *scmi_dev);
-int scmi_version_get(const struct scmi_handle *h, u8 protocol, u32 *version);
-void scmi_setup_protocol_implemented(const struct scmi_handle *handle,
+void scmi_setup_protocol_implemented(const struct scmi_protocol_handle *ph,
 				     u8 *prot_imp);
 
-int scmi_base_protocol_init(struct scmi_handle *h);
+typedef int (*scmi_prot_init_ph_fn_t)(const struct scmi_protocol_handle *);
+
+/**
+ * struct scmi_protocol  - Protocol descriptor
+ * @id: Protocol ID.
+ * @owner: Module reference if any.
+ * @instance_init: Mandatory protocol initialization function.
+ * @instance_deinit: Optional protocol de-initialization function.
+ * @ops: Optional reference to the operations provided by the protocol and
+ *	 exposed in scmi_protocol.h.
+ * @events: An optional reference to the events supported by this protocol.
+ */
+struct scmi_protocol {
+	const u8				id;
+	struct module				*owner;
+	const scmi_prot_init_ph_fn_t		instance_init;
+	const scmi_prot_init_ph_fn_t		instance_deinit;
+	const void				*ops;
+	const struct scmi_protocol_events	*events;
+};
 
 int __init scmi_bus_init(void);
 void __exit scmi_bus_exit(void);
@@ -164,6 +237,7 @@ void __exit scmi_bus_exit(void);
 #define DECLARE_SCMI_REGISTER_UNREGISTER(func)		\
 	int __init scmi_##func##_register(void);	\
 	void __exit scmi_##func##_unregister(void)
+DECLARE_SCMI_REGISTER_UNREGISTER(base);
 DECLARE_SCMI_REGISTER_UNREGISTER(clock);
 DECLARE_SCMI_REGISTER_UNREGISTER(perf);
 DECLARE_SCMI_REGISTER_UNREGISTER(power);
@@ -172,17 +246,25 @@ DECLARE_SCMI_REGISTER_UNREGISTER(sensors);
 DECLARE_SCMI_REGISTER_UNREGISTER(voltage);
 DECLARE_SCMI_REGISTER_UNREGISTER(system);
 
-#define DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(id, name) \
-int __init scmi_##name##_register(void) \
-{ \
-	return scmi_protocol_register((id), &scmi_##name##_protocol_init); \
-} \
-\
-void __exit scmi_##name##_unregister(void) \
-{ \
-	scmi_protocol_unregister((id)); \
+#define DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(name, proto)	\
+static const struct scmi_protocol *__this_proto = &(proto);	\
+								\
+int __init scmi_##name##_register(void)				\
+{								\
+	return scmi_protocol_register(__this_proto);		\
+}								\
+								\
+void __exit scmi_##name##_unregister(void)			\
+{								\
+	scmi_protocol_unregister(__this_proto);			\
 }
 
+const struct scmi_protocol *scmi_protocol_get(int protocol_id);
+void scmi_protocol_put(int protocol_id);
+
+int scmi_protocol_acquire(const struct scmi_handle *handle, u8 protocol_id);
+void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id);
+
 /* SCMI Transport */
 /**
  * struct scmi_chan_info - Structure representing a SCMI channel information
@@ -227,6 +309,11 @@ struct scmi_transport_ops {
 	bool (*poll_done)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer);
 };
 
+int scmi_protocol_device_request(const struct scmi_device_id *id_table);
+void scmi_protocol_device_unrequest(const struct scmi_device_id *id_table);
+struct scmi_device *scmi_child_dev_find(struct device *parent,
+					int prot_id, const char *name);
+
 /**
  * struct scmi_desc - Description of SoC integration
  *
@@ -265,4 +352,8 @@ void shmem_clear_channel(struct scmi_shared_mem __iomem *shmem);
 bool shmem_poll_done(struct scmi_shared_mem __iomem *shmem,
 		     struct scmi_xfer *xfer);
 
+void scmi_notification_instance_data_set(const struct scmi_handle *handle,
+					 void *priv);
+void *scmi_notification_instance_data_get(const struct scmi_handle *handle);
+
 #endif /* _SCMI_COMMON_H */
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index cacdf1589b10..66eb3f0e5daf 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -11,18 +11,22 @@
  * various power domain DVFS including the core/cluster, certain system
  * clocks configuration, thermal sensors and many others.
  *
- * Copyright (C) 2018 ARM Ltd.
+ * Copyright (C) 2018-2021 ARM Ltd.
  */
 
 #include <linux/bitmap.h>
+#include <linux/device.h>
 #include <linux/export.h>
+#include <linux/idr.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/ktime.h>
+#include <linux/list.h>
 #include <linux/module.h>
 #include <linux/of_address.h>
 #include <linux/of_device.h>
 #include <linux/processor.h>
+#include <linux/refcount.h>
 #include <linux/slab.h>
 
 #include "common.h"
@@ -53,6 +57,14 @@ static DEFINE_MUTEX(scmi_list_mutex);
 /* Track the unique id for the transfers for debug & profiling purpose */
 static atomic_t transfer_last_id;
 
+static DEFINE_IDR(scmi_requested_devices);
+static DEFINE_MUTEX(scmi_requested_devices_mtx);
+
+struct scmi_requested_dev {
+	const struct scmi_device_id *id_table;
+	struct list_head node;
+};
+
 /**
  * struct scmi_xfers_info - Structure to manage transfer information
  *
@@ -69,6 +81,30 @@ struct scmi_xfers_info {
 };
 
 /**
+ * struct scmi_protocol_instance  - Describe an initialized protocol instance.
+ * @handle: Reference to the SCMI handle associated to this protocol instance.
+ * @proto: A reference to the protocol descriptor.
+ * @gid: A reference for per-protocol devres management.
+ * @users: A refcount to track effective users of this protocol.
+ * @priv: Reference for optional protocol private data.
+ * @ph: An embedded protocol handle that will be passed down to protocol
+ *	initialization code to identify this instance.
+ *
+ * Each protocol is initialized independently once for each SCMI platform in
+ * which is defined by DT and implemented by the SCMI server fw.
+ */
+struct scmi_protocol_instance {
+	const struct scmi_handle	*handle;
+	const struct scmi_protocol	*proto;
+	void				*gid;
+	refcount_t			users;
+	void				*priv;
+	struct scmi_protocol_handle	ph;
+};
+
+#define ph_to_pi(h)	container_of(h, struct scmi_protocol_instance, ph)
+
+/**
  * struct scmi_info - Structure representing a SCMI instance
  *
  * @dev: Device pointer
@@ -80,8 +116,15 @@ struct scmi_xfers_info {
  * @rx_minfo: Universal Receive Message management info
  * @tx_idr: IDR object to map protocol id to Tx channel info pointer
  * @rx_idr: IDR object to map protocol id to Rx channel info pointer
+ * @protocols: IDR for protocols' instance descriptors initialized for
+ *	       this SCMI instance: populated on protocol's first attempted
+ *	       usage.
+ * @protocols_mtx: A mutex to protect protocols instances initialization.
  * @protocols_imp: List of protocols implemented, currently maximum of
  *	MAX_PROTOCOLS_IMP elements allocated by the base protocol
+ * @active_protocols: IDR storing device_nodes for protocols actually defined
+ *		      in the DT and confirmed as implemented by fw.
+ * @notify_priv: Pointer to private data structure specific to notifications.
  * @node: List head
  * @users: Number of users of this instance
  */
@@ -94,7 +137,12 @@ struct scmi_info {
 	struct scmi_xfers_info rx_minfo;
 	struct idr tx_idr;
 	struct idr rx_idr;
+	struct idr protocols;
+	/* Ensure mutual exclusive access to protocols instance array */
+	struct mutex protocols_mtx;
 	u8 *protocols_imp;
+	struct idr active_protocols;
+	void *notify_priv;
 	struct list_head node;
 	int users;
 };
@@ -136,6 +184,25 @@ static inline void scmi_dump_header_dbg(struct device *dev,
 		hdr->id, hdr->seq, hdr->protocol_id);
 }
 
+void scmi_notification_instance_data_set(const struct scmi_handle *handle,
+					 void *priv)
+{
+	struct scmi_info *info = handle_to_scmi_info(handle);
+
+	info->notify_priv = priv;
+	/* Ensure updated protocol private date are visible */
+	smp_wmb();
+}
+
+void *scmi_notification_instance_data_get(const struct scmi_handle *handle)
+{
+	struct scmi_info *info = handle_to_scmi_info(handle);
+
+	/* Ensure protocols_private_data has been updated */
+	smp_rmb();
+	return info->notify_priv;
+}
+
 /**
  * scmi_xfer_get() - Allocate one message
  *
@@ -316,14 +383,16 @@ void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr)
 }
 
 /**
- * scmi_xfer_put() - Release a transmit message
+ * xfer_put() - Release a transmit message
  *
- * @handle: Pointer to SCMI entity handle
+ * @ph: Pointer to SCMI protocol handle
  * @xfer: message that was reserved by scmi_xfer_get
  */
-void scmi_xfer_put(const struct scmi_handle *handle, struct scmi_xfer *xfer)
+static void xfer_put(const struct scmi_protocol_handle *ph,
+		     struct scmi_xfer *xfer)
 {
-	struct scmi_info *info = handle_to_scmi_info(handle);
+	const struct scmi_protocol_instance *pi = ph_to_pi(ph);
+	struct scmi_info *info = handle_to_scmi_info(pi->handle);
 
 	__scmi_xfer_put(&info->tx_minfo, xfer);
 }
@@ -340,23 +409,32 @@ static bool scmi_xfer_done_no_timeout(struct scmi_chan_info *cinfo,
 }
 
 /**
- * scmi_do_xfer() - Do one transfer
+ * do_xfer() - Do one transfer
  *
- * @handle: Pointer to SCMI entity handle
+ * @ph: Pointer to SCMI protocol handle
  * @xfer: Transfer to initiate and wait for response
  *
  * Return: -ETIMEDOUT in case of no response, if transmit error,
  *	return corresponding error, else if all goes well,
  *	return 0.
  */
-int scmi_do_xfer(const struct scmi_handle *handle, struct scmi_xfer *xfer)
+static int do_xfer(const struct scmi_protocol_handle *ph,
+		   struct scmi_xfer *xfer)
 {
 	int ret;
 	int timeout;
-	struct scmi_info *info = handle_to_scmi_info(handle);
+	const struct scmi_protocol_instance *pi = ph_to_pi(ph);
+	struct scmi_info *info = handle_to_scmi_info(pi->handle);
 	struct device *dev = info->dev;
 	struct scmi_chan_info *cinfo;
 
+	/*
+	 * Re-instate protocol id here from protocol handle so that cannot be
+	 * overridden by mistake (or malice) by the protocol code mangling with
+	 * the scmi_xfer structure.
+	 */
+	xfer->hdr.protocol_id = pi->proto->id;
+
 	cinfo = idr_find(&info->tx_idr, xfer->hdr.protocol_id);
 	if (unlikely(!cinfo))
 		return -EINVAL;
@@ -402,10 +480,11 @@ int scmi_do_xfer(const struct scmi_handle *handle, struct scmi_xfer *xfer)
 	return ret;
 }
 
-void scmi_reset_rx_to_maxsz(const struct scmi_handle *handle,
-			    struct scmi_xfer *xfer)
+static void reset_rx_to_maxsz(const struct scmi_protocol_handle *ph,
+			      struct scmi_xfer *xfer)
 {
-	struct scmi_info *info = handle_to_scmi_info(handle);
+	const struct scmi_protocol_instance *pi = ph_to_pi(ph);
+	struct scmi_info *info = handle_to_scmi_info(pi->handle);
 
 	xfer->rx.len = info->desc->max_msg_size;
 }
@@ -413,24 +492,27 @@ void scmi_reset_rx_to_maxsz(const struct scmi_handle *handle,
 #define SCMI_MAX_RESPONSE_TIMEOUT	(2 * MSEC_PER_SEC)
 
 /**
- * scmi_do_xfer_with_response() - Do one transfer and wait until the delayed
+ * do_xfer_with_response() - Do one transfer and wait until the delayed
  *	response is received
  *
- * @handle: Pointer to SCMI entity handle
+ * @ph: Pointer to SCMI protocol handle
  * @xfer: Transfer to initiate and wait for response
  *
  * Return: -ETIMEDOUT in case of no delayed response, if transmit error,
  *	return corresponding error, else if all goes well, return 0.
  */
-int scmi_do_xfer_with_response(const struct scmi_handle *handle,
-			       struct scmi_xfer *xfer)
+static int do_xfer_with_response(const struct scmi_protocol_handle *ph,
+				 struct scmi_xfer *xfer)
 {
 	int ret, timeout = msecs_to_jiffies(SCMI_MAX_RESPONSE_TIMEOUT);
+	const struct scmi_protocol_instance *pi = ph_to_pi(ph);
 	DECLARE_COMPLETION_ONSTACK(async_response);
 
+	xfer->hdr.protocol_id = pi->proto->id;
+
 	xfer->async_done = &async_response;
 
-	ret = scmi_do_xfer(handle, xfer);
+	ret = do_xfer(ph, xfer);
 	if (!ret && !wait_for_completion_timeout(xfer->async_done, timeout))
 		ret = -ETIMEDOUT;
 
@@ -439,11 +521,10 @@ int scmi_do_xfer_with_response(const struct scmi_handle *handle,
 }
 
 /**
- * scmi_xfer_get_init() - Allocate and initialise one message for transmit
+ * xfer_get_init() - Allocate and initialise one message for transmit
  *
- * @handle: Pointer to SCMI entity handle
+ * @ph: Pointer to SCMI protocol handle
  * @msg_id: Message identifier
- * @prot_id: Protocol identifier for the message
  * @tx_size: transmit message size
  * @rx_size: receive message size
  * @p: pointer to the allocated and initialised message
@@ -454,12 +535,14 @@ int scmi_do_xfer_with_response(const struct scmi_handle *handle,
  * Return: 0 if all went fine with @p pointing to message, else
  *	corresponding error.
  */
-int scmi_xfer_get_init(const struct scmi_handle *handle, u8 msg_id, u8 prot_id,
-		       size_t tx_size, size_t rx_size, struct scmi_xfer **p)
+static int xfer_get_init(const struct scmi_protocol_handle *ph,
+			 u8 msg_id, size_t tx_size, size_t rx_size,
+			 struct scmi_xfer **p)
 {
 	int ret;
 	struct scmi_xfer *xfer;
-	struct scmi_info *info = handle_to_scmi_info(handle);
+	const struct scmi_protocol_instance *pi = ph_to_pi(ph);
+	struct scmi_info *info = handle_to_scmi_info(pi->handle);
 	struct scmi_xfers_info *minfo = &info->tx_minfo;
 	struct device *dev = info->dev;
 
@@ -468,7 +551,7 @@ int scmi_xfer_get_init(const struct scmi_handle *handle, u8 msg_id, u8 prot_id,
 	    tx_size > info->desc->max_msg_size)
 		return -ERANGE;
 
-	xfer = scmi_xfer_get(handle, minfo);
+	xfer = scmi_xfer_get(pi->handle, minfo);
 	if (IS_ERR(xfer)) {
 		ret = PTR_ERR(xfer);
 		dev_err(dev, "failed to get free message slot(%d)\n", ret);
@@ -478,7 +561,7 @@ int scmi_xfer_get_init(const struct scmi_handle *handle, u8 msg_id, u8 prot_id,
 	xfer->tx.len = tx_size;
 	xfer->rx.len = rx_size ? : info->desc->max_msg_size;
 	xfer->hdr.id = msg_id;
-	xfer->hdr.protocol_id = prot_id;
+	xfer->hdr.protocol_id = pi->proto->id;
 	xfer->hdr.poll_completion = false;
 
 	*p = xfer;
@@ -487,43 +570,276 @@ int scmi_xfer_get_init(const struct scmi_handle *handle, u8 msg_id, u8 prot_id,
 }
 
 /**
- * scmi_version_get() - command to get the revision of the SCMI entity
+ * version_get() - command to get the revision of the SCMI entity
  *
- * @handle: Pointer to SCMI entity handle
- * @protocol: Protocol identifier for the message
+ * @ph: Pointer to SCMI protocol handle
  * @version: Holds returned version of protocol.
  *
  * Updates the SCMI information in the internal data structure.
  *
  * Return: 0 if all went fine, else return appropriate error.
  */
-int scmi_version_get(const struct scmi_handle *handle, u8 protocol,
-		     u32 *version)
+static int version_get(const struct scmi_protocol_handle *ph, u32 *version)
 {
 	int ret;
 	__le32 *rev_info;
 	struct scmi_xfer *t;
 
-	ret = scmi_xfer_get_init(handle, PROTOCOL_VERSION, protocol, 0,
-				 sizeof(*version), &t);
+	ret = xfer_get_init(ph, PROTOCOL_VERSION, 0, sizeof(*version), &t);
 	if (ret)
 		return ret;
 
-	ret = scmi_do_xfer(handle, t);
+	ret = do_xfer(ph, t);
 	if (!ret) {
 		rev_info = t->rx.buf;
 		*version = le32_to_cpu(*rev_info);
 	}
 
-	scmi_xfer_put(handle, t);
+	xfer_put(ph, t);
 	return ret;
 }
 
-void scmi_setup_protocol_implemented(const struct scmi_handle *handle,
-				     u8 *prot_imp)
+/**
+ * scmi_set_protocol_priv  - Set protocol specific data at init time
+ *
+ * @ph: A reference to the protocol handle.
+ * @priv: The private data to set.
+ *
+ * Return: 0 on Success
+ */
+static int scmi_set_protocol_priv(const struct scmi_protocol_handle *ph,
+				  void *priv)
 {
+	struct scmi_protocol_instance *pi = ph_to_pi(ph);
+
+	pi->priv = priv;
+
+	return 0;
+}
+
+/**
+ * scmi_get_protocol_priv  - Set protocol specific data at init time
+ *
+ * @ph: A reference to the protocol handle.
+ *
+ * Return: Protocol private data if any was set.
+ */
+static void *scmi_get_protocol_priv(const struct scmi_protocol_handle *ph)
+{
+	const struct scmi_protocol_instance *pi = ph_to_pi(ph);
+
+	return pi->priv;
+}
+
+static const struct scmi_xfer_ops xfer_ops = {
+	.version_get = version_get,
+	.xfer_get_init = xfer_get_init,
+	.reset_rx_to_maxsz = reset_rx_to_maxsz,
+	.do_xfer = do_xfer,
+	.do_xfer_with_response = do_xfer_with_response,
+	.xfer_put = xfer_put,
+};
+
+/**
+ * scmi_revision_area_get  - Retrieve version memory area.
+ *
+ * @ph: A reference to the protocol handle.
+ *
+ * A helper to grab the version memory area reference during SCMI Base protocol
+ * initialization.
+ *
+ * Return: A reference to the version memory area associated to the SCMI
+ *	   instance underlying this protocol handle.
+ */
+struct scmi_revision_info *
+scmi_revision_area_get(const struct scmi_protocol_handle *ph)
+{
+	const struct scmi_protocol_instance *pi = ph_to_pi(ph);
+
+	return pi->handle->version;
+}
+
+/**
+ * scmi_alloc_init_protocol_instance  - Allocate and initialize a protocol
+ * instance descriptor.
+ * @info: The reference to the related SCMI instance.
+ * @proto: The protocol descriptor.
+ *
+ * Allocate a new protocol instance descriptor, using the provided @proto
+ * description, against the specified SCMI instance @info, and initialize it;
+ * all resources management is handled via a dedicated per-protocol devres
+ * group.
+ *
+ * Context: Assumes to be called with @protocols_mtx already acquired.
+ * Return: A reference to a freshly allocated and initialized protocol instance
+ *	   or ERR_PTR on failure. On failure the @proto reference is at first
+ *	   put using @scmi_protocol_put() before releasing all the devres group.
+ */
+static struct scmi_protocol_instance *
+scmi_alloc_init_protocol_instance(struct scmi_info *info,
+				  const struct scmi_protocol *proto)
+{
+	int ret = -ENOMEM;
+	void *gid;
+	struct scmi_protocol_instance *pi;
+	const struct scmi_handle *handle = &info->handle;
+
+	/* Protocol specific devres group */
+	gid = devres_open_group(handle->dev, NULL, GFP_KERNEL);
+	if (!gid) {
+		scmi_protocol_put(proto->id);
+		goto out;
+	}
+
+	pi = devm_kzalloc(handle->dev, sizeof(*pi), GFP_KERNEL);
+	if (!pi)
+		goto clean;
+
+	pi->gid = gid;
+	pi->proto = proto;
+	pi->handle = handle;
+	pi->ph.dev = handle->dev;
+	pi->ph.xops = &xfer_ops;
+	pi->ph.set_priv = scmi_set_protocol_priv;
+	pi->ph.get_priv = scmi_get_protocol_priv;
+	refcount_set(&pi->users, 1);
+	/* proto->init is assured NON NULL by scmi_protocol_register */
+	ret = pi->proto->instance_init(&pi->ph);
+	if (ret)
+		goto clean;
+
+	ret = idr_alloc(&info->protocols, pi, proto->id, proto->id + 1,
+			GFP_KERNEL);
+	if (ret != proto->id)
+		goto clean;
+
+	/*
+	 * Warn but ignore events registration errors since we do not want
+	 * to skip whole protocols if their notifications are messed up.
+	 */
+	if (pi->proto->events) {
+		ret = scmi_register_protocol_events(handle, pi->proto->id,
+						    &pi->ph,
+						    pi->proto->events);
+		if (ret)
+			dev_warn(handle->dev,
+				 "Protocol:%X - Events Registration Failed - err:%d\n",
+				 pi->proto->id, ret);
+	}
+
+	devres_close_group(handle->dev, pi->gid);
+	dev_dbg(handle->dev, "Initialized protocol: 0x%X\n", pi->proto->id);
+
+	return pi;
+
+clean:
+	/* Take care to put the protocol module's owner before releasing all */
+	scmi_protocol_put(proto->id);
+	devres_release_group(handle->dev, gid);
+out:
+	return ERR_PTR(ret);
+}
+
+/**
+ * scmi_get_protocol_instance  - Protocol initialization helper.
+ * @handle: A reference to the SCMI platform instance.
+ * @protocol_id: The protocol being requested.
+ *
+ * In case the required protocol has never been requested before for this
+ * instance, allocate and initialize all the needed structures while handling
+ * resource allocation with a dedicated per-protocol devres subgroup.
+ *
+ * Return: A reference to an initialized protocol instance or error on failure:
+ *	   in particular returns -EPROBE_DEFER when the desired protocol could
+ *	   NOT be found.
+ */
+static struct scmi_protocol_instance * __must_check
+scmi_get_protocol_instance(const struct scmi_handle *handle, u8 protocol_id)
+{
+	struct scmi_protocol_instance *pi;
 	struct scmi_info *info = handle_to_scmi_info(handle);
 
+	mutex_lock(&info->protocols_mtx);
+	pi = idr_find(&info->protocols, protocol_id);
+
+	if (pi) {
+		refcount_inc(&pi->users);
+	} else {
+		const struct scmi_protocol *proto;
+
+		/* Fails if protocol not registered on bus */
+		proto = scmi_protocol_get(protocol_id);
+		if (proto)
+			pi = scmi_alloc_init_protocol_instance(info, proto);
+		else
+			pi = ERR_PTR(-EPROBE_DEFER);
+	}
+	mutex_unlock(&info->protocols_mtx);
+
+	return pi;
+}
+
+/**
+ * scmi_protocol_acquire  - Protocol acquire
+ * @handle: A reference to the SCMI platform instance.
+ * @protocol_id: The protocol being requested.
+ *
+ * Register a new user for the requested protocol on the specified SCMI
+ * platform instance, possibly triggering its initialization on first user.
+ *
+ * Return: 0 if protocol was acquired successfully.
+ */
+int scmi_protocol_acquire(const struct scmi_handle *handle, u8 protocol_id)
+{
+	return PTR_ERR_OR_ZERO(scmi_get_protocol_instance(handle, protocol_id));
+}
+
+/**
+ * scmi_protocol_release  - Protocol de-initialization helper.
+ * @handle: A reference to the SCMI platform instance.
+ * @protocol_id: The protocol being requested.
+ *
+ * Remove one user for the specified protocol and triggers de-initialization
+ * and resources de-allocation once the last user has gone.
+ */
+void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id)
+{
+	struct scmi_info *info = handle_to_scmi_info(handle);
+	struct scmi_protocol_instance *pi;
+
+	mutex_lock(&info->protocols_mtx);
+	pi = idr_find(&info->protocols, protocol_id);
+	if (WARN_ON(!pi))
+		goto out;
+
+	if (refcount_dec_and_test(&pi->users)) {
+		void *gid = pi->gid;
+
+		if (pi->proto->events)
+			scmi_deregister_protocol_events(handle, protocol_id);
+
+		if (pi->proto->instance_deinit)
+			pi->proto->instance_deinit(&pi->ph);
+
+		idr_remove(&info->protocols, protocol_id);
+
+		scmi_protocol_put(protocol_id);
+
+		devres_release_group(handle->dev, gid);
+		dev_dbg(handle->dev, "De-Initialized protocol: 0x%X\n",
+			protocol_id);
+	}
+
+out:
+	mutex_unlock(&info->protocols_mtx);
+}
+
+void scmi_setup_protocol_implemented(const struct scmi_protocol_handle *ph,
+				     u8 *prot_imp)
+{
+	const struct scmi_protocol_instance *pi = ph_to_pi(ph);
+	struct scmi_info *info = handle_to_scmi_info(pi->handle);
+
 	info->protocols_imp = prot_imp;
 }
 
@@ -542,6 +858,102 @@ scmi_is_protocol_implemented(const struct scmi_handle *handle, u8 prot_id)
 	return false;
 }
 
+struct scmi_protocol_devres {
+	const struct scmi_handle *handle;
+	u8 protocol_id;
+};
+
+static void scmi_devm_release_protocol(struct device *dev, void *res)
+{
+	struct scmi_protocol_devres *dres = res;
+
+	scmi_protocol_release(dres->handle, dres->protocol_id);
+}
+
+/**
+ * scmi_devm_protocol_get  - Devres managed get protocol operations and handle
+ * @sdev: A reference to an scmi_device whose embedded struct device is to
+ *	  be used for devres accounting.
+ * @protocol_id: The protocol being requested.
+ * @ph: A pointer reference used to pass back the associated protocol handle.
+ *
+ * Get hold of a protocol accounting for its usage, eventually triggering its
+ * initialization, and returning the protocol specific operations and related
+ * protocol handle which will be used as first argument in most of the
+ * protocols operations methods.
+ * Being a devres based managed method, protocol hold will be automatically
+ * released, and possibly de-initialized on last user, once the SCMI driver
+ * owning the scmi_device is unbound from it.
+ *
+ * Return: A reference to the requested protocol operations or error.
+ *	   Must be checked for errors by caller.
+ */
+static const void __must_check *
+scmi_devm_protocol_get(struct scmi_device *sdev, u8 protocol_id,
+		       struct scmi_protocol_handle **ph)
+{
+	struct scmi_protocol_instance *pi;
+	struct scmi_protocol_devres *dres;
+	struct scmi_handle *handle = sdev->handle;
+
+	if (!ph)
+		return ERR_PTR(-EINVAL);
+
+	dres = devres_alloc(scmi_devm_release_protocol,
+			    sizeof(*dres), GFP_KERNEL);
+	if (!dres)
+		return ERR_PTR(-ENOMEM);
+
+	pi = scmi_get_protocol_instance(handle, protocol_id);
+	if (IS_ERR(pi)) {
+		devres_free(dres);
+		return pi;
+	}
+
+	dres->handle = handle;
+	dres->protocol_id = protocol_id;
+	devres_add(&sdev->dev, dres);
+
+	*ph = &pi->ph;
+
+	return pi->proto->ops;
+}
+
+static int scmi_devm_protocol_match(struct device *dev, void *res, void *data)
+{
+	struct scmi_protocol_devres *dres = res;
+
+	if (WARN_ON(!dres || !data))
+		return 0;
+
+	return dres->protocol_id == *((u8 *)data);
+}
+
+/**
+ * scmi_devm_protocol_put  - Devres managed put protocol operations and handle
+ * @sdev: A reference to an scmi_device whose embedded struct device is to
+ *	  be used for devres accounting.
+ * @protocol_id: The protocol being requested.
+ *
+ * Explicitly release a protocol hold previously obtained calling the above
+ * @scmi_devm_protocol_get.
+ */
+static void scmi_devm_protocol_put(struct scmi_device *sdev, u8 protocol_id)
+{
+	int ret;
+
+	ret = devres_release(&sdev->dev, scmi_devm_release_protocol,
+			     scmi_devm_protocol_match, &protocol_id);
+	WARN_ON(ret);
+}
+
+static inline
+struct scmi_handle *scmi_handle_get_from_info_unlocked(struct scmi_info *info)
+{
+	info->users++;
+	return &info->handle;
+}
+
 /**
  * scmi_handle_get() - Get the SCMI handle for a device
  *
@@ -563,8 +975,7 @@ struct scmi_handle *scmi_handle_get(struct device *dev)
 	list_for_each(p, &scmi_list) {
 		info = list_entry(p, struct scmi_info, node);
 		if (dev->parent == info->dev) {
-			handle = &info->handle;
-			info->users++;
+			handle = scmi_handle_get_from_info_unlocked(info);
 			break;
 		}
 	}
@@ -707,63 +1118,268 @@ scmi_txrx_setup(struct scmi_info *info, struct device *dev, int prot_id)
 	return ret;
 }
 
-static inline void
-scmi_create_protocol_device(struct device_node *np, struct scmi_info *info,
-			    int prot_id, const char *name)
+/**
+ * scmi_get_protocol_device  - Helper to get/create an SCMI device.
+ *
+ * @np: A device node representing a valid active protocols for the referred
+ * SCMI instance.
+ * @info: The referred SCMI instance for which we are getting/creating this
+ * device.
+ * @prot_id: The protocol ID.
+ * @name: The device name.
+ *
+ * Referring to the specific SCMI instance identified by @info, this helper
+ * takes care to return a properly initialized device matching the requested
+ * @proto_id and @name: if device was still not existent it is created as a
+ * child of the specified SCMI instance @info and its transport properly
+ * initialized as usual.
+ */
+static inline struct scmi_device *
+scmi_get_protocol_device(struct device_node *np, struct scmi_info *info,
+			 int prot_id, const char *name)
 {
 	struct scmi_device *sdev;
 
+	/* Already created for this parent SCMI instance ? */
+	sdev = scmi_child_dev_find(info->dev, prot_id, name);
+	if (sdev)
+		return sdev;
+
+	pr_debug("Creating SCMI device (%s) for protocol %x\n", name, prot_id);
+
 	sdev = scmi_device_create(np, info->dev, prot_id, name);
 	if (!sdev) {
 		dev_err(info->dev, "failed to create %d protocol device\n",
 			prot_id);
-		return;
+		return NULL;
 	}
 
 	if (scmi_txrx_setup(info, &sdev->dev, prot_id)) {
 		dev_err(&sdev->dev, "failed to setup transport\n");
 		scmi_device_destroy(sdev);
-		return;
+		return NULL;
 	}
 
+	return sdev;
+}
+
+static inline void
+scmi_create_protocol_device(struct device_node *np, struct scmi_info *info,
+			    int prot_id, const char *name)
+{
+	struct scmi_device *sdev;
+
+	sdev = scmi_get_protocol_device(np, info, prot_id, name);
+	if (!sdev)
+		return;
+
 	/* setup handle now as the transport is ready */
 	scmi_set_handle(sdev);
 }
 
-#define MAX_SCMI_DEV_PER_PROTOCOL	2
-struct scmi_prot_devnames {
-	int protocol_id;
-	char *names[MAX_SCMI_DEV_PER_PROTOCOL];
-};
+/**
+ * scmi_create_protocol_devices  - Create devices for all pending requests for
+ * this SCMI instance.
+ *
+ * @np: The device node describing the protocol
+ * @info: The SCMI instance descriptor
+ * @prot_id: The protocol ID
+ *
+ * All devices previously requested for this instance (if any) are found and
+ * created by scanning the proper @&scmi_requested_devices entry.
+ */
+static void scmi_create_protocol_devices(struct device_node *np,
+					 struct scmi_info *info, int prot_id)
+{
+	struct list_head *phead;
 
-static struct scmi_prot_devnames devnames[] = {
-	{ SCMI_PROTOCOL_POWER,  { "genpd" },},
-	{ SCMI_PROTOCOL_SYSTEM, { "syspower" },},
-	{ SCMI_PROTOCOL_PERF,   { "cpufreq" },},
-	{ SCMI_PROTOCOL_CLOCK,  { "clocks" },},
-	{ SCMI_PROTOCOL_SENSOR, { "hwmon" },},
-	{ SCMI_PROTOCOL_RESET,  { "reset" },},
-	{ SCMI_PROTOCOL_VOLTAGE,  { "regulator" },},
-};
+	mutex_lock(&scmi_requested_devices_mtx);
+	phead = idr_find(&scmi_requested_devices, prot_id);
+	if (phead) {
+		struct scmi_requested_dev *rdev;
 
-static inline void
-scmi_create_protocol_devices(struct device_node *np, struct scmi_info *info,
-			     int prot_id)
+		list_for_each_entry(rdev, phead, node)
+			scmi_create_protocol_device(np, info, prot_id,
+						    rdev->id_table->name);
+	}
+	mutex_unlock(&scmi_requested_devices_mtx);
+}
+
+/**
+ * scmi_protocol_device_request  - Helper to request a device
+ *
+ * @id_table: A protocol/name pair descriptor for the device to be created.
+ *
+ * This helper let an SCMI driver request specific devices identified by the
+ * @id_table to be created for each active SCMI instance.
+ *
+ * The requested device name MUST NOT be already existent for any protocol;
+ * at first the freshly requested @id_table is annotated in the IDR table
+ * @scmi_requested_devices, then a matching device is created for each already
+ * active SCMI instance. (if any)
+ *
+ * This way the requested device is created straight-away for all the already
+ * initialized(probed) SCMI instances (handles) and it remains also annotated
+ * as pending creation if the requesting SCMI driver was loaded before some
+ * SCMI instance and related transports were available: when such late instance
+ * is probed, its probe will take care to scan the list of pending requested
+ * devices and create those on its own (see @scmi_create_protocol_devices and
+ * its enclosing loop)
+ *
+ * Return: 0 on Success
+ */
+int scmi_protocol_device_request(const struct scmi_device_id *id_table)
 {
-	int loop, cnt;
+	int ret = 0;
+	unsigned int id = 0;
+	struct list_head *head, *phead = NULL;
+	struct scmi_requested_dev *rdev;
+	struct scmi_info *info;
 
-	for (loop = 0; loop < ARRAY_SIZE(devnames); loop++) {
-		if (devnames[loop].protocol_id != prot_id)
-			continue;
+	pr_debug("Requesting SCMI device (%s) for protocol %x\n",
+		 id_table->name, id_table->protocol_id);
 
-		for (cnt = 0; cnt < ARRAY_SIZE(devnames[loop].names); cnt++) {
-			const char *name = devnames[loop].names[cnt];
+	/*
+	 * Search for the matching protocol rdev list and then search
+	 * of any existent equally named device...fails if any duplicate found.
+	 */
+	mutex_lock(&scmi_requested_devices_mtx);
+	idr_for_each_entry(&scmi_requested_devices, head, id) {
+		if (!phead) {
+			/* A list found registered in the IDR is never empty */
+			rdev = list_first_entry(head, struct scmi_requested_dev,
+						node);
+			if (rdev->id_table->protocol_id ==
+			    id_table->protocol_id)
+				phead = head;
+		}
+		list_for_each_entry(rdev, head, node) {
+			if (!strcmp(rdev->id_table->name, id_table->name)) {
+				pr_err("Ignoring duplicate request [%d] %s\n",
+				       rdev->id_table->protocol_id,
+				       rdev->id_table->name);
+				ret = -EINVAL;
+				goto out;
+			}
+		}
+	}
+
+	/*
+	 * No duplicate found for requested id_table, so let's create a new
+	 * requested device entry for this new valid request.
+	 */
+	rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
+	if (!rdev) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	rdev->id_table = id_table;
 
-			if (name)
-				scmi_create_protocol_device(np, info, prot_id,
-							    name);
+	/*
+	 * Append the new requested device table descriptor to the head of the
+	 * related protocol list, eventually creating such head if not already
+	 * there.
+	 */
+	if (!phead) {
+		phead = kzalloc(sizeof(*phead), GFP_KERNEL);
+		if (!phead) {
+			kfree(rdev);
+			ret = -ENOMEM;
+			goto out;
+		}
+		INIT_LIST_HEAD(phead);
+
+		ret = idr_alloc(&scmi_requested_devices, (void *)phead,
+				id_table->protocol_id,
+				id_table->protocol_id + 1, GFP_KERNEL);
+		if (ret != id_table->protocol_id) {
+			pr_err("Failed to save SCMI device - ret:%d\n", ret);
+			kfree(rdev);
+			kfree(phead);
+			ret = -EINVAL;
+			goto out;
 		}
+		ret = 0;
 	}
+	list_add(&rdev->node, phead);
+
+	/*
+	 * Now effectively create and initialize the requested device for every
+	 * already initialized SCMI instance which has registered the requested
+	 * protocol as a valid active one: i.e. defined in DT and supported by
+	 * current platform FW.
+	 */
+	mutex_lock(&scmi_list_mutex);
+	list_for_each_entry(info, &scmi_list, node) {
+		struct device_node *child;
+
+		child = idr_find(&info->active_protocols,
+				 id_table->protocol_id);
+		if (child) {
+			struct scmi_device *sdev;
+
+			sdev = scmi_get_protocol_device(child, info,
+							id_table->protocol_id,
+							id_table->name);
+			/* Set handle if not already set: device existed */
+			if (sdev && !sdev->handle)
+				sdev->handle =
+					scmi_handle_get_from_info_unlocked(info);
+		} else {
+			dev_err(info->dev,
+				"Failed. SCMI protocol %d not active.\n",
+				id_table->protocol_id);
+		}
+	}
+	mutex_unlock(&scmi_list_mutex);
+
+out:
+	mutex_unlock(&scmi_requested_devices_mtx);
+
+	return ret;
+}
+
+/**
+ * scmi_protocol_device_unrequest  - Helper to unrequest a device
+ *
+ * @id_table: A protocol/name pair descriptor for the device to be unrequested.
+ *
+ * An helper to let an SCMI driver release its request about devices; note that
+ * devices are created and initialized once the first SCMI driver request them
+ * but they destroyed only on SCMI core unloading/unbinding.
+ *
+ * The current SCMI transport layer uses such devices as internal references and
+ * as such they could be shared as same transport between multiple drivers so
+ * that cannot be safely destroyed till the whole SCMI stack is removed.
+ * (unless adding further burden of refcounting.)
+ */
+void scmi_protocol_device_unrequest(const struct scmi_device_id *id_table)
+{
+	struct list_head *phead;
+
+	pr_debug("Unrequesting SCMI device (%s) for protocol %x\n",
+		 id_table->name, id_table->protocol_id);
+
+	mutex_lock(&scmi_requested_devices_mtx);
+	phead = idr_find(&scmi_requested_devices, id_table->protocol_id);
+	if (phead) {
+		struct scmi_requested_dev *victim, *tmp;
+
+		list_for_each_entry_safe(victim, tmp, phead, node) {
+			if (!strcmp(victim->id_table->name, id_table->name)) {
+				list_del(&victim->node);
+				kfree(victim);
+				break;
+			}
+		}
+
+		if (list_empty(phead)) {
+			idr_remove(&scmi_requested_devices,
+				   id_table->protocol_id);
+			kfree(phead);
+		}
+	}
+	mutex_unlock(&scmi_requested_devices_mtx);
 }
 
 static int scmi_probe(struct platform_device *pdev)
@@ -786,6 +1402,9 @@ static int scmi_probe(struct platform_device *pdev)
 	info->dev = dev;
 	info->desc = desc;
 	INIT_LIST_HEAD(&info->node);
+	idr_init(&info->protocols);
+	mutex_init(&info->protocols_mtx);
+	idr_init(&info->active_protocols);
 
 	platform_set_drvdata(pdev, info);
 	idr_init(&info->tx_idr);
@@ -794,6 +1413,8 @@ static int scmi_probe(struct platform_device *pdev)
 	handle = &info->handle;
 	handle->dev = info->dev;
 	handle->version = &info->version;
+	handle->devm_protocol_get = scmi_devm_protocol_get;
+	handle->devm_protocol_put = scmi_devm_protocol_put;
 
 	ret = scmi_txrx_setup(info, dev, SCMI_PROTOCOL_BASE);
 	if (ret)
@@ -806,9 +1427,14 @@ static int scmi_probe(struct platform_device *pdev)
 	if (scmi_notification_init(handle))
 		dev_err(dev, "SCMI Notifications NOT available.\n");
 
-	ret = scmi_base_protocol_init(handle);
+	/*
+	 * Trigger SCMI Base protocol initialization.
+	 * It's mandatory and won't be ever released/deinit until the
+	 * SCMI stack is shutdown/unloaded as a whole.
+	 */
+	ret = scmi_protocol_acquire(handle, SCMI_PROTOCOL_BASE);
 	if (ret) {
-		dev_err(dev, "unable to communicate with SCMI(%d)\n", ret);
+		dev_err(dev, "unable to communicate with SCMI\n");
 		return ret;
 	}
 
@@ -831,6 +1457,19 @@ static int scmi_probe(struct platform_device *pdev)
 			continue;
 		}
 
+		/*
+		 * Save this valid DT protocol descriptor amongst
+		 * @active_protocols for this SCMI instance/
+		 */
+		ret = idr_alloc(&info->active_protocols, child,
+				prot_id, prot_id + 1, GFP_KERNEL);
+		if (ret != prot_id) {
+			dev_err(dev, "SCMI protocol %d already activated. Skip\n",
+				prot_id);
+			continue;
+		}
+
+		of_node_get(child);
 		scmi_create_protocol_devices(child, info, prot_id);
 	}
 
@@ -844,9 +1483,10 @@ void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id)
 
 static int scmi_remove(struct platform_device *pdev)
 {
-	int ret = 0;
+	int ret = 0, id;
 	struct scmi_info *info = platform_get_drvdata(pdev);
 	struct idr *idr = &info->tx_idr;
+	struct device_node *child;
 
 	mutex_lock(&scmi_list_mutex);
 	if (info->users)
@@ -860,6 +1500,14 @@ static int scmi_remove(struct platform_device *pdev)
 
 	scmi_notification_exit(&info->handle);
 
+	mutex_lock(&info->protocols_mtx);
+	idr_destroy(&info->protocols);
+	mutex_unlock(&info->protocols_mtx);
+
+	idr_for_each_entry(&info->active_protocols, child, id)
+		of_node_put(child);
+	idr_destroy(&info->active_protocols);
+
 	/* Safe to free channels since no more users */
 	ret = idr_for_each(idr, info->desc->ops->chan_free, idr);
 	idr_destroy(&info->tx_idr);
@@ -942,6 +1590,8 @@ static int __init scmi_driver_init(void)
 {
 	scmi_bus_init();
 
+	scmi_base_register();
+
 	scmi_clock_register();
 	scmi_perf_register();
 	scmi_power_register();
@@ -956,7 +1606,7 @@ subsys_initcall(scmi_driver_init);
 
 static void __exit scmi_driver_exit(void)
 {
-	scmi_bus_exit();
+	scmi_base_unregister();
 
 	scmi_clock_unregister();
 	scmi_perf_unregister();
@@ -966,6 +1616,8 @@ static void __exit scmi_driver_exit(void)
 	scmi_voltage_unregister();
 	scmi_system_unregister();
 
+	scmi_bus_exit();
+
 	platform_driver_unregister(&scmi_driver);
 }
 module_exit(scmi_driver_exit);
diff --git a/drivers/firmware/arm_scmi/notify.c b/drivers/firmware/arm_scmi/notify.c
index 66196b293b6c..d860bebd984a 100644
--- a/drivers/firmware/arm_scmi/notify.c
+++ b/drivers/firmware/arm_scmi/notify.c
@@ -2,7 +2,7 @@
 /*
  * System Control and Management Interface (SCMI) Notification support
  *
- * Copyright (C) 2020 ARM Ltd.
+ * Copyright (C) 2020-2021 ARM Ltd.
  */
 /**
  * DOC: Theory of operation
@@ -91,6 +91,7 @@
 #include <linux/types.h>
 #include <linux/workqueue.h>
 
+#include "common.h"
 #include "notify.h"
 
 #define SCMI_MAX_PROTO		256
@@ -177,7 +178,7 @@
 #define REVT_NOTIFY_SET_STATUS(revt, eid, sid, state)		\
 ({								\
 	typeof(revt) r = revt;					\
-	r->proto->ops->set_notify_enabled(r->proto->ni->handle,	\
+	r->proto->ops->set_notify_enabled(r->proto->ph,		\
 					(eid), (sid), (state));	\
 })
 
@@ -190,7 +191,7 @@
 #define REVT_FILL_REPORT(revt, ...)				\
 ({								\
 	typeof(revt) r = revt;					\
-	r->proto->ops->fill_custom_report(r->proto->ni->handle,	\
+	r->proto->ops->fill_custom_report(r->proto->ph,		\
 					  __VA_ARGS__);		\
 })
 
@@ -278,6 +279,7 @@ struct scmi_registered_event;
  *		       events' descriptors, whose fixed-size is determined at
  *		       compile time.
  * @registered_mtx: A mutex to protect @registered_events_handlers
+ * @ph: SCMI protocol handle reference
  * @registered_events_handlers: An hashtable containing all events' handlers
  *				descriptors registered for this protocol
  *
@@ -302,6 +304,7 @@ struct scmi_registered_events_desc {
 	struct scmi_registered_event	**registered_events;
 	/* mutex to protect registered_events_handlers */
 	struct mutex			registered_mtx;
+	const struct scmi_protocol_handle	*ph;
 	DECLARE_HASHTABLE(registered_events_handlers, SCMI_REGISTERED_HASH_SZ);
 };
 
@@ -368,7 +371,7 @@ static struct scmi_event_handler *
 scmi_get_active_handler(struct scmi_notify_instance *ni, u32 evt_key);
 static void scmi_put_active_handler(struct scmi_notify_instance *ni,
 				    struct scmi_event_handler *hndl);
-static void scmi_put_handler_unlocked(struct scmi_notify_instance *ni,
+static bool scmi_put_handler_unlocked(struct scmi_notify_instance *ni,
 				      struct scmi_event_handler *hndl);
 
 /**
@@ -579,11 +582,9 @@ int scmi_notify(const struct scmi_handle *handle, u8 proto_id, u8 evt_id,
 	struct scmi_event_header eh;
 	struct scmi_notify_instance *ni;
 
-	/* Ensure notify_priv is updated */
-	smp_rmb();
-	if (!handle->notify_priv)
+	ni = scmi_notification_instance_data_get(handle);
+	if (!ni)
 		return 0;
-	ni = handle->notify_priv;
 
 	r_evt = SCMI_GET_REVT(ni, proto_id, evt_id);
 	if (!r_evt)
@@ -732,14 +733,10 @@ scmi_allocate_registered_events_desc(struct scmi_notify_instance *ni,
 /**
  * scmi_register_protocol_events()  - Register Protocol Events with the core
  * @handle: The handle identifying the platform instance against which the
- *	    the protocol's events are registered
+ *	    protocol's events are registered
  * @proto_id: Protocol ID
- * @queue_sz: Size in bytes of the associated queue to be allocated
- * @ops: Protocol specific event-related operations
- * @evt: Event descriptor array
- * @num_events: Number of events in @evt array
- * @num_sources: Number of possible sources for this protocol on this
- *		 platform.
+ * @ph: SCMI protocol handle.
+ * @ee: A structure describing the events supported by this protocol.
  *
  * Used by SCMI Protocols initialization code to register with the notification
  * core the list of supported events and their descriptors: takes care to
@@ -748,60 +745,69 @@ scmi_allocate_registered_events_desc(struct scmi_notify_instance *ni,
  *
  * Return: 0 on Success
  */
-int scmi_register_protocol_events(const struct scmi_handle *handle,
-				  u8 proto_id, size_t queue_sz,
-				  const struct scmi_event_ops *ops,
-				  const struct scmi_event *evt, int num_events,
-				  int num_sources)
+int scmi_register_protocol_events(const struct scmi_handle *handle, u8 proto_id,
+				  const struct scmi_protocol_handle *ph,
+				  const struct scmi_protocol_events *ee)
 {
 	int i;
+	unsigned int num_sources;
 	size_t payld_sz = 0;
 	struct scmi_registered_events_desc *pd;
 	struct scmi_notify_instance *ni;
+	const struct scmi_event *evt;
 
-	if (!ops || !evt)
+	if (!ee || !ee->ops || !ee->evts || !ph ||
+	    (!ee->num_sources && !ee->ops->get_num_sources))
 		return -EINVAL;
 
-	/* Ensure notify_priv is updated */
-	smp_rmb();
-	if (!handle->notify_priv)
+	ni = scmi_notification_instance_data_get(handle);
+	if (!ni)
 		return -ENOMEM;
-	ni = handle->notify_priv;
 
-	/* Attach to the notification main devres group */
-	if (!devres_open_group(ni->handle->dev, ni->gid, GFP_KERNEL))
-		return -ENOMEM;
+	/* num_sources cannot be <= 0 */
+	if (ee->num_sources) {
+		num_sources = ee->num_sources;
+	} else {
+		int nsrc = ee->ops->get_num_sources(ph);
 
-	for (i = 0; i < num_events; i++)
+		if (nsrc <= 0)
+			return -EINVAL;
+		num_sources = nsrc;
+	}
+
+	evt = ee->evts;
+	for (i = 0; i < ee->num_events; i++)
 		payld_sz = max_t(size_t, payld_sz, evt[i].max_payld_sz);
 	payld_sz += sizeof(struct scmi_event_header);
 
-	pd = scmi_allocate_registered_events_desc(ni, proto_id, queue_sz,
-						  payld_sz, num_events, ops);
+	pd = scmi_allocate_registered_events_desc(ni, proto_id, ee->queue_sz,
+						  payld_sz, ee->num_events,
+						  ee->ops);
 	if (IS_ERR(pd))
-		goto err;
+		return PTR_ERR(pd);
 
-	for (i = 0; i < num_events; i++, evt++) {
+	pd->ph = ph;
+	for (i = 0; i < ee->num_events; i++, evt++) {
 		struct scmi_registered_event *r_evt;
 
 		r_evt = devm_kzalloc(ni->handle->dev, sizeof(*r_evt),
 				     GFP_KERNEL);
 		if (!r_evt)
-			goto err;
+			return -ENOMEM;
 		r_evt->proto = pd;
 		r_evt->evt = evt;
 
 		r_evt->sources = devm_kcalloc(ni->handle->dev, num_sources,
 					      sizeof(refcount_t), GFP_KERNEL);
 		if (!r_evt->sources)
-			goto err;
+			return -ENOMEM;
 		r_evt->num_sources = num_sources;
 		mutex_init(&r_evt->sources_mtx);
 
 		r_evt->report = devm_kzalloc(ni->handle->dev,
 					     evt->max_report_sz, GFP_KERNEL);
 		if (!r_evt->report)
-			goto err;
+			return -ENOMEM;
 
 		pd->registered_events[i] = r_evt;
 		/* Ensure events are updated */
@@ -815,8 +821,6 @@ int scmi_register_protocol_events(const struct scmi_handle *handle,
 	/* Ensure protocols are updated */
 	smp_wmb();
 
-	devres_close_group(ni->handle->dev, ni->gid);
-
 	/*
 	 * Finalize any pending events' handler which could have been waiting
 	 * for this protocol's events registration.
@@ -824,13 +828,33 @@ int scmi_register_protocol_events(const struct scmi_handle *handle,
 	schedule_work(&ni->init_work);
 
 	return 0;
+}
 
-err:
-	dev_warn(handle->dev, "Proto:%X - Registration Failed !\n", proto_id);
-	/* A failing protocol registration does not trigger full failure */
-	devres_close_group(ni->handle->dev, ni->gid);
+/**
+ * scmi_deregister_protocol_events  - Deregister protocol events with the core
+ * @handle: The handle identifying the platform instance against which the
+ *	    protocol's events are registered
+ * @proto_id: Protocol ID
+ */
+void scmi_deregister_protocol_events(const struct scmi_handle *handle,
+				     u8 proto_id)
+{
+	struct scmi_notify_instance *ni;
+	struct scmi_registered_events_desc *pd;
 
-	return -ENOMEM;
+	ni = scmi_notification_instance_data_get(handle);
+	if (!ni)
+		return;
+
+	pd = ni->registered_protocols[proto_id];
+	if (!pd)
+		return;
+
+	ni->registered_protocols[proto_id] = NULL;
+	/* Ensure protocols are updated */
+	smp_wmb();
+
+	cancel_work_sync(&pd->equeue.notify_work);
 }
 
 /**
@@ -900,9 +924,21 @@ static inline int scmi_bind_event_handler(struct scmi_notify_instance *ni,
 	if (!r_evt)
 		return -EINVAL;
 
-	/* Remove from pending and insert into registered */
+	/*
+	 * Remove from pending and insert into registered while getting hold
+	 * of protocol instance.
+	 */
 	hash_del(&hndl->hash);
+	/*
+	 * Acquire protocols only for NON pending handlers, so as NOT to trigger
+	 * protocol initialization when a notifier is registered against a still
+	 * not registered protocol, since it would make little sense to force init
+	 * protocols for which still no SCMI driver user exists: they wouldn't
+	 * emit any event anyway till some SCMI driver starts using it.
+	 */
+	scmi_protocol_acquire(ni->handle, KEY_XTRACT_PROTO_ID(hndl->key));
 	hndl->r_evt = r_evt;
+
 	mutex_lock(&r_evt->proto->registered_mtx);
 	hash_add(r_evt->proto->registered_events_handlers,
 		 &hndl->hash, hndl->key);
@@ -1193,41 +1229,65 @@ static int scmi_disable_events(struct scmi_event_handler *hndl)
  * * unregister and free the handler itself
  *
  * Context: Assumes all the proper locking has been managed by the caller.
+ *
+ * Return: True if handler was freed (users dropped to zero)
  */
-static void scmi_put_handler_unlocked(struct scmi_notify_instance *ni,
+static bool scmi_put_handler_unlocked(struct scmi_notify_instance *ni,
 				      struct scmi_event_handler *hndl)
 {
+	bool freed = false;
+
 	if (refcount_dec_and_test(&hndl->users)) {
 		if (!IS_HNDL_PENDING(hndl))
 			scmi_disable_events(hndl);
 		scmi_free_event_handler(hndl);
+		freed = true;
 	}
+
+	return freed;
 }
 
 static void scmi_put_handler(struct scmi_notify_instance *ni,
 			     struct scmi_event_handler *hndl)
 {
+	bool freed;
+	u8 protocol_id;
 	struct scmi_registered_event *r_evt = hndl->r_evt;
 
 	mutex_lock(&ni->pending_mtx);
-	if (r_evt)
+	if (r_evt) {
+		protocol_id = r_evt->proto->id;
 		mutex_lock(&r_evt->proto->registered_mtx);
+	}
 
-	scmi_put_handler_unlocked(ni, hndl);
+	freed = scmi_put_handler_unlocked(ni, hndl);
 
-	if (r_evt)
+	if (r_evt) {
 		mutex_unlock(&r_evt->proto->registered_mtx);
+		/*
+		 * Only registered handler acquired protocol; must be here
+		 * released only AFTER unlocking registered_mtx, since
+		 * releasing a protocol can trigger its de-initialization
+		 * (ie. including r_evt and registered_mtx)
+		 */
+		if (freed)
+			scmi_protocol_release(ni->handle, protocol_id);
+	}
 	mutex_unlock(&ni->pending_mtx);
 }
 
 static void scmi_put_active_handler(struct scmi_notify_instance *ni,
 				    struct scmi_event_handler *hndl)
 {
+	bool freed;
 	struct scmi_registered_event *r_evt = hndl->r_evt;
+	u8 protocol_id = r_evt->proto->id;
 
 	mutex_lock(&r_evt->proto->registered_mtx);
-	scmi_put_handler_unlocked(ni, hndl);
+	freed = scmi_put_handler_unlocked(ni, hndl);
 	mutex_unlock(&r_evt->proto->registered_mtx);
+	if (freed)
+		scmi_protocol_release(ni->handle, protocol_id);
 }
 
 /**
@@ -1247,7 +1307,7 @@ static int scmi_event_handler_enable_events(struct scmi_event_handler *hndl)
 }
 
 /**
- * scmi_register_notifier()  - Register a notifier_block for an event
+ * scmi_notifier_register()  - Register a notifier_block for an event
  * @handle: The handle identifying the platform instance against which the
  *	    callback is registered
  * @proto_id: Protocol ID
@@ -1279,8 +1339,8 @@ static int scmi_event_handler_enable_events(struct scmi_event_handler *hndl)
  *
  * Return: 0 on Success
  */
-static int scmi_register_notifier(const struct scmi_handle *handle,
-				  u8 proto_id, u8 evt_id, u32 *src_id,
+static int scmi_notifier_register(const struct scmi_handle *handle,
+				  u8 proto_id, u8 evt_id, const u32 *src_id,
 				  struct notifier_block *nb)
 {
 	int ret = 0;
@@ -1288,11 +1348,9 @@ static int scmi_register_notifier(const struct scmi_handle *handle,
 	struct scmi_event_handler *hndl;
 	struct scmi_notify_instance *ni;
 
-	/* Ensure notify_priv is updated */
-	smp_rmb();
-	if (!handle->notify_priv)
+	ni = scmi_notification_instance_data_get(handle);
+	if (!ni)
 		return -ENODEV;
-	ni = handle->notify_priv;
 
 	evt_key = MAKE_HASH_KEY(proto_id, evt_id,
 				src_id ? *src_id : SRC_ID_MASK);
@@ -1313,7 +1371,7 @@ static int scmi_register_notifier(const struct scmi_handle *handle,
 }
 
 /**
- * scmi_unregister_notifier()  - Unregister a notifier_block for an event
+ * scmi_notifier_unregister()  - Unregister a notifier_block for an event
  * @handle: The handle identifying the platform instance against which the
  *	    callback is unregistered
  * @proto_id: Protocol ID
@@ -1328,19 +1386,17 @@ static int scmi_register_notifier(const struct scmi_handle *handle,
  *
  * Return: 0 on Success
  */
-static int scmi_unregister_notifier(const struct scmi_handle *handle,
-				    u8 proto_id, u8 evt_id, u32 *src_id,
+static int scmi_notifier_unregister(const struct scmi_handle *handle,
+				    u8 proto_id, u8 evt_id, const u32 *src_id,
 				    struct notifier_block *nb)
 {
 	u32 evt_key;
 	struct scmi_event_handler *hndl;
 	struct scmi_notify_instance *ni;
 
-	/* Ensure notify_priv is updated */
-	smp_rmb();
-	if (!handle->notify_priv)
+	ni = scmi_notification_instance_data_get(handle);
+	if (!ni)
 		return -ENODEV;
-	ni = handle->notify_priv;
 
 	evt_key = MAKE_HASH_KEY(proto_id, evt_id,
 				src_id ? *src_id : SRC_ID_MASK);
@@ -1356,7 +1412,7 @@ static int scmi_unregister_notifier(const struct scmi_handle *handle,
 	scmi_put_handler(ni, hndl);
 
 	/*
-	 * This balances the initial get issued in @scmi_register_notifier.
+	 * This balances the initial get issued in @scmi_notifier_register.
 	 * If this notifier_block happened to be the last known user callback
 	 * for this event, the handler is here freed and the event's generation
 	 * stopped.
@@ -1371,6 +1427,129 @@ static int scmi_unregister_notifier(const struct scmi_handle *handle,
 	return 0;
 }
 
+struct scmi_notifier_devres {
+	const struct scmi_handle *handle;
+	u8 proto_id;
+	u8 evt_id;
+	u32 __src_id;
+	u32 *src_id;
+	struct notifier_block *nb;
+};
+
+static void scmi_devm_release_notifier(struct device *dev, void *res)
+{
+	struct scmi_notifier_devres *dres = res;
+
+	scmi_notifier_unregister(dres->handle, dres->proto_id, dres->evt_id,
+				 dres->src_id, dres->nb);
+}
+
+/**
+ * scmi_devm_notifier_register()  - Managed registration of a notifier_block
+ * for an event
+ * @sdev: A reference to an scmi_device whose embedded struct device is to
+ *	  be used for devres accounting.
+ * @proto_id: Protocol ID
+ * @evt_id: Event ID
+ * @src_id: Source ID, when NULL register for events coming form ALL possible
+ *	    sources
+ * @nb: A standard notifier block to register for the specified event
+ *
+ * Generic devres managed helper to register a notifier_block against a
+ * protocol event.
+ */
+static int scmi_devm_notifier_register(struct scmi_device *sdev,
+				       u8 proto_id, u8 evt_id,
+				       const u32 *src_id,
+				       struct notifier_block *nb)
+{
+	int ret;
+	struct scmi_notifier_devres *dres;
+
+	dres = devres_alloc(scmi_devm_release_notifier,
+			    sizeof(*dres), GFP_KERNEL);
+	if (!dres)
+		return -ENOMEM;
+
+	ret = scmi_notifier_register(sdev->handle, proto_id,
+				     evt_id, src_id, nb);
+	if (ret) {
+		devres_free(dres);
+		return ret;
+	}
+
+	dres->handle = sdev->handle;
+	dres->proto_id = proto_id;
+	dres->evt_id = evt_id;
+	dres->nb = nb;
+	if (src_id) {
+		dres->__src_id = *src_id;
+		dres->src_id = &dres->__src_id;
+	} else {
+		dres->src_id = NULL;
+	}
+	devres_add(&sdev->dev, dres);
+
+	return ret;
+}
+
+static int scmi_devm_notifier_match(struct device *dev, void *res, void *data)
+{
+	struct scmi_notifier_devres *dres = res;
+	struct scmi_notifier_devres *xres = data;
+
+	if (WARN_ON(!dres || !xres))
+		return 0;
+
+	return dres->proto_id == xres->proto_id &&
+		dres->evt_id == xres->evt_id &&
+		dres->nb == xres->nb &&
+		((!dres->src_id && !xres->src_id) ||
+		  (dres->src_id && xres->src_id &&
+		   dres->__src_id == xres->__src_id));
+}
+
+/**
+ * scmi_devm_notifier_unregister()  - Managed un-registration of a
+ * notifier_block for an event
+ * @sdev: A reference to an scmi_device whose embedded struct device is to
+ *	  be used for devres accounting.
+ * @proto_id: Protocol ID
+ * @evt_id: Event ID
+ * @src_id: Source ID, when NULL register for events coming form ALL possible
+ *	    sources
+ * @nb: A standard notifier block to register for the specified event
+ *
+ * Generic devres managed helper to explicitly un-register a notifier_block
+ * against a protocol event, which was previously registered using the above
+ * @scmi_devm_notifier_register.
+ */
+static int scmi_devm_notifier_unregister(struct scmi_device *sdev,
+					 u8 proto_id, u8 evt_id,
+					 const u32 *src_id,
+					 struct notifier_block *nb)
+{
+	int ret;
+	struct scmi_notifier_devres dres;
+
+	dres.handle = sdev->handle;
+	dres.proto_id = proto_id;
+	dres.evt_id = evt_id;
+	if (src_id) {
+		dres.__src_id = *src_id;
+		dres.src_id = &dres.__src_id;
+	} else {
+		dres.src_id = NULL;
+	}
+
+	ret = devres_release(&sdev->dev, scmi_devm_release_notifier,
+			     scmi_devm_notifier_match, &dres);
+
+	WARN_ON(ret);
+
+	return ret;
+}
+
 /**
  * scmi_protocols_late_init()  - Worker for late initialization
  * @work: The work item to use associated to the proper SCMI instance
@@ -1428,8 +1607,10 @@ static void scmi_protocols_late_init(struct work_struct *work)
  * directly from an scmi_driver to register its own notifiers.
  */
 static const struct scmi_notify_ops notify_ops = {
-	.register_event_notifier = scmi_register_notifier,
-	.unregister_event_notifier = scmi_unregister_notifier,
+	.devm_event_notifier_register = scmi_devm_notifier_register,
+	.devm_event_notifier_unregister = scmi_devm_notifier_unregister,
+	.event_notifier_register = scmi_notifier_register,
+	.event_notifier_unregister = scmi_notifier_unregister,
 };
 
 /**
@@ -1490,8 +1671,8 @@ int scmi_notification_init(struct scmi_handle *handle)
 
 	INIT_WORK(&ni->init_work, scmi_protocols_late_init);
 
+	scmi_notification_instance_data_set(handle, ni);
 	handle->notify_ops = &notify_ops;
-	handle->notify_priv = ni;
 	/* Ensure handle is up to date */
 	smp_wmb();
 
@@ -1503,7 +1684,7 @@ int scmi_notification_init(struct scmi_handle *handle)
 
 err:
 	dev_warn(handle->dev, "Initialization Failed.\n");
-	devres_release_group(handle->dev, NULL);
+	devres_release_group(handle->dev, gid);
 	return -ENOMEM;
 }
 
@@ -1515,15 +1696,10 @@ void scmi_notification_exit(struct scmi_handle *handle)
 {
 	struct scmi_notify_instance *ni;
 
-	/* Ensure notify_priv is updated */
-	smp_rmb();
-	if (!handle->notify_priv)
+	ni = scmi_notification_instance_data_get(handle);
+	if (!ni)
 		return;
-	ni = handle->notify_priv;
-
-	handle->notify_priv = NULL;
-	/* Ensure handle is up to date */
-	smp_wmb();
+	scmi_notification_instance_data_set(handle, NULL);
 
 	/* Destroy while letting pending work complete */
 	destroy_workqueue(ni->notify_wq);
diff --git a/drivers/firmware/arm_scmi/notify.h b/drivers/firmware/arm_scmi/notify.h
index 3485f20fa70e..ce0324be6c71 100644
--- a/drivers/firmware/arm_scmi/notify.h
+++ b/drivers/firmware/arm_scmi/notify.h
@@ -4,7 +4,7 @@
  * notification header file containing some definitions, structures
  * and function prototypes related to SCMI Notification handling.
  *
- * Copyright (C) 2020 ARM Ltd.
+ * Copyright (C) 2020-2021 ARM Ltd.
  */
 #ifndef _SCMI_NOTIFY_H
 #define _SCMI_NOTIFY_H
@@ -31,8 +31,12 @@ struct scmi_event {
 	size_t	max_report_sz;
 };
 
+struct scmi_protocol_handle;
+
 /**
  * struct scmi_event_ops  - Protocol helpers called by the notification core.
+ * @get_num_sources: Returns the number of possible events' sources for this
+ *		     protocol
  * @set_notify_enabled: Enable/disable the required evt_id/src_id notifications
  *			using the proper custom protocol commands.
  *			Return 0 on Success
@@ -46,22 +50,42 @@ struct scmi_event {
  *	    process context.
  */
 struct scmi_event_ops {
-	int (*set_notify_enabled)(const struct scmi_handle *handle,
+	int (*get_num_sources)(const struct scmi_protocol_handle *ph);
+	int (*set_notify_enabled)(const struct scmi_protocol_handle *ph,
 				  u8 evt_id, u32 src_id, bool enabled);
-	void *(*fill_custom_report)(const struct scmi_handle *handle,
+	void *(*fill_custom_report)(const struct scmi_protocol_handle *ph,
 				    u8 evt_id, ktime_t timestamp,
 				    const void *payld, size_t payld_sz,
 				    void *report, u32 *src_id);
 };
 
+/**
+ * struct scmi_protocol_events  - Per-protocol description of available events
+ * @queue_sz: Size in bytes of the per-protocol queue to use.
+ * @ops: Array of protocol-specific events operations.
+ * @evts: Array of supported protocol's events.
+ * @num_events: Number of supported protocol's events described in @evts.
+ * @num_sources: Number of protocol's sources, should be greater than 0; if not
+ *		 available at compile time, it will be provided at run-time via
+ *		 @get_num_sources.
+ */
+struct scmi_protocol_events {
+	size_t				queue_sz;
+	const struct scmi_event_ops	*ops;
+	const struct scmi_event		*evts;
+	unsigned int			num_events;
+	unsigned int			num_sources;
+};
+
 int scmi_notification_init(struct scmi_handle *handle);
 void scmi_notification_exit(struct scmi_handle *handle);
 
-int scmi_register_protocol_events(const struct scmi_handle *handle,
-				  u8 proto_id, size_t queue_sz,
-				  const struct scmi_event_ops *ops,
-				  const struct scmi_event *evt, int num_events,
-				  int num_sources);
+struct scmi_protocol_handle;
+int scmi_register_protocol_events(const struct scmi_handle *handle, u8 proto_id,
+				  const struct scmi_protocol_handle *ph,
+				  const struct scmi_protocol_events *ee);
+void scmi_deregister_protocol_events(const struct scmi_handle *handle,
+				     u8 proto_id);
 int scmi_notify(const struct scmi_handle *handle, u8 proto_id, u8 evt_id,
 		const void *buf, size_t len, ktime_t ts);
 
diff --git a/drivers/firmware/arm_scmi/perf.c b/drivers/firmware/arm_scmi/perf.c
index e374b1125fca..f4cd5193b961 100644
--- a/drivers/firmware/arm_scmi/perf.c
+++ b/drivers/firmware/arm_scmi/perf.c
@@ -2,7 +2,7 @@
 /*
  * System Control and Management Interface (SCMI) Performance Protocol
  *
- * Copyright (C) 2018 ARM Ltd.
+ * Copyright (C) 2018-2021 ARM Ltd.
  */
 
 #define pr_fmt(fmt) "SCMI Notifications PERF - " fmt
@@ -11,6 +11,7 @@
 #include <linux/of.h>
 #include <linux/io.h>
 #include <linux/io-64-nonatomic-hi-lo.h>
+#include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/pm_opp.h>
 #include <linux/scmi_protocol.h>
@@ -175,21 +176,21 @@ static enum scmi_performance_protocol_cmd evt_2_cmd[] = {
 	PERF_NOTIFY_LEVEL,
 };
 
-static int scmi_perf_attributes_get(const struct scmi_handle *handle,
+static int scmi_perf_attributes_get(const struct scmi_protocol_handle *ph,
 				    struct scmi_perf_info *pi)
 {
 	int ret;
 	struct scmi_xfer *t;
 	struct scmi_msg_resp_perf_attributes *attr;
 
-	ret = scmi_xfer_get_init(handle, PROTOCOL_ATTRIBUTES,
-				 SCMI_PROTOCOL_PERF, 0, sizeof(*attr), &t);
+	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES, 0,
+				      sizeof(*attr), &t);
 	if (ret)
 		return ret;
 
 	attr = t->rx.buf;
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 	if (!ret) {
 		u16 flags = le16_to_cpu(attr->flags);
 
@@ -200,28 +201,27 @@ static int scmi_perf_attributes_get(const struct scmi_handle *handle,
 		pi->stats_size = le32_to_cpu(attr->stats_size);
 	}
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
 static int
-scmi_perf_domain_attributes_get(const struct scmi_handle *handle, u32 domain,
-				struct perf_dom_info *dom_info)
+scmi_perf_domain_attributes_get(const struct scmi_protocol_handle *ph,
+				u32 domain, struct perf_dom_info *dom_info)
 {
 	int ret;
 	struct scmi_xfer *t;
 	struct scmi_msg_resp_perf_domain_attributes *attr;
 
-	ret = scmi_xfer_get_init(handle, PERF_DOMAIN_ATTRIBUTES,
-				 SCMI_PROTOCOL_PERF, sizeof(domain),
-				 sizeof(*attr), &t);
+	ret = ph->xops->xfer_get_init(ph, PERF_DOMAIN_ATTRIBUTES,
+				     sizeof(domain), sizeof(*attr), &t);
 	if (ret)
 		return ret;
 
 	put_unaligned_le32(domain, t->tx.buf);
 	attr = t->rx.buf;
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 	if (!ret) {
 		u32 flags = le32_to_cpu(attr->flags);
 
@@ -245,7 +245,7 @@ scmi_perf_domain_attributes_get(const struct scmi_handle *handle, u32 domain,
 		strlcpy(dom_info->name, attr->name, SCMI_MAX_STR_SIZE);
 	}
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
@@ -257,7 +257,7 @@ static int opp_cmp_func(const void *opp1, const void *opp2)
 }
 
 static int
-scmi_perf_describe_levels_get(const struct scmi_handle *handle, u32 domain,
+scmi_perf_describe_levels_get(const struct scmi_protocol_handle *ph, u32 domain,
 			      struct perf_dom_info *perf_dom)
 {
 	int ret, cnt;
@@ -268,8 +268,8 @@ scmi_perf_describe_levels_get(const struct scmi_handle *handle, u32 domain,
 	struct scmi_msg_perf_describe_levels *dom_info;
 	struct scmi_msg_resp_perf_describe_levels *level_info;
 
-	ret = scmi_xfer_get_init(handle, PERF_DESCRIBE_LEVELS,
-				 SCMI_PROTOCOL_PERF, sizeof(*dom_info), 0, &t);
+	ret = ph->xops->xfer_get_init(ph, PERF_DESCRIBE_LEVELS,
+				      sizeof(*dom_info), 0, &t);
 	if (ret)
 		return ret;
 
@@ -281,14 +281,14 @@ scmi_perf_describe_levels_get(const struct scmi_handle *handle, u32 domain,
 		/* Set the number of OPPs to be skipped/already read */
 		dom_info->level_index = cpu_to_le32(tot_opp_cnt);
 
-		ret = scmi_do_xfer(handle, t);
+		ret = ph->xops->do_xfer(ph, t);
 		if (ret)
 			break;
 
 		num_returned = le16_to_cpu(level_info->num_returned);
 		num_remaining = le16_to_cpu(level_info->num_remaining);
 		if (tot_opp_cnt + num_returned > MAX_OPPS) {
-			dev_err(handle->dev, "No. of OPPs exceeded MAX_OPPS");
+			dev_err(ph->dev, "No. of OPPs exceeded MAX_OPPS");
 			break;
 		}
 
@@ -299,13 +299,13 @@ scmi_perf_describe_levels_get(const struct scmi_handle *handle, u32 domain,
 			opp->trans_latency_us = le16_to_cpu
 				(level_info->opp[cnt].transition_latency_us);
 
-			dev_dbg(handle->dev, "Level %d Power %d Latency %dus\n",
+			dev_dbg(ph->dev, "Level %d Power %d Latency %dus\n",
 				opp->perf, opp->power, opp->trans_latency_us);
 		}
 
 		tot_opp_cnt += num_returned;
 
-		scmi_reset_rx_to_maxsz(handle, t);
+		ph->xops->reset_rx_to_maxsz(ph, t);
 		/*
 		 * check for both returned and remaining to avoid infinite
 		 * loop due to buggy firmware
@@ -313,7 +313,7 @@ scmi_perf_describe_levels_get(const struct scmi_handle *handle, u32 domain,
 	} while (num_returned && num_remaining);
 
 	perf_dom->opp_count = tot_opp_cnt;
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 
 	sort(perf_dom->opp, tot_opp_cnt, sizeof(*opp), opp_cmp_func, NULL);
 	return ret;
@@ -353,15 +353,15 @@ static void scmi_perf_fc_ring_db(struct scmi_fc_db_info *db)
 #endif
 }
 
-static int scmi_perf_mb_limits_set(const struct scmi_handle *handle, u32 domain,
-				   u32 max_perf, u32 min_perf)
+static int scmi_perf_mb_limits_set(const struct scmi_protocol_handle *ph,
+				   u32 domain, u32 max_perf, u32 min_perf)
 {
 	int ret;
 	struct scmi_xfer *t;
 	struct scmi_perf_set_limits *limits;
 
-	ret = scmi_xfer_get_init(handle, PERF_LIMITS_SET, SCMI_PROTOCOL_PERF,
-				 sizeof(*limits), 0, &t);
+	ret = ph->xops->xfer_get_init(ph, PERF_LIMITS_SET,
+				      sizeof(*limits), 0, &t);
 	if (ret)
 		return ret;
 
@@ -370,16 +370,16 @@ static int scmi_perf_mb_limits_set(const struct scmi_handle *handle, u32 domain,
 	limits->max_level = cpu_to_le32(max_perf);
 	limits->min_level = cpu_to_le32(min_perf);
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
-static int scmi_perf_limits_set(const struct scmi_handle *handle, u32 domain,
-				u32 max_perf, u32 min_perf)
+static int scmi_perf_limits_set(const struct scmi_protocol_handle *ph,
+				u32 domain, u32 max_perf, u32 min_perf)
 {
-	struct scmi_perf_info *pi = handle->perf_priv;
+	struct scmi_perf_info *pi = ph->get_priv(ph);
 	struct perf_dom_info *dom = pi->dom_info + domain;
 
 	if (dom->fc_info && dom->fc_info->limit_set_addr) {
@@ -389,24 +389,24 @@ static int scmi_perf_limits_set(const struct scmi_handle *handle, u32 domain,
 		return 0;
 	}
 
-	return scmi_perf_mb_limits_set(handle, domain, max_perf, min_perf);
+	return scmi_perf_mb_limits_set(ph, domain, max_perf, min_perf);
 }
 
-static int scmi_perf_mb_limits_get(const struct scmi_handle *handle, u32 domain,
-				   u32 *max_perf, u32 *min_perf)
+static int scmi_perf_mb_limits_get(const struct scmi_protocol_handle *ph,
+				   u32 domain, u32 *max_perf, u32 *min_perf)
 {
 	int ret;
 	struct scmi_xfer *t;
 	struct scmi_perf_get_limits *limits;
 
-	ret = scmi_xfer_get_init(handle, PERF_LIMITS_GET, SCMI_PROTOCOL_PERF,
-				 sizeof(__le32), 0, &t);
+	ret = ph->xops->xfer_get_init(ph, PERF_LIMITS_GET,
+				      sizeof(__le32), 0, &t);
 	if (ret)
 		return ret;
 
 	put_unaligned_le32(domain, t->tx.buf);
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 	if (!ret) {
 		limits = t->rx.buf;
 
@@ -414,14 +414,14 @@ static int scmi_perf_mb_limits_get(const struct scmi_handle *handle, u32 domain,
 		*min_perf = le32_to_cpu(limits->min_level);
 	}
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
-static int scmi_perf_limits_get(const struct scmi_handle *handle, u32 domain,
-				u32 *max_perf, u32 *min_perf)
+static int scmi_perf_limits_get(const struct scmi_protocol_handle *ph,
+				u32 domain, u32 *max_perf, u32 *min_perf)
 {
-	struct scmi_perf_info *pi = handle->perf_priv;
+	struct scmi_perf_info *pi = ph->get_priv(ph);
 	struct perf_dom_info *dom = pi->dom_info + domain;
 
 	if (dom->fc_info && dom->fc_info->limit_get_addr) {
@@ -430,18 +430,17 @@ static int scmi_perf_limits_get(const struct scmi_handle *handle, u32 domain,
 		return 0;
 	}
 
-	return scmi_perf_mb_limits_get(handle, domain, max_perf, min_perf);
+	return scmi_perf_mb_limits_get(ph, domain, max_perf, min_perf);
 }
 
-static int scmi_perf_mb_level_set(const struct scmi_handle *handle, u32 domain,
-				  u32 level, bool poll)
+static int scmi_perf_mb_level_set(const struct scmi_protocol_handle *ph,
+				  u32 domain, u32 level, bool poll)
 {
 	int ret;
 	struct scmi_xfer *t;
 	struct scmi_perf_set_level *lvl;
 
-	ret = scmi_xfer_get_init(handle, PERF_LEVEL_SET, SCMI_PROTOCOL_PERF,
-				 sizeof(*lvl), 0, &t);
+	ret = ph->xops->xfer_get_init(ph, PERF_LEVEL_SET, sizeof(*lvl), 0, &t);
 	if (ret)
 		return ret;
 
@@ -450,16 +449,16 @@ static int scmi_perf_mb_level_set(const struct scmi_handle *handle, u32 domain,
 	lvl->domain = cpu_to_le32(domain);
 	lvl->level = cpu_to_le32(level);
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
-static int scmi_perf_level_set(const struct scmi_handle *handle, u32 domain,
-			       u32 level, bool poll)
+static int scmi_perf_level_set(const struct scmi_protocol_handle *ph,
+			       u32 domain, u32 level, bool poll)
 {
-	struct scmi_perf_info *pi = handle->perf_priv;
+	struct scmi_perf_info *pi = ph->get_priv(ph);
 	struct perf_dom_info *dom = pi->dom_info + domain;
 
 	if (dom->fc_info && dom->fc_info->level_set_addr) {
@@ -468,35 +467,35 @@ static int scmi_perf_level_set(const struct scmi_handle *handle, u32 domain,
 		return 0;
 	}
 
-	return scmi_perf_mb_level_set(handle, domain, level, poll);
+	return scmi_perf_mb_level_set(ph, domain, level, poll);
 }
 
-static int scmi_perf_mb_level_get(const struct scmi_handle *handle, u32 domain,
-				  u32 *level, bool poll)
+static int scmi_perf_mb_level_get(const struct scmi_protocol_handle *ph,
+				  u32 domain, u32 *level, bool poll)
 {
 	int ret;
 	struct scmi_xfer *t;
 
-	ret = scmi_xfer_get_init(handle, PERF_LEVEL_GET, SCMI_PROTOCOL_PERF,
-				 sizeof(u32), sizeof(u32), &t);
+	ret = ph->xops->xfer_get_init(ph, PERF_LEVEL_GET,
+				     sizeof(u32), sizeof(u32), &t);
 	if (ret)
 		return ret;
 
 	t->hdr.poll_completion = poll;
 	put_unaligned_le32(domain, t->tx.buf);
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 	if (!ret)
 		*level = get_unaligned_le32(t->rx.buf);
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
-static int scmi_perf_level_get(const struct scmi_handle *handle, u32 domain,
-			       u32 *level, bool poll)
+static int scmi_perf_level_get(const struct scmi_protocol_handle *ph,
+			       u32 domain, u32 *level, bool poll)
 {
-	struct scmi_perf_info *pi = handle->perf_priv;
+	struct scmi_perf_info *pi = ph->get_priv(ph);
 	struct perf_dom_info *dom = pi->dom_info + domain;
 
 	if (dom->fc_info && dom->fc_info->level_get_addr) {
@@ -504,10 +503,10 @@ static int scmi_perf_level_get(const struct scmi_handle *handle, u32 domain,
 		return 0;
 	}
 
-	return scmi_perf_mb_level_get(handle, domain, level, poll);
+	return scmi_perf_mb_level_get(ph, domain, level, poll);
 }
 
-static int scmi_perf_level_limits_notify(const struct scmi_handle *handle,
+static int scmi_perf_level_limits_notify(const struct scmi_protocol_handle *ph,
 					 u32 domain, int message_id,
 					 bool enable)
 {
@@ -515,8 +514,7 @@ static int scmi_perf_level_limits_notify(const struct scmi_handle *handle,
 	struct scmi_xfer *t;
 	struct scmi_perf_notify_level_or_limits *notify;
 
-	ret = scmi_xfer_get_init(handle, message_id, SCMI_PROTOCOL_PERF,
-				 sizeof(*notify), 0, &t);
+	ret = ph->xops->xfer_get_init(ph, message_id, sizeof(*notify), 0, &t);
 	if (ret)
 		return ret;
 
@@ -524,9 +522,9 @@ static int scmi_perf_level_limits_notify(const struct scmi_handle *handle,
 	notify->domain = cpu_to_le32(domain);
 	notify->notify_enable = enable ? cpu_to_le32(BIT(0)) : 0;
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
@@ -540,7 +538,7 @@ static bool scmi_perf_fc_size_is_valid(u32 msg, u32 size)
 }
 
 static void
-scmi_perf_domain_desc_fc(const struct scmi_handle *handle, u32 domain,
+scmi_perf_domain_desc_fc(const struct scmi_protocol_handle *ph, u32 domain,
 			 u32 message_id, void __iomem **p_addr,
 			 struct scmi_fc_db_info **p_db)
 {
@@ -557,9 +555,8 @@ scmi_perf_domain_desc_fc(const struct scmi_handle *handle, u32 domain,
 	if (!p_addr)
 		return;
 
-	ret = scmi_xfer_get_init(handle, PERF_DESCRIBE_FASTCHANNEL,
-				 SCMI_PROTOCOL_PERF,
-				 sizeof(*info), sizeof(*resp), &t);
+	ret = ph->xops->xfer_get_init(ph, PERF_DESCRIBE_FASTCHANNEL,
+				      sizeof(*info), sizeof(*resp), &t);
 	if (ret)
 		return;
 
@@ -567,7 +564,7 @@ scmi_perf_domain_desc_fc(const struct scmi_handle *handle, u32 domain,
 	info->domain = cpu_to_le32(domain);
 	info->message_id = cpu_to_le32(message_id);
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 	if (ret)
 		goto err_xfer;
 
@@ -579,20 +576,20 @@ scmi_perf_domain_desc_fc(const struct scmi_handle *handle, u32 domain,
 
 	phys_addr = le32_to_cpu(resp->chan_addr_low);
 	phys_addr |= (u64)le32_to_cpu(resp->chan_addr_high) << 32;
-	addr = devm_ioremap(handle->dev, phys_addr, size);
+	addr = devm_ioremap(ph->dev, phys_addr, size);
 	if (!addr)
 		goto err_xfer;
 	*p_addr = addr;
 
 	if (p_db && SUPPORTS_DOORBELL(flags)) {
-		db = devm_kzalloc(handle->dev, sizeof(*db), GFP_KERNEL);
+		db = devm_kzalloc(ph->dev, sizeof(*db), GFP_KERNEL);
 		if (!db)
 			goto err_xfer;
 
 		size = 1 << DOORBELL_REG_WIDTH(flags);
 		phys_addr = le32_to_cpu(resp->db_addr_low);
 		phys_addr |= (u64)le32_to_cpu(resp->db_addr_high) << 32;
-		addr = devm_ioremap(handle->dev, phys_addr, size);
+		addr = devm_ioremap(ph->dev, phys_addr, size);
 		if (!addr)
 			goto err_xfer;
 
@@ -605,25 +602,25 @@ scmi_perf_domain_desc_fc(const struct scmi_handle *handle, u32 domain,
 		*p_db = db;
 	}
 err_xfer:
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 }
 
-static void scmi_perf_domain_init_fc(const struct scmi_handle *handle,
+static void scmi_perf_domain_init_fc(const struct scmi_protocol_handle *ph,
 				     u32 domain, struct scmi_fc_info **p_fc)
 {
 	struct scmi_fc_info *fc;
 
-	fc = devm_kzalloc(handle->dev, sizeof(*fc), GFP_KERNEL);
+	fc = devm_kzalloc(ph->dev, sizeof(*fc), GFP_KERNEL);
 	if (!fc)
 		return;
 
-	scmi_perf_domain_desc_fc(handle, domain, PERF_LEVEL_SET,
+	scmi_perf_domain_desc_fc(ph, domain, PERF_LEVEL_SET,
 				 &fc->level_set_addr, &fc->level_set_db);
-	scmi_perf_domain_desc_fc(handle, domain, PERF_LEVEL_GET,
+	scmi_perf_domain_desc_fc(ph, domain, PERF_LEVEL_GET,
 				 &fc->level_get_addr, NULL);
-	scmi_perf_domain_desc_fc(handle, domain, PERF_LIMITS_SET,
+	scmi_perf_domain_desc_fc(ph, domain, PERF_LIMITS_SET,
 				 &fc->limit_set_addr, &fc->limit_set_db);
-	scmi_perf_domain_desc_fc(handle, domain, PERF_LIMITS_GET,
+	scmi_perf_domain_desc_fc(ph, domain, PERF_LIMITS_GET,
 				 &fc->limit_get_addr, NULL);
 	*p_fc = fc;
 }
@@ -640,14 +637,14 @@ static int scmi_dev_domain_id(struct device *dev)
 	return clkspec.args[0];
 }
 
-static int scmi_dvfs_device_opps_add(const struct scmi_handle *handle,
+static int scmi_dvfs_device_opps_add(const struct scmi_protocol_handle *ph,
 				     struct device *dev)
 {
 	int idx, ret, domain;
 	unsigned long freq;
 	struct scmi_opp *opp;
 	struct perf_dom_info *dom;
-	struct scmi_perf_info *pi = handle->perf_priv;
+	struct scmi_perf_info *pi = ph->get_priv(ph);
 
 	domain = scmi_dev_domain_id(dev);
 	if (domain < 0)
@@ -672,11 +669,12 @@ static int scmi_dvfs_device_opps_add(const struct scmi_handle *handle,
 	return 0;
 }
 
-static int scmi_dvfs_transition_latency_get(const struct scmi_handle *handle,
-					    struct device *dev)
+static int
+scmi_dvfs_transition_latency_get(const struct scmi_protocol_handle *ph,
+				 struct device *dev)
 {
 	struct perf_dom_info *dom;
-	struct scmi_perf_info *pi = handle->perf_priv;
+	struct scmi_perf_info *pi = ph->get_priv(ph);
 	int domain = scmi_dev_domain_id(dev);
 
 	if (domain < 0)
@@ -687,35 +685,35 @@ static int scmi_dvfs_transition_latency_get(const struct scmi_handle *handle,
 	return dom->opp[dom->opp_count - 1].trans_latency_us * 1000;
 }
 
-static int scmi_dvfs_freq_set(const struct scmi_handle *handle, u32 domain,
+static int scmi_dvfs_freq_set(const struct scmi_protocol_handle *ph, u32 domain,
 			      unsigned long freq, bool poll)
 {
-	struct scmi_perf_info *pi = handle->perf_priv;
+	struct scmi_perf_info *pi = ph->get_priv(ph);
 	struct perf_dom_info *dom = pi->dom_info + domain;
 
-	return scmi_perf_level_set(handle, domain, freq / dom->mult_factor,
-				   poll);
+	return scmi_perf_level_set(ph, domain, freq / dom->mult_factor, poll);
 }
 
-static int scmi_dvfs_freq_get(const struct scmi_handle *handle, u32 domain,
+static int scmi_dvfs_freq_get(const struct scmi_protocol_handle *ph, u32 domain,
 			      unsigned long *freq, bool poll)
 {
 	int ret;
 	u32 level;
-	struct scmi_perf_info *pi = handle->perf_priv;
+	struct scmi_perf_info *pi = ph->get_priv(ph);
 	struct perf_dom_info *dom = pi->dom_info + domain;
 
-	ret = scmi_perf_level_get(handle, domain, &level, poll);
+	ret = scmi_perf_level_get(ph, domain, &level, poll);
 	if (!ret)
 		*freq = level * dom->mult_factor;
 
 	return ret;
 }
 
-static int scmi_dvfs_est_power_get(const struct scmi_handle *handle, u32 domain,
-				   unsigned long *freq, unsigned long *power)
+static int scmi_dvfs_est_power_get(const struct scmi_protocol_handle *ph,
+				   u32 domain, unsigned long *freq,
+				   unsigned long *power)
 {
-	struct scmi_perf_info *pi = handle->perf_priv;
+	struct scmi_perf_info *pi = ph->get_priv(ph);
 	struct perf_dom_info *dom;
 	unsigned long opp_freq;
 	int idx, ret = -EINVAL;
@@ -739,25 +737,25 @@ static int scmi_dvfs_est_power_get(const struct scmi_handle *handle, u32 domain,
 	return ret;
 }
 
-static bool scmi_fast_switch_possible(const struct scmi_handle *handle,
+static bool scmi_fast_switch_possible(const struct scmi_protocol_handle *ph,
 				      struct device *dev)
 {
 	struct perf_dom_info *dom;
-	struct scmi_perf_info *pi = handle->perf_priv;
+	struct scmi_perf_info *pi = ph->get_priv(ph);
 
 	dom = pi->dom_info + scmi_dev_domain_id(dev);
 
 	return dom->fc_info && dom->fc_info->level_set_addr;
 }
 
-static bool scmi_power_scale_mw_get(const struct scmi_handle *handle)
+static bool scmi_power_scale_mw_get(const struct scmi_protocol_handle *ph)
 {
-	struct scmi_perf_info *pi = handle->perf_priv;
+	struct scmi_perf_info *pi = ph->get_priv(ph);
 
 	return pi->power_scale_mw;
 }
 
-static const struct scmi_perf_ops perf_ops = {
+static const struct scmi_perf_proto_ops perf_proto_ops = {
 	.limits_set = scmi_perf_limits_set,
 	.limits_get = scmi_perf_limits_get,
 	.level_set = scmi_perf_level_set,
@@ -772,7 +770,7 @@ static const struct scmi_perf_ops perf_ops = {
 	.power_scale_mw_get = scmi_power_scale_mw_get,
 };
 
-static int scmi_perf_set_notify_enabled(const struct scmi_handle *handle,
+static int scmi_perf_set_notify_enabled(const struct scmi_protocol_handle *ph,
 					u8 evt_id, u32 src_id, bool enable)
 {
 	int ret, cmd_id;
@@ -781,7 +779,7 @@ static int scmi_perf_set_notify_enabled(const struct scmi_handle *handle,
 		return -EINVAL;
 
 	cmd_id = evt_2_cmd[evt_id];
-	ret = scmi_perf_level_limits_notify(handle, src_id, cmd_id, enable);
+	ret = scmi_perf_level_limits_notify(ph, src_id, cmd_id, enable);
 	if (ret)
 		pr_debug("FAIL_ENABLED - evt[%X] dom[%d] - ret:%d\n",
 			 evt_id, src_id, ret);
@@ -789,7 +787,7 @@ static int scmi_perf_set_notify_enabled(const struct scmi_handle *handle,
 	return ret;
 }
 
-static void *scmi_perf_fill_custom_report(const struct scmi_handle *handle,
+static void *scmi_perf_fill_custom_report(const struct scmi_protocol_handle *ph,
 					  u8 evt_id, ktime_t timestamp,
 					  const void *payld, size_t payld_sz,
 					  void *report, u32 *src_id)
@@ -837,6 +835,16 @@ static void *scmi_perf_fill_custom_report(const struct scmi_handle *handle,
 	return rep;
 }
 
+static int scmi_perf_get_num_sources(const struct scmi_protocol_handle *ph)
+{
+	struct scmi_perf_info *pi = ph->get_priv(ph);
+
+	if (!pi)
+		return -EINVAL;
+
+	return pi->num_domains;
+}
+
 static const struct scmi_event perf_events[] = {
 	{
 		.id = SCMI_EVENT_PERFORMANCE_LIMITS_CHANGED,
@@ -851,28 +859,36 @@ static const struct scmi_event perf_events[] = {
 };
 
 static const struct scmi_event_ops perf_event_ops = {
+	.get_num_sources = scmi_perf_get_num_sources,
 	.set_notify_enabled = scmi_perf_set_notify_enabled,
 	.fill_custom_report = scmi_perf_fill_custom_report,
 };
 
-static int scmi_perf_protocol_init(struct scmi_handle *handle)
+static const struct scmi_protocol_events perf_protocol_events = {
+	.queue_sz = SCMI_PROTO_QUEUE_SZ,
+	.ops = &perf_event_ops,
+	.evts = perf_events,
+	.num_events = ARRAY_SIZE(perf_events),
+};
+
+static int scmi_perf_protocol_init(const struct scmi_protocol_handle *ph)
 {
 	int domain;
 	u32 version;
 	struct scmi_perf_info *pinfo;
 
-	scmi_version_get(handle, SCMI_PROTOCOL_PERF, &version);
+	ph->xops->version_get(ph, &version);
 
-	dev_dbg(handle->dev, "Performance Version %d.%d\n",
+	dev_dbg(ph->dev, "Performance Version %d.%d\n",
 		PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
 
-	pinfo = devm_kzalloc(handle->dev, sizeof(*pinfo), GFP_KERNEL);
+	pinfo = devm_kzalloc(ph->dev, sizeof(*pinfo), GFP_KERNEL);
 	if (!pinfo)
 		return -ENOMEM;
 
-	scmi_perf_attributes_get(handle, pinfo);
+	scmi_perf_attributes_get(ph, pinfo);
 
-	pinfo->dom_info = devm_kcalloc(handle->dev, pinfo->num_domains,
+	pinfo->dom_info = devm_kcalloc(ph->dev, pinfo->num_domains,
 				       sizeof(*pinfo->dom_info), GFP_KERNEL);
 	if (!pinfo->dom_info)
 		return -ENOMEM;
@@ -880,24 +896,24 @@ static int scmi_perf_protocol_init(struct scmi_handle *handle)
 	for (domain = 0; domain < pinfo->num_domains; domain++) {
 		struct perf_dom_info *dom = pinfo->dom_info + domain;
 
-		scmi_perf_domain_attributes_get(handle, domain, dom);
-		scmi_perf_describe_levels_get(handle, domain, dom);
+		scmi_perf_domain_attributes_get(ph, domain, dom);
+		scmi_perf_describe_levels_get(ph, domain, dom);
 
 		if (dom->perf_fastchannels)
-			scmi_perf_domain_init_fc(handle, domain, &dom->fc_info);
+			scmi_perf_domain_init_fc(ph, domain, &dom->fc_info);
 	}
 
-	scmi_register_protocol_events(handle,
-				      SCMI_PROTOCOL_PERF, SCMI_PROTO_QUEUE_SZ,
-				      &perf_event_ops, perf_events,
-				      ARRAY_SIZE(perf_events),
-				      pinfo->num_domains);
-
 	pinfo->version = version;
-	handle->perf_ops = &perf_ops;
-	handle->perf_priv = pinfo;
 
-	return 0;
+	return ph->set_priv(ph, pinfo);
 }
 
-DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(SCMI_PROTOCOL_PERF, perf)
+static const struct scmi_protocol scmi_perf = {
+	.id = SCMI_PROTOCOL_PERF,
+	.owner = THIS_MODULE,
+	.instance_init = &scmi_perf_protocol_init,
+	.ops = &perf_proto_ops,
+	.events = &perf_protocol_events,
+};
+
+DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(perf, scmi_perf)
diff --git a/drivers/firmware/arm_scmi/power.c b/drivers/firmware/arm_scmi/power.c
index 1f37258e9bee..ad2ab080f344 100644
--- a/drivers/firmware/arm_scmi/power.c
+++ b/drivers/firmware/arm_scmi/power.c
@@ -2,11 +2,12 @@
 /*
  * System Control and Management Interface (SCMI) Power Protocol
  *
- * Copyright (C) 2018 ARM Ltd.
+ * Copyright (C) 2018-2021 ARM Ltd.
  */
 
 #define pr_fmt(fmt) "SCMI Notifications POWER - " fmt
 
+#include <linux/module.h>
 #include <linux/scmi_protocol.h>
 
 #include "common.h"
@@ -68,21 +69,21 @@ struct scmi_power_info {
 	struct power_dom_info *dom_info;
 };
 
-static int scmi_power_attributes_get(const struct scmi_handle *handle,
+static int scmi_power_attributes_get(const struct scmi_protocol_handle *ph,
 				     struct scmi_power_info *pi)
 {
 	int ret;
 	struct scmi_xfer *t;
 	struct scmi_msg_resp_power_attributes *attr;
 
-	ret = scmi_xfer_get_init(handle, PROTOCOL_ATTRIBUTES,
-				 SCMI_PROTOCOL_POWER, 0, sizeof(*attr), &t);
+	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES,
+				      0, sizeof(*attr), &t);
 	if (ret)
 		return ret;
 
 	attr = t->rx.buf;
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 	if (!ret) {
 		pi->num_domains = le16_to_cpu(attr->num_domains);
 		pi->stats_addr = le32_to_cpu(attr->stats_addr_low) |
@@ -90,28 +91,27 @@ static int scmi_power_attributes_get(const struct scmi_handle *handle,
 		pi->stats_size = le32_to_cpu(attr->stats_size);
 	}
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
 static int
-scmi_power_domain_attributes_get(const struct scmi_handle *handle, u32 domain,
-				 struct power_dom_info *dom_info)
+scmi_power_domain_attributes_get(const struct scmi_protocol_handle *ph,
+				 u32 domain, struct power_dom_info *dom_info)
 {
 	int ret;
 	struct scmi_xfer *t;
 	struct scmi_msg_resp_power_domain_attributes *attr;
 
-	ret = scmi_xfer_get_init(handle, POWER_DOMAIN_ATTRIBUTES,
-				 SCMI_PROTOCOL_POWER, sizeof(domain),
-				 sizeof(*attr), &t);
+	ret = ph->xops->xfer_get_init(ph, POWER_DOMAIN_ATTRIBUTES,
+				      sizeof(domain), sizeof(*attr), &t);
 	if (ret)
 		return ret;
 
 	put_unaligned_le32(domain, t->tx.buf);
 	attr = t->rx.buf;
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 	if (!ret) {
 		u32 flags = le32_to_cpu(attr->flags);
 
@@ -121,19 +121,18 @@ scmi_power_domain_attributes_get(const struct scmi_handle *handle, u32 domain,
 		strlcpy(dom_info->name, attr->name, SCMI_MAX_STR_SIZE);
 	}
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
-static int
-scmi_power_state_set(const struct scmi_handle *handle, u32 domain, u32 state)
+static int scmi_power_state_set(const struct scmi_protocol_handle *ph,
+				u32 domain, u32 state)
 {
 	int ret;
 	struct scmi_xfer *t;
 	struct scmi_power_set_state *st;
 
-	ret = scmi_xfer_get_init(handle, POWER_STATE_SET, SCMI_PROTOCOL_POWER,
-				 sizeof(*st), 0, &t);
+	ret = ph->xops->xfer_get_init(ph, POWER_STATE_SET, sizeof(*st), 0, &t);
 	if (ret)
 		return ret;
 
@@ -142,64 +141,64 @@ scmi_power_state_set(const struct scmi_handle *handle, u32 domain, u32 state)
 	st->domain = cpu_to_le32(domain);
 	st->state = cpu_to_le32(state);
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
-static int
-scmi_power_state_get(const struct scmi_handle *handle, u32 domain, u32 *state)
+static int scmi_power_state_get(const struct scmi_protocol_handle *ph,
+				u32 domain, u32 *state)
 {
 	int ret;
 	struct scmi_xfer *t;
 
-	ret = scmi_xfer_get_init(handle, POWER_STATE_GET, SCMI_PROTOCOL_POWER,
-				 sizeof(u32), sizeof(u32), &t);
+	ret = ph->xops->xfer_get_init(ph, POWER_STATE_GET, sizeof(u32), sizeof(u32), &t);
 	if (ret)
 		return ret;
 
 	put_unaligned_le32(domain, t->tx.buf);
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 	if (!ret)
 		*state = get_unaligned_le32(t->rx.buf);
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
-static int scmi_power_num_domains_get(const struct scmi_handle *handle)
+static int scmi_power_num_domains_get(const struct scmi_protocol_handle *ph)
 {
-	struct scmi_power_info *pi = handle->power_priv;
+	struct scmi_power_info *pi = ph->get_priv(ph);
 
 	return pi->num_domains;
 }
 
-static char *scmi_power_name_get(const struct scmi_handle *handle, u32 domain)
+static char *scmi_power_name_get(const struct scmi_protocol_handle *ph,
+				 u32 domain)
 {
-	struct scmi_power_info *pi = handle->power_priv;
+	struct scmi_power_info *pi = ph->get_priv(ph);
 	struct power_dom_info *dom = pi->dom_info + domain;
 
 	return dom->name;
 }
 
-static const struct scmi_power_ops power_ops = {
+static const struct scmi_power_proto_ops power_proto_ops = {
 	.num_domains_get = scmi_power_num_domains_get,
 	.name_get = scmi_power_name_get,
 	.state_set = scmi_power_state_set,
 	.state_get = scmi_power_state_get,
 };
 
-static int scmi_power_request_notify(const struct scmi_handle *handle,
+static int scmi_power_request_notify(const struct scmi_protocol_handle *ph,
 				     u32 domain, bool enable)
 {
 	int ret;
 	struct scmi_xfer *t;
 	struct scmi_power_state_notify *notify;
 
-	ret = scmi_xfer_get_init(handle, POWER_STATE_NOTIFY,
-				 SCMI_PROTOCOL_POWER, sizeof(*notify), 0, &t);
+	ret = ph->xops->xfer_get_init(ph, POWER_STATE_NOTIFY,
+				      sizeof(*notify), 0, &t);
 	if (ret)
 		return ret;
 
@@ -207,18 +206,18 @@ static int scmi_power_request_notify(const struct scmi_handle *handle,
 	notify->domain = cpu_to_le32(domain);
 	notify->notify_enable = enable ? cpu_to_le32(BIT(0)) : 0;
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
-static int scmi_power_set_notify_enabled(const struct scmi_handle *handle,
+static int scmi_power_set_notify_enabled(const struct scmi_protocol_handle *ph,
 					 u8 evt_id, u32 src_id, bool enable)
 {
 	int ret;
 
-	ret = scmi_power_request_notify(handle, src_id, enable);
+	ret = scmi_power_request_notify(ph, src_id, enable);
 	if (ret)
 		pr_debug("FAIL_ENABLE - evt[%X] dom[%d] - ret:%d\n",
 			 evt_id, src_id, ret);
@@ -226,10 +225,11 @@ static int scmi_power_set_notify_enabled(const struct scmi_handle *handle,
 	return ret;
 }
 
-static void *scmi_power_fill_custom_report(const struct scmi_handle *handle,
-					   u8 evt_id, ktime_t timestamp,
-					   const void *payld, size_t payld_sz,
-					   void *report, u32 *src_id)
+static void *
+scmi_power_fill_custom_report(const struct scmi_protocol_handle *ph,
+			      u8 evt_id, ktime_t timestamp,
+			      const void *payld, size_t payld_sz,
+			      void *report, u32 *src_id)
 {
 	const struct scmi_power_state_notify_payld *p = payld;
 	struct scmi_power_state_changed_report *r = report;
@@ -246,6 +246,16 @@ static void *scmi_power_fill_custom_report(const struct scmi_handle *handle,
 	return r;
 }
 
+static int scmi_power_get_num_sources(const struct scmi_protocol_handle *ph)
+{
+	struct scmi_power_info *pinfo = ph->get_priv(ph);
+
+	if (!pinfo)
+		return -EINVAL;
+
+	return pinfo->num_domains;
+}
+
 static const struct scmi_event power_events[] = {
 	{
 		.id = SCMI_EVENT_POWER_STATE_CHANGED,
@@ -256,28 +266,36 @@ static const struct scmi_event power_events[] = {
 };
 
 static const struct scmi_event_ops power_event_ops = {
+	.get_num_sources = scmi_power_get_num_sources,
 	.set_notify_enabled = scmi_power_set_notify_enabled,
 	.fill_custom_report = scmi_power_fill_custom_report,
 };
 
-static int scmi_power_protocol_init(struct scmi_handle *handle)
+static const struct scmi_protocol_events power_protocol_events = {
+	.queue_sz = SCMI_PROTO_QUEUE_SZ,
+	.ops = &power_event_ops,
+	.evts = power_events,
+	.num_events = ARRAY_SIZE(power_events),
+};
+
+static int scmi_power_protocol_init(const struct scmi_protocol_handle *ph)
 {
 	int domain;
 	u32 version;
 	struct scmi_power_info *pinfo;
 
-	scmi_version_get(handle, SCMI_PROTOCOL_POWER, &version);
+	ph->xops->version_get(ph, &version);
 
-	dev_dbg(handle->dev, "Power Version %d.%d\n",
+	dev_dbg(ph->dev, "Power Version %d.%d\n",
 		PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
 
-	pinfo = devm_kzalloc(handle->dev, sizeof(*pinfo), GFP_KERNEL);
+	pinfo = devm_kzalloc(ph->dev, sizeof(*pinfo), GFP_KERNEL);
 	if (!pinfo)
 		return -ENOMEM;
 
-	scmi_power_attributes_get(handle, pinfo);
+	scmi_power_attributes_get(ph, pinfo);
 
-	pinfo->dom_info = devm_kcalloc(handle->dev, pinfo->num_domains,
+	pinfo->dom_info = devm_kcalloc(ph->dev, pinfo->num_domains,
 				       sizeof(*pinfo->dom_info), GFP_KERNEL);
 	if (!pinfo->dom_info)
 		return -ENOMEM;
@@ -285,20 +303,20 @@ static int scmi_power_protocol_init(struct scmi_handle *handle)
 	for (domain = 0; domain < pinfo->num_domains; domain++) {
 		struct power_dom_info *dom = pinfo->dom_info + domain;
 
-		scmi_power_domain_attributes_get(handle, domain, dom);
+		scmi_power_domain_attributes_get(ph, domain, dom);
 	}
 
-	scmi_register_protocol_events(handle,
-				      SCMI_PROTOCOL_POWER, SCMI_PROTO_QUEUE_SZ,
-				      &power_event_ops, power_events,
-				      ARRAY_SIZE(power_events),
-				      pinfo->num_domains);
-
 	pinfo->version = version;
-	handle->power_ops = &power_ops;
-	handle->power_priv = pinfo;
 
-	return 0;
+	return ph->set_priv(ph, pinfo);
 }
 
-DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(SCMI_PROTOCOL_POWER, power)
+static const struct scmi_protocol scmi_power = {
+	.id = SCMI_PROTOCOL_POWER,
+	.owner = THIS_MODULE,
+	.instance_init = &scmi_power_protocol_init,
+	.ops = &power_proto_ops,
+	.events = &power_protocol_events,
+};
+
+DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(power, scmi_power)
diff --git a/drivers/firmware/arm_scmi/reset.c b/drivers/firmware/arm_scmi/reset.c
index a981a22cfe89..9bf2478ec6d1 100644
--- a/drivers/firmware/arm_scmi/reset.c
+++ b/drivers/firmware/arm_scmi/reset.c
@@ -2,11 +2,12 @@
 /*
  * System Control and Management Interface (SCMI) Reset Protocol
  *
- * Copyright (C) 2019 ARM Ltd.
+ * Copyright (C) 2019-2021 ARM Ltd.
  */
 
 #define pr_fmt(fmt) "SCMI Notifications RESET - " fmt
 
+#include <linux/module.h>
 #include <linux/scmi_protocol.h>
 
 #include "common.h"
@@ -64,46 +65,45 @@ struct scmi_reset_info {
 	struct reset_dom_info *dom_info;
 };
 
-static int scmi_reset_attributes_get(const struct scmi_handle *handle,
+static int scmi_reset_attributes_get(const struct scmi_protocol_handle *ph,
 				     struct scmi_reset_info *pi)
 {
 	int ret;
 	struct scmi_xfer *t;
 	u32 attr;
 
-	ret = scmi_xfer_get_init(handle, PROTOCOL_ATTRIBUTES,
-				 SCMI_PROTOCOL_RESET, 0, sizeof(attr), &t);
+	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES,
+				      0, sizeof(attr), &t);
 	if (ret)
 		return ret;
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 	if (!ret) {
 		attr = get_unaligned_le32(t->rx.buf);
 		pi->num_domains = attr & NUM_RESET_DOMAIN_MASK;
 	}
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
 static int
-scmi_reset_domain_attributes_get(const struct scmi_handle *handle, u32 domain,
-				 struct reset_dom_info *dom_info)
+scmi_reset_domain_attributes_get(const struct scmi_protocol_handle *ph,
+				 u32 domain, struct reset_dom_info *dom_info)
 {
 	int ret;
 	struct scmi_xfer *t;
 	struct scmi_msg_resp_reset_domain_attributes *attr;
 
-	ret = scmi_xfer_get_init(handle, RESET_DOMAIN_ATTRIBUTES,
-				 SCMI_PROTOCOL_RESET, sizeof(domain),
-				 sizeof(*attr), &t);
+	ret = ph->xops->xfer_get_init(ph, RESET_DOMAIN_ATTRIBUTES,
+				      sizeof(domain), sizeof(*attr), &t);
 	if (ret)
 		return ret;
 
 	put_unaligned_le32(domain, t->tx.buf);
 	attr = t->rx.buf;
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 	if (!ret) {
 		u32 attributes = le32_to_cpu(attr->attributes);
 
@@ -115,47 +115,49 @@ scmi_reset_domain_attributes_get(const struct scmi_handle *handle, u32 domain,
 		strlcpy(dom_info->name, attr->name, SCMI_MAX_STR_SIZE);
 	}
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
-static int scmi_reset_num_domains_get(const struct scmi_handle *handle)
+static int scmi_reset_num_domains_get(const struct scmi_protocol_handle *ph)
 {
-	struct scmi_reset_info *pi = handle->reset_priv;
+	struct scmi_reset_info *pi = ph->get_priv(ph);
 
 	return pi->num_domains;
 }
 
-static char *scmi_reset_name_get(const struct scmi_handle *handle, u32 domain)
+static char *scmi_reset_name_get(const struct scmi_protocol_handle *ph,
+				 u32 domain)
 {
-	struct scmi_reset_info *pi = handle->reset_priv;
+	struct scmi_reset_info *pi = ph->get_priv(ph);
+
 	struct reset_dom_info *dom = pi->dom_info + domain;
 
 	return dom->name;
 }
 
-static int scmi_reset_latency_get(const struct scmi_handle *handle, u32 domain)
+static int scmi_reset_latency_get(const struct scmi_protocol_handle *ph,
+				  u32 domain)
 {
-	struct scmi_reset_info *pi = handle->reset_priv;
+	struct scmi_reset_info *pi = ph->get_priv(ph);
 	struct reset_dom_info *dom = pi->dom_info + domain;
 
 	return dom->latency_us;
 }
 
-static int scmi_domain_reset(const struct scmi_handle *handle, u32 domain,
+static int scmi_domain_reset(const struct scmi_protocol_handle *ph, u32 domain,
 			     u32 flags, u32 state)
 {
 	int ret;
 	struct scmi_xfer *t;
 	struct scmi_msg_reset_domain_reset *dom;
-	struct scmi_reset_info *pi = handle->reset_priv;
+	struct scmi_reset_info *pi = ph->get_priv(ph);
 	struct reset_dom_info *rdom = pi->dom_info + domain;
 
 	if (rdom->async_reset)
 		flags |= ASYNCHRONOUS_RESET;
 
-	ret = scmi_xfer_get_init(handle, RESET, SCMI_PROTOCOL_RESET,
-				 sizeof(*dom), 0, &t);
+	ret = ph->xops->xfer_get_init(ph, RESET, sizeof(*dom), 0, &t);
 	if (ret)
 		return ret;
 
@@ -165,34 +167,35 @@ static int scmi_domain_reset(const struct scmi_handle *handle, u32 domain,
 	dom->reset_state = cpu_to_le32(state);
 
 	if (rdom->async_reset)
-		ret = scmi_do_xfer_with_response(handle, t);
+		ret = ph->xops->do_xfer_with_response(ph, t);
 	else
-		ret = scmi_do_xfer(handle, t);
+		ret = ph->xops->do_xfer(ph, t);
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
-static int scmi_reset_domain_reset(const struct scmi_handle *handle, u32 domain)
+static int scmi_reset_domain_reset(const struct scmi_protocol_handle *ph,
+				   u32 domain)
 {
-	return scmi_domain_reset(handle, domain, AUTONOMOUS_RESET,
+	return scmi_domain_reset(ph, domain, AUTONOMOUS_RESET,
 				 ARCH_COLD_RESET);
 }
 
 static int
-scmi_reset_domain_assert(const struct scmi_handle *handle, u32 domain)
+scmi_reset_domain_assert(const struct scmi_protocol_handle *ph, u32 domain)
 {
-	return scmi_domain_reset(handle, domain, EXPLICIT_RESET_ASSERT,
+	return scmi_domain_reset(ph, domain, EXPLICIT_RESET_ASSERT,
 				 ARCH_COLD_RESET);
 }
 
 static int
-scmi_reset_domain_deassert(const struct scmi_handle *handle, u32 domain)
+scmi_reset_domain_deassert(const struct scmi_protocol_handle *ph, u32 domain)
 {
-	return scmi_domain_reset(handle, domain, 0, ARCH_COLD_RESET);
+	return scmi_domain_reset(ph, domain, 0, ARCH_COLD_RESET);
 }
 
-static const struct scmi_reset_ops reset_ops = {
+static const struct scmi_reset_proto_ops reset_proto_ops = {
 	.num_domains_get = scmi_reset_num_domains_get,
 	.name_get = scmi_reset_name_get,
 	.latency_get = scmi_reset_latency_get,
@@ -201,16 +204,15 @@ static const struct scmi_reset_ops reset_ops = {
 	.deassert = scmi_reset_domain_deassert,
 };
 
-static int scmi_reset_notify(const struct scmi_handle *handle, u32 domain_id,
-			     bool enable)
+static int scmi_reset_notify(const struct scmi_protocol_handle *ph,
+			     u32 domain_id, bool enable)
 {
 	int ret;
 	u32 evt_cntl = enable ? RESET_TP_NOTIFY_ALL : 0;
 	struct scmi_xfer *t;
 	struct scmi_msg_reset_notify *cfg;
 
-	ret = scmi_xfer_get_init(handle, RESET_NOTIFY,
-				 SCMI_PROTOCOL_RESET, sizeof(*cfg), 0, &t);
+	ret = ph->xops->xfer_get_init(ph, RESET_NOTIFY, sizeof(*cfg), 0, &t);
 	if (ret)
 		return ret;
 
@@ -218,18 +220,18 @@ static int scmi_reset_notify(const struct scmi_handle *handle, u32 domain_id,
 	cfg->id = cpu_to_le32(domain_id);
 	cfg->event_control = cpu_to_le32(evt_cntl);
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
-static int scmi_reset_set_notify_enabled(const struct scmi_handle *handle,
+static int scmi_reset_set_notify_enabled(const struct scmi_protocol_handle *ph,
 					 u8 evt_id, u32 src_id, bool enable)
 {
 	int ret;
 
-	ret = scmi_reset_notify(handle, src_id, enable);
+	ret = scmi_reset_notify(ph, src_id, enable);
 	if (ret)
 		pr_debug("FAIL_ENABLED - evt[%X] dom[%d] - ret:%d\n",
 			 evt_id, src_id, ret);
@@ -237,10 +239,11 @@ static int scmi_reset_set_notify_enabled(const struct scmi_handle *handle,
 	return ret;
 }
 
-static void *scmi_reset_fill_custom_report(const struct scmi_handle *handle,
-					   u8 evt_id, ktime_t timestamp,
-					   const void *payld, size_t payld_sz,
-					   void *report, u32 *src_id)
+static void *
+scmi_reset_fill_custom_report(const struct scmi_protocol_handle *ph,
+			      u8 evt_id, ktime_t timestamp,
+			      const void *payld, size_t payld_sz,
+			      void *report, u32 *src_id)
 {
 	const struct scmi_reset_issued_notify_payld *p = payld;
 	struct scmi_reset_issued_report *r = report;
@@ -257,6 +260,16 @@ static void *scmi_reset_fill_custom_report(const struct scmi_handle *handle,
 	return r;
 }
 
+static int scmi_reset_get_num_sources(const struct scmi_protocol_handle *ph)
+{
+	struct scmi_reset_info *pinfo = ph->get_priv(ph);
+
+	if (!pinfo)
+		return -EINVAL;
+
+	return pinfo->num_domains;
+}
+
 static const struct scmi_event reset_events[] = {
 	{
 		.id = SCMI_EVENT_RESET_ISSUED,
@@ -266,28 +279,36 @@ static const struct scmi_event reset_events[] = {
 };
 
 static const struct scmi_event_ops reset_event_ops = {
+	.get_num_sources = scmi_reset_get_num_sources,
 	.set_notify_enabled = scmi_reset_set_notify_enabled,
 	.fill_custom_report = scmi_reset_fill_custom_report,
 };
 
-static int scmi_reset_protocol_init(struct scmi_handle *handle)
+static const struct scmi_protocol_events reset_protocol_events = {
+	.queue_sz = SCMI_PROTO_QUEUE_SZ,
+	.ops = &reset_event_ops,
+	.evts = reset_events,
+	.num_events = ARRAY_SIZE(reset_events),
+};
+
+static int scmi_reset_protocol_init(const struct scmi_protocol_handle *ph)
 {
 	int domain;
 	u32 version;
 	struct scmi_reset_info *pinfo;
 
-	scmi_version_get(handle, SCMI_PROTOCOL_RESET, &version);
+	ph->xops->version_get(ph, &version);
 
-	dev_dbg(handle->dev, "Reset Version %d.%d\n",
+	dev_dbg(ph->dev, "Reset Version %d.%d\n",
 		PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
 
-	pinfo = devm_kzalloc(handle->dev, sizeof(*pinfo), GFP_KERNEL);
+	pinfo = devm_kzalloc(ph->dev, sizeof(*pinfo), GFP_KERNEL);
 	if (!pinfo)
 		return -ENOMEM;
 
-	scmi_reset_attributes_get(handle, pinfo);
+	scmi_reset_attributes_get(ph, pinfo);
 
-	pinfo->dom_info = devm_kcalloc(handle->dev, pinfo->num_domains,
+	pinfo->dom_info = devm_kcalloc(ph->dev, pinfo->num_domains,
 				       sizeof(*pinfo->dom_info), GFP_KERNEL);
 	if (!pinfo->dom_info)
 		return -ENOMEM;
@@ -295,20 +316,19 @@ static int scmi_reset_protocol_init(struct scmi_handle *handle)
 	for (domain = 0; domain < pinfo->num_domains; domain++) {
 		struct reset_dom_info *dom = pinfo->dom_info + domain;
 
-		scmi_reset_domain_attributes_get(handle, domain, dom);
+		scmi_reset_domain_attributes_get(ph, domain, dom);
 	}
 
-	scmi_register_protocol_events(handle,
-				      SCMI_PROTOCOL_RESET, SCMI_PROTO_QUEUE_SZ,
-				      &reset_event_ops, reset_events,
-				      ARRAY_SIZE(reset_events),
-				      pinfo->num_domains);
-
 	pinfo->version = version;
-	handle->reset_ops = &reset_ops;
-	handle->reset_priv = pinfo;
-
-	return 0;
+	return ph->set_priv(ph, pinfo);
 }
 
-DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(SCMI_PROTOCOL_RESET, reset)
+static const struct scmi_protocol scmi_reset = {
+	.id = SCMI_PROTOCOL_RESET,
+	.owner = THIS_MODULE,
+	.instance_init = &scmi_reset_protocol_init,
+	.ops = &reset_proto_ops,
+	.events = &reset_protocol_events,
+};
+
+DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(reset, scmi_reset)
diff --git a/drivers/firmware/arm_scmi/scmi_pm_domain.c b/drivers/firmware/arm_scmi/scmi_pm_domain.c
index 9e44479f0284..9d36d5c0622d 100644
--- a/drivers/firmware/arm_scmi/scmi_pm_domain.c
+++ b/drivers/firmware/arm_scmi/scmi_pm_domain.c
@@ -2,7 +2,7 @@
 /*
  * SCMI Generic power domain support.
  *
- * Copyright (C) 2018 ARM Ltd.
+ * Copyright (C) 2018-2021 ARM Ltd.
  */
 
 #include <linux/err.h>
@@ -11,9 +11,11 @@
 #include <linux/pm_domain.h>
 #include <linux/scmi_protocol.h>
 
+static const struct scmi_power_proto_ops *power_ops;
+
 struct scmi_pm_domain {
 	struct generic_pm_domain genpd;
-	const struct scmi_handle *handle;
+	const struct scmi_protocol_handle *ph;
 	const char *name;
 	u32 domain;
 };
@@ -25,16 +27,15 @@ static int scmi_pd_power(struct generic_pm_domain *domain, bool power_on)
 	int ret;
 	u32 state, ret_state;
 	struct scmi_pm_domain *pd = to_scmi_pd(domain);
-	const struct scmi_power_ops *ops = pd->handle->power_ops;
 
 	if (power_on)
 		state = SCMI_POWER_STATE_GENERIC_ON;
 	else
 		state = SCMI_POWER_STATE_GENERIC_OFF;
 
-	ret = ops->state_set(pd->handle, pd->domain, state);
+	ret = power_ops->state_set(pd->ph, pd->domain, state);
 	if (!ret)
-		ret = ops->state_get(pd->handle, pd->domain, &ret_state);
+		ret = power_ops->state_get(pd->ph, pd->domain, &ret_state);
 	if (!ret && state != ret_state)
 		return -EIO;
 
@@ -60,11 +61,16 @@ static int scmi_pm_domain_probe(struct scmi_device *sdev)
 	struct genpd_onecell_data *scmi_pd_data;
 	struct generic_pm_domain **domains;
 	const struct scmi_handle *handle = sdev->handle;
+	struct scmi_protocol_handle *ph;
 
-	if (!handle || !handle->power_ops)
+	if (!handle)
 		return -ENODEV;
 
-	num_domains = handle->power_ops->num_domains_get(handle);
+	power_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_POWER, &ph);
+	if (IS_ERR(power_ops))
+		return PTR_ERR(power_ops);
+
+	num_domains = power_ops->num_domains_get(ph);
 	if (num_domains < 0) {
 		dev_err(dev, "number of domains not found\n");
 		return num_domains;
@@ -85,14 +91,14 @@ static int scmi_pm_domain_probe(struct scmi_device *sdev)
 	for (i = 0; i < num_domains; i++, scmi_pd++) {
 		u32 state;
 
-		if (handle->power_ops->state_get(handle, i, &state)) {
+		if (power_ops->state_get(ph, i, &state)) {
 			dev_warn(dev, "failed to get state for domain %d\n", i);
 			continue;
 		}
 
 		scmi_pd->domain = i;
-		scmi_pd->handle = handle;
-		scmi_pd->name = handle->power_ops->name_get(handle, i);
+		scmi_pd->ph = ph;
+		scmi_pd->name = power_ops->name_get(ph, i);
 		scmi_pd->genpd.name = scmi_pd->name;
 		scmi_pd->genpd.power_off = scmi_pd_power_off;
 		scmi_pd->genpd.power_on = scmi_pd_power_on;
diff --git a/drivers/firmware/arm_scmi/sensors.c b/drivers/firmware/arm_scmi/sensors.c
index 4541b891b733..2c88aa221559 100644
--- a/drivers/firmware/arm_scmi/sensors.c
+++ b/drivers/firmware/arm_scmi/sensors.c
@@ -2,12 +2,13 @@
 /*
  * System Control and Management Interface (SCMI) Sensor Protocol
  *
- * Copyright (C) 2018-2020 ARM Ltd.
+ * Copyright (C) 2018-2021 ARM Ltd.
  */
 
 #define pr_fmt(fmt) "SCMI Notifications SENSOR - " fmt
 
 #include <linux/bitfield.h>
+#include <linux/module.h>
 #include <linux/scmi_protocol.h>
 
 #include "common.h"
@@ -201,21 +202,21 @@ struct sensors_info {
 	struct scmi_sensor_info *sensors;
 };
 
-static int scmi_sensor_attributes_get(const struct scmi_handle *handle,
+static int scmi_sensor_attributes_get(const struct scmi_protocol_handle *ph,
 				      struct sensors_info *si)
 {
 	int ret;
 	struct scmi_xfer *t;
 	struct scmi_msg_resp_sensor_attributes *attr;
 
-	ret = scmi_xfer_get_init(handle, PROTOCOL_ATTRIBUTES,
-				 SCMI_PROTOCOL_SENSOR, 0, sizeof(*attr), &t);
+	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES,
+				      0, sizeof(*attr), &t);
 	if (ret)
 		return ret;
 
 	attr = t->rx.buf;
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 	if (!ret) {
 		si->num_sensors = le16_to_cpu(attr->num_sensors);
 		si->max_requests = attr->max_requests;
@@ -224,7 +225,7 @@ static int scmi_sensor_attributes_get(const struct scmi_handle *handle,
 		si->reg_size = le32_to_cpu(attr->reg_size);
 	}
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
@@ -235,7 +236,7 @@ static inline void scmi_parse_range_attrs(struct scmi_range_attrs *out,
 	out->max_range = get_unaligned_le64((void *)&in->max_range_low);
 }
 
-static int scmi_sensor_update_intervals(const struct scmi_handle *handle,
+static int scmi_sensor_update_intervals(const struct scmi_protocol_handle *ph,
 					struct scmi_sensor_info *s)
 {
 	int ret, cnt;
@@ -245,8 +246,8 @@ static int scmi_sensor_update_intervals(const struct scmi_handle *handle,
 	struct scmi_msg_resp_sensor_list_update_intervals *buf;
 	struct scmi_msg_sensor_list_update_intervals *msg;
 
-	ret = scmi_xfer_get_init(handle, SENSOR_LIST_UPDATE_INTERVALS,
-				 SCMI_PROTOCOL_SENSOR, sizeof(*msg), 0, &ti);
+	ret = ph->xops->xfer_get_init(ph, SENSOR_LIST_UPDATE_INTERVALS,
+				      sizeof(*msg), 0, &ti);
 	if (ret)
 		return ret;
 
@@ -259,7 +260,7 @@ static int scmi_sensor_update_intervals(const struct scmi_handle *handle,
 		msg->id = cpu_to_le32(s->id);
 		msg->index = cpu_to_le32(desc_index);
 
-		ret = scmi_do_xfer(handle, ti);
+		ret = ph->xops->do_xfer(ph, ti);
 		if (ret)
 			break;
 
@@ -277,7 +278,7 @@ static int scmi_sensor_update_intervals(const struct scmi_handle *handle,
 			/* segmented intervals are reported in one triplet */
 			if (s->intervals.segmented &&
 			    (num_remaining || num_returned != 3)) {
-				dev_err(handle->dev,
+				dev_err(ph->dev,
 					"Sensor ID:%d advertises an invalid segmented interval (%d)\n",
 					s->id, s->intervals.count);
 				s->intervals.segmented = false;
@@ -288,7 +289,7 @@ static int scmi_sensor_update_intervals(const struct scmi_handle *handle,
 			/* Direct allocation when exceeding pre-allocated */
 			if (s->intervals.count >= SCMI_MAX_PREALLOC_POOL) {
 				s->intervals.desc =
-					devm_kcalloc(handle->dev,
+					devm_kcalloc(ph->dev,
 						     s->intervals.count,
 						     sizeof(*s->intervals.desc),
 						     GFP_KERNEL);
@@ -300,7 +301,7 @@ static int scmi_sensor_update_intervals(const struct scmi_handle *handle,
 				}
 			}
 		} else if (desc_index + num_returned > s->intervals.count) {
-			dev_err(handle->dev,
+			dev_err(ph->dev,
 				"No. of update intervals can't exceed %d\n",
 				s->intervals.count);
 			ret = -EINVAL;
@@ -313,18 +314,18 @@ static int scmi_sensor_update_intervals(const struct scmi_handle *handle,
 
 		desc_index += num_returned;
 
-		scmi_reset_rx_to_maxsz(handle, ti);
+		ph->xops->reset_rx_to_maxsz(ph, ti);
 		/*
 		 * check for both returned and remaining to avoid infinite
 		 * loop due to buggy firmware
 		 */
 	} while (num_returned && num_remaining);
 
-	scmi_xfer_put(handle, ti);
+	ph->xops->xfer_put(ph, ti);
 	return ret;
 }
 
-static int scmi_sensor_axis_description(const struct scmi_handle *handle,
+static int scmi_sensor_axis_description(const struct scmi_protocol_handle *ph,
 					struct scmi_sensor_info *s)
 {
 	int ret, cnt;
@@ -334,13 +335,13 @@ static int scmi_sensor_axis_description(const struct scmi_handle *handle,
 	struct scmi_msg_resp_sensor_axis_description *buf;
 	struct scmi_msg_sensor_axis_description_get *msg;
 
-	s->axis = devm_kcalloc(handle->dev, s->num_axis,
+	s->axis = devm_kcalloc(ph->dev, s->num_axis,
 			       sizeof(*s->axis), GFP_KERNEL);
 	if (!s->axis)
 		return -ENOMEM;
 
-	ret = scmi_xfer_get_init(handle, SENSOR_AXIS_DESCRIPTION_GET,
-				 SCMI_PROTOCOL_SENSOR, sizeof(*msg), 0, &te);
+	ret = ph->xops->xfer_get_init(ph, SENSOR_AXIS_DESCRIPTION_GET,
+				      sizeof(*msg), 0, &te);
 	if (ret)
 		return ret;
 
@@ -354,7 +355,7 @@ static int scmi_sensor_axis_description(const struct scmi_handle *handle,
 		msg->id = cpu_to_le32(s->id);
 		msg->axis_desc_index = cpu_to_le32(desc_index);
 
-		ret = scmi_do_xfer(handle, te);
+		ret = ph->xops->do_xfer(ph, te);
 		if (ret)
 			break;
 
@@ -363,7 +364,7 @@ static int scmi_sensor_axis_description(const struct scmi_handle *handle,
 		num_remaining = NUM_AXIS_REMAINING(flags);
 
 		if (desc_index + num_returned > s->num_axis) {
-			dev_err(handle->dev, "No. of axis can't exceed %d\n",
+			dev_err(ph->dev, "No. of axis can't exceed %d\n",
 				s->num_axis);
 			break;
 		}
@@ -405,18 +406,18 @@ static int scmi_sensor_axis_description(const struct scmi_handle *handle,
 
 		desc_index += num_returned;
 
-		scmi_reset_rx_to_maxsz(handle, te);
+		ph->xops->reset_rx_to_maxsz(ph, te);
 		/*
 		 * check for both returned and remaining to avoid infinite
 		 * loop due to buggy firmware
 		 */
 	} while (num_returned && num_remaining);
 
-	scmi_xfer_put(handle, te);
+	ph->xops->xfer_put(ph, te);
 	return ret;
 }
 
-static int scmi_sensor_description_get(const struct scmi_handle *handle,
+static int scmi_sensor_description_get(const struct scmi_protocol_handle *ph,
 				       struct sensors_info *si)
 {
 	int ret, cnt;
@@ -425,8 +426,8 @@ static int scmi_sensor_description_get(const struct scmi_handle *handle,
 	struct scmi_xfer *t;
 	struct scmi_msg_resp_sensor_description *buf;
 
-	ret = scmi_xfer_get_init(handle, SENSOR_DESCRIPTION_GET,
-				 SCMI_PROTOCOL_SENSOR, sizeof(__le32), 0, &t);
+	ret = ph->xops->xfer_get_init(ph, SENSOR_DESCRIPTION_GET,
+				      sizeof(__le32), 0, &t);
 	if (ret)
 		return ret;
 
@@ -437,7 +438,8 @@ static int scmi_sensor_description_get(const struct scmi_handle *handle,
 
 		/* Set the number of sensors to be skipped/already read */
 		put_unaligned_le32(desc_index, t->tx.buf);
-		ret = scmi_do_xfer(handle, t);
+
+		ret = ph->xops->do_xfer(ph, t);
 		if (ret)
 			break;
 
@@ -445,7 +447,7 @@ static int scmi_sensor_description_get(const struct scmi_handle *handle,
 		num_remaining = le16_to_cpu(buf->num_remaining);
 
 		if (desc_index + num_returned > si->num_sensors) {
-			dev_err(handle->dev, "No. of sensors can't exceed %d",
+			dev_err(ph->dev, "No. of sensors can't exceed %d",
 				si->num_sensors);
 			break;
 		}
@@ -500,8 +502,8 @@ static int scmi_sensor_description_get(const struct scmi_handle *handle,
 				 * Since the command is optional, on error carry
 				 * on without any update interval.
 				 */
-				if (scmi_sensor_update_intervals(handle, s))
-					dev_dbg(handle->dev,
+				if (scmi_sensor_update_intervals(ph, s))
+					dev_dbg(ph->dev,
 						"Update Intervals not available for sensor ID:%d\n",
 						s->id);
 			}
@@ -535,7 +537,7 @@ static int scmi_sensor_description_get(const struct scmi_handle *handle,
 				}
 			}
 			if (s->num_axis > 0) {
-				ret = scmi_sensor_axis_description(handle, s);
+				ret = scmi_sensor_axis_description(ph, s);
 				if (ret)
 					goto out;
 			}
@@ -545,7 +547,7 @@ static int scmi_sensor_description_get(const struct scmi_handle *handle,
 
 		desc_index += num_returned;
 
-		scmi_reset_rx_to_maxsz(handle, t);
+		ph->xops->reset_rx_to_maxsz(ph, t);
 		/*
 		 * check for both returned and remaining to avoid infinite
 		 * loop due to buggy firmware
@@ -553,12 +555,12 @@ static int scmi_sensor_description_get(const struct scmi_handle *handle,
 	} while (num_returned && num_remaining);
 
 out:
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
 static inline int
-scmi_sensor_request_notify(const struct scmi_handle *handle, u32 sensor_id,
+scmi_sensor_request_notify(const struct scmi_protocol_handle *ph, u32 sensor_id,
 			   u8 message_id, bool enable)
 {
 	int ret;
@@ -566,8 +568,7 @@ scmi_sensor_request_notify(const struct scmi_handle *handle, u32 sensor_id,
 	struct scmi_xfer *t;
 	struct scmi_msg_sensor_request_notify *cfg;
 
-	ret = scmi_xfer_get_init(handle, message_id,
-				 SCMI_PROTOCOL_SENSOR, sizeof(*cfg), 0, &t);
+	ret = ph->xops->xfer_get_init(ph, message_id, sizeof(*cfg), 0, &t);
 	if (ret)
 		return ret;
 
@@ -575,40 +576,40 @@ scmi_sensor_request_notify(const struct scmi_handle *handle, u32 sensor_id,
 	cfg->id = cpu_to_le32(sensor_id);
 	cfg->event_control = cpu_to_le32(evt_cntl);
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
-static int scmi_sensor_trip_point_notify(const struct scmi_handle *handle,
+static int scmi_sensor_trip_point_notify(const struct scmi_protocol_handle *ph,
 					 u32 sensor_id, bool enable)
 {
-	return scmi_sensor_request_notify(handle, sensor_id,
+	return scmi_sensor_request_notify(ph, sensor_id,
 					  SENSOR_TRIP_POINT_NOTIFY,
 					  enable);
 }
 
 static int
-scmi_sensor_continuous_update_notify(const struct scmi_handle *handle,
+scmi_sensor_continuous_update_notify(const struct scmi_protocol_handle *ph,
 				     u32 sensor_id, bool enable)
 {
-	return scmi_sensor_request_notify(handle, sensor_id,
+	return scmi_sensor_request_notify(ph, sensor_id,
 					  SENSOR_CONTINUOUS_UPDATE_NOTIFY,
 					  enable);
 }
 
 static int
-scmi_sensor_trip_point_config(const struct scmi_handle *handle, u32 sensor_id,
-			      u8 trip_id, u64 trip_value)
+scmi_sensor_trip_point_config(const struct scmi_protocol_handle *ph,
+			      u32 sensor_id, u8 trip_id, u64 trip_value)
 {
 	int ret;
 	u32 evt_cntl = SENSOR_TP_BOTH;
 	struct scmi_xfer *t;
 	struct scmi_msg_set_sensor_trip_point *trip;
 
-	ret = scmi_xfer_get_init(handle, SENSOR_TRIP_POINT_CONFIG,
-				 SCMI_PROTOCOL_SENSOR, sizeof(*trip), 0, &t);
+	ret = ph->xops->xfer_get_init(ph, SENSOR_TRIP_POINT_CONFIG,
+				      sizeof(*trip), 0, &t);
 	if (ret)
 		return ret;
 
@@ -618,47 +619,46 @@ scmi_sensor_trip_point_config(const struct scmi_handle *handle, u32 sensor_id,
 	trip->value_low = cpu_to_le32(trip_value & 0xffffffff);
 	trip->value_high = cpu_to_le32(trip_value >> 32);
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
-static int scmi_sensor_config_get(const struct scmi_handle *handle,
+static int scmi_sensor_config_get(const struct scmi_protocol_handle *ph,
 				  u32 sensor_id, u32 *sensor_config)
 {
 	int ret;
 	struct scmi_xfer *t;
 
-	ret = scmi_xfer_get_init(handle, SENSOR_CONFIG_GET,
-				 SCMI_PROTOCOL_SENSOR, sizeof(__le32),
-				 sizeof(__le32), &t);
+	ret = ph->xops->xfer_get_init(ph, SENSOR_CONFIG_GET,
+				      sizeof(__le32), sizeof(__le32), &t);
 	if (ret)
 		return ret;
 
 	put_unaligned_le32(cpu_to_le32(sensor_id), t->tx.buf);
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 	if (!ret) {
-		struct sensors_info *si = handle->sensor_priv;
+		struct sensors_info *si = ph->get_priv(ph);
 		struct scmi_sensor_info *s = si->sensors + sensor_id;
 
 		*sensor_config = get_unaligned_le64(t->rx.buf);
 		s->sensor_config = *sensor_config;
 	}
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
-static int scmi_sensor_config_set(const struct scmi_handle *handle,
+static int scmi_sensor_config_set(const struct scmi_protocol_handle *ph,
 				  u32 sensor_id, u32 sensor_config)
 {
 	int ret;
 	struct scmi_xfer *t;
 	struct scmi_msg_sensor_config_set *msg;
 
-	ret = scmi_xfer_get_init(handle, SENSOR_CONFIG_SET,
-				 SCMI_PROTOCOL_SENSOR, sizeof(*msg), 0, &t);
+	ret = ph->xops->xfer_get_init(ph, SENSOR_CONFIG_SET,
+				      sizeof(*msg), 0, &t);
 	if (ret)
 		return ret;
 
@@ -666,21 +666,21 @@ static int scmi_sensor_config_set(const struct scmi_handle *handle,
 	msg->id = cpu_to_le32(sensor_id);
 	msg->sensor_config = cpu_to_le32(sensor_config);
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 	if (!ret) {
-		struct sensors_info *si = handle->sensor_priv;
+		struct sensors_info *si = ph->get_priv(ph);
 		struct scmi_sensor_info *s = si->sensors + sensor_id;
 
 		s->sensor_config = sensor_config;
 	}
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
 /**
  * scmi_sensor_reading_get  - Read scalar sensor value
- * @handle: Platform handle
+ * @ph: Protocol handle
  * @sensor_id: Sensor ID
  * @value: The 64bit value sensor reading
  *
@@ -693,17 +693,17 @@ static int scmi_sensor_config_set(const struct scmi_handle *handle,
  *
  * Return: 0 on Success
  */
-static int scmi_sensor_reading_get(const struct scmi_handle *handle,
+static int scmi_sensor_reading_get(const struct scmi_protocol_handle *ph,
 				   u32 sensor_id, u64 *value)
 {
 	int ret;
 	struct scmi_xfer *t;
 	struct scmi_msg_sensor_reading_get *sensor;
-	struct sensors_info *si = handle->sensor_priv;
+	struct sensors_info *si = ph->get_priv(ph);
 	struct scmi_sensor_info *s = si->sensors + sensor_id;
 
-	ret = scmi_xfer_get_init(handle, SENSOR_READING_GET,
-				 SCMI_PROTOCOL_SENSOR, sizeof(*sensor), 0, &t);
+	ret = ph->xops->xfer_get_init(ph, SENSOR_READING_GET,
+				      sizeof(*sensor), 0, &t);
 	if (ret)
 		return ret;
 
@@ -711,7 +711,7 @@ static int scmi_sensor_reading_get(const struct scmi_handle *handle,
 	sensor->id = cpu_to_le32(sensor_id);
 	if (s->async) {
 		sensor->flags = cpu_to_le32(SENSOR_READ_ASYNC);
-		ret = scmi_do_xfer_with_response(handle, t);
+		ret = ph->xops->do_xfer_with_response(ph, t);
 		if (!ret) {
 			struct scmi_resp_sensor_reading_complete *resp;
 
@@ -723,12 +723,12 @@ static int scmi_sensor_reading_get(const struct scmi_handle *handle,
 		}
 	} else {
 		sensor->flags = cpu_to_le32(0);
-		ret = scmi_do_xfer(handle, t);
+		ret = ph->xops->do_xfer(ph, t);
 		if (!ret)
 			*value = get_unaligned_le64(t->rx.buf);
 	}
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
@@ -742,7 +742,7 @@ scmi_parse_sensor_readings(struct scmi_sensor_reading *out,
 
 /**
  * scmi_sensor_reading_get_timestamped  - Read multiple-axis timestamped values
- * @handle: Platform handle
+ * @ph: Protocol handle
  * @sensor_id: Sensor ID
  * @count: The length of the provided @readings array
  * @readings: An array of elements each representing a timestamped per-axis
@@ -755,22 +755,22 @@ scmi_parse_sensor_readings(struct scmi_sensor_reading *out,
  * Return: 0 on Success
  */
 static int
-scmi_sensor_reading_get_timestamped(const struct scmi_handle *handle,
+scmi_sensor_reading_get_timestamped(const struct scmi_protocol_handle *ph,
 				    u32 sensor_id, u8 count,
 				    struct scmi_sensor_reading *readings)
 {
 	int ret;
 	struct scmi_xfer *t;
 	struct scmi_msg_sensor_reading_get *sensor;
-	struct sensors_info *si = handle->sensor_priv;
+	struct sensors_info *si = ph->get_priv(ph);
 	struct scmi_sensor_info *s = si->sensors + sensor_id;
 
 	if (!count || !readings ||
 	    (!s->num_axis && count > 1) || (s->num_axis && count > s->num_axis))
 		return -EINVAL;
 
-	ret = scmi_xfer_get_init(handle, SENSOR_READING_GET,
-				 SCMI_PROTOCOL_SENSOR, sizeof(*sensor), 0, &t);
+	ret = ph->xops->xfer_get_init(ph, SENSOR_READING_GET,
+				      sizeof(*sensor), 0, &t);
 	if (ret)
 		return ret;
 
@@ -778,7 +778,7 @@ scmi_sensor_reading_get_timestamped(const struct scmi_handle *handle,
 	sensor->id = cpu_to_le32(sensor_id);
 	if (s->async) {
 		sensor->flags = cpu_to_le32(SENSOR_READ_ASYNC);
-		ret = scmi_do_xfer_with_response(handle, t);
+		ret = ph->xops->do_xfer_with_response(ph, t);
 		if (!ret) {
 			int i;
 			struct scmi_resp_sensor_reading_complete_v3 *resp;
@@ -794,7 +794,7 @@ scmi_sensor_reading_get_timestamped(const struct scmi_handle *handle,
 		}
 	} else {
 		sensor->flags = cpu_to_le32(0);
-		ret = scmi_do_xfer(handle, t);
+		ret = ph->xops->do_xfer(ph, t);
 		if (!ret) {
 			int i;
 			struct scmi_sensor_reading_resp *resp_readings;
@@ -806,26 +806,26 @@ scmi_sensor_reading_get_timestamped(const struct scmi_handle *handle,
 		}
 	}
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
 static const struct scmi_sensor_info *
-scmi_sensor_info_get(const struct scmi_handle *handle, u32 sensor_id)
+scmi_sensor_info_get(const struct scmi_protocol_handle *ph, u32 sensor_id)
 {
-	struct sensors_info *si = handle->sensor_priv;
+	struct sensors_info *si = ph->get_priv(ph);
 
 	return si->sensors + sensor_id;
 }
 
-static int scmi_sensor_count_get(const struct scmi_handle *handle)
+static int scmi_sensor_count_get(const struct scmi_protocol_handle *ph)
 {
-	struct sensors_info *si = handle->sensor_priv;
+	struct sensors_info *si = ph->get_priv(ph);
 
 	return si->num_sensors;
 }
 
-static const struct scmi_sensor_ops sensor_ops = {
+static const struct scmi_sensor_proto_ops sensor_proto_ops = {
 	.count_get = scmi_sensor_count_get,
 	.info_get = scmi_sensor_info_get,
 	.trip_point_config = scmi_sensor_trip_point_config,
@@ -835,18 +835,17 @@ static const struct scmi_sensor_ops sensor_ops = {
 	.config_set = scmi_sensor_config_set,
 };
 
-static int scmi_sensor_set_notify_enabled(const struct scmi_handle *handle,
+static int scmi_sensor_set_notify_enabled(const struct scmi_protocol_handle *ph,
 					  u8 evt_id, u32 src_id, bool enable)
 {
 	int ret;
 
 	switch (evt_id) {
 	case SCMI_EVENT_SENSOR_TRIP_POINT_EVENT:
-		ret = scmi_sensor_trip_point_notify(handle, src_id, enable);
+		ret = scmi_sensor_trip_point_notify(ph, src_id, enable);
 		break;
 	case SCMI_EVENT_SENSOR_UPDATE:
-		ret = scmi_sensor_continuous_update_notify(handle, src_id,
-							   enable);
+		ret = scmi_sensor_continuous_update_notify(ph, src_id, enable);
 		break;
 	default:
 		ret = -EINVAL;
@@ -860,10 +859,11 @@ static int scmi_sensor_set_notify_enabled(const struct scmi_handle *handle,
 	return ret;
 }
 
-static void *scmi_sensor_fill_custom_report(const struct scmi_handle *handle,
-					    u8 evt_id, ktime_t timestamp,
-					    const void *payld, size_t payld_sz,
-					    void *report, u32 *src_id)
+static void *
+scmi_sensor_fill_custom_report(const struct scmi_protocol_handle *ph,
+			       u8 evt_id, ktime_t timestamp,
+			       const void *payld, size_t payld_sz,
+			       void *report, u32 *src_id)
 {
 	void *rep = NULL;
 
@@ -890,7 +890,7 @@ static void *scmi_sensor_fill_custom_report(const struct scmi_handle *handle,
 		struct scmi_sensor_info *s;
 		const struct scmi_sensor_update_notify_payld *p = payld;
 		struct scmi_sensor_update_report *r = report;
-		struct sensors_info *sinfo = handle->sensor_priv;
+		struct sensors_info *sinfo = ph->get_priv(ph);
 
 		/* payld_sz is variable for this event */
 		r->sensor_id = le32_to_cpu(p->sensor_id);
@@ -920,6 +920,13 @@ static void *scmi_sensor_fill_custom_report(const struct scmi_handle *handle,
 	return rep;
 }
 
+static int scmi_sensor_get_num_sources(const struct scmi_protocol_handle *ph)
+{
+	struct sensors_info *si = ph->get_priv(ph);
+
+	return si->num_sensors;
+}
+
 static const struct scmi_event sensor_events[] = {
 	{
 		.id = SCMI_EVENT_SENSOR_TRIP_POINT_EVENT,
@@ -939,48 +946,55 @@ static const struct scmi_event sensor_events[] = {
 };
 
 static const struct scmi_event_ops sensor_event_ops = {
+	.get_num_sources = scmi_sensor_get_num_sources,
 	.set_notify_enabled = scmi_sensor_set_notify_enabled,
 	.fill_custom_report = scmi_sensor_fill_custom_report,
 };
 
-static int scmi_sensors_protocol_init(struct scmi_handle *handle)
+static const struct scmi_protocol_events sensor_protocol_events = {
+	.queue_sz = SCMI_PROTO_QUEUE_SZ,
+	.ops = &sensor_event_ops,
+	.evts = sensor_events,
+	.num_events = ARRAY_SIZE(sensor_events),
+};
+
+static int scmi_sensors_protocol_init(const struct scmi_protocol_handle *ph)
 {
 	u32 version;
 	int ret;
 	struct sensors_info *sinfo;
 
-	scmi_version_get(handle, SCMI_PROTOCOL_SENSOR, &version);
+	ph->xops->version_get(ph, &version);
 
-	dev_dbg(handle->dev, "Sensor Version %d.%d\n",
+	dev_dbg(ph->dev, "Sensor Version %d.%d\n",
 		PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
 
-	sinfo = devm_kzalloc(handle->dev, sizeof(*sinfo), GFP_KERNEL);
+	sinfo = devm_kzalloc(ph->dev, sizeof(*sinfo), GFP_KERNEL);
 	if (!sinfo)
 		return -ENOMEM;
 	sinfo->version = version;
 
-	ret = scmi_sensor_attributes_get(handle, sinfo);
+	ret = scmi_sensor_attributes_get(ph, sinfo);
 	if (ret)
 		return ret;
-	sinfo->sensors = devm_kcalloc(handle->dev, sinfo->num_sensors,
+	sinfo->sensors = devm_kcalloc(ph->dev, sinfo->num_sensors,
 				      sizeof(*sinfo->sensors), GFP_KERNEL);
 	if (!sinfo->sensors)
 		return -ENOMEM;
 
-	ret = scmi_sensor_description_get(handle, sinfo);
+	ret = scmi_sensor_description_get(ph, sinfo);
 	if (ret)
 		return ret;
 
-	scmi_register_protocol_events(handle,
-				      SCMI_PROTOCOL_SENSOR, SCMI_PROTO_QUEUE_SZ,
-				      &sensor_event_ops, sensor_events,
-				      ARRAY_SIZE(sensor_events),
-				      sinfo->num_sensors);
-
-	handle->sensor_priv = sinfo;
-	handle->sensor_ops = &sensor_ops;
-
-	return 0;
+	return ph->set_priv(ph, sinfo);
 }
 
-DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(SCMI_PROTOCOL_SENSOR, sensors)
+static const struct scmi_protocol scmi_sensors = {
+	.id = SCMI_PROTOCOL_SENSOR,
+	.owner = THIS_MODULE,
+	.instance_init = &scmi_sensors_protocol_init,
+	.ops = &sensor_proto_ops,
+	.events = &sensor_protocol_events,
+};
+
+DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(sensors, scmi_sensors)
diff --git a/drivers/firmware/arm_scmi/system.c b/drivers/firmware/arm_scmi/system.c
index 283e12d5f24b..e5175ef73b40 100644
--- a/drivers/firmware/arm_scmi/system.c
+++ b/drivers/firmware/arm_scmi/system.c
@@ -2,11 +2,12 @@
 /*
  * System Control and Management Interface (SCMI) System Power Protocol
  *
- * Copyright (C) 2020 ARM Ltd.
+ * Copyright (C) 2020-2021 ARM Ltd.
  */
 
 #define pr_fmt(fmt) "SCMI Notifications SYSTEM - " fmt
 
+#include <linux/module.h>
 #include <linux/scmi_protocol.h>
 
 #include "common.h"
@@ -32,43 +33,44 @@ struct scmi_system_info {
 	u32 version;
 };
 
-static int scmi_system_request_notify(const struct scmi_handle *handle,
+static int scmi_system_request_notify(const struct scmi_protocol_handle *ph,
 				      bool enable)
 {
 	int ret;
 	struct scmi_xfer *t;
 	struct scmi_system_power_state_notify *notify;
 
-	ret = scmi_xfer_get_init(handle, SYSTEM_POWER_STATE_NOTIFY,
-				 SCMI_PROTOCOL_SYSTEM, sizeof(*notify), 0, &t);
+	ret = ph->xops->xfer_get_init(ph, SYSTEM_POWER_STATE_NOTIFY,
+				      sizeof(*notify), 0, &t);
 	if (ret)
 		return ret;
 
 	notify = t->tx.buf;
 	notify->notify_enable = enable ? cpu_to_le32(BIT(0)) : 0;
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
-static int scmi_system_set_notify_enabled(const struct scmi_handle *handle,
+static int scmi_system_set_notify_enabled(const struct scmi_protocol_handle *ph,
 					  u8 evt_id, u32 src_id, bool enable)
 {
 	int ret;
 
-	ret = scmi_system_request_notify(handle, enable);
+	ret = scmi_system_request_notify(ph, enable);
 	if (ret)
 		pr_debug("FAIL_ENABLE - evt[%X] - ret:%d\n", evt_id, ret);
 
 	return ret;
 }
 
-static void *scmi_system_fill_custom_report(const struct scmi_handle *handle,
-					    u8 evt_id, ktime_t timestamp,
-					    const void *payld, size_t payld_sz,
-					    void *report, u32 *src_id)
+static void *
+scmi_system_fill_custom_report(const struct scmi_protocol_handle *ph,
+			       u8 evt_id, ktime_t timestamp,
+			       const void *payld, size_t payld_sz,
+			       void *report, u32 *src_id)
 {
 	const struct scmi_system_power_state_notifier_payld *p = payld;
 	struct scmi_system_power_state_notifier_report *r = report;
@@ -101,31 +103,38 @@ static const struct scmi_event_ops system_event_ops = {
 	.fill_custom_report = scmi_system_fill_custom_report,
 };
 
-static int scmi_system_protocol_init(struct scmi_handle *handle)
+static const struct scmi_protocol_events system_protocol_events = {
+	.queue_sz = SCMI_PROTO_QUEUE_SZ,
+	.ops = &system_event_ops,
+	.evts = system_events,
+	.num_events = ARRAY_SIZE(system_events),
+	.num_sources = SCMI_SYSTEM_NUM_SOURCES,
+};
+
+static int scmi_system_protocol_init(const struct scmi_protocol_handle *ph)
 {
 	u32 version;
 	struct scmi_system_info *pinfo;
 
-	scmi_version_get(handle, SCMI_PROTOCOL_SYSTEM, &version);
+	ph->xops->version_get(ph, &version);
 
-	dev_dbg(handle->dev, "System Power Version %d.%d\n",
+	dev_dbg(ph->dev, "System Power Version %d.%d\n",
 		PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
 
-	pinfo = devm_kzalloc(handle->dev, sizeof(*pinfo), GFP_KERNEL);
+	pinfo = devm_kzalloc(ph->dev, sizeof(*pinfo), GFP_KERNEL);
 	if (!pinfo)
 		return -ENOMEM;
 
-	scmi_register_protocol_events(handle,
-				      SCMI_PROTOCOL_SYSTEM, SCMI_PROTO_QUEUE_SZ,
-				      &system_event_ops,
-				      system_events,
-				      ARRAY_SIZE(system_events),
-				      SCMI_SYSTEM_NUM_SOURCES);
-
 	pinfo->version = version;
-	handle->system_priv = pinfo;
-
-	return 0;
+	return ph->set_priv(ph, pinfo);
 }
 
-DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(SCMI_PROTOCOL_SYSTEM, system)
+static const struct scmi_protocol scmi_system = {
+	.id = SCMI_PROTOCOL_SYSTEM,
+	.owner = THIS_MODULE,
+	.instance_init = &scmi_system_protocol_init,
+	.ops = NULL,
+	.events = &system_protocol_events,
+};
+
+DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(system, scmi_system)
diff --git a/drivers/firmware/arm_scmi/voltage.c b/drivers/firmware/arm_scmi/voltage.c
index e794e4349ae6..a5048956a0be 100644
--- a/drivers/firmware/arm_scmi/voltage.c
+++ b/drivers/firmware/arm_scmi/voltage.c
@@ -2,9 +2,10 @@
 /*
  * System Control and Management Interface (SCMI) Voltage Protocol
  *
- * Copyright (C) 2020 ARM Ltd.
+ * Copyright (C) 2020-2021 ARM Ltd.
  */
 
+#include <linux/module.h>
 #include <linux/scmi_protocol.h>
 
 #include "common.h"
@@ -59,23 +60,23 @@ struct voltage_info {
 	struct scmi_voltage_info *domains;
 };
 
-static int scmi_protocol_attributes_get(const struct scmi_handle *handle,
+static int scmi_protocol_attributes_get(const struct scmi_protocol_handle *ph,
 					struct voltage_info *vinfo)
 {
 	int ret;
 	struct scmi_xfer *t;
 
-	ret = scmi_xfer_get_init(handle, PROTOCOL_ATTRIBUTES,
-				 SCMI_PROTOCOL_VOLTAGE, 0, sizeof(__le32), &t);
+	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES, 0,
+				      sizeof(__le32), &t);
 	if (ret)
 		return ret;
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 	if (!ret)
 		vinfo->num_domains =
 			NUM_VOLTAGE_DOMAINS(get_unaligned_le32(t->rx.buf));
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
@@ -109,24 +110,23 @@ static int scmi_init_voltage_levels(struct device *dev,
 	return 0;
 }
 
-static int scmi_voltage_descriptors_get(const struct scmi_handle *handle,
+static int scmi_voltage_descriptors_get(const struct scmi_protocol_handle *ph,
 					struct voltage_info *vinfo)
 {
 	int ret, dom;
 	struct scmi_xfer *td, *tl;
-	struct device *dev = handle->dev;
+	struct device *dev = ph->dev;
 	struct scmi_msg_resp_domain_attributes *resp_dom;
 	struct scmi_msg_resp_describe_levels *resp_levels;
 
-	ret = scmi_xfer_get_init(handle, VOLTAGE_DOMAIN_ATTRIBUTES,
-				 SCMI_PROTOCOL_VOLTAGE, sizeof(__le32),
-				 sizeof(*resp_dom), &td);
+	ret = ph->xops->xfer_get_init(ph, VOLTAGE_DOMAIN_ATTRIBUTES,
+				      sizeof(__le32), sizeof(*resp_dom), &td);
 	if (ret)
 		return ret;
 	resp_dom = td->rx.buf;
 
-	ret = scmi_xfer_get_init(handle, VOLTAGE_DESCRIBE_LEVELS,
-				 SCMI_PROTOCOL_VOLTAGE, sizeof(__le64), 0, &tl);
+	ret = ph->xops->xfer_get_init(ph, VOLTAGE_DESCRIBE_LEVELS,
+				      sizeof(__le64), 0, &tl);
 	if (ret)
 		goto outd;
 	resp_levels = tl->rx.buf;
@@ -139,7 +139,7 @@ static int scmi_voltage_descriptors_get(const struct scmi_handle *handle,
 
 		/* Retrieve domain attributes at first ... */
 		put_unaligned_le32(dom, td->tx.buf);
-		ret = scmi_do_xfer(handle, td);
+		ret = ph->xops->do_xfer(ph, td);
 		/* Skip domain on comms error */
 		if (ret)
 			continue;
@@ -157,7 +157,7 @@ static int scmi_voltage_descriptors_get(const struct scmi_handle *handle,
 
 			cmd->domain_id = cpu_to_le32(v->id);
 			cmd->level_index = desc_index;
-			ret = scmi_do_xfer(handle, tl);
+			ret = ph->xops->do_xfer(ph, tl);
 			if (ret)
 				break;
 
@@ -176,7 +176,7 @@ static int scmi_voltage_descriptors_get(const struct scmi_handle *handle,
 			}
 
 			if (desc_index + num_returned > v->num_levels) {
-				dev_err(handle->dev,
+				dev_err(ph->dev,
 					"No. of voltage levels can't exceed %d\n",
 					v->num_levels);
 				ret = -EINVAL;
@@ -195,7 +195,7 @@ static int scmi_voltage_descriptors_get(const struct scmi_handle *handle,
 
 			desc_index += num_returned;
 
-			scmi_reset_rx_to_maxsz(handle, tl);
+			ph->xops->reset_rx_to_maxsz(ph, tl);
 			/* check both to avoid infinite loop due to buggy fw */
 		} while (num_returned && num_remaining);
 
@@ -204,55 +204,52 @@ static int scmi_voltage_descriptors_get(const struct scmi_handle *handle,
 			devm_kfree(dev, v->levels_uv);
 		}
 
-		scmi_reset_rx_to_maxsz(handle, td);
+		ph->xops->reset_rx_to_maxsz(ph, td);
 	}
 
-	scmi_xfer_put(handle, tl);
+	ph->xops->xfer_put(ph, tl);
 outd:
-	scmi_xfer_put(handle, td);
+	ph->xops->xfer_put(ph, td);
 
 	return ret;
 }
 
-static int __scmi_voltage_get_u32(const struct scmi_handle *handle,
+static int __scmi_voltage_get_u32(const struct scmi_protocol_handle *ph,
 				  u8 cmd_id, u32 domain_id, u32 *value)
 {
 	int ret;
 	struct scmi_xfer *t;
-	struct voltage_info *vinfo = handle->voltage_priv;
+	struct voltage_info *vinfo = ph->get_priv(ph);
 
 	if (domain_id >= vinfo->num_domains)
 		return -EINVAL;
 
-	ret = scmi_xfer_get_init(handle, cmd_id,
-				 SCMI_PROTOCOL_VOLTAGE,
-				 sizeof(__le32), 0, &t);
+	ret = ph->xops->xfer_get_init(ph, cmd_id, sizeof(__le32), 0, &t);
 	if (ret)
 		return ret;
 
 	put_unaligned_le32(domain_id, t->tx.buf);
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 	if (!ret)
 		*value = get_unaligned_le32(t->rx.buf);
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
-static int scmi_voltage_config_set(const struct scmi_handle *handle,
+static int scmi_voltage_config_set(const struct scmi_protocol_handle *ph,
 				   u32 domain_id, u32 config)
 {
 	int ret;
 	struct scmi_xfer *t;
-	struct voltage_info *vinfo = handle->voltage_priv;
+	struct voltage_info *vinfo = ph->get_priv(ph);
 	struct scmi_msg_cmd_config_set *cmd;
 
 	if (domain_id >= vinfo->num_domains)
 		return -EINVAL;
 
-	ret = scmi_xfer_get_init(handle, VOLTAGE_CONFIG_SET,
-				 SCMI_PROTOCOL_VOLTAGE,
-				 sizeof(*cmd), 0, &t);
+	ret = ph->xops->xfer_get_init(ph, VOLTAGE_CONFIG_SET,
+				     sizeof(*cmd), 0, &t);
 	if (ret)
 		return ret;
 
@@ -260,33 +257,32 @@ static int scmi_voltage_config_set(const struct scmi_handle *handle,
 	cmd->domain_id = cpu_to_le32(domain_id);
 	cmd->config = cpu_to_le32(config & GENMASK(3, 0));
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
-static int scmi_voltage_config_get(const struct scmi_handle *handle,
+static int scmi_voltage_config_get(const struct scmi_protocol_handle *ph,
 				   u32 domain_id, u32 *config)
 {
-	return __scmi_voltage_get_u32(handle, VOLTAGE_CONFIG_GET,
+	return __scmi_voltage_get_u32(ph, VOLTAGE_CONFIG_GET,
 				      domain_id, config);
 }
 
-static int scmi_voltage_level_set(const struct scmi_handle *handle,
+static int scmi_voltage_level_set(const struct scmi_protocol_handle *ph,
 				  u32 domain_id, u32 flags, s32 volt_uV)
 {
 	int ret;
 	struct scmi_xfer *t;
-	struct voltage_info *vinfo = handle->voltage_priv;
+	struct voltage_info *vinfo = ph->get_priv(ph);
 	struct scmi_msg_cmd_level_set *cmd;
 
 	if (domain_id >= vinfo->num_domains)
 		return -EINVAL;
 
-	ret = scmi_xfer_get_init(handle, VOLTAGE_LEVEL_SET,
-				 SCMI_PROTOCOL_VOLTAGE,
-				 sizeof(*cmd), 0, &t);
+	ret = ph->xops->xfer_get_init(ph, VOLTAGE_LEVEL_SET,
+				      sizeof(*cmd), 0, &t);
 	if (ret)
 		return ret;
 
@@ -295,23 +291,23 @@ static int scmi_voltage_level_set(const struct scmi_handle *handle,
 	cmd->flags = cpu_to_le32(flags);
 	cmd->voltage_level = cpu_to_le32(volt_uV);
 
-	ret = scmi_do_xfer(handle, t);
+	ret = ph->xops->do_xfer(ph, t);
 
-	scmi_xfer_put(handle, t);
+	ph->xops->xfer_put(ph, t);
 	return ret;
 }
 
-static int scmi_voltage_level_get(const struct scmi_handle *handle,
+static int scmi_voltage_level_get(const struct scmi_protocol_handle *ph,
 				  u32 domain_id, s32 *volt_uV)
 {
-	return __scmi_voltage_get_u32(handle, VOLTAGE_LEVEL_GET,
+	return __scmi_voltage_get_u32(ph, VOLTAGE_LEVEL_GET,
 				      domain_id, (u32 *)volt_uV);
 }
 
 static const struct scmi_voltage_info * __must_check
-scmi_voltage_info_get(const struct scmi_handle *handle, u32 domain_id)
+scmi_voltage_info_get(const struct scmi_protocol_handle *ph, u32 domain_id)
 {
-	struct voltage_info *vinfo = handle->voltage_priv;
+	struct voltage_info *vinfo = ph->get_priv(ph);
 
 	if (domain_id >= vinfo->num_domains ||
 	    !vinfo->domains[domain_id].num_levels)
@@ -320,14 +316,14 @@ scmi_voltage_info_get(const struct scmi_handle *handle, u32 domain_id)
 	return vinfo->domains + domain_id;
 }
 
-static int scmi_voltage_domains_num_get(const struct scmi_handle *handle)
+static int scmi_voltage_domains_num_get(const struct scmi_protocol_handle *ph)
 {
-	struct voltage_info *vinfo = handle->voltage_priv;
+	struct voltage_info *vinfo = ph->get_priv(ph);
 
 	return vinfo->num_domains;
 }
 
-static struct scmi_voltage_ops voltage_ops = {
+static struct scmi_voltage_proto_ops voltage_proto_ops = {
 	.num_domains_get = scmi_voltage_domains_num_get,
 	.info_get = scmi_voltage_info_get,
 	.config_set = scmi_voltage_config_set,
@@ -336,45 +332,49 @@ static struct scmi_voltage_ops voltage_ops = {
 	.level_get = scmi_voltage_level_get,
 };
 
-static int scmi_voltage_protocol_init(struct scmi_handle *handle)
+static int scmi_voltage_protocol_init(const struct scmi_protocol_handle *ph)
 {
 	int ret;
 	u32 version;
 	struct voltage_info *vinfo;
 
-	ret = scmi_version_get(handle, SCMI_PROTOCOL_VOLTAGE, &version);
+	ret = ph->xops->version_get(ph, &version);
 	if (ret)
 		return ret;
 
-	dev_dbg(handle->dev, "Voltage Version %d.%d\n",
+	dev_dbg(ph->dev, "Voltage Version %d.%d\n",
 		PROTOCOL_REV_MAJOR(version), PROTOCOL_REV_MINOR(version));
 
-	vinfo = devm_kzalloc(handle->dev, sizeof(*vinfo), GFP_KERNEL);
+	vinfo = devm_kzalloc(ph->dev, sizeof(*vinfo), GFP_KERNEL);
 	if (!vinfo)
 		return -ENOMEM;
 	vinfo->version = version;
 
-	ret = scmi_protocol_attributes_get(handle, vinfo);
+	ret = scmi_protocol_attributes_get(ph, vinfo);
 	if (ret)
 		return ret;
 
 	if (vinfo->num_domains) {
-		vinfo->domains = devm_kcalloc(handle->dev, vinfo->num_domains,
+		vinfo->domains = devm_kcalloc(ph->dev, vinfo->num_domains,
 					      sizeof(*vinfo->domains),
 					      GFP_KERNEL);
 		if (!vinfo->domains)
 			return -ENOMEM;
-		ret = scmi_voltage_descriptors_get(handle, vinfo);
+		ret = scmi_voltage_descriptors_get(ph, vinfo);
 		if (ret)
 			return ret;
 	} else {
-		dev_warn(handle->dev, "No Voltage domains found.\n");
+		dev_warn(ph->dev, "No Voltage domains found.\n");
 	}
 
-	handle->voltage_ops = &voltage_ops;
-	handle->voltage_priv = vinfo;
-
-	return 0;
+	return ph->set_priv(ph, vinfo);
 }
 
-DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(SCMI_PROTOCOL_VOLTAGE, voltage)
+static const struct scmi_protocol scmi_voltage = {
+	.id = SCMI_PROTOCOL_VOLTAGE,
+	.owner = THIS_MODULE,
+	.instance_init = &scmi_voltage_protocol_init,
+	.ops = &voltage_proto_ops,
+};
+
+DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(voltage, scmi_voltage)