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/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
V4L2 device support header.
Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl>
*/
#ifndef _V4L2_DEVICE_H
#define _V4L2_DEVICE_H
#include <media/media-device.h>
#include <media/v4l2-subdev.h>
#include <media/v4l2-dev.h>
struct v4l2_ctrl_handler;
/**
* struct v4l2_device - main struct to for V4L2 device drivers
*
* @dev: pointer to struct device.
* @mdev: pointer to struct media_device, may be NULL.
* @subdevs: used to keep track of the registered subdevs
* @lock: lock this struct; can be used by the driver as well
* if this struct is embedded into a larger struct.
* @name: unique device name, by default the driver name + bus ID
* @notify: notify operation called by some sub-devices.
* @ctrl_handler: The control handler. May be %NULL.
* @prio: Device's priority state
* @ref: Keep track of the references to this struct.
* @release: Release function that is called when the ref count
* goes to 0.
*
* Each instance of a V4L2 device should create the v4l2_device struct,
* either stand-alone or embedded in a larger struct.
*
* It allows easy access to sub-devices (see v4l2-subdev.h) and provides
* basic V4L2 device-level support.
*
* .. note::
*
* #) @dev->driver_data points to this struct.
* #) @dev might be %NULL if there is no parent device
*/
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.
*
* .. note:: This function sets @v4l2_dev->dev to NULL.
*/
void v4l2_device_disconnect(struct v4l2_device *v4l2_dev);
/**
* v4l2_device_unregister - Unregister all sub-devices and any other
* resources related to @v4l2_dev.
*
* @v4l2_dev: pointer to struct v4l2_device
*/
void v4l2_device_unregister(struct v4l2_device *v4l2_dev);
/**
* v4l2_device_register_subdev - Registers a subdev with a v4l2 device.
*
* @v4l2_dev: pointer to struct &v4l2_device
* @sd: pointer to &struct v4l2_subdev
*
* While registered, the subdev module is marked as in-use.
*
* An error is returned if the module is no longer loaded on any attempts
* to register it.
*/
int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
struct v4l2_subdev *sd);
/**
* v4l2_device_unregister_subdev - Unregisters a subdev with a v4l2 device.
*
* @sd: pointer to &struct v4l2_subdev
*
* .. note ::
*
* Can also be called if the subdev wasn't registered. In such
* case, it will do nothing.
*/
void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
/**
* __v4l2_device_register_subdev_nodes - Registers device nodes for
* all subdevs of the v4l2 device that are marked with the
* %V4L2_SUBDEV_FL_HAS_DEVNODE flag.
*
* @v4l2_dev: pointer to struct v4l2_device
* @read_only: subdevices read-only flag. True to register the subdevices
* device nodes in read-only mode, false to allow full access to the
* subdevice userspace API.
*/
int __must_check
__v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev,
bool read_only);
/**
* v4l2_device_register_subdev_nodes - Registers subdevices device nodes with
* unrestricted access to the subdevice userspace operations
*
* Internally calls __v4l2_device_register_subdev_nodes(). See its documentation
* for more details.
*
* @v4l2_dev: pointer to struct v4l2_device
*/
static inline int __must_check
v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)
{
#if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)
return __v4l2_device_register_subdev_nodes(v4l2_dev, false);
#else
return 0;
#endif
}
/**
* v4l2_device_register_ro_subdev_nodes - Registers subdevices device nodes
* in read-only mode
*
* Internally calls __v4l2_device_register_subdev_nodes(). See its documentation
* for more details.
*
* @v4l2_dev: pointer to struct v4l2_device
*/
static inline int __must_check
v4l2_device_register_ro_subdev_nodes(struct v4l2_device *v4l2_dev)
{
#if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)
return __v4l2_device_register_subdev_nodes(v4l2_dev, true);
#else
return 0;
#endif
}
/**
* v4l2_subdev_notify - Sends a notification to v4l2_device.
*
* @sd: pointer to &struct v4l2_subdev
* @notification: type of notification. Please notice that the notification
* type is driver-specific.
* @arg: arguments for the notification. Those are specific to each
* notification type.
*/
static inline void v4l2_subdev_notify(struct v4l2_subdev *sd,
unsigned int notification, void *arg)
{
if (sd && sd->v4l2_dev && sd->v4l2_dev->notify)
sd->v4l2_dev->notify(sd, notification, arg);
}
/**
* v4l2_device_supports_requests - Test if requests are supported.
*
* @v4l2_dev: pointer to struct v4l2_device
*/
static inline bool v4l2_device_supports_requests(struct v4l2_device *v4l2_dev)
{
return v4l2_dev->mdev && v4l2_dev->mdev->ops &&
v4l2_dev->mdev->ops->req_queue;
}
/* Helper macros to iterate over all subdevs. */
/**
* v4l2_device_for_each_subdev - Helper macro that interates over all
* sub-devices of a given &v4l2_device.
*
* @sd: pointer that will be filled by the macro with all
* &struct v4l2_subdev pointer used as an iterator by the loop.
* @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
*
* This macro iterates over all sub-devices owned by the @v4l2_dev device.
* It acts as a for loop iterator and executes the next statement with
* the @sd variable pointing to each sub-device in turn.
*/
#define v4l2_device_for_each_subdev(sd, v4l2_dev) \
list_for_each_entry(sd, &(v4l2_dev)->subdevs, list)
/**
* __v4l2_device_call_subdevs_p - Calls the specified operation for
* all subdevs matching the condition.
*
* @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
* @sd: pointer that will be filled by the macro with all
* &struct v4l2_subdev pointer used as an iterator by the loop.
* @cond: condition to be match
* @o: name of the element at &struct v4l2_subdev_ops that contains @f.
* Each element there groups a set of operations functions.
* @f: operation function that will be called if @cond matches.
* The operation functions are defined in groups, according to
* each element at &struct v4l2_subdev_ops.
* @args: arguments for @f.
*
* Ignore any errors.
*
* Note: subdevs cannot be added or deleted while walking
* the subdevs list.
*/
#define __v4l2_device_call_subdevs_p(v4l2_dev, sd, cond, o, f, args...) \
do { \
list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) \
if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \
(sd)->ops->o->f((sd) , ##args); \
} while (0)
/**
* __v4l2_device_call_subdevs - Calls the specified operation for
* all subdevs matching the condition.
*
* @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
* @cond: condition to be match
* @o: name of the element at &struct v4l2_subdev_ops that contains @f.
* Each element there groups a set of operations functions.
* @f: operation function that will be called if @cond matches.
* The operation functions are defined in groups, according to
* each element at &struct v4l2_subdev_ops.
* @args: arguments for @f.
*
* Ignore any errors.
*
* Note: subdevs cannot be added or deleted while walking
* the subdevs list.
*/
#define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...) \
do { \
struct v4l2_subdev *__sd; \
\
__v4l2_device_call_subdevs_p(v4l2_dev, __sd, cond, o, \
f , ##args); \
} while (0)
/**
* __v4l2_device_call_subdevs_until_err_p - Calls the specified operation for
* all subdevs matching the condition.
*
* @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
* @sd: pointer that will be filled by the macro with all
* &struct v4l2_subdev sub-devices associated with @v4l2_dev.
* @cond: condition to be match
* @o: name of the element at &struct v4l2_subdev_ops that contains @f.
* Each element there groups a set of operations functions.
* @f: operation function that will be called if @cond matches.
* The operation functions are defined in groups, according to
* each element at &struct v4l2_subdev_ops.
* @args: arguments for @f.
*
* Return:
*
* If the operation returns an error other than 0 or ``-ENOIOCTLCMD``
* for any subdevice, then abort and return with that error code, zero
* otherwise.
*
* Note: subdevs cannot be added or deleted while walking
* the subdevs list.
*/
#define __v4l2_device_call_subdevs_until_err_p(v4l2_dev, sd, cond, o, f, args...) \
({ \
long __err = 0; \
\
list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) { \
if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \
__err = (sd)->ops->o->f((sd) , ##args); \
if (__err && __err != -ENOIOCTLCMD) \
break; \
} \
(__err == -ENOIOCTLCMD) ? 0 : __err; \
})
/**
* __v4l2_device_call_subdevs_until_err - Calls the specified operation for
* all subdevs matching the condition.
*
* @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
* @cond: condition to be match
* @o: name of the element at &struct v4l2_subdev_ops that contains @f.
* Each element there groups a set of operations functions.
* @f: operation function that will be called if @cond matches.
* The operation functions are defined in groups, according to
* each element at &struct v4l2_subdev_ops.
* @args: arguments for @f.
*
* Return:
*
* If the operation returns an error other than 0 or ``-ENOIOCTLCMD``
* for any subdevice, then abort and return with that error code,
* zero otherwise.
*
* Note: subdevs cannot be added or deleted while walking
* the subdevs list.
*/
#define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \
({ \
struct v4l2_subdev *__sd; \
__v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, cond, o, \
f , ##args); \
})
/**
* v4l2_device_call_all - Calls the specified operation for
* all subdevs matching the &v4l2_subdev.grp_id, as assigned
* by the bridge driver.
*
* @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
* @grpid: &struct v4l2_subdev->grp_id group ID to match.
* Use 0 to match them all.
* @o: name of the element at &struct v4l2_subdev_ops that contains @f.
* Each element there groups a set of operations functions.
* @f: operation function that will be called if @cond matches.
* The operation functions are defined in groups, according to
* each element at &struct v4l2_subdev_ops.
* @args: arguments for @f.
*
* Ignore any errors.
*
* Note: subdevs cannot be added or deleted while walking
* the subdevs list.
*/
#define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...) \
do { \
struct v4l2_subdev *__sd; \
\
__v4l2_device_call_subdevs_p(v4l2_dev, __sd, \
(grpid) == 0 || __sd->grp_id == (grpid), o, f , \
##args); \
} while (0)
/**
* v4l2_device_call_until_err - Calls the specified operation for
* all subdevs matching the &v4l2_subdev.grp_id, as assigned
* by the bridge driver, until an error occurs.
*
* @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
* @grpid: &struct v4l2_subdev->grp_id group ID to match.
* Use 0 to match them all.
* @o: name of the element at &struct v4l2_subdev_ops that contains @f.
* Each element there groups a set of operations functions.
* @f: operation function that will be called if @cond matches.
* The operation functions are defined in groups, according to
* each element at &struct v4l2_subdev_ops.
* @args: arguments for @f.
*
* Return:
*
* If the operation returns an error other than 0 or ``-ENOIOCTLCMD``
* for any subdevice, then abort and return with that error code,
* zero otherwise.
*
* Note: subdevs cannot be added or deleted while walking
* the subdevs list.
*/
#define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...) \
({ \
struct v4l2_subdev *__sd; \
__v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \
(grpid) == 0 || __sd->grp_id == (grpid), o, f , \
##args); \
})
/**
* v4l2_device_mask_call_all - Calls the specified operation for
* all subdevices where a group ID matches a specified bitmask.
*
* @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
* @grpmsk: bitmask to be checked against &struct v4l2_subdev->grp_id
* group ID to be matched. Use 0 to match them all.
* @o: name of the element at &struct v4l2_subdev_ops that contains @f.
* Each element there groups a set of operations functions.
* @f: operation function that will be called if @cond matches.
* The operation functions are defined in groups, according to
* each element at &struct v4l2_subdev_ops.
* @args: arguments for @f.
*
* Ignore any errors.
*
* Note: subdevs cannot be added or deleted while walking
* the subdevs list.
*/
#define v4l2_device_mask_call_all(v4l2_dev, grpmsk, o, f, args...) \
do { \
struct v4l2_subdev *__sd; \
\
__v4l2_device_call_subdevs_p(v4l2_dev, __sd, \
(grpmsk) == 0 || (__sd->grp_id & (grpmsk)), o, \
f , ##args); \
} while (0)
/**
* v4l2_device_mask_call_until_err - Calls the specified operation for
* all subdevices where a group ID matches a specified bitmask.
*
* @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
* @grpmsk: bitmask to be checked against &struct v4l2_subdev->grp_id
* group ID to be matched. Use 0 to match them all.
* @o: name of the element at &struct v4l2_subdev_ops that contains @f.
* Each element there groups a set of operations functions.
* @f: operation function that will be called if @cond matches.
* The operation functions are defined in groups, according to
* each element at &struct v4l2_subdev_ops.
* @args: arguments for @f.
*
* Return:
*
* If the operation returns an error other than 0 or ``-ENOIOCTLCMD``
* for any subdevice, then abort and return with that error code,
* zero otherwise.
*
* Note: subdevs cannot be added or deleted while walking
* the subdevs list.
*/
#define v4l2_device_mask_call_until_err(v4l2_dev, grpmsk, o, f, args...) \
({ \
struct v4l2_subdev *__sd; \
__v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \
(grpmsk) == 0 || (__sd->grp_id & (grpmsk)), o, \
f , ##args); \
})
/**
* v4l2_device_has_op - checks if any subdev with matching grpid has a
* given ops.
*
* @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
* @grpid: &struct v4l2_subdev->grp_id group ID to match.
* Use 0 to match them all.
* @o: name of the element at &struct v4l2_subdev_ops that contains @f.
* Each element there groups a set of operations functions.
* @f: operation function that will be called if @cond matches.
* The operation functions are defined in groups, according to
* each element at &struct v4l2_subdev_ops.
*/
#define v4l2_device_has_op(v4l2_dev, grpid, o, f) \
({ \
struct v4l2_subdev *__sd; \
bool __result = false; \
list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \
if ((grpid) && __sd->grp_id != (grpid)) \
continue; \
if (v4l2_subdev_has_op(__sd, o, f)) { \
__result = true; \
break; \
} \
} \
__result; \
})
/**
* v4l2_device_mask_has_op - checks if any subdev with matching group
* mask has a given ops.
*
* @v4l2_dev: &struct v4l2_device owning the sub-devices to iterate over.
* @grpmsk: bitmask to be checked against &struct v4l2_subdev->grp_id
* group ID to be matched. Use 0 to match them all.
* @o: name of the element at &struct v4l2_subdev_ops that contains @f.
* Each element there groups a set of operations functions.
* @f: operation function that will be called if @cond matches.
* The operation functions are defined in groups, according to
* each element at &struct v4l2_subdev_ops.
*/
#define v4l2_device_mask_has_op(v4l2_dev, grpmsk, o, f) \
({ \
struct v4l2_subdev *__sd; \
bool __result = false; \
list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \
if ((grpmsk) && !(__sd->grp_id & (grpmsk))) \
continue; \
if (v4l2_subdev_has_op(__sd, o, f)) { \
__result = true; \
break; \
} \
} \
__result; \
})
#endif