Commit | Line | Data |
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9b5d0f1e SA |
1 | /* |
2 | * drivers/media/video/v4l2-int-device.c | |
3 | * | |
4 | * V4L2 internal ioctl interface. | |
5 | * | |
6 | * Copyright (C) 2007 Nokia Corporation. | |
7 | * | |
8 | * Contact: Sakari Ailus <sakari.ailus@nokia.com> | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public License | |
12 | * version 2 as published by the Free Software Foundation. | |
13 | * | |
14 | * This program is distributed in the hope that it will be useful, but | |
15 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
17 | * General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU General Public License | |
20 | * along with this program; if not, write to the Free Software | |
21 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA | |
22 | * 02110-1301 USA | |
23 | */ | |
24 | ||
25 | #include <linux/kernel.h> | |
26 | #include <linux/list.h> | |
27 | #include <linux/sort.h> | |
28 | #include <linux/string.h> | |
29 | ||
30 | #include <media/v4l2-int-device.h> | |
31 | ||
32 | static DEFINE_MUTEX(mutex); | |
33 | static LIST_HEAD(int_list); | |
34 | ||
35 | static void v4l2_int_device_try_attach_all(void) | |
36 | { | |
a991f44b | 37 | struct v4l2_int_device *m, *s; |
9b5d0f1e | 38 | |
a991f44b | 39 | list_for_each_entry(m, &int_list, head) { |
9b5d0f1e SA |
40 | if (m->type != v4l2_int_type_master) |
41 | continue; | |
42 | ||
a991f44b | 43 | list_for_each_entry(s, &int_list, head) { |
9b5d0f1e SA |
44 | if (s->type != v4l2_int_type_slave) |
45 | continue; | |
46 | ||
47 | /* Slave is connected? */ | |
48 | if (s->u.slave->master) | |
49 | continue; | |
50 | ||
51 | /* Slave wants to attach to master? */ | |
52 | if (s->u.slave->attach_to[0] != 0 | |
53 | && strncmp(m->name, s->u.slave->attach_to, | |
54 | V4L2NAMESIZE)) | |
55 | continue; | |
56 | ||
57 | if (!try_module_get(m->module)) | |
58 | continue; | |
59 | ||
2c94a674 SA |
60 | s->u.slave->master = m; |
61 | if (m->u.master->attach(s)) { | |
62 | s->u.slave->master = NULL; | |
9b5d0f1e SA |
63 | module_put(m->module); |
64 | continue; | |
65 | } | |
9b5d0f1e SA |
66 | } |
67 | } | |
68 | } | |
69 | ||
70 | static int ioctl_sort_cmp(const void *a, const void *b) | |
71 | { | |
72 | const struct v4l2_int_ioctl_desc *d1 = a, *d2 = b; | |
73 | ||
74 | if (d1->num > d2->num) | |
75 | return 1; | |
76 | ||
77 | if (d1->num < d2->num) | |
78 | return -1; | |
79 | ||
80 | return 0; | |
81 | } | |
82 | ||
83 | int v4l2_int_device_register(struct v4l2_int_device *d) | |
84 | { | |
85 | if (d->type == v4l2_int_type_slave) | |
86 | sort(d->u.slave->ioctls, d->u.slave->num_ioctls, | |
87 | sizeof(struct v4l2_int_ioctl_desc), | |
88 | &ioctl_sort_cmp, NULL); | |
89 | mutex_lock(&mutex); | |
90 | list_add(&d->head, &int_list); | |
91 | v4l2_int_device_try_attach_all(); | |
92 | mutex_unlock(&mutex); | |
93 | ||
94 | return 0; | |
95 | } | |
261efd12 | 96 | EXPORT_SYMBOL_GPL(v4l2_int_device_register); |
9b5d0f1e SA |
97 | |
98 | void v4l2_int_device_unregister(struct v4l2_int_device *d) | |
99 | { | |
100 | mutex_lock(&mutex); | |
101 | list_del(&d->head); | |
102 | if (d->type == v4l2_int_type_slave | |
103 | && d->u.slave->master != NULL) { | |
104 | d->u.slave->master->u.master->detach(d); | |
105 | module_put(d->u.slave->master->module); | |
106 | d->u.slave->master = NULL; | |
107 | } | |
108 | mutex_unlock(&mutex); | |
109 | } | |
261efd12 | 110 | EXPORT_SYMBOL_GPL(v4l2_int_device_unregister); |
9b5d0f1e | 111 | |
9b5d0f1e | 112 | /* Adapted from search_extable in extable.c. */ |
63116feb SA |
113 | static v4l2_int_ioctl_func *find_ioctl(struct v4l2_int_slave *slave, int cmd, |
114 | v4l2_int_ioctl_func *no_such_ioctl) | |
9b5d0f1e SA |
115 | { |
116 | const struct v4l2_int_ioctl_desc *first = slave->ioctls; | |
117 | const struct v4l2_int_ioctl_desc *last = | |
118 | first + slave->num_ioctls - 1; | |
119 | ||
120 | while (first <= last) { | |
121 | const struct v4l2_int_ioctl_desc *mid; | |
122 | ||
123 | mid = (last - first) / 2 + first; | |
124 | ||
125 | if (mid->num < cmd) | |
126 | first = mid + 1; | |
127 | else if (mid->num > cmd) | |
128 | last = mid - 1; | |
129 | else | |
130 | return mid->func; | |
131 | } | |
132 | ||
63116feb SA |
133 | return no_such_ioctl; |
134 | } | |
135 | ||
136 | static int no_such_ioctl_0(struct v4l2_int_device *d) | |
137 | { | |
61c310dc | 138 | return -ENOIOCTLCMD; |
9b5d0f1e SA |
139 | } |
140 | ||
141 | int v4l2_int_ioctl_0(struct v4l2_int_device *d, int cmd) | |
142 | { | |
63116feb SA |
143 | return ((v4l2_int_ioctl_func_0 *) |
144 | find_ioctl(d->u.slave, cmd, | |
098c645e | 145 | (v4l2_int_ioctl_func *)no_such_ioctl_0))(d); |
63116feb SA |
146 | } |
147 | ||
148 | static int no_such_ioctl_1(struct v4l2_int_device *d, void *arg) | |
149 | { | |
61c310dc | 150 | return -ENOIOCTLCMD; |
9b5d0f1e SA |
151 | } |
152 | ||
153 | int v4l2_int_ioctl_1(struct v4l2_int_device *d, int cmd, void *arg) | |
154 | { | |
63116feb SA |
155 | return ((v4l2_int_ioctl_func_1 *) |
156 | find_ioctl(d->u.slave, cmd, | |
098c645e | 157 | (v4l2_int_ioctl_func *)no_such_ioctl_1))(d, arg); |
9b5d0f1e | 158 | } |