ce64fe16bc604137d3522af06931ab562983865c
[linux-2.6.git] / drivers / media / video / v4l2-device.c
1 /*
2     V4L2 device support.
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 #include <linux/types.h>
22 #include <linux/ioctl.h>
23 #include <linux/i2c.h>
24 #if defined(CONFIG_SPI)
25 #include <linux/spi/spi.h>
26 #endif
27 #include <linux/videodev2.h>
28 #include <media/v4l2-device.h>
29 #include <media/v4l2-ctrls.h>
30
31 int v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev)
32 {
33         if (v4l2_dev == NULL)
34                 return -EINVAL;
35
36         INIT_LIST_HEAD(&v4l2_dev->subdevs);
37         spin_lock_init(&v4l2_dev->lock);
38         mutex_init(&v4l2_dev->ioctl_lock);
39         v4l2_dev->dev = dev;
40         if (dev == NULL) {
41                 /* If dev == NULL, then name must be filled in by the caller */
42                 WARN_ON(!v4l2_dev->name[0]);
43                 return 0;
44         }
45
46         /* Set name to driver name + device name if it is empty. */
47         if (!v4l2_dev->name[0])
48                 snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), "%s %s",
49                         dev->driver->name, dev_name(dev));
50         if (dev_get_drvdata(dev))
51                 v4l2_warn(v4l2_dev, "Non-NULL drvdata on register\n");
52         dev_set_drvdata(dev, v4l2_dev);
53         return 0;
54 }
55 EXPORT_SYMBOL_GPL(v4l2_device_register);
56
57 int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename,
58                                                 atomic_t *instance)
59 {
60         int num = atomic_inc_return(instance) - 1;
61         int len = strlen(basename);
62
63         if (basename[len - 1] >= '0' && basename[len - 1] <= '9')
64                 snprintf(v4l2_dev->name, sizeof(v4l2_dev->name),
65                                 "%s-%d", basename, num);
66         else
67                 snprintf(v4l2_dev->name, sizeof(v4l2_dev->name),
68                                 "%s%d", basename, num);
69         return num;
70 }
71 EXPORT_SYMBOL_GPL(v4l2_device_set_name);
72
73 void v4l2_device_disconnect(struct v4l2_device *v4l2_dev)
74 {
75         if (v4l2_dev->dev) {
76                 dev_set_drvdata(v4l2_dev->dev, NULL);
77                 v4l2_dev->dev = NULL;
78         }
79 }
80 EXPORT_SYMBOL_GPL(v4l2_device_disconnect);
81
82 void v4l2_device_unregister(struct v4l2_device *v4l2_dev)
83 {
84         struct v4l2_subdev *sd, *next;
85
86         if (v4l2_dev == NULL)
87                 return;
88         v4l2_device_disconnect(v4l2_dev);
89
90         /* Unregister subdevs */
91         list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list) {
92                 v4l2_device_unregister_subdev(sd);
93 #if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE))
94                 if (sd->flags & V4L2_SUBDEV_FL_IS_I2C) {
95                         struct i2c_client *client = v4l2_get_subdevdata(sd);
96
97                         /* We need to unregister the i2c client explicitly.
98                            We cannot rely on i2c_del_adapter to always
99                            unregister clients for us, since if the i2c bus
100                            is a platform bus, then it is never deleted. */
101                         if (client)
102                                 i2c_unregister_device(client);
103                         continue;
104                 }
105 #endif
106 #if defined(CONFIG_SPI)
107                 if (sd->flags & V4L2_SUBDEV_FL_IS_SPI) {
108                         struct spi_device *spi = v4l2_get_subdevdata(sd);
109
110                         if (spi)
111                                 spi_unregister_device(spi);
112                         continue;
113                 }
114 #endif
115         }
116 }
117 EXPORT_SYMBOL_GPL(v4l2_device_unregister);
118
119 int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
120                                                 struct v4l2_subdev *sd)
121 {
122         int err;
123
124         /* Check for valid input */
125         if (v4l2_dev == NULL || sd == NULL || !sd->name[0])
126                 return -EINVAL;
127         /* Warn if we apparently re-register a subdev */
128         WARN_ON(sd->v4l2_dev != NULL);
129         if (!try_module_get(sd->owner))
130                 return -ENODEV;
131         sd->v4l2_dev = v4l2_dev;
132         if (sd->internal_ops && sd->internal_ops->registered) {
133                 err = sd->internal_ops->registered(sd);
134                 if (err)
135                         return err;
136         }
137         /* This just returns 0 if either of the two args is NULL */
138         err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler);
139         if (err) {
140                 if (sd->internal_ops && sd->internal_ops->unregistered)
141                         sd->internal_ops->unregistered(sd);
142                 return err;
143         }
144         spin_lock(&v4l2_dev->lock);
145         list_add_tail(&sd->list, &v4l2_dev->subdevs);
146         spin_unlock(&v4l2_dev->lock);
147         return 0;
148 }
149 EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);
150
151 void v4l2_device_unregister_subdev(struct v4l2_subdev *sd)
152 {
153         /* return if it isn't registered */
154         if (sd == NULL || sd->v4l2_dev == NULL)
155                 return;
156         spin_lock(&sd->v4l2_dev->lock);
157         list_del(&sd->list);
158         spin_unlock(&sd->v4l2_dev->lock);
159         if (sd->internal_ops && sd->internal_ops->unregistered)
160                 sd->internal_ops->unregistered(sd);
161         sd->v4l2_dev = NULL;
162         module_put(sd->owner);
163 }
164 EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev);