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Hans Verkuil2a1fcdf2008-11-29 21:36:58 -03001/*
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
33#define V4L2_DEVICE_NAME_SIZE (BUS_ID_SIZE + 16)
34
35struct v4l2_device {
36 /* dev->driver_data points to this struct */
37 struct device *dev;
38 /* used to keep track of the registered subdevs */
39 struct list_head subdevs;
40 /* lock this struct; can be used by the driver as well if this
41 struct is embedded into a larger struct. */
42 spinlock_t lock;
43 /* unique device name, by default the driver name + bus ID */
44 char name[V4L2_DEVICE_NAME_SIZE];
45};
46
47/* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev */
48int __must_check v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev);
49/* Set v4l2_dev->dev->driver_data to NULL and unregister all sub-devices */
50void v4l2_device_unregister(struct v4l2_device *v4l2_dev);
51
52/* Register a subdev with a v4l2 device. While registered the subdev module
53 is marked as in-use. An error is returned if the module is no longer
54 loaded when you attempt to register it. */
55int __must_check v4l2_device_register_subdev(struct v4l2_device *dev, struct v4l2_subdev *sd);
56/* Unregister a subdev with a v4l2 device. Can also be called if the subdev
57 wasn't registered. In that case it will do nothing. */
58void v4l2_device_unregister_subdev(struct v4l2_subdev *sd);
59
60/* Iterate over all subdevs. */
61#define v4l2_device_for_each_subdev(sd, dev) \
62 list_for_each_entry(sd, &(dev)->subdevs, list)
63
64/* Call the specified callback for all subdevs matching the condition.
65 Ignore any errors. Note that you cannot add or delete a subdev
66 while walking the subdevs list. */
67#define __v4l2_device_call_subdevs(dev, cond, o, f, args...) \
68 do { \
69 struct v4l2_subdev *sd; \
70 \
71 list_for_each_entry(sd, &(dev)->subdevs, list) \
72 if ((cond) && sd->ops->o && sd->ops->o->f) \
73 sd->ops->o->f(sd , ##args); \
74 } while (0)
75
76/* Call the specified callback for all subdevs matching the condition.
77 If the callback returns an error other than 0 or -ENOIOCTLCMD, then
78 return with that error code. Note that you cannot add or delete a
79 subdev while walking the subdevs list. */
80#define __v4l2_device_call_subdevs_until_err(dev, cond, o, f, args...) \
81({ \
82 struct v4l2_subdev *sd; \
Hans Verkuil069b7472008-12-30 07:04:34 -030083 long err = 0; \
Hans Verkuil2a1fcdf2008-11-29 21:36:58 -030084 \
85 list_for_each_entry(sd, &(dev)->subdevs, list) { \
86 if ((cond) && sd->ops->o && sd->ops->o->f) \
87 err = sd->ops->o->f(sd , ##args); \
88 if (err && err != -ENOIOCTLCMD) \
89 break; \
90 } \
91 (err == -ENOIOCTLCMD) ? 0 : err; \
92})
93
94/* Call the specified callback for all subdevs matching grp_id (if 0, then
95 match them all). Ignore any errors. Note that you cannot add or delete
96 a subdev while walking the subdevs list. */
97#define v4l2_device_call_all(dev, grp_id, o, f, args...) \
98 __v4l2_device_call_subdevs(dev, \
99 !(grp_id) || sd->grp_id == (grp_id), o, f , ##args)
100
101/* Call the specified callback for all subdevs matching grp_id (if 0, then
102 match them all). If the callback returns an error other than 0 or
103 -ENOIOCTLCMD, then return with that error code. Note that you cannot
104 add or delete a subdev while walking the subdevs list. */
105#define v4l2_device_call_until_err(dev, grp_id, o, f, args...) \
106 __v4l2_device_call_subdevs_until_err(dev, \
107 !(grp_id) || sd->grp_id == (grp_id), o, f , ##args)
108
109#endif