include/media/v4l2-device.h - maze/linux - Git at Google

 /*
     V4L2 device support header.

     Copyright (C) 2008  Hans Verkuil <hverkuil@xs4all.nl>

     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);					\
 })

 #endif
	/*
	V4L2 device support header.

	Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl>

	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); \
	})

	#endif