Merge tag 'char-misc-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc updates from Greg KH:
 "Here is the big set of char/misc and other small driver subsystem
  changes for 6.7-rc1. Included in here are:

   - IIO subsystem driver updates and additions (largest part of this
     pull request)

   - FPGA subsystem driver updates

   - Counter subsystem driver updates

   - ICC subsystem driver updates

   - extcon subsystem driver updates

   - mei driver updates and additions

   - nvmem subsystem driver updates and additions

   - comedi subsystem dependency fixes

   - parport driver fixups

   - cdx subsystem driver and core updates

   - splice support for /dev/zero and /dev/full

   - other smaller driver cleanups

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (326 commits)
  cdx: add sysfs for subsystem, class and revision
  cdx: add sysfs for bus reset
  cdx: add support for bus enable and disable
  cdx: Register cdx bus as a device on cdx subsystem
  cdx: Create symbol namespaces for cdx subsystem
  cdx: Introduce lock to protect controller ops
  cdx: Remove cdx controller list from cdx bus system
  dts: ti: k3-am625-beagleplay: Add beaglecc1352
  greybus: Add BeaglePlay Linux Driver
  dt-bindings: net: Add ti,cc1352p7
  dt-bindings: eeprom: at24: allow NVMEM cells based on old syntax
  dt-bindings: nvmem: SID: allow NVMEM cells based on old syntax
  Revert "nvmem: add new config option"
  MAINTAINERS: coresight: Add missing Coresight files
  misc: pci_endpoint_test: Add deviceID for J721S2 PCIe EP device support
  firmware: xilinx: Move EXPORT_SYMBOL_GPL next to zynqmp_pm_feature definition
  uacce: make uacce_class constant
  ocxl: make ocxl_class constant
  cxl: make cxl_class constant
  misc: phantom: make phantom_class constant
  ...

7 files changed, 382 insertions, 29 deletions

diff --git a/drivers/cdx/Makefile b/drivers/cdx/Makefile
index 0324e4914f6e..5d1ea482419f 100644
--- a/drivers/cdx/Makefile
+++ b/drivers/cdx/Makefile
@@ -5,4 +5,6 @@
 # Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
 #
 
+ccflags-y += -DDEFAULT_SYMBOL_NAMESPACE=CDX_BUS
+
 obj-$(CONFIG_CDX_BUS) += cdx.o controller/
diff --git a/drivers/cdx/cdx.c b/drivers/cdx/cdx.c
index 9efb7584f952..4461c6c9313f 100644
--- a/drivers/cdx/cdx.c
+++ b/drivers/cdx/cdx.c
@@ -60,7 +60,7 @@
 #include <linux/of_device.h>
 #include <linux/slab.h>
 #include <linux/mm.h>
-#include <linux/xarray.h>
+#include <linux/idr.h>
 #include <linux/cdx/cdx_bus.h>
 #include <linux/iommu.h>
 #include <linux/dma-map-ops.h>
@@ -70,8 +70,12 @@
 #define CDX_DEFAULT_DMA_MASK	(~0ULL)
 #define MAX_CDX_CONTROLLERS 16
 
-/* CDX controllers registered with the CDX bus */
-static DEFINE_XARRAY_ALLOC(cdx_controllers);
+/* IDA for CDX controllers registered with the CDX bus */
+static DEFINE_IDA(cdx_controller_ida);
+/* Lock to protect controller ops */
+static DEFINE_MUTEX(cdx_controller_lock);
+
+static char *compat_node_name = "xlnx,versal-net-cdx";
 
 /**
  * cdx_dev_reset - Reset a CDX device
@@ -107,6 +111,20 @@ int cdx_dev_reset(struct device *dev)
 EXPORT_SYMBOL_GPL(cdx_dev_reset);
 
 /**
+ * reset_cdx_device - Reset a CDX device
+ * @dev: CDX device
+ * @data: This is always passed as NULL, and is not used in this API,
+ *    but is required here as the device_for_each_child() API expects
+ *    the passed function to have this as an argument.
+ *
+ * Return: -errno on failure, 0 on success.
+ */
+static int reset_cdx_device(struct device *dev, void *data)
+{
+	return cdx_dev_reset(dev);
+}
+
+/**
  * cdx_unregister_device - Unregister a CDX device
  * @dev: CDX device
  * @data: This is always passed as NULL, and is not used in this API,
@@ -120,9 +138,17 @@ static int cdx_unregister_device(struct device *dev,
 				 void *data)
 {
 	struct cdx_device *cdx_dev = to_cdx_device(dev);
+	struct cdx_controller *cdx = cdx_dev->cdx;
+
+	if (cdx_dev->is_bus) {
+		device_for_each_child(dev, NULL, cdx_unregister_device);
+		if (cdx_dev->enabled && cdx->ops->bus_disable)
+			cdx->ops->bus_disable(cdx, cdx_dev->bus_num);
+	} else {
+		kfree(cdx_dev->driver_override);
+		cdx_dev->driver_override = NULL;
+	}
 
-	kfree(cdx_dev->driver_override);
-	cdx_dev->driver_override = NULL;
 	/*
 	 * Do not free cdx_dev here as it would be freed in
 	 * cdx_device_release() called from within put_device().
@@ -153,7 +179,10 @@ cdx_match_one_device(const struct cdx_device_id *id,
 {
 	/* Use vendor ID and device ID for matching */
 	if ((id->vendor == CDX_ANY_ID || id->vendor == dev->vendor) &&
-	    (id->device == CDX_ANY_ID || id->device == dev->device))
+	    (id->device == CDX_ANY_ID || id->device == dev->device) &&
+	    (id->subvendor == CDX_ANY_ID || id->subvendor == dev->subsystem_vendor) &&
+	    (id->subdevice == CDX_ANY_ID || id->subdevice == dev->subsystem_device) &&
+	    !((id->class ^ dev->class) & id->class_mask))
 		return id;
 	return NULL;
 }
@@ -229,6 +258,9 @@ static int cdx_bus_match(struct device *dev, struct device_driver *drv)
 	const struct cdx_device_id *found_id = NULL;
 	const struct cdx_device_id *ids;
 
+	if (cdx_dev->is_bus)
+		return false;
+
 	ids = cdx_drv->match_id_table;
 
 	/* When driver_override is set, only bind to the matching driver */
@@ -293,10 +325,11 @@ static int cdx_dma_configure(struct device *dev)
 {
 	struct cdx_driver *cdx_drv = to_cdx_driver(dev->driver);
 	struct cdx_device *cdx_dev = to_cdx_device(dev);
+	struct cdx_controller *cdx = cdx_dev->cdx;
 	u32 input_id = cdx_dev->req_id;
 	int ret;
 
-	ret = of_dma_configure_id(dev, dev->parent->of_node, 0, &input_id);
+	ret = of_dma_configure_id(dev, cdx->dev->of_node, 0, &input_id);
 	if (ret && ret != -EPROBE_DEFER) {
 		dev_err(dev, "of_dma_configure_id() failed\n");
 		return ret;
@@ -331,6 +364,10 @@ static DEVICE_ATTR_RO(field)
 
 cdx_config_attr(vendor, "0x%04x\n");
 cdx_config_attr(device, "0x%04x\n");
+cdx_config_attr(subsystem_vendor, "0x%04x\n");
+cdx_config_attr(subsystem_device, "0x%04x\n");
+cdx_config_attr(revision, "0x%02x\n");
+cdx_config_attr(class, "0x%06x\n");
 
 static ssize_t remove_store(struct device *dev,
 			    struct device_attribute *attr,
@@ -359,6 +396,7 @@ static DEVICE_ATTR_WO(remove);
 static ssize_t reset_store(struct device *dev, struct device_attribute *attr,
 			   const char *buf, size_t count)
 {
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
 	bool val;
 	int ret;
 
@@ -368,14 +406,27 @@ static ssize_t reset_store(struct device *dev, struct device_attribute *attr,
 	if (!val)
 		return -EINVAL;
 
-	ret = cdx_dev_reset(dev);
-	if (ret)
-		return ret;
+	if (cdx_dev->is_bus)
+		/* Reset all the devices attached to cdx bus */
+		ret = device_for_each_child(dev, NULL, reset_cdx_device);
+	else
+		ret = cdx_dev_reset(dev);
 
-	return count;
+	return ret < 0 ? ret : count;
 }
 static DEVICE_ATTR_WO(reset);
 
+static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+
+	return sprintf(buf, "cdx:v%04Xd%04Xsv%04Xsd%04Xc%06X\n", cdx_dev->vendor,
+			cdx_dev->device, cdx_dev->subsystem_vendor, cdx_dev->subsystem_device,
+			cdx_dev->class);
+}
+static DEVICE_ATTR_RO(modalias);
+
 static ssize_t driver_override_store(struct device *dev,
 				     struct device_attribute *attr,
 				     const char *buf, size_t count)
@@ -402,21 +453,107 @@ static ssize_t driver_override_show(struct device *dev,
 }
 static DEVICE_ATTR_RW(driver_override);
 
+static ssize_t enable_store(struct device *dev, struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+	struct cdx_controller *cdx = cdx_dev->cdx;
+	bool enable;
+	int ret;
+
+	if (kstrtobool(buf, &enable) < 0)
+		return -EINVAL;
+
+	if (enable == cdx_dev->enabled)
+		return count;
+
+	if (enable && cdx->ops->bus_enable)
+		ret = cdx->ops->bus_enable(cdx, cdx_dev->bus_num);
+	else if (!enable && cdx->ops->bus_disable)
+		ret = cdx->ops->bus_disable(cdx, cdx_dev->bus_num);
+	else
+		ret = -EOPNOTSUPP;
+
+	if (!ret)
+		cdx_dev->enabled = enable;
+
+	return ret < 0 ? ret : count;
+}
+
+static ssize_t enable_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+
+	return sysfs_emit(buf, "%u\n", cdx_dev->enabled);
+}
+static DEVICE_ATTR_RW(enable);
+
+static umode_t cdx_dev_attrs_are_visible(struct kobject *kobj, struct attribute *a, int n)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct cdx_device *cdx_dev;
+
+	cdx_dev = to_cdx_device(dev);
+	if (!cdx_dev->is_bus)
+		return a->mode;
+
+	return 0;
+}
+
+static umode_t cdx_bus_attrs_are_visible(struct kobject *kobj, struct attribute *a, int n)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct cdx_device *cdx_dev;
+
+	cdx_dev = to_cdx_device(dev);
+	if (cdx_dev->is_bus)
+		return a->mode;
+
+	return 0;
+}
+
 static struct attribute *cdx_dev_attrs[] = {
 	&dev_attr_remove.attr,
 	&dev_attr_reset.attr,
 	&dev_attr_vendor.attr,
 	&dev_attr_device.attr,
+	&dev_attr_subsystem_vendor.attr,
+	&dev_attr_subsystem_device.attr,
+	&dev_attr_class.attr,
+	&dev_attr_revision.attr,
+	&dev_attr_modalias.attr,
 	&dev_attr_driver_override.attr,
 	NULL,
 };
-ATTRIBUTE_GROUPS(cdx_dev);
+
+static const struct attribute_group cdx_dev_group = {
+	.attrs = cdx_dev_attrs,
+	.is_visible = cdx_dev_attrs_are_visible,
+};
+
+static struct attribute *cdx_bus_dev_attrs[] = {
+	&dev_attr_enable.attr,
+	&dev_attr_reset.attr,
+	NULL,
+};
+
+static const struct attribute_group cdx_bus_dev_group = {
+	.attrs = cdx_bus_dev_attrs,
+	.is_visible = cdx_bus_attrs_are_visible,
+};
+
+static const struct attribute_group *cdx_dev_groups[] = {
+	&cdx_dev_group,
+	&cdx_bus_dev_group,
+	NULL,
+};
 
 static ssize_t rescan_store(const struct bus_type *bus,
 			    const char *buf, size_t count)
 {
 	struct cdx_controller *cdx;
-	unsigned long index;
+	struct platform_device *pd;
+	struct device_node *np;
 	bool val;
 
 	if (kstrtobool(buf, &val) < 0)
@@ -425,18 +562,29 @@ static ssize_t rescan_store(const struct bus_type *bus,
 	if (!val)
 		return -EINVAL;
 
+	mutex_lock(&cdx_controller_lock);
+
 	/* Unregister all the devices on the bus */
 	cdx_unregister_devices(&cdx_bus_type);
 
 	/* Rescan all the devices */
-	xa_for_each(&cdx_controllers, index, cdx) {
-		int ret;
+	for_each_compatible_node(np, NULL, compat_node_name) {
+		if (!np)
+			return -EINVAL;
 
-		ret = cdx->ops->scan(cdx);
-		if (ret)
-			dev_err(cdx->dev, "cdx bus scanning failed\n");
+		pd = of_find_device_by_node(np);
+		if (!pd)
+			return -EINVAL;
+
+		cdx = platform_get_drvdata(pd);
+		if (cdx && cdx->controller_registered && cdx->ops->scan)
+			cdx->ops->scan(cdx);
+
+		put_device(&pd->dev);
 	}
 
+	mutex_unlock(&cdx_controller_lock);
+
 	return count;
 }
 static BUS_ATTR_WO(rescan);
@@ -495,7 +643,6 @@ static void cdx_device_release(struct device *dev)
 int cdx_device_add(struct cdx_dev_params *dev_params)
 {
 	struct cdx_controller *cdx = dev_params->cdx;
-	struct device *parent = cdx->dev;
 	struct cdx_device *cdx_dev;
 	int ret;
 
@@ -512,6 +659,10 @@ int cdx_device_add(struct cdx_dev_params *dev_params)
 	cdx_dev->req_id = dev_params->req_id;
 	cdx_dev->vendor = dev_params->vendor;
 	cdx_dev->device = dev_params->device;
+	cdx_dev->subsystem_vendor = dev_params->subsys_vendor;
+	cdx_dev->subsystem_device = dev_params->subsys_device;
+	cdx_dev->class = dev_params->class;
+	cdx_dev->revision = dev_params->revision;
 	cdx_dev->bus_num = dev_params->bus_num;
 	cdx_dev->dev_num = dev_params->dev_num;
 	cdx_dev->cdx = dev_params->cdx;
@@ -519,7 +670,7 @@ int cdx_device_add(struct cdx_dev_params *dev_params)
 
 	/* Initialize generic device */
 	device_initialize(&cdx_dev->dev);
-	cdx_dev->dev.parent = parent;
+	cdx_dev->dev.parent = dev_params->parent;
 	cdx_dev->dev.bus = &cdx_bus_type;
 	cdx_dev->dev.dma_mask = &cdx_dev->dma_mask;
 	cdx_dev->dev.release = cdx_device_release;
@@ -546,37 +697,94 @@ fail:
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(cdx_device_add);
+EXPORT_SYMBOL_NS_GPL(cdx_device_add, CDX_BUS_CONTROLLER);
 
-int cdx_register_controller(struct cdx_controller *cdx)
+struct device *cdx_bus_add(struct cdx_controller *cdx, u8 bus_num)
 {
+	struct cdx_device *cdx_dev;
 	int ret;
 
-	ret = xa_alloc(&cdx_controllers, &cdx->id, cdx,
-		       XA_LIMIT(0, MAX_CDX_CONTROLLERS - 1), GFP_KERNEL);
+	cdx_dev = kzalloc(sizeof(*cdx_dev), GFP_KERNEL);
+	if (!cdx_dev)
+		return NULL;
+
+	device_initialize(&cdx_dev->dev);
+	cdx_dev->cdx = cdx;
+
+	cdx_dev->dev.parent = cdx->dev;
+	cdx_dev->dev.bus = &cdx_bus_type;
+	cdx_dev->dev.release = cdx_device_release;
+	cdx_dev->is_bus = true;
+	cdx_dev->bus_num = bus_num;
+
+	dev_set_name(&cdx_dev->dev, "cdx-%02x",
+		     ((cdx->id << CDX_CONTROLLER_ID_SHIFT) | (bus_num & CDX_BUS_NUM_MASK)));
+
+	ret = device_add(&cdx_dev->dev);
 	if (ret) {
+		dev_err(&cdx_dev->dev, "cdx bus device add failed: %d\n", ret);
+		goto device_add_fail;
+	}
+
+	if (cdx->ops->bus_enable) {
+		ret = cdx->ops->bus_enable(cdx, bus_num);
+		if (ret && ret != -EALREADY) {
+			dev_err(cdx->dev, "cdx bus enable failed: %d\n", ret);
+			goto bus_enable_fail;
+		}
+	}
+
+	cdx_dev->enabled = true;
+	return &cdx_dev->dev;
+
+bus_enable_fail:
+	device_del(&cdx_dev->dev);
+device_add_fail:
+	put_device(&cdx_dev->dev);
+
+	return NULL;
+}
+EXPORT_SYMBOL_NS_GPL(cdx_bus_add, CDX_BUS_CONTROLLER);
+
+int cdx_register_controller(struct cdx_controller *cdx)
+{
+	int ret;
+
+	ret = ida_alloc_range(&cdx_controller_ida, 0,  MAX_CDX_CONTROLLERS - 1, GFP_KERNEL);
+	if (ret < 0) {
 		dev_err(cdx->dev,
 			"No free index available. Maximum controllers already registered\n");
 		cdx->id = (u8)MAX_CDX_CONTROLLERS;
 		return ret;
 	}
 
+	mutex_lock(&cdx_controller_lock);
+	cdx->id = ret;
+
 	/* Scan all the devices */
-	cdx->ops->scan(cdx);
+	if (cdx->ops->scan)
+		cdx->ops->scan(cdx);
+	cdx->controller_registered = true;
+	mutex_unlock(&cdx_controller_lock);
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(cdx_register_controller);
+EXPORT_SYMBOL_NS_GPL(cdx_register_controller, CDX_BUS_CONTROLLER);
 
 void cdx_unregister_controller(struct cdx_controller *cdx)
 {
 	if (cdx->id >= MAX_CDX_CONTROLLERS)
 		return;
 
+	mutex_lock(&cdx_controller_lock);
+
+	cdx->controller_registered = false;
 	device_for_each_child(cdx->dev, NULL, cdx_unregister_device);
-	xa_erase(&cdx_controllers, cdx->id);
+	ida_free(&cdx_controller_ida, cdx->id);
+
+	mutex_unlock(&cdx_controller_lock);
 }
-EXPORT_SYMBOL_GPL(cdx_unregister_controller);
+EXPORT_SYMBOL_NS_GPL(cdx_unregister_controller, CDX_BUS_CONTROLLER);
 
 static int __init cdx_bus_init(void)
 {
diff --git a/drivers/cdx/cdx.h b/drivers/cdx/cdx.h
index c436ac7ac86f..300ad8be7a34 100644
--- a/drivers/cdx/cdx.h
+++ b/drivers/cdx/cdx.h
@@ -13,24 +13,33 @@
 /**
  * struct cdx_dev_params - CDX device parameters
  * @cdx: CDX controller associated with the device
- * @parent: Associated CDX controller
+ * @parent: Associated CDX Bus device
  * @vendor: Vendor ID for CDX device
  * @device: Device ID for CDX device
+ * @subsys_vendor: Sub vendor ID for CDX device
+ * @subsys_device: Sub device ID for CDX device
  * @bus_num: Bus number for this CDX device
  * @dev_num: Device number for this device
  * @res: array of MMIO region entries
  * @res_count: number of valid MMIO regions
  * @req_id: Requestor ID associated with CDX device
+ * @class: Class of the CDX Device
+ * @revision: Revision of the CDX device
  */
 struct cdx_dev_params {
 	struct cdx_controller *cdx;
+	struct device *parent;
 	u16 vendor;
 	u16 device;
+	u16 subsys_vendor;
+	u16 subsys_device;
 	u8 bus_num;
 	u8 dev_num;
 	struct resource res[MAX_CDX_DEV_RESOURCES];
 	u8 res_count;
 	u32 req_id;
+	u32 class;
+	u8 revision;
 };
 
 /**
@@ -59,4 +68,15 @@ void cdx_unregister_controller(struct cdx_controller *cdx);
  */
 int cdx_device_add(struct cdx_dev_params *dev_params);
 
+/**
+ * cdx_bus_add - Add a CDX bus. This function adds a bus on the CDX bus
+ *		subsystem. It creates a CDX device for the corresponding bus and
+ *		also registers an associated Linux generic device.
+ * @cdx: Associated CDX controller
+ * @us_num: Bus number
+ *
+ * Return: associated Linux generic device pointer on success or NULL on failure.
+ */
+struct device *cdx_bus_add(struct cdx_controller *cdx, u8 bus_num);
+
 #endif /* _CDX_H_ */
diff --git a/drivers/cdx/controller/cdx_controller.c b/drivers/cdx/controller/cdx_controller.c
index 7828dac8edb1..85fe4b1c4e5e 100644
--- a/drivers/cdx/controller/cdx_controller.c
+++ b/drivers/cdx/controller/cdx_controller.c
@@ -33,6 +33,16 @@ static const struct cdx_mcdi_ops mcdi_ops = {
 	.mcdi_request = cdx_mcdi_request,
 };
 
+static int cdx_bus_enable(struct cdx_controller *cdx, u8 bus_num)
+{
+	return cdx_mcdi_bus_enable(cdx->priv, bus_num);
+}
+
+static int cdx_bus_disable(struct cdx_controller *cdx, u8 bus_num)
+{
+	return cdx_mcdi_bus_disable(cdx->priv, bus_num);
+}
+
 void cdx_rpmsg_post_probe(struct cdx_controller *cdx)
 {
 	/* Register CDX controller with CDX bus driver */
@@ -83,8 +93,14 @@ static int cdx_scan_devices(struct cdx_controller *cdx)
 	num_cdx_bus = (u8)ret;
 
 	for (bus_num = 0; bus_num < num_cdx_bus; bus_num++) {
+		struct device *bus_dev;
 		u8 num_cdx_dev;
 
+		/* Add the bus on cdx subsystem */
+		bus_dev = cdx_bus_add(cdx, bus_num);
+		if (!bus_dev)
+			continue;
+
 		/* MCDI FW Read: Fetch the number of devices present */
 		ret = cdx_mcdi_get_num_devs(cdx_mcdi, bus_num);
 		if (ret < 0) {
@@ -107,6 +123,7 @@ static int cdx_scan_devices(struct cdx_controller *cdx)
 				continue;
 			}
 			dev_params.cdx = cdx;
+			dev_params.parent = bus_dev;
 
 			/* Add the device to the cdx bus */
 			ret = cdx_device_add(&dev_params);
@@ -125,6 +142,8 @@ static int cdx_scan_devices(struct cdx_controller *cdx)
 }
 
 static struct cdx_ops cdx_ops = {
+	.bus_enable		= cdx_bus_enable,
+	.bus_disable	= cdx_bus_disable,
 	.scan		= cdx_scan_devices,
 	.dev_configure	= cdx_configure_device,
 };
@@ -233,3 +252,4 @@ module_exit(cdx_controller_exit);
 MODULE_AUTHOR("AMD Inc.");
 MODULE_DESCRIPTION("CDX controller for AMD devices");
 MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(CDX_BUS_CONTROLLER);
diff --git a/drivers/cdx/controller/mc_cdx_pcol.h b/drivers/cdx/controller/mc_cdx_pcol.h
index 4ccb7b52951b..2de019406b57 100644
--- a/drivers/cdx/controller/mc_cdx_pcol.h
+++ b/drivers/cdx/controller/mc_cdx_pcol.h
@@ -457,6 +457,60 @@
 
 /***********************************/
 /*
+ * MC_CMD_CDX_BUS_DOWN
+ * Asserting reset on the CDX bus causes all devices on the bus to be quiesced.
+ * DMA bus mastering is disabled and any pending DMA request are flushed. Once
+ * the response is returned, the devices are guaranteed to no longer issue DMA
+ * requests or raise MSI interrupts. Further device MMIO accesses may have
+ * undefined results. While the bus reset is asserted, any of the enumeration
+ * or device configuration MCDIs will fail with EAGAIN. It is only legal to
+ * reload the relevant PL region containing CDX devices if the corresponding CDX
+ * bus is in reset. Depending on the implementation, the firmware may or may
+ * not enforce this restriction and it is up to the caller to make sure this
+ * requirement is satisfied.
+ */
+#define MC_CMD_CDX_BUS_DOWN					0x4
+#define MC_CMD_CDX_BUS_DOWN_MSGSET			0x4
+
+/* MC_CMD_CDX_BUS_DOWN_IN msgrequest */
+#define MC_CMD_CDX_BUS_DOWN_IN_LEN			4
+/* Bus number to put in reset, in range 0 to BUS_COUNT-1 */
+#define MC_CMD_CDX_BUS_DOWN_IN_BUS_OFST		0
+#define MC_CMD_CDX_BUS_DOWN_IN_BUS_LEN		4
+
+/*
+ * MC_CMD_CDX_BUS_DOWN_OUT msgresponse: The bus is quiesced, no further
+ * upstream traffic for devices on this bus.
+ */
+#define MC_CMD_CDX_BUS_DOWN_OUT_LEN			0
+
+/***********************************/
+/*
+ * MC_CMD_CDX_BUS_UP
+ * After bus reset is de-asserted, devices are in a state which is functionally
+ * equivalent to each device having been reset with MC_CMD_CDX_DEVICE_RESET. In
+ * other words, device logic is reset in a hardware-specific way, MMIO accesses
+ * are forwarded to the device, DMA bus mastering is disabled and needs to be
+ * re-enabled with MC_CMD_CDX_DEVICE_DMA_ENABLE once the driver is ready to
+ * start servicing DMA. If the underlying number of devices or device resources
+ * changed (e.g. if PL was reloaded) while the bus was in reset, the bus driver
+ * is expected to re-enumerate the bus. Returns EALREADY if the bus was already
+ * up before the call.
+ */
+#define MC_CMD_CDX_BUS_UP					0x5
+#define MC_CMD_CDX_BUS_UP_MSGSET			0x5
+
+/* MC_CMD_CDX_BUS_UP_IN msgrequest */
+#define MC_CMD_CDX_BUS_UP_IN_LEN			4
+/* Bus number to take out of reset, in range 0 to BUS_COUNT-1 */
+#define MC_CMD_CDX_BUS_UP_IN_BUS_OFST		0
+#define MC_CMD_CDX_BUS_UP_IN_BUS_LEN		4
+
+/* MC_CMD_CDX_BUS_UP_OUT msgresponse: The bus can now be enumerated. */
+#define MC_CMD_CDX_BUS_UP_OUT_LEN			0
+
+/***********************************/
+/*
  * MC_CMD_CDX_DEVICE_RESET
  * After this call completes, device DMA and interrupts are quiesced, devices
  * logic is reset in a hardware-specific way and DMA bus mastering is disabled.
diff --git a/drivers/cdx/controller/mcdi_functions.c b/drivers/cdx/controller/mcdi_functions.c
index fc82435d5dea..b1f530946389 100644
--- a/drivers/cdx/controller/mcdi_functions.c
+++ b/drivers/cdx/controller/mcdi_functions.c
@@ -120,10 +120,41 @@ int cdx_mcdi_get_dev_config(struct cdx_mcdi *cdx,
 
 	dev_params->vendor = MCDI_WORD(outbuf, CDX_BUS_GET_DEVICE_CONFIG_OUT_VENDOR_ID);
 	dev_params->device = MCDI_WORD(outbuf, CDX_BUS_GET_DEVICE_CONFIG_OUT_DEVICE_ID);
+	dev_params->subsys_vendor = MCDI_WORD(outbuf,
+					      CDX_BUS_GET_DEVICE_CONFIG_OUT_SUBSYS_VENDOR_ID);
+	dev_params->subsys_device = MCDI_WORD(outbuf,
+					      CDX_BUS_GET_DEVICE_CONFIG_OUT_SUBSYS_DEVICE_ID);
+	dev_params->class = MCDI_DWORD(outbuf,
+				       CDX_BUS_GET_DEVICE_CONFIG_OUT_DEVICE_CLASS) & 0xFFFFFF;
+	dev_params->revision = MCDI_BYTE(outbuf, CDX_BUS_GET_DEVICE_CONFIG_OUT_DEVICE_REVISION);
 
 	return 0;
 }
 
+int cdx_mcdi_bus_enable(struct cdx_mcdi *cdx, u8 bus_num)
+{
+	MCDI_DECLARE_BUF(inbuf, MC_CMD_CDX_BUS_UP_IN_LEN);
+	int ret;
+
+	MCDI_SET_DWORD(inbuf, CDX_BUS_UP_IN_BUS, bus_num);
+	ret = cdx_mcdi_rpc(cdx, MC_CMD_CDX_BUS_UP, inbuf, sizeof(inbuf),
+			   NULL, 0, NULL);
+
+	return ret;
+}
+
+int cdx_mcdi_bus_disable(struct cdx_mcdi *cdx, u8 bus_num)
+{
+	MCDI_DECLARE_BUF(inbuf, MC_CMD_CDX_BUS_DOWN_IN_LEN);
+	int ret;
+
+	MCDI_SET_DWORD(inbuf, CDX_BUS_DOWN_IN_BUS, bus_num);
+	ret = cdx_mcdi_rpc(cdx, MC_CMD_CDX_BUS_DOWN, inbuf, sizeof(inbuf),
+			   NULL, 0, NULL);
+
+	return ret;
+}
+
 int cdx_mcdi_reset_device(struct cdx_mcdi *cdx, u8 bus_num, u8 dev_num)
 {
 	MCDI_DECLARE_BUF(inbuf, MC_CMD_CDX_DEVICE_RESET_IN_LEN);
diff --git a/drivers/cdx/controller/mcdi_functions.h b/drivers/cdx/controller/mcdi_functions.h
index a448d6581eb4..258a5462fbe3 100644
--- a/drivers/cdx/controller/mcdi_functions.h
+++ b/drivers/cdx/controller/mcdi_functions.h
@@ -48,6 +48,24 @@ int cdx_mcdi_get_dev_config(struct cdx_mcdi *cdx,
 			    struct cdx_dev_params *dev_params);
 
 /**
+ * cdx_mcdi_bus_enable - Enable CDX bus represented by bus_num
+ * @cdx: pointer to MCDI interface.
+ * @bus_num: Bus number.
+ *
+ * Return: 0 on success, <0 on failure
+ */
+int cdx_mcdi_bus_enable(struct cdx_mcdi *cdx, u8 bus_num);
+
+/**
+ * cdx_mcdi_bus_disable - Disable CDX bus represented by bus_num
+ * @cdx: pointer to MCDI interface.
+ * @bus_num: Bus number.
+ *
+ * Return: 0 on success, <0 on failure
+ */
+int cdx_mcdi_bus_disable(struct cdx_mcdi *cdx, u8 bus_num);
+
+/**
  * cdx_mcdi_reset_device - Reset cdx device represented by bus_num:dev_num
  * @cdx: pointer to MCDI interface.
  * @bus_num: Bus number.