[alsa-devel] [PATCH 03/31] media: Media Controller register/unregister entity_notify API
Mauro Carvalho Chehab
mchehab at osg.samsung.com
Thu Jan 28 16:13:58 CET 2016
Em Wed, 6 Jan 2016 13:26:52 -0700
Shuah Khan <shuahkh at osg.samsung.com> escreveu:
> 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 at osg.samsung.com>
> ---
> 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
> + */
Please put the documentation only at the header files. Please mention that
it locks the addition using the mdev->lock spinlock.
Also, please follow the format that we're using with other KernelDoc
tags:
/**
* function() - short description
*
* @foo: foo description
* @bar: bar description
*
* detailed description
*/
In case of doubts, please check Documentation/kernel-doc-nano-HOWTO.txt.
Don't forget to check if the documentation looks sane by compiling it
with:
make cleandocs
make DOCBOOKS=device-drivers.xml htmldocs
Same applies to other documentation below and on other patches in this
series.
> +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)
__must_check
> +{
> + 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);
> +};
Please document the structure.
> +
> /**
> * 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;
> +
Please document the new field at the Kernel-doc header.
> /* 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);
> +
Documentation?
> /**
> * 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;
Documentation?
Regards,
Mauro
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