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git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - include/media/v4l2-device.h
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.
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
21 #ifndef _V4L2_DEVICE_H
22 #define _V4L2_DEVICE_H
24 #include <media/v4l2-subdev.h>
26 /* Each instance of a V4L2 device should create the v4l2_device struct,
27 either stand-alone or embedded in a larger struct.
29 It allows easy access to sub-devices (see v4l2-subdev.h) and provides
30 basic V4L2 device-level support.
33 #define V4L2_DEVICE_NAME_SIZE (20 + 16)
36 /* dev->driver_data points to this struct.
37 Note: dev might be NULL if there is no parent device
38 as is the case with e.g. ISA devices. */
40 /* used to keep track of the registered subdevs */
41 struct list_head subdevs
;
42 /* lock this struct; can be used by the driver as well if this
43 struct is embedded into a larger struct. */
45 /* unique device name, by default the driver name + bus ID */
46 char name
[V4L2_DEVICE_NAME_SIZE
];
47 /* notify callback called by some sub-devices. */
48 void (*notify
)(struct v4l2_subdev
*sd
,
49 unsigned int notification
, void *arg
);
52 /* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev.
53 dev may be NULL in rare cases (ISA devices). In that case you
54 must fill in the v4l2_dev->name field before calling this function. */
55 int __must_check
v4l2_device_register(struct device
*dev
, struct v4l2_device
*v4l2_dev
);
57 /* Optional function to initialize the name field of struct v4l2_device using
58 the driver name and a driver-global atomic_t instance.
59 This function will increment the instance counter and returns the instance
60 value used in the name.
64 static atomic_t drv_instance = ATOMIC_INIT(0);
68 instance = v4l2_device_set_name(&v4l2_dev, "foo", &drv_instance);
70 The first time this is called the name field will be set to foo0 and
71 this function returns 0. If the name ends with a digit (e.g. cx18),
72 then the name will be set to cx18-0 since cx180 looks really odd. */
73 int v4l2_device_set_name(struct v4l2_device
*v4l2_dev
, const char *basename
,
76 /* Set v4l2_dev->dev to NULL. Call when the USB parent disconnects.
77 Since the parent disappears this ensures that v4l2_dev doesn't have an
78 invalid parent pointer. */
79 void v4l2_device_disconnect(struct v4l2_device
*v4l2_dev
);
81 /* Unregister all sub-devices and any other resources related to v4l2_dev. */
82 void v4l2_device_unregister(struct v4l2_device
*v4l2_dev
);
84 /* Register a subdev with a v4l2 device. While registered the subdev module
85 is marked as in-use. An error is returned if the module is no longer
86 loaded when you attempt to register it. */
87 int __must_check
v4l2_device_register_subdev(struct v4l2_device
*v4l2_dev
,
88 struct v4l2_subdev
*sd
);
89 /* Unregister a subdev with a v4l2 device. Can also be called if the subdev
90 wasn't registered. In that case it will do nothing. */
91 void v4l2_device_unregister_subdev(struct v4l2_subdev
*sd
);
93 /* Iterate over all subdevs. */
94 #define v4l2_device_for_each_subdev(sd, v4l2_dev) \
95 list_for_each_entry(sd, &(v4l2_dev)->subdevs, list)
97 /* Call the specified callback for all subdevs matching the condition.
98 Ignore any errors. Note that you cannot add or delete a subdev
99 while walking the subdevs list. */
100 #define __v4l2_device_call_subdevs(v4l2_dev, cond, o, f, args...) \
102 struct v4l2_subdev *sd; \
104 list_for_each_entry(sd, &(v4l2_dev)->subdevs, list) \
105 if ((cond) && sd->ops->o && sd->ops->o->f) \
106 sd->ops->o->f(sd , ##args); \
109 /* Call the specified callback for all subdevs matching the condition.
110 If the callback returns an error other than 0 or -ENOIOCTLCMD, then
111 return with that error code. Note that you cannot add or delete a
112 subdev while walking the subdevs list. */
113 #define __v4l2_device_call_subdevs_until_err(v4l2_dev, cond, o, f, args...) \
115 struct v4l2_subdev *sd; \
118 list_for_each_entry(sd, &(v4l2_dev)->subdevs, list) { \
119 if ((cond) && sd->ops->o && sd->ops->o->f) \
120 err = sd->ops->o->f(sd , ##args); \
121 if (err && err != -ENOIOCTLCMD) \
124 (err == -ENOIOCTLCMD) ? 0 : err; \
127 /* Call the specified callback for all subdevs matching grp_id (if 0, then
128 match them all). Ignore any errors. Note that you cannot add or delete
129 a subdev while walking the subdevs list. */
130 #define v4l2_device_call_all(v4l2_dev, grpid, o, f, args...) \
131 __v4l2_device_call_subdevs(v4l2_dev, \
132 !(grpid) || sd->grp_id == (grpid), o, f , ##args)
134 /* Call the specified callback for all subdevs matching grp_id (if 0, then
135 match them all). If the callback returns an error other than 0 or
136 -ENOIOCTLCMD, then return with that error code. Note that you cannot
137 add or delete a subdev while walking the subdevs list. */
138 #define v4l2_device_call_until_err(v4l2_dev, grpid, o, f, args...) \
139 __v4l2_device_call_subdevs_until_err(v4l2_dev, \
140 !(grpid) || sd->grp_id == (grpid), o, f , ##args)