Add new interfaces to register and unregister entity_notify
hook to media device to allow drivers to take appropriate
actions when as new entities get added to the shared media
device.When a new entity is registered, all registered
entity_notify hooks are invoked to allow drivers or modules
that registered hook to take appropriate action. For example,
ALSA driver registers an entity_notify hook to parse the list
of registered entities to determine if decoder has been linked
to ALSA entity. au0828 bridge driver registers an entity_notify
hook to create media graph for the device.
Signed-off-by: Shuah Khan <shuahkh@xxxxxxxxxxxxxxx>
---
drivers/media/media-device.c | 45 ++++++++++++++++++++++++++++++++++++++++++++
include/media/media-device.h | 23 ++++++++++++++++++++++
2 files changed, 68 insertions(+)
diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
index c55ab50..22565a8 100644
--- a/drivers/media/media-device.c
+++ b/drivers/media/media-device.c
@@ -381,6 +381,7 @@ int __must_check __media_device_register(struct media_device *mdev,
mdev->entity_id = 1;
INIT_LIST_HEAD(&mdev->entities);
+ INIT_LIST_HEAD(&mdev->entity_notify);
spin_lock_init(&mdev->lock);
mutex_init(&mdev->graph_mutex);
@@ -411,9 +412,12 @@ void media_device_unregister(struct media_device *mdev)
{
struct media_entity *entity;
struct media_entity *next;
+ struct media_entity_notify *notify, *nextp;
list_for_each_entry_safe(entity, next, &mdev->entities, list)
media_device_unregister_entity(entity);
+ list_for_each_entry_safe(notify, nextp, &mdev->entity_notify, list)
+ media_device_unregister_entity_notify(mdev, notify);
device_remove_file(&mdev->devnode.dev, &dev_attr_model);
media_devnode_unregister(&mdev->devnode);
@@ -421,6 +425,39 @@ void media_device_unregister(struct media_device *mdev)
EXPORT_SYMBOL_GPL(media_device_unregister);
/**
+ * media_device_register_entity_notify - Register a media entity notify
+ * callback with a media device. When a new entity is registered, all
+ * the registered media_entity_notify callbacks are invoked.
+ * @mdev: The media device
+ * @nptr: The media_entity_notify
+ */
+int __must_check media_device_register_entity_notify(struct media_device *mdev,
+ struct media_entity_notify *nptr)
+{
+ spin_lock(&mdev->lock);
+ list_add_tail(&nptr->list, &mdev->entity_notify);
+ spin_unlock(&mdev->lock);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(media_device_register_entity_notify);
+
+/**
+ * media_device_unregister_entity_notify - Unregister a media entity notify
+ * callback with a media device. When a new entity is registered, all
+ * the registered media_entity_notify callbacks are invoked.
+ * @mdev: The media device
+ * @nptr: The media_entity_notify
+ */
+void media_device_unregister_entity_notify(struct media_device *mdev,
+ struct media_entity_notify *nptr)
+{
+ spin_lock(&mdev->lock);
+ list_del(&nptr->list);
+ spin_unlock(&mdev->lock);
+}
+EXPORT_SYMBOL_GPL(media_device_unregister_entity_notify);
+
+/**
* media_device_register_entity - Register an entity with a media device
* @mdev: The media device
* @entity: The entity
@@ -428,6 +465,8 @@ EXPORT_SYMBOL_GPL(media_device_unregister);
int __must_check media_device_register_entity(struct media_device *mdev,
struct media_entity *entity)
{
+ struct media_entity_notify *notify, *next;
+
/* Warn if we apparently re-register an entity */
WARN_ON(entity->parent != NULL);
entity->parent = mdev;
@@ -440,6 +479,11 @@ int __must_check media_device_register_entity(struct media_device *mdev,
list_add_tail(&entity->list, &mdev->entities);
spin_unlock(&mdev->lock);
+ /* invoke entity_notify callbacks */
+ list_for_each_entry_safe(notify, next, &mdev->entity_notify, list) {
+ (notify)->notify(entity, notify->notify_data);
+ }
+
return 0;
}
EXPORT_SYMBOL_GPL(media_device_register_entity);
@@ -462,6 +506,7 @@ void media_device_unregister_entity(struct media_entity *entity)
list_del(&entity->list);
spin_unlock(&mdev->lock);
entity->parent = NULL;
+ /* invoke entity_notify callbacks to handle entity removal?? */
}
EXPORT_SYMBOL_GPL(media_device_unregister_entity);
diff --git a/include/media/media-device.h b/include/media/media-device.h
index a44f18f..a3854f6 100644
--- a/include/media/media-device.h
+++ b/include/media/media-device.h
@@ -32,6 +32,12 @@
struct device;
+struct media_entity_notify {
+ struct list_head list;
+ void *notify_data;
+ void (*notify)(struct media_entity *entity, void *notify_data);
+};
+
/**
* struct media_device - Media device
* @dev: Parent device
@@ -70,6 +76,8 @@ struct media_device {
u32 entity_id;
struct list_head entities;
+ /* notify callback list invoked when a new entity is registered */
+ struct list_head entity_notify;
/* Protects the entities list */
spinlock_t lock;
@@ -94,6 +102,10 @@ int __must_check __media_device_register(struct media_device *mdev,
#define media_device_register(mdev) __media_device_register(mdev, THIS_MODULE)
void media_device_unregister(struct media_device *mdev);
+int __must_check media_device_register_entity_notify(struct media_device *mdev,
+ struct media_entity_notify *nptr);
+void media_device_unregister_entity_notify(struct media_device *mdev,
+ struct media_entity_notify *nptr);
int __must_check media_device_register_entity(struct media_device *mdev,
struct media_entity *entity);
void media_device_unregister_entity(struct media_entity *entity);
@@ -112,6 +124,17 @@ static inline int media_device_register(struct media_device *mdev)
static inline void media_device_unregister(struct media_device *mdev)
{
}
+static inline int media_device_register_entity_notify(
+ struct media_device *mdev,
+ struct media_entity_notify *nptr)
+{
+ return 0;
+}
+static inline void media_device_unregister_entity_notify(
+ struct media_device *mdev,
+ struct media_entity_notify *nptr)
+{
+}
static inline int media_device_register_entity(struct media_device *mdev,
struct media_entity *entity)
{
--
2.1.4
--
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