diff options
Diffstat (limited to 'extras/recipes-kernel/linux/linux-omap/media/0018-v4l-Make-video_device-inherit-from-media_entity.patch')
| -rw-r--r-- | extras/recipes-kernel/linux/linux-omap/media/0018-v4l-Make-video_device-inherit-from-media_entity.patch | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/extras/recipes-kernel/linux/linux-omap/media/0018-v4l-Make-video_device-inherit-from-media_entity.patch b/extras/recipes-kernel/linux/linux-omap/media/0018-v4l-Make-video_device-inherit-from-media_entity.patch new file mode 100644 index 00000000..6417d1db --- /dev/null +++ b/extras/recipes-kernel/linux/linux-omap/media/0018-v4l-Make-video_device-inherit-from-media_entity.patch @@ -0,0 +1,234 @@ +From e31cb57c733341b49256a47f086fa4cc1c1c56ac Mon Sep 17 00:00:00 2001 +From: Laurent Pinchart <laurent.pinchart@ideasonboard.com> +Date: Wed, 9 Dec 2009 12:40:10 +0100 +Subject: [PATCH 18/43] v4l: Make video_device inherit from media_entity + +V4L2 devices are media entities. As such they need to inherit from +(include) the media_entity structure. + +When registering/unregistering the device, 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@maxwell.research.nokia.com> +--- + Documentation/video4linux/v4l2-framework.txt | 38 ++++++++++++++++++-- + drivers/media/video/v4l2-dev.c | 49 +++++++++++++++++++++++-- + include/media/v4l2-dev.h | 7 ++++ + 3 files changed, 87 insertions(+), 7 deletions(-) + +diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt +index aeb2a22..f231bc2 100644 +--- a/Documentation/video4linux/v4l2-framework.txt ++++ b/Documentation/video4linux/v4l2-framework.txt +@@ -71,6 +71,10 @@ sub-device instances, the video_device struct stores V4L2 device node data + and in the future a v4l2_fh struct will keep track of filehandle instances + (this is not yet implemented). + ++The V4L2 framework also optionally integrates with the media framework. If a ++driver sets the struct v4l2_device mdev field, sub-devices and video nodes ++will automatically appear in the media framework as entities. ++ + + struct v4l2_device + ------------------ +@@ -84,11 +88,14 @@ You must register the device instance: + v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev); + + Registration will initialize the v4l2_device struct. If the dev->driver_data +-field is NULL, it will be linked to v4l2_dev. Drivers that use the media +-device framework in addition to the V4L2 framework need to set ++field is NULL, it will be linked to v4l2_dev. ++ ++Drivers that want integration with the media device framework need to set + dev->driver_data manually to point to the driver-specific device structure + that embed the struct v4l2_device instance. This is achieved by a +-dev_set_drvdata() call before registering the V4L2 device instance. ++dev_set_drvdata() call before registering the V4L2 device instance. They must ++also set the struct v4l2_device mdev field to point to a properly initialized ++and registered media_device instance. + + If v4l2_dev->name is empty then it will be set to a value derived from dev + (driver name followed by the bus_id, to be precise). If you set it up before +@@ -532,6 +539,21 @@ If you use v4l2_ioctl_ops, then you should set either .unlocked_ioctl or + The v4l2_file_operations struct is a subset of file_operations. The main + difference is that the inode argument is omitted since it is never used. + ++If integration with the media framework is needed, you must initialize the ++media_entity struct embedded in the video_device struct (entity field) by ++calling media_entity_init(): ++ ++ struct media_pad *pad = &my_vdev->pad; ++ int err; ++ ++ err = media_entity_init(&vdev->entity, 1, pad, 0); ++ ++The pads array must have been previously initialized. There is no need to ++manually set the struct media_entity type and name fields. ++ ++A reference to the entity will be automatically acquired/released when the ++video device is opened/closed. ++ + v4l2_file_operations and locking + -------------------------------- + +@@ -561,6 +583,9 @@ for you. + return err; + } + ++If the v4l2_device parent device has a non-NULL mdev field, the video device ++entity will be automatically registered with the media device. ++ + Which device is registered depends on the type argument. The following + types exist: + +@@ -636,6 +661,13 @@ release, of course) will return an error as well. + When the last user of the video device node exits, then the vdev->release() + callback is called and you can do the final cleanup there. + ++Don't forget to cleanup the media entity associated with the video device if ++it has been initialized: ++ ++ media_entity_cleanup(&vdev->entity); ++ ++This can be done from the release callback. ++ + + video_device helper functions + ----------------------------- +diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c +index f22bd41..f91348f 100644 +--- a/drivers/media/video/v4l2-dev.c ++++ b/drivers/media/video/v4l2-dev.c +@@ -303,6 +303,9 @@ static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm) + static int v4l2_open(struct inode *inode, struct file *filp) + { + struct video_device *vdev; ++#if defined(CONFIG_MEDIA_CONTROLLER) ++ struct media_entity *entity = NULL; ++#endif + int ret = 0; + + /* Check if the video device is available */ +@@ -316,6 +319,16 @@ static int v4l2_open(struct inode *inode, struct file *filp) + /* and increase the device refcount */ + video_get(vdev); + mutex_unlock(&videodev_lock); ++#if defined(CONFIG_MEDIA_CONTROLLER) ++ if (vdev->v4l2_dev && vdev->v4l2_dev->mdev) { ++ entity = media_entity_get(&vdev->entity); ++ if (!entity) { ++ ret = -EBUSY; ++ video_put(vdev); ++ return ret; ++ } ++ } ++#endif + if (vdev->fops->open) { + if (vdev->lock && mutex_lock_interruptible(vdev->lock)) { + ret = -ERESTARTSYS; +@@ -331,8 +344,13 @@ static int v4l2_open(struct inode *inode, struct file *filp) + + err: + /* decrease the refcount in case of an error */ +- if (ret) ++ if (ret) { ++#if defined(CONFIG_MEDIA_CONTROLLER) ++ if (vdev->v4l2_dev && vdev->v4l2_dev->mdev) ++ media_entity_put(entity); ++#endif + video_put(vdev); ++ } + return ret; + } + +@@ -349,7 +367,10 @@ static int v4l2_release(struct inode *inode, struct file *filp) + if (vdev->lock) + mutex_unlock(vdev->lock); + } +- ++#if defined(CONFIG_MEDIA_CONTROLLER) ++ if (vdev->v4l2_dev && vdev->v4l2_dev->mdev) ++ media_entity_put(&vdev->entity); ++#endif + /* decrease the refcount unconditionally since the release() + return value is ignored. */ + video_put(vdev); +@@ -586,12 +607,27 @@ int __video_register_device(struct video_device *vdev, int type, int nr, + if (nr != -1 && nr != vdev->num && warn_if_nr_in_use) + printk(KERN_WARNING "%s: requested %s%d, got %s\n", __func__, + name_base, nr, video_device_node_name(vdev)); +- +- /* Part 5: Activate this minor. The char device can now be used. */ ++#if defined(CONFIG_MEDIA_CONTROLLER) ++ /* Part 5: Register the entity. */ ++ if (vdev->v4l2_dev && vdev->v4l2_dev->mdev) { ++ vdev->entity.type = MEDIA_ENT_T_DEVNODE_V4L; ++ vdev->entity.name = vdev->name; ++ vdev->entity.v4l.major = VIDEO_MAJOR; ++ vdev->entity.v4l.minor = vdev->minor; ++ ret = media_device_register_entity(vdev->v4l2_dev->mdev, ++ &vdev->entity); ++ if (ret < 0) ++ printk(KERN_WARNING ++ "%s: media_device_register_entity failed\n", ++ __func__); ++ } ++#endif ++ /* Part 6: Activate this minor. The char device can now be used. */ + set_bit(V4L2_FL_REGISTERED, &vdev->flags); + mutex_lock(&videodev_lock); + video_device[vdev->minor] = vdev; + mutex_unlock(&videodev_lock); ++ + return 0; + + cleanup: +@@ -619,6 +655,11 @@ void video_unregister_device(struct video_device *vdev) + if (!vdev || !video_is_registered(vdev)) + return; + ++#if defined(CONFIG_MEDIA_CONTROLLER) ++ if (vdev->v4l2_dev && vdev->v4l2_dev->mdev) ++ media_device_unregister_entity(&vdev->entity); ++#endif ++ + mutex_lock(&videodev_lock); + /* This must be in a critical section to prevent a race with v4l2_open. + * Once this bit has been cleared video_get may never be called again. +diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h +index 4fe6831..51b2c51 100644 +--- a/include/media/v4l2-dev.h ++++ b/include/media/v4l2-dev.h +@@ -16,6 +16,8 @@ + #include <linux/mutex.h> + #include <linux/videodev2.h> + ++#include <media/media-entity.h> ++ + #define VIDEO_MAJOR 81 + + #define VFL_TYPE_GRABBER 0 +@@ -55,6 +57,9 @@ struct v4l2_file_operations { + + struct video_device + { ++#if defined(CONFIG_MEDIA_CONTROLLER) ++ struct media_entity entity; ++#endif + /* device ops */ + const struct v4l2_file_operations *fops; + +@@ -100,6 +105,8 @@ struct video_device + struct mutex *lock; + }; + ++#define media_entity_to_video_device(entity) \ ++ container_of(entity, struct video_device, entity) + /* dev to video-device */ + #define to_video_device(cd) container_of(cd, struct video_device, dev) + +-- +1.6.6.1 + |