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[media] media: Media Controller register/unregister entity_notify API
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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.

[[email protected]: simple comments should be /* and not /**]

Signed-off-by: Shuah Khan <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>
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@mchehab
Shuah Khan authored and mchehab committed Feb 27, 2016
1 parent 7a2eba1 commit afcbdb5
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Showing 2 changed files with 98 additions and 0 deletions.
42 changes: 42 additions & 0 deletions drivers/media/media-device.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -542,6 +542,7 @@ 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;

Expand Down Expand Up @@ -581,6 +582,11 @@ 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;
Expand Down Expand Up @@ -614,6 +620,8 @@ 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;
}

Expand Down Expand Up @@ -646,6 +654,7 @@ 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);
Expand Down Expand Up @@ -691,11 +700,40 @@ 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;
Expand All @@ -712,6 +750,10 @@ 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) {
Expand Down
56 changes: 56 additions & 0 deletions include/media/media-device.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -264,6 +264,22 @@
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
Expand All @@ -287,6 +303,7 @@ 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
Expand Down Expand Up @@ -324,6 +341,9 @@ 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. */
Expand Down Expand Up @@ -506,6 +526,31 @@ 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
Expand Down Expand Up @@ -594,6 +639,17 @@ 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;
Expand Down

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