[PATCH v2 3/8] firmware: arm_scmi: introduce new protocol operations support
Cristian Marussi
cristian.marussi at arm.com
Wed Oct 28 16:29:09 EDT 2020
Expose a new generic get/put protocols API based on protocol handles;
provide also a devres managed version also for notifications.
All SCMI drivers still keep using the old handle based interface.
Signed-off-by: Cristian Marussi <cristian.marussi at arm.com>
---
drivers/firmware/arm_scmi/driver.c | 126 +++++++++++++++++++++++++++++
drivers/firmware/arm_scmi/notify.c | 123 ++++++++++++++++++++++++++++
include/linux/scmi_protocol.h | 34 +++++++-
3 files changed, 282 insertions(+), 1 deletion(-)
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 8ca04acb6abb..4d86aafbf465 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>
@@ -728,6 +729,38 @@ void scmi_release_protocol(struct scmi_handle *handle, u8 protocol_id)
mutex_unlock(&info->protocols_mtx);
}
+/**
+ * scmi_get_protocol_operations - Get protocol operations
+ * @handle: A reference to the SCMI platform instance.
+ * @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.
+ *
+ * Return: A reference to the requested protocol operations or error.
+ * Must be checked for errors by caller.
+ */
+static const void __must_check *
+scmi_get_protocol_operations(struct scmi_handle *handle, u8 protocol_id,
+ struct scmi_protocol_handle **ph)
+{
+ struct scmi_protocol_instance *pi;
+
+ if (!ph)
+ return ERR_PTR(-EINVAL);
+
+ pi = scmi_get_protocol_instance(handle, protocol_id);
+ if (IS_ERR(pi))
+ return pi;
+
+ *ph = &pi->ph;
+
+ return pi->proto->ops;
+}
+
void scmi_setup_protocol_implemented(const struct scmi_handle *handle,
u8 *prot_imp)
{
@@ -751,6 +784,95 @@ 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_release_protocol(dres->handle, dres->protocol_id);
+}
+
+/**
+ * scmi_devm_get_protocol_ops - Devres managed get protocol operations
+ * @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_get_protocol_ops(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_put_protocol_ops - Devres managed put protocol operations
+ * @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_get_protocol_ops.
+ */
+static void scmi_devm_put_protocol_ops(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
*
@@ -1004,6 +1126,10 @@ static int scmi_probe(struct platform_device *pdev)
handle = &info->handle;
handle->dev = info->dev;
handle->version = &info->version;
+ handle->devm_get_ops = scmi_devm_get_protocol_ops;
+ handle->devm_put_ops = scmi_devm_put_protocol_ops;
+ handle->get_ops = scmi_get_protocol_operations;
+ handle->put_ops = scmi_release_protocol;
ret = scmi_txrx_setup(info, dev, SCMI_PROTOCOL_BASE);
if (ret)
diff --git a/drivers/firmware/arm_scmi/notify.c b/drivers/firmware/arm_scmi/notify.c
index eae58b2a92cc..64d43e425644 100644
--- a/drivers/firmware/arm_scmi/notify.c
+++ b/drivers/firmware/arm_scmi/notify.c
@@ -1370,6 +1370,127 @@ 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_unregister_notifier(dres->handle, dres->proto_id, dres->evt_id,
+ dres->src_id, dres->nb);
+}
+
+/**
+ * scmi_devm_register_notifier() - 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_register_notifier(struct scmi_device *sdev,
+ u8 proto_id, u8 evt_id, 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_register_notifier(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_unregister_notifier() - 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_register_notifier.
+ */
+static int scmi_devm_unregister_notifier(struct scmi_device *sdev,
+ u8 proto_id, u8 evt_id, 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
@@ -1427,6 +1548,8 @@ 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 = {
+ .devm_register_event_notifier = scmi_devm_register_notifier,
+ .devm_unregister_event_notifier = scmi_devm_unregister_notifier,
.register_event_notifier = scmi_register_notifier,
.unregister_event_notifier = scmi_unregister_notifier,
};
diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index d726ddc3dcc0..d95e43c3ea08 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h
@@ -56,6 +56,8 @@ struct scmi_clock_info {
};
struct scmi_handle;
+struct scmi_device;
+struct scmi_protocol_handle;
/**
* struct scmi_clk_ops - represents the various operations provided
@@ -212,6 +214,10 @@ struct scmi_reset_ops {
/**
* struct scmi_notify_ops - represents notifications' operations provided by
* SCMI core
+ * @devm_register_event_notifier: Managed registration of a notifier_block for
+ * the requested event
+ * @devm_unregister_event_notifier: Managed unregistration of a notifier_block
+ * for the requested event
* @register_event_notifier: Register a notifier_block for the requested event
* @unregister_event_notifier: Unregister a notifier_block for the requested
* event
@@ -221,7 +227,9 @@ struct scmi_reset_ops {
* tuple: (proto_id, evt_id, src_id) using the provided register/unregister
* interface where:
*
- * @handle: The handle identifying the platform instance to use
+ * @sdev: The scmi_device to use when calling the devres managed ops devm_
+ * @handle: The handle identifying the platform instance to use, when not
+ * calling the managed ops devm_
* @proto_id: The protocol ID as in SCMI Specification
* @evt_id: The message ID of the desired event as in SCMI Specification
* @src_id: A pointer to the desired source ID if different sources are
@@ -244,6 +252,13 @@ struct scmi_reset_ops {
* @report: A custom struct describing the specific event delivered
*/
struct scmi_notify_ops {
+ int (*devm_register_event_notifier)(struct scmi_device *sdev,
+ u8 proto_id, u8 evt_id, u32 *src_id,
+ struct notifier_block *nb);
+ int (*devm_unregister_event_notifier)(struct scmi_device *sdev,
+ u8 proto_id, u8 evt_id,
+ u32 *src_id,
+ struct notifier_block *nb);
int (*register_event_notifier)(const struct scmi_handle *handle,
u8 proto_id, u8 evt_id, u32 *src_id,
struct notifier_block *nb);
@@ -262,6 +277,12 @@ struct scmi_notify_ops {
* @clk_ops: pointer to set of clock protocol operations
* @sensor_ops: pointer to set of sensor protocol operations
* @reset_ops: pointer to set of reset protocol operations
+ * @devm_get_ops: devres managed method to acquire a protocol and get specific
+ * operations and a dedicated protocol handler
+ * @devm_put_ops: devres managed method to release a protocol
+ * @get_ops: method to acquire a protocol and get specific operations and a
+ * dedicated protocol handler
+ * @put_ops: method to release a protocol
* @notify_ops: pointer to set of notifications related operations
* @perf_priv: pointer to private data structure specific to performance
* protocol(for internal use only)
@@ -284,6 +305,17 @@ struct scmi_handle {
const struct scmi_power_ops *power_ops;
const struct scmi_sensor_ops *sensor_ops;
const struct scmi_reset_ops *reset_ops;
+
+ const void __must_check *
+ (*devm_get_ops)(struct scmi_device *sdev, u8 proto,
+ struct scmi_protocol_handle **ph);
+ void (*devm_put_ops)(struct scmi_device *sdev, u8 proto);
+
+ const void __must_check *
+ (*get_ops)(struct scmi_handle *handle, u8 proto,
+ struct scmi_protocol_handle **ph);
+ void (*put_ops)(struct scmi_handle *handle, u8 proto);
+
const struct scmi_notify_ops *notify_ops;
/* for protocol internal use */
void *perf_priv;
--
2.17.1
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