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 | 61 ++++++++++++++++++++++++++++++++++++++++++++
include/media/media-device.h | 25 ++++++++++++++++++
2 files changed, 86 insertions(+)
diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
index b786b10..20c85a9 100644
--- a/drivers/media/media-device.c
+++ b/drivers/media/media-device.c
@@ -536,6 +536,7 @@ static void media_device_release(struct media_devnode *mdev)
int __must_check media_device_register_entity(struct media_device *mdev,
struct media_entity *entity)
{
+ struct media_entity_notify *notify, *next;
unsigned int i;
int ret;
@@ -575,6 +576,11 @@ int __must_check media_device_register_entity(struct media_device *mdev,
media_gobj_create(mdev, MEDIA_GRAPH_PAD,
&entity->pads[i].graph_obj);
+ /* invoke entity_notify callbacks */
+ list_for_each_entry_safe(notify, next, &mdev->entity_notify, list) {
+ (notify)->notify(entity, notify->notify_data);
+ }
+
spin_unlock(&mdev->lock);
return 0;
@@ -608,6 +614,8 @@ static void __media_device_unregister_entity(struct media_entity *entity)
/* Remove the entity */
media_gobj_destroy(&entity->graph_obj);
+ /* invoke entity_notify callbacks to handle entity removal?? */
+
entity->graph_obj.mdev = NULL;
}
@@ -633,6 +641,7 @@ int __must_check media_device_init(struct media_device *mdev)
INIT_LIST_HEAD(&mdev->interfaces);
INIT_LIST_HEAD(&mdev->pads);
INIT_LIST_HEAD(&mdev->links);
+ INIT_LIST_HEAD(&mdev->entity_notify);
spin_lock_init(&mdev->lock);
mutex_init(&mdev->graph_mutex);
ida_init(&mdev->entity_internal_idx);
@@ -680,11 +689,59 @@ int __must_check __media_device_register(struct media_device *mdev,
}
EXPORT_SYMBOL_GPL(__media_device_register);
+/**
+ * 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
+ * Non-locking version. Should be called with mdev->lock held.
+ */
+static void __media_device_unregister_entity_notify(struct media_device *mdev,
+ struct media_entity_notify *nptr)
+{
+ list_del(&nptr->list);
+}
+
+/**
+ * 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);
+ __media_device_unregister_entity_notify(mdev, nptr);
+ spin_unlock(&mdev->lock);
+}
+EXPORT_SYMBOL_GPL(media_device_unregister_entity_notify);
+
void media_device_unregister(struct media_device *mdev)
{
struct media_entity *entity;
struct media_entity *next;
struct media_interface *intf, *tmp_intf;
+ struct media_entity_notify *notify, *nextp;
if (mdev == NULL)
return;
@@ -701,6 +758,10 @@ void media_device_unregister(struct media_device *mdev)
list_for_each_entry_safe(entity, next, &mdev->entities, graph_obj.list)
__media_device_unregister_entity(entity);
+ /* Remove all entity_notify callbacks from the media device */
+ list_for_each_entry_safe(notify, nextp, &mdev->entity_notify, list)
+ __media_device_unregister_entity_notify(mdev, notify);
+
/* Remove all interfaces from the media device */
list_for_each_entry_safe(intf, tmp_intf, &mdev->interfaces,
graph_obj.list) {
diff --git a/include/media/media-device.h b/include/media/media-device.h
index 122963a..6520d1c 100644
--- a/include/media/media-device.h
+++ b/include/media/media-device.h
@@ -264,6 +264,12 @@
struct ida;
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
@@ -319,6 +325,9 @@ struct media_device {
struct list_head pads;
struct list_head links;
+ /* notify callback list invoked when a new entity is registered */
+ struct list_head entity_notify;
+
/* Protects the graph objects creation/removal */
spinlock_t lock;
/* Serializes graph operations. */
@@ -497,6 +506,11 @@ int __must_check media_device_register_entity(struct media_device *mdev,
*/
void media_device_unregister_entity(struct media_entity *entity);
+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);
+
/**
* media_device_get_devres() - get media device as device resource
* creates if one doesn't exist
@@ -552,6 +566,17 @@ static inline int media_device_register_entity(struct media_device *mdev,
static inline void media_device_unregister_entity(struct media_entity *entity)
{
}
+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 struct media_device *media_device_get_devres(struct device *dev)
{
return NULL;
--
2.5.0
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