[deliverable/linux.git] / include / media / v4l2-device.h

/*
    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/v4l2-subdev.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;
	/* 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;
	/* BKL replacement mutex. Temporary solution only. */
	struct mutex ioctl_lock;
};

/* 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);

/* 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
Commit	Line	Data
2a1fcdf0 HV	1	/*
	2	V4L2 device support header.
	3
	4	Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl>
	5
	6	This program is free software; you can redistribute it and/or modify
	7	it under the terms of the GNU General Public License as published by
	8	the Free Software Foundation; either version 2 of the License, or
	9	(at your option) any later version.
	10
	11	This program is distributed in the hope that it will be useful,
	12	but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	GNU General Public License for more details.
	15
	16	You should have received a copy of the GNU General Public License
	17	along with this program; if not, write to the Free Software
	18	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	19	*/
	20
	21	#ifndef _V4L2_DEVICE_H
	22	#define _V4L2_DEVICE_H
	23
	24	#include <media/v4l2-subdev.h>
	25
	26	/* Each instance of a V4L2 device should create the v4l2_device struct,
	27	either stand-alone or embedded in a larger struct.
	28
	29	It allows easy access to sub-devices (see v4l2-subdev.h) and provides
	30	basic V4L2 device-level support.
	31	*/
	32
1351a58c	33	#define V4L2_DEVICE_NAME_SIZE (20 + 16)
2a1fcdf0	34
0996517c HV	35	struct v4l2_ctrl_handler;
0996517c HV	36
2a1fcdf0	37	struct v4l2_device {
3a63e449 HV	38	/* dev->driver_data points to this struct.
	39	Note: dev might be NULL if there is no parent device
	40	as is the case with e.g. ISA devices. */
2a1fcdf0 HV	41	struct device *dev;
	42	/* used to keep track of the registered subdevs */
	43	struct list_head subdevs;
	44	/* lock this struct; can be used by the driver as well if this
	45	struct is embedded into a larger struct. */
	46	spinlock_t lock;
	47	/* unique device name, by default the driver name + bus ID */
	48	char name[V4L2_DEVICE_NAME_SIZE];
98ec6339 HV	49	/* notify callback called by some sub-devices. */
	50	void (notify)(struct v4l2_subdev sd,
	51	unsigned int notification, void *arg);
0996517c HV	52	/* The control handler. May be NULL. */
0996517c HV	53	struct v4l2_ctrl_handler *ctrl_handler;
879aa24d HV	54	/* BKL replacement mutex. Temporary solution only. */
879aa24d HV	55	struct mutex ioctl_lock;
2a1fcdf0 HV	56	};
2a1fcdf0 HV	57
3a63e449 HV	58	/* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev.
	59	dev may be NULL in rare cases (ISA devices). In that case you
	60	must fill in the v4l2_dev->name field before calling this function. */
2a1fcdf0	61	int __must_check v4l2_device_register(struct device dev, struct v4l2_device v4l2_dev);
102e7813 HV	62
	63	/* Optional function to initialize the name field of struct v4l2_device using
	64	the driver name and a driver-global atomic_t instance.
	65	This function will increment the instance counter and returns the instance
	66	value used in the name.
	67
	68	Example:
	69
	70	static atomic_t drv_instance = ATOMIC_INIT(0);
	71
	72	...
	73
	74	instance = v4l2_device_set_name(&v4l2_dev, "foo", &drv_instance);
	75
	76	The first time this is called the name field will be set to foo0 and
	77	this function returns 0. If the name ends with a digit (e.g. cx18),
	78	then the name will be set to cx18-0 since cx180 looks really odd. */
	79	int v4l2_device_set_name(struct v4l2_device v4l2_dev, const char basename,
	80	atomic_t *instance);
	81
ae6cfaac HV	82	/* Set v4l2_dev->dev to NULL. Call when the USB parent disconnects.
	83	Since the parent disappears this ensures that v4l2_dev doesn't have an
	84	invalid parent pointer. */
	85	void v4l2_device_disconnect(struct v4l2_device *v4l2_dev);
102e7813	86
ae6cfaac	87	/* Unregister all sub-devices and any other resources related to v4l2_dev. */
2a1fcdf0 HV	88	void v4l2_device_unregister(struct v4l2_device *v4l2_dev);
	89
	90	/* Register a subdev with a v4l2 device. While registered the subdev module
	91	is marked as in-use. An error is returned if the module is no longer
	92	loaded when you attempt to register it. */
3a63e449 HV	93	int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
3a63e449 HV	94	struct v4l2_subdev *sd);
2a1fcdf0 HV	95	/* Unregister a subdev with a v4l2 device. Can also be called if the subdev
	96	wasn't registered. In that case it will do nothing. */
	97	void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
	98
	99	/* Iterate over all subdevs. */
3a63e449 HV	100	#define v4l2_device_for_each_subdev(sd, v4l2_dev) \
3a63e449 HV	101	list_for_each_entry(sd, &(v4l2_dev)->subdevs, list)
2a1fcdf0 HV	102
	103	/* Call the specified callback for all subdevs matching the condition.
	104	Ignore any errors. Note that you cannot add or delete a subdev
	105	while walking the subdevs list. */
6c2d4dd1	106	#define __v4l2_device_call_subdevs_p(v4l2_dev, sd, cond, o, f, args...) \
2a1fcdf0	107	do { \
6c2d4dd1 GL	108	list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) \
	109	if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \
	110	(sd)->ops->o->f((sd) , ##args); \
	111	} while (0)
	112
	113	#define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...) \
	114	do { \
	115	struct v4l2_subdev *__sd; \
2a1fcdf0	116	\
6c2d4dd1 GL	117	__v4l2_device_call_subdevs_p(v4l2_dev, __sd, cond, o, \
6c2d4dd1 GL	118	f , ##args); \
2a1fcdf0 HV	119	} while (0)
	120
	121	/* Call the specified callback for all subdevs matching the condition.
	122	If the callback returns an error other than 0 or -ENOIOCTLCMD, then
	123	return with that error code. Note that you cannot add or delete a
	124	subdev while walking the subdevs list. */
6c2d4dd1	125	#define __v4l2_device_call_subdevs_until_err_p(v4l2_dev, sd, cond, o, f, args...) \
2a1fcdf0	126	({ \
6c2d4dd1	127	long __err = 0; \
2a1fcdf0	128	\
6c2d4dd1 GL	129	list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) { \
	130	if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \
	131	__err = (sd)->ops->o->f((sd) , ##args); \
	132	if (__err && __err != -ENOIOCTLCMD) \
2a1fcdf0 HV	133	break; \
2a1fcdf0 HV	134	} \
6c2d4dd1 GL	135	(__err == -ENOIOCTLCMD) ? 0 : __err; \
	136	})
	137
	138	#define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \
	139	({ \
	140	struct v4l2_subdev *__sd; \
	141	__v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, cond, o, \
	142	f, args...); \
2a1fcdf0 HV	143	})
	144
	145	/* Call the specified callback for all subdevs matching grp_id (if 0, then
	146	match them all). Ignore any errors. Note that you cannot add or delete
	147	a subdev while walking the subdevs list. */
6c2d4dd1 GL	148	#define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...) \
	149	do { \
	150	struct v4l2_subdev *__sd; \
	151	\
	152	__v4l2_device_call_subdevs_p(v4l2_dev, __sd, \
	153	!(grpid) \|\| __sd->grp_id == (grpid), o, f , \
	154	##args); \
	155	} while (0)
2a1fcdf0 HV	156
	157	/* Call the specified callback for all subdevs matching grp_id (if 0, then
	158	match them all). If the callback returns an error other than 0 or
	159	-ENOIOCTLCMD, then return with that error code. Note that you cannot
	160	add or delete a subdev while walking the subdevs list. */
3a63e449	161	#define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...) \
6c2d4dd1 GL	162	({ \
	163	struct v4l2_subdev *__sd; \
	164	__v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \
	165	!(grpid) \|\| __sd->grp_id == (grpid), o, f , \
	166	##args); \
	167	})
2a1fcdf0 HV	168
2a1fcdf0 HV	169	#endif