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v4l2-device.h
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v4l2-device.h
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/*
V4L2 device support header.
Copyright (C) 2008 Hans Verkuil <[email protected]>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef _V4L2_DEVICE_H
#define _V4L2_DEVICE_H
#include <media/media-device.h>
#include <media/v4l2-subdev.h>
#include <media/v4l2-dev.h>
/* 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.
*/
#define V4L2_DEVICE_NAME_SIZE (20 + 16)
struct v4l2_ctrl_handler;
struct v4l2_device {
/* dev->driver_data points to this struct.
Note: dev might be NULL if there is no parent device
as is the case with e.g. ISA devices. */
struct device *dev;
#if defined(CONFIG_MEDIA_CONTROLLER)
struct media_device *mdev;
#endif
/* used to keep track of the registered subdevs */
struct list_head subdevs;
/* lock this struct; can be used by the driver as well if this
struct is embedded into a larger struct. */
spinlock_t lock;
/* unique device name, by default the driver name + bus ID */
char name[V4L2_DEVICE_NAME_SIZE];
/* notify callback called by some sub-devices. */
void (*notify)(struct v4l2_subdev *sd,
unsigned int notification, void *arg);
/* The control handler. May be NULL. */
struct v4l2_ctrl_handler *ctrl_handler;
/* Device's priority state */
struct v4l2_prio_state prio;
/* BKL replacement mutex. Temporary solution only. */
struct mutex ioctl_lock;
/* Keep track of the references to this struct. */
struct kref ref;
/* Release function that is called when the ref count goes to 0. */
void (*release)(struct v4l2_device *v4l2_dev);
};
static inline void v4l2_device_get(struct v4l2_device *v4l2_dev)
{
kref_get(&v4l2_dev->ref);
}
int v4l2_device_put(struct v4l2_device *v4l2_dev);
/* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev.
dev may be NULL in rare cases (ISA devices). In that case you
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);
/* Optional function to initialize 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 looks really odd. */
int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename,
atomic_t *instance);
/* Set v4l2_dev->dev to NULL. Call when the USB parent disconnects.
Since the parent disappears this ensures that v4l2_dev doesn't have an
invalid parent pointer. */
void v4l2_device_disconnect(struct v4l2_device *v4l2_dev);
/* Unregister all sub-devices and any other resources related to v4l2_dev. */
void v4l2_device_unregister(struct v4l2_device *v4l2_dev);
/* Register a subdev with a v4l2 device. While registered the subdev module
is marked as in-use. An error is returned if the module is no longer
loaded when you attempt to register it. */
int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
struct v4l2_subdev *sd);
/* Unregister a subdev with a v4l2 device. Can also be called if the subdev
wasn't registered. In that case it will do nothing. */
void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
/* Register device nodes for all subdev of the v4l2 device that are marked with
* the V4L2_SUBDEV_FL_HAS_DEVNODE flag.
*/
int __must_check
v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev);
/* Iterate over all subdevs. */
#define v4l2_device_for_each_subdev(sd, v4l2_dev) \
list_for_each_entry(sd, &(v4l2_dev)->subdevs, list)
/* Call the specified callback for all subdevs matching the condition.
Ignore any errors. Note that you cannot add or delete a subdev
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)
#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)
/* Call the specified callback for all subdevs matching the condition.
If the callback returns an error other than 0 or -ENOIOCTLCMD, then
return with that error code. Note that you cannot add or delete a
subdev 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; \
})
#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); \
})
/* Call the specified callback for all subdevs matching grp_id (if 0, then
match them all). Ignore any errors. Note that you cannot add or delete
a subdev 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) || __sd->grp_id == (grpid), o, f , \
##args); \
} while (0)
/* Call the specified callback for all subdevs matching grp_id (if 0, then
match them all). If the callback returns an error other than 0 or
-ENOIOCTLCMD, then return with that error code. Note that you cannot
add or delete a subdev 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) || __sd->grp_id == (grpid), o, f , \
##args); \
})
#define v4l2_device_has_op(v4l2_dev, o, f) \
({ \
struct v4l2_subdev *__sd; \
bool __result = false; \
list_for_each_entry(__sd, &(v4l2_dev)->subdevs, list) { \
if (v4l2_subdev_has_op(__sd, o, f)) { \
__result = true; \
break; \
} \
} \
__result; \
})
#endif