V4L2 subdevices are media entities. As such they need to inherit from (include) the media_entity structure.
When registering/unregistering the subdevice, the media entity is automatically registered/unregistered. The entity is acquired on device open and released on device close.
Signed-off-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Signed-off-by: Sakari Ailus sakari.ailus@iki.fi --- Documentation/video4linux/v4l2-framework.txt | 23 ++++++++++++++++ drivers/media/video/v4l2-device.c | 36 +++++++++++++++++++++++--- drivers/media/video/v4l2-subdev.c | 28 ++++++++++++++++++- include/media/v4l2-subdev.h | 6 ++++ 4 files changed, 87 insertions(+), 6 deletions(-)
diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt index 0627081..77d96f4 100644 --- a/Documentation/video4linux/v4l2-framework.txt +++ b/Documentation/video4linux/v4l2-framework.txt @@ -268,6 +268,26 @@ A sub-device driver initializes the v4l2_subdev struct using: Afterwards you need to initialize subdev->name with a unique name and set the module owner. This is done for you if you use the i2c helper functions.
+If integration with the media framework is needed, you must initialize the +media_entity struct embedded in the v4l2_subdev struct (entity field) by +calling media_entity_init(): + + struct media_pad *pads = &my_sd->pads; + int err; + + err = media_entity_init(&sd->entity, npads, pads, 0); + +The pads array must have been previously initialized. There is no need to +manually set the struct media_entity type and name fields, but the revision +field must be initialized if needed. + +A reference to the entity will be automatically acquired/released when the +subdev device node (if any) is opened/closed. + +Don't forget to cleanup the media entity before the sub-device is destroyed: + + media_entity_cleanup(&sd->entity); + A device (bridge) driver needs to register the v4l2_subdev with the v4l2_device:
@@ -277,6 +297,9 @@ This can fail if the subdev module disappeared before it could be registered. After this function was called successfully the subdev->dev field points to the v4l2_device.
+If the v4l2_device parent device has a non-NULL mdev field, the sub-device +entity will be automatically registered with the media device. + You can unregister a sub-device using:
v4l2_device_unregister_subdev(sd); diff --git a/drivers/media/video/v4l2-device.c b/drivers/media/video/v4l2-device.c index 0af46e4..259415b 100644 --- a/drivers/media/video/v4l2-device.c +++ b/drivers/media/video/v4l2-device.c @@ -118,8 +118,11 @@ void v4l2_device_unregister(struct v4l2_device *v4l2_dev) EXPORT_SYMBOL_GPL(v4l2_device_unregister);
int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev, - struct v4l2_subdev *sd) + struct v4l2_subdev *sd) { +#if defined(CONFIG_MEDIA_CONTROLLER) + struct media_entity *entity = &sd->entity; +#endif int err;
/* Check for valid input */ @@ -147,6 +150,19 @@ int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev, return err; }
+#if defined(CONFIG_MEDIA_CONTROLLER) + /* Register the entity. */ + if (v4l2_dev->mdev) { + err = media_device_register_entity(v4l2_dev->mdev, entity); + if (err < 0) { + if (sd->internal_ops && sd->internal_ops->unregistered) + sd->internal_ops->unregistered(sd); + module_put(sd->owner); + return err; + } + } +#endif + spin_lock(&v4l2_dev->lock); list_add_tail(&sd->list, &v4l2_dev->subdevs); spin_unlock(&v4l2_dev->lock); @@ -177,25 +193,37 @@ int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev) sd->owner); if (err < 0) return err; +#if defined(CONFIG_MEDIA_CONTROLLER) + sd->entity.v4l.major = VIDEO_MAJOR; + sd->entity.v4l.minor = vdev->minor; +#endif } - return 0; } EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_nodes);
void v4l2_device_unregister_subdev(struct v4l2_subdev *sd) { + struct v4l2_device *v4l2_dev; + /* return if it isn't registered */ if (sd == NULL || sd->v4l2_dev == NULL) return;
- spin_lock(&sd->v4l2_dev->lock); + v4l2_dev = sd->v4l2_dev; + + spin_lock(&v4l2_dev->lock); list_del(&sd->list); - spin_unlock(&sd->v4l2_dev->lock); + spin_unlock(&v4l2_dev->lock); + if (sd->internal_ops && sd->internal_ops->unregistered) sd->internal_ops->unregistered(sd); sd->v4l2_dev = NULL;
+#if defined(CONFIG_MEDIA_CONTROLLER) + if (v4l2_dev->mdev) + media_device_unregister_entity(&sd->entity); +#endif video_unregister_device(&sd->devnode); module_put(sd->owner); } diff --git a/drivers/media/video/v4l2-subdev.c b/drivers/media/video/v4l2-subdev.c index 9374406..29b7ddf 100644 --- a/drivers/media/video/v4l2-subdev.c +++ b/drivers/media/video/v4l2-subdev.c @@ -35,7 +35,10 @@ static int subdev_open(struct file *file) { struct video_device *vdev = video_devdata(file); struct v4l2_subdev *sd = vdev_to_v4l2_subdev(vdev); - struct v4l2_fh *vfh; +#if defined(CONFIG_MEDIA_CONTROLLER) + struct media_entity *entity; +#endif + struct v4l2_fh *vfh = NULL; int ret;
if (sd->flags & V4L2_SUBDEV_FL_HAS_EVENTS) { @@ -58,11 +61,20 @@ static int subdev_open(struct file *file) v4l2_fh_add(vfh); file->private_data = vfh; } - +#if defined(CONFIG_MEDIA_CONTROLLER) + if (sd->v4l2_dev->mdev) { + entity = media_entity_get(&sd->entity); + if (!entity) { + ret = -EBUSY; + goto err; + } + } +#endif return 0;
err: if (vfh != NULL) { + v4l2_fh_del(vfh); v4l2_fh_exit(vfh); kfree(vfh); } @@ -72,8 +84,16 @@ err:
static int subdev_close(struct file *file) { +#if defined(CONFIG_MEDIA_CONTROLLER) + struct video_device *vdev = video_devdata(file); + struct v4l2_subdev *sd = vdev_to_v4l2_subdev(vdev); +#endif struct v4l2_fh *vfh = file->private_data;
+#if defined(CONFIG_MEDIA_CONTROLLER) + if (sd->v4l2_dev->mdev) + media_entity_put(&sd->entity); +#endif if (vfh != NULL) { v4l2_fh_del(vfh); v4l2_fh_exit(vfh); @@ -172,5 +192,9 @@ void v4l2_subdev_init(struct v4l2_subdev *sd, const struct v4l2_subdev_ops *ops) sd->grp_id = 0; sd->dev_priv = NULL; sd->host_priv = NULL; +#if defined(CONFIG_MEDIA_CONTROLLER) + sd->entity.name = sd->name; + sd->entity.type = MEDIA_ENT_T_V4L2_SUBDEV; +#endif } EXPORT_SYMBOL(v4l2_subdev_init); diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h index 3f4e0d1..c37d6e4 100644 --- a/include/media/v4l2-subdev.h +++ b/include/media/v4l2-subdev.h @@ -21,6 +21,7 @@ #ifndef _V4L2_SUBDEV_H #define _V4L2_SUBDEV_H
+#include <media/media-entity.h> #include <media/v4l2-common.h> #include <media/v4l2-dev.h> #include <media/v4l2-mediabus.h> @@ -448,6 +449,9 @@ struct v4l2_subdev_internal_ops { stand-alone or embedded in a larger struct. */ struct v4l2_subdev { +#if defined(CONFIG_MEDIA_CONTROLLER) + struct media_entity entity; +#endif struct list_head list; struct module *owner; u32 flags; @@ -470,6 +474,8 @@ struct v4l2_subdev { unsigned int nevents; };
+#define media_entity_to_v4l2_subdev(ent) \ + container_of(ent, struct v4l2_subdev, entity) #define vdev_to_v4l2_subdev(vdev) \ container_of(vdev, struct v4l2_subdev, devnode)