summaryrefslogtreecommitdiff
path: root/drivers
diff options
context:
space:
mode:
authorCristian Marussi <cristian.marussi@arm.com>2021-03-16 12:48:28 +0000
committerSudeep Holla <sudeep.holla@arm.com>2021-03-29 10:00:16 +0100
commit23934efe3748f6d9d8ac0760178a5ef1ed8320f4 (patch)
treee4ce4707a5ed15c78028a90ad1e11693c7eb8659 /drivers
parentd7b6cc563a600762597ff608f487f90dc8b66f16 (diff)
firmware: arm_scmi: Introduce devres get/put protocols operations
Expose to the SCMI drivers a new devres managed common protocols API based on generic get/put methods and protocol handles. All drivers still keep using the old API, no functional change. Link: https://lore.kernel.org/r/20210316124903.35011-4-cristian.marussi@arm.com Tested-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/firmware/arm_scmi/driver.c92
1 files changed, 92 insertions, 0 deletions
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index b6f1a2866248..5a960a7fd973 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -15,6 +15,7 @@
*/
#include <linux/bitmap.h>
+#include <linux/device.h>
#include <linux/export.h>
#include <linux/idr.h>
#include <linux/io.h>
@@ -755,6 +756,95 @@ scmi_is_protocol_implemented(const struct scmi_handle *handle, u8 prot_id)
return false;
}
+struct scmi_protocol_devres {
+ 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);
+}
+
/**
* scmi_handle_get() - Get the SCMI handle for a device
*
@@ -1009,6 +1099,8 @@ 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)