[media] v4l: subdev: Add device node support
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / media / v4l2-device.h
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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
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35struct v4l2_ctrl_handler;
36
2a1fcdf0 37struct v4l2_device {
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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. */
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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];
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49 /* notify callback called by some sub-devices. */
50 void (*notify)(struct v4l2_subdev *sd,
51 unsigned int notification, void *arg);
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52 /* The control handler. May be NULL. */
53 struct v4l2_ctrl_handler *ctrl_handler;
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54 /* BKL replacement mutex. Temporary solution only. */
55 struct mutex ioctl_lock;
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56};
57
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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 61int __must_check v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev);
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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. */
79int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename,
80 atomic_t *instance);
81
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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. */
85void v4l2_device_disconnect(struct v4l2_device *v4l2_dev);
102e7813 86
ae6cfaac 87/* Unregister all sub-devices and any other resources related to v4l2_dev. */
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88void 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. */
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93int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
94 struct v4l2_subdev *sd);
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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. */
97void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
98
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99/* Register device nodes for all subdev of the v4l2 device that are marked with
100 * the V4L2_SUBDEV_FL_HAS_DEVNODE flag.
101 */
102int __must_check
103v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev);
104
2a1fcdf0 105/* Iterate over all subdevs. */
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106#define v4l2_device_for_each_subdev(sd, v4l2_dev) \
107 list_for_each_entry(sd, &(v4l2_dev)->subdevs, list)
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108
109/* Call the specified callback for all subdevs matching the condition.
110 Ignore any errors. Note that you cannot add or delete a subdev
111 while walking the subdevs list. */
6c2d4dd1 112#define __v4l2_device_call_subdevs_p(v4l2_dev, sd, cond, o, f, args...) \
2a1fcdf0 113 do { \
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114 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) \
115 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \
116 (sd)->ops->o->f((sd) , ##args); \
117 } while (0)
118
119#define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...) \
120 do { \
121 struct v4l2_subdev *__sd; \
2a1fcdf0 122 \
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123 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, cond, o, \
124 f , ##args); \
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125 } while (0)
126
127/* Call the specified callback for all subdevs matching the condition.
128 If the callback returns an error other than 0 or -ENOIOCTLCMD, then
129 return with that error code. Note that you cannot add or delete a
130 subdev while walking the subdevs list. */
6c2d4dd1 131#define __v4l2_device_call_subdevs_until_err_p(v4l2_dev, sd, cond, o, f, args...) \
2a1fcdf0 132({ \
6c2d4dd1 133 long __err = 0; \
2a1fcdf0 134 \
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135 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) { \
136 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \
137 __err = (sd)->ops->o->f((sd) , ##args); \
138 if (__err && __err != -ENOIOCTLCMD) \
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139 break; \
140 } \
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141 (__err == -ENOIOCTLCMD) ? 0 : __err; \
142})
143
144#define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \
145({ \
146 struct v4l2_subdev *__sd; \
147 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, cond, o, \
148 f, args...); \
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149})
150
151/* Call the specified callback for all subdevs matching grp_id (if 0, then
152 match them all). Ignore any errors. Note that you cannot add or delete
153 a subdev while walking the subdevs list. */
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154#define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...) \
155 do { \
156 struct v4l2_subdev *__sd; \
157 \
158 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \
159 !(grpid) || __sd->grp_id == (grpid), o, f , \
160 ##args); \
161 } while (0)
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162
163/* Call the specified callback for all subdevs matching grp_id (if 0, then
164 match them all). If the callback returns an error other than 0 or
165 -ENOIOCTLCMD, then return with that error code. Note that you cannot
166 add or delete a subdev while walking the subdevs list. */
3a63e449 167#define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...) \
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168({ \
169 struct v4l2_subdev *__sd; \
170 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \
171 !(grpid) || __sd->grp_id == (grpid), o, f , \
172 ##args); \
173})
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174
175#endif