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[media] v4l2-device.h: document functions
The functions at v4l2-device.h are not using the proper markups. Add it, and include at the v4l2-core.rst. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
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Mauro Carvalho Chehab
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commit
575f93084d
@ -11,6 +11,8 @@ Video2Linux devices
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.. kernel-doc:: include/media/v4l2-ctrls.h
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.. kernel-doc:: include/media/v4l2-device.h
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.. kernel-doc:: include/media/v4l2-dv-timings.h
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.. kernel-doc:: include/media/v4l2-event.h
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@ -25,100 +25,188 @@
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#include <media/v4l2-subdev.h>
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#include <media/v4l2-dev.h>
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/* Each instance of a V4L2 device should create the v4l2_device struct,
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either stand-alone or embedded in a larger struct.
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It allows easy access to sub-devices (see v4l2-subdev.h) and provides
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basic V4L2 device-level support.
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*/
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#define V4L2_DEVICE_NAME_SIZE (20 + 16)
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struct v4l2_ctrl_handler;
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/**
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* struct v4l2_device - main struct to for V4L2 device drivers
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*
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* @dev: pointer to struct device.
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* @mdev: pointer to struct media_device
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* @subdevs: used to keep track of the registered subdevs
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* @lock: lock this struct; can be used by the driver as well
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* if this struct is embedded into a larger struct.
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* @name: unique device name, by default the driver name + bus ID
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* @notify: notify callback called by some sub-devices.
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* @ctrl_handler: The control handler. May be NULL.
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* @prio: Device's priority state
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* @ref: Keep track of the references to this struct.
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* @release: Release function that is called when the ref count
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* goes to 0.
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*
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* Each instance of a V4L2 device should create the v4l2_device struct,
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* either stand-alone or embedded in a larger struct.
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*
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* It allows easy access to sub-devices (see v4l2-subdev.h) and provides
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* basic V4L2 device-level support.
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*
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* .. note::
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*
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* #) dev->driver_data points to this struct.
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* #) dev might be NULL if there is no parent device
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*/
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struct v4l2_device {
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/* dev->driver_data points to this struct.
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Note: dev might be NULL if there is no parent device
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as is the case with e.g. ISA devices. */
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struct device *dev;
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#if defined(CONFIG_MEDIA_CONTROLLER)
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struct media_device *mdev;
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#endif
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/* used to keep track of the registered subdevs */
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struct list_head subdevs;
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/* lock this struct; can be used by the driver as well if this
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struct is embedded into a larger struct. */
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spinlock_t lock;
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/* unique device name, by default the driver name + bus ID */
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char name[V4L2_DEVICE_NAME_SIZE];
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/* notify callback called by some sub-devices. */
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void (*notify)(struct v4l2_subdev *sd,
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unsigned int notification, void *arg);
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/* The control handler. May be NULL. */
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struct v4l2_ctrl_handler *ctrl_handler;
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/* Device's priority state */
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struct v4l2_prio_state prio;
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/* Keep track of the references to this struct. */
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struct kref ref;
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/* Release function that is called when the ref count goes to 0. */
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void (*release)(struct v4l2_device *v4l2_dev);
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};
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/**
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* v4l2_device_get - gets a V4L2 device reference
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*
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* @v4l2_dev: pointer to struct v4l2_device
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*
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* This is an ancillary routine meant to increment the usage for the
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* struct v4l2_device pointed by @v4l2_dev.
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*/
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static inline void v4l2_device_get(struct v4l2_device *v4l2_dev)
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{
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kref_get(&v4l2_dev->ref);
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}
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/**
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* v4l2_device_put - putss a V4L2 device reference
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*
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* @v4l2_dev: pointer to struct v4l2_device
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*
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* This is an ancillary routine meant to decrement the usage for the
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* struct v4l2_device pointed by @v4l2_dev.
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*/
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int v4l2_device_put(struct v4l2_device *v4l2_dev);
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/* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev.
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dev may be NULL in rare cases (ISA devices). In that case you
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must fill in the v4l2_dev->name field before calling this function. */
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int __must_check v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev);
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/**
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* v4l2_device_register -Initialize v4l2_dev and make dev->driver_data
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* point to v4l2_dev.
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*
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* @dev: pointer to struct device
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* @v4l2_dev: pointer to struct v4l2_device
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*
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* .. note::
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* dev may be NULL in rare cases (ISA devices).
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* In such case the caller must fill in the v4l2_dev->name field
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* before calling this function.
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*/
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int __must_check v4l2_device_register(struct device *dev,
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struct v4l2_device *v4l2_dev);
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/* Optional function to initialize the name field of struct v4l2_device using
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the driver name and a driver-global atomic_t instance.
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This function will increment the instance counter and returns the instance
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value used in the name.
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Example:
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static atomic_t drv_instance = ATOMIC_INIT(0);
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...
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instance = v4l2_device_set_name(&v4l2_dev, "foo", &drv_instance);
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The first time this is called the name field will be set to foo0 and
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this function returns 0. If the name ends with a digit (e.g. cx18),
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then the name will be set to cx18-0 since cx180 looks really odd. */
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/**
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* v4l2_device_set_name - Optional function to initialize the
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* name field of struct v4l2_device
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*
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* @v4l2_dev: pointer to struct v4l2_device
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* @basename: base name for the device name
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* @instance: pointer to a static atomic_t var with the instance usage for
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* the device driver.
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*
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* v4l2_device_set_name() initializes the name field of struct v4l2_device
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* using the driver name and a driver-global atomic_t instance.
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*
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* This function will increment the instance counter and returns the
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* instance value used in the name.
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*
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* Example:
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*
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* static atomic_t drv_instance = ATOMIC_INIT(0);
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*
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* ...
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*
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* instance = v4l2_device_set_name(&v4l2_dev, "foo", &drv_instance);
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*
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* The first time this is called the name field will be set to foo0 and
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* this function returns 0. If the name ends with a digit (e.g. cx18),
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* then the name will be set to cx18-0 since cx180 would look really odd.
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*/
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int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename,
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atomic_t *instance);
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atomic_t *instance);
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/* Set v4l2_dev->dev to NULL. Call when the USB parent disconnects.
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Since the parent disappears this ensures that v4l2_dev doesn't have an
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invalid parent pointer. */
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/**
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* v4l2_device_disconnect - Change V4L2 device state to disconnected.
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*
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* @v4l2_dev: pointer to struct v4l2_device
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*
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* Should be called when the USB parent disconnects.
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* Since the parent disappears, this ensures that v4l2_dev doesn't have
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* an invalid parent pointer.
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*
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* .. note:: This function sets v4l2_dev->dev to NULL.
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*/
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void v4l2_device_disconnect(struct v4l2_device *v4l2_dev);
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/* Unregister all sub-devices and any other resources related to v4l2_dev. */
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/**
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* v4l2_device_unregister - Unregister all sub-devices and any other
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* resources related to v4l2_dev.
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*
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* @v4l2_dev: pointer to struct v4l2_device
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*/
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void v4l2_device_unregister(struct v4l2_device *v4l2_dev);
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/* Register a subdev with a v4l2 device. While registered the subdev module
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is marked as in-use. An error is returned if the module is no longer
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loaded when you attempt to register it. */
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/**
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* v4l2_device_register_subdev - Registers a subdev with a v4l2 device.
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*
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* @v4l2_dev: pointer to struct v4l2_device
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* @sd: pointer to struct v4l2_subdev
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*
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* While registered, the subdev module is marked as in-use.
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*
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* An error is returned if the module is no longer loaded on any attempts
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* to register it.
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*/
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int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
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struct v4l2_subdev *sd);
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/* Unregister a subdev with a v4l2 device. Can also be called if the subdev
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wasn't registered. In that case it will do nothing. */
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struct v4l2_subdev *sd);
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/**
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* v4l2_device_unregister_subdev - Unregisters a subdev with a v4l2 device.
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*
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* @sd: pointer to struct v4l2_subdev
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*
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* .. note ::
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*
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* Can also be called if the subdev wasn't registered. In such
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* case, it will do nothing.
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*/
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void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
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/* Register device nodes for all subdev of the v4l2 device that are marked with
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* the V4L2_SUBDEV_FL_HAS_DEVNODE flag.
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/**
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* v4l2_device_register_subdev_nodes - Registers device nodes for all subdevs
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* of the v4l2 device that are marked with
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* the V4L2_SUBDEV_FL_HAS_DEVNODE flag.
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*
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* @v4l2_dev: pointer to struct v4l2_device
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*/
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int __must_check
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v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev);
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/* Send a notification to v4l2_device. */
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/**
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* v4l2_subdev_notify - Sends a notification to v4l2_device.
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*
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* @sd: pointer to struct v4l2_subdev
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* @notification: type of notification. Please notice that the notification
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* type is driver-specific.
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* @arg: arguments for the notification. Those are specific to each
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* notification type.
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*/
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static inline void v4l2_subdev_notify(struct v4l2_subdev *sd,
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unsigned int notification, void *arg)
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{
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