2 V4L2 device support header.
4 Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl>
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.
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.
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18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 #ifndef _V4L2_DEVICE_H
22 #define _V4L2_DEVICE_H
24 #include <media/media-device.h>
25 #include <media/v4l2-subdev.h>
27 /* Each instance of a V4L2 device should create the v4l2_device struct,
28 either stand-alone or embedded in a larger struct.
30 It allows easy access to sub-devices (see v4l2-subdev.h) and provides
31 basic V4L2 device-level support.
34 #define V4L2_DEVICE_NAME_SIZE (20 + 16)
36 struct v4l2_ctrl_handler;
39 /* dev->driver_data points to this struct.
40 Note: dev might be NULL if there is no parent device
41 as is the case with e.g. ISA devices. */
43 #if defined(CONFIG_MEDIA_CONTROLLER)
44 struct media_device *mdev;
46 /* used to keep track of the registered subdevs */
47 struct list_head subdevs;
48 /* lock this struct; can be used by the driver as well if this
49 struct is embedded into a larger struct. */
51 /* unique device name, by default the driver name + bus ID */
52 char name[V4L2_DEVICE_NAME_SIZE];
53 /* notify callback called by some sub-devices. */
54 void (*notify)(struct v4l2_subdev *sd,
55 unsigned int notification, void *arg);
56 /* The control handler. May be NULL. */
57 struct v4l2_ctrl_handler *ctrl_handler;
58 /* BKL replacement mutex. Temporary solution only. */
59 struct mutex ioctl_lock;
62 /* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev.
63 dev may be NULL in rare cases (ISA devices). In that case you
64 must fill in the v4l2_dev->name field before calling this function. */
65 int __must_check v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev);
67 /* Optional function to initialize the name field of struct v4l2_device using
68 the driver name and a driver-global atomic_t instance.
69 This function will increment the instance counter and returns the instance
70 value used in the name.
74 static atomic_t drv_instance = ATOMIC_INIT(0);
78 instance = v4l2_device_set_name(&v4l2_dev, "foo", &drv_instance);
80 The first time this is called the name field will be set to foo0 and
81 this function returns 0. If the name ends with a digit (e.g. cx18),
82 then the name will be set to cx18-0 since cx180 looks really odd. */
83 int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename,
86 /* Set v4l2_dev->dev to NULL. Call when the USB parent disconnects.
87 Since the parent disappears this ensures that v4l2_dev doesn't have an
88 invalid parent pointer. */
89 void v4l2_device_disconnect(struct v4l2_device *v4l2_dev);
91 /* Unregister all sub-devices and any other resources related to v4l2_dev. */
92 void v4l2_device_unregister(struct v4l2_device *v4l2_dev);
94 /* Register a subdev with a v4l2 device. While registered the subdev module
95 is marked as in-use. An error is returned if the module is no longer
96 loaded when you attempt to register it. */
97 int __must_check v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
98 struct v4l2_subdev *sd);
99 /* Unregister a subdev with a v4l2 device. Can also be called if the subdev
100 wasn't registered. In that case it will do nothing. */
101 void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
103 /* Register device nodes for all subdev of the v4l2 device that are marked with
104 * the V4L2_SUBDEV_FL_HAS_DEVNODE flag.
107 v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev);
109 /* Iterate over all subdevs. */
110 #define v4l2_device_for_each_subdev(sd, v4l2_dev) \
111 list_for_each_entry(sd, &(v4l2_dev)->subdevs, list)
113 /* Call the specified callback for all subdevs matching the condition.
114 Ignore any errors. Note that you cannot add or delete a subdev
115 while walking the subdevs list. */
116 #define __v4l2_device_call_subdevs_p(v4l2_dev, sd, cond, o, f, args...) \
118 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) \
119 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \
120 (sd)->ops->o->f((sd) , ##args); \
123 #define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...) \
125 struct v4l2_subdev *__sd; \
127 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, cond, o, \
131 /* Call the specified callback for all subdevs matching the condition.
132 If the callback returns an error other than 0 or -ENOIOCTLCMD, then
133 return with that error code. Note that you cannot add or delete a
134 subdev while walking the subdevs list. */
135 #define __v4l2_device_call_subdevs_until_err_p(v4l2_dev, sd, cond, o, f, args...) \
139 list_for_each_entry((sd), &(v4l2_dev)->subdevs, list) { \
140 if ((cond) && (sd)->ops->o && (sd)->ops->o->f) \
141 __err = (sd)->ops->o->f((sd) , ##args); \
142 if (__err && __err != -ENOIOCTLCMD) \
145 (__err == -ENOIOCTLCMD) ? 0 : __err; \
148 #define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \
150 struct v4l2_subdev *__sd; \
151 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, cond, o, \
155 /* Call the specified callback for all subdevs matching grp_id (if 0, then
156 match them all). Ignore any errors. Note that you cannot add or delete
157 a subdev while walking the subdevs list. */
158 #define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...) \
160 struct v4l2_subdev *__sd; \
162 __v4l2_device_call_subdevs_p(v4l2_dev, __sd, \
163 !(grpid) || __sd->grp_id == (grpid), o, f , \
167 /* Call the specified callback for all subdevs matching grp_id (if 0, then
168 match them all). If the callback returns an error other than 0 or
169 -ENOIOCTLCMD, then return with that error code. Note that you cannot
170 add or delete a subdev while walking the subdevs list. */
171 #define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...) \
173 struct v4l2_subdev *__sd; \
174 __v4l2_device_call_subdevs_until_err_p(v4l2_dev, __sd, \
175 !(grpid) || __sd->grp_id == (grpid), o, f , \