include/media/v4l2-device.h

Source file repositories/reference/linux-study-clean/include/media/v4l2-device.h

File Facts

System
Linux kernel
Corpus path
include/media/v4l2-device.h
Extension
.h
Size
19054 bytes
Lines
570
Domain
Repository Root And Misc
Bucket
include
Inferred role
Repository Root And Misc: implementation source
Status
source implementation candidate

Why This File Exists

Top-level or miscellaneous repository surface. Use this as map coverage unless a later manual pass promotes the file into a deeper subsystem dossier.

Dependency Surface

Detected Declarations

Annotated Snippet

struct v4l2_device {
	struct device *dev;
	struct media_device *mdev;
	struct list_head subdevs;
	spinlock_t lock;
	char name[36];
	void (*notify)(struct v4l2_subdev *sd,
			unsigned int notification, void *arg);
	struct v4l2_ctrl_handler *ctrl_handler;
	struct v4l2_prio_state prio;
	struct kref ref;
	void (*release)(struct v4l2_device *v4l2_dev);
};

/**
 * v4l2_device_get - gets a V4L2 device reference
 *
 * @v4l2_dev: pointer to struct &v4l2_device
 *
 * This is an ancillary routine meant to increment the usage for the
 * struct &v4l2_device pointed by @v4l2_dev.
 */
static inline void v4l2_device_get(struct v4l2_device *v4l2_dev)
{
	kref_get(&v4l2_dev->ref);
}

/**
 * v4l2_device_put - puts a V4L2 device reference
 *
 * @v4l2_dev: pointer to struct &v4l2_device
 *
 * This is an ancillary routine meant to decrement the usage for the
 * struct &v4l2_device pointed by @v4l2_dev.
 */
int v4l2_device_put(struct v4l2_device *v4l2_dev);

/**
 * v4l2_device_register - Initialize v4l2_dev and make @dev->driver_data
 *	point to @v4l2_dev.
 *
 * @dev: pointer to struct &device
 * @v4l2_dev: pointer to struct &v4l2_device
 *
 * .. note::
 *	@dev may be %NULL in rare cases (ISA devices).
 *	In such case the caller must fill in the @v4l2_dev->name field
 *	before calling this function.
 */
int __must_check v4l2_device_register(struct device *dev,
				      struct v4l2_device *v4l2_dev);

/**
 * v4l2_device_set_name - Optional function to initialize the
 *	name field of struct &v4l2_device
 *
 * @v4l2_dev: pointer to struct &v4l2_device
 * @basename: base name for the device name
 * @instance: pointer to a static atomic_t var with the instance usage for
 *	the device driver.
 *
 * v4l2_device_set_name() initializes the name field of struct &v4l2_device
 * using the driver name and a driver-global atomic_t instance.
 *
 * This function will increment the instance counter and returns the
 * instance value used in the name.
 *
 * Example:
 *
 *   static atomic_t drv_instance = ATOMIC_INIT(0);
 *
 *   ...
 *
 *   instance = v4l2_device_set_name(&\ v4l2_dev, "foo", &\ drv_instance);
 *
 * The first time this is called the name field will be set to foo0 and
 * this function returns 0. If the name ends with a digit (e.g. cx18),
 * then the name will be set to cx18-0 since cx180 would look really odd.
 */
int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename,
			 atomic_t *instance);

/**
 * v4l2_device_disconnect - Change V4L2 device state to disconnected.
 *
 * @v4l2_dev: pointer to struct v4l2_device
 *
 * Should be called when the USB parent disconnects.
 * Since the parent disappears, this ensures that @v4l2_dev doesn't have
 * an invalid parent pointer.

Annotation

Implementation Notes