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@osg.samsung.com --- 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) {