[PATCH v3 05/22] media: Media Controller register/unregister entity_notify API

Shuah Khan
2016-02-11T23:42:17Z

Add new interfaces to register and unregister entity_notify
hook to media device. These interfaces allow drivers to add
hooks to take appropriate actions when new entities get added
to a shared media device. For example, au0828 bridge driver
registers an entity_notify hook to create links as needed
between media graph nodes.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
---
drivers/media/media-device.c | 42 +++++++++++++++++++++++++++++++++
include/media/media-device.h | 56 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 98 insertions(+)

diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
index 4d1c13d..9c1cf70 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;
}

@@ -640,6 +648,7 @@ void 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);
@@ -685,11 +694,40 @@ int __must_check __media_device_register(struct media_device *mdev,
}
EXPORT_SYMBOL_GPL(__media_device_register);

+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);
+
+/**
+ * Note: 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);
+}
+
+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;
@@ -706,6 +744,10 @@ 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 d385589..075a482 100644
--- a/include/media/media-device.h
+++ b/include/media/media-device.h
@@ -265,6 +265,22 @@ struct ida;
struct device;

/**
+ * struct media_entity_notify - Media Entity Notify
+ *
+ * @list: List head
+ * @notify_data: Input data to invoke the callback
+ * @notify: Callback function pointer
+ *
+ * Drivers may register a callback to take action when
+ * new entities get registered with the media 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
* @devnode: Media device node
@@ -283,6 +299,7 @@ struct device;
* @interfaces: List of registered interfaces
* @pads: List of registered pads
* @links: List of registered links
+ * @entity_notify: List of registered entity_notify callbacks
* @lock: Entities list lock
* @graph_mutex: Entities graph operation lock
* @link_notify: Link state change notification callback
@@ -319,6 +336,9 @@ 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. */
@@ -498,6 +518,31 @@ int __must_check media_device_register_entity(struct media_device *mdev,
void media_device_unregister_entity(struct media_entity *entity);

/**
+ * media_device_register_entity_notify() - Registers a media entity_notify
+ * callback
+ *
+ * @mdev: The media device
+ * @nptr: The media_entity_notify
+ *
+ * Note: When a new entity is registered, all the registered
+ * media_entity_notify callbacks are invoked.
+ */
+
+int __must_check media_device_register_entity_notify(struct media_device *mdev,
+ struct media_entity_notify *nptr);
+
+/**
+ * media_device_unregister_entity_notify() - Unregister a media entity notify
+ * callback
+ *
+ * @mdev: The media device
+ * @nptr: The media_entity_notify
+ *
+ */
+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 +597,17 @@ 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