2 * drivers/media/video/v4l2-int-device.c
4 * V4L2 internal ioctl interface.
6 * Copyright (C) 2007 Nokia Corporation.
8 * Contact: Sakari Ailus <sakari.ailus@nokia.com>
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.
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.
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
25 #include <linux/kernel.h>
26 #include <linux/list.h>
27 #include <linux/sort.h>
28 #include <linux/string.h>
30 #include <media/v4l2-int-device.h>
32 static DEFINE_MUTEX(mutex
);
33 static LIST_HEAD(int_list
);
35 static void v4l2_int_device_try_attach_all(void)
37 struct list_head
*head_master
;
39 list_for_each(head_master
, &int_list
) {
40 struct list_head
*head_slave
;
41 struct v4l2_int_device
*m
=
42 list_entry(head_master
, struct v4l2_int_device
, head
);
44 if (m
->type
!= v4l2_int_type_master
)
47 list_for_each(head_slave
, &int_list
) {
48 struct v4l2_int_device
*s
=
49 list_entry(head_slave
,
50 struct v4l2_int_device
, head
);
52 if (s
->type
!= v4l2_int_type_slave
)
55 /* Slave is connected? */
56 if (s
->u
.slave
->master
)
59 /* Slave wants to attach to master? */
60 if (s
->u
.slave
->attach_to
[0] != 0
61 && strncmp(m
->name
, s
->u
.slave
->attach_to
,
65 if (!try_module_get(m
->module
))
68 if (m
->u
.master
->attach(m
, s
)) {
69 module_put(m
->module
);
73 s
->u
.slave
->master
= m
;
78 static int ioctl_sort_cmp(const void *a
, const void *b
)
80 const struct v4l2_int_ioctl_desc
*d1
= a
, *d2
= b
;
82 if (d1
->num
> d2
->num
)
85 if (d1
->num
< d2
->num
)
91 int v4l2_int_device_register(struct v4l2_int_device
*d
)
93 if (d
->type
== v4l2_int_type_slave
)
94 sort(d
->u
.slave
->ioctls
, d
->u
.slave
->num_ioctls
,
95 sizeof(struct v4l2_int_ioctl_desc
),
96 &ioctl_sort_cmp
, NULL
);
98 list_add(&d
->head
, &int_list
);
99 v4l2_int_device_try_attach_all();
100 mutex_unlock(&mutex
);
104 EXPORT_SYMBOL_GPL(v4l2_int_device_register
);
106 void v4l2_int_device_unregister(struct v4l2_int_device
*d
)
110 if (d
->type
== v4l2_int_type_slave
111 && d
->u
.slave
->master
!= NULL
) {
112 d
->u
.slave
->master
->u
.master
->detach(d
);
113 module_put(d
->u
.slave
->master
->module
);
114 d
->u
.slave
->master
= NULL
;
116 mutex_unlock(&mutex
);
118 EXPORT_SYMBOL_GPL(v4l2_int_device_unregister
);
120 /* Adapted from search_extable in extable.c. */
121 static v4l2_int_ioctl_func
*find_ioctl(struct v4l2_int_slave
*slave
, int cmd
,
122 v4l2_int_ioctl_func
*no_such_ioctl
)
124 const struct v4l2_int_ioctl_desc
*first
= slave
->ioctls
;
125 const struct v4l2_int_ioctl_desc
*last
=
126 first
+ slave
->num_ioctls
- 1;
128 while (first
<= last
) {
129 const struct v4l2_int_ioctl_desc
*mid
;
131 mid
= (last
- first
) / 2 + first
;
135 else if (mid
->num
> cmd
)
141 return no_such_ioctl
;
144 static int no_such_ioctl_0(struct v4l2_int_device
*d
)
149 int v4l2_int_ioctl_0(struct v4l2_int_device
*d
, int cmd
)
151 return ((v4l2_int_ioctl_func_0
*)
152 find_ioctl(d
->u
.slave
, cmd
,
153 (v4l2_int_ioctl_func
*)&no_such_ioctl_0
))(d
);
156 static int no_such_ioctl_1(struct v4l2_int_device
*d
, void *arg
)
161 int v4l2_int_ioctl_1(struct v4l2_int_device
*d
, int cmd
, void *arg
)
163 return ((v4l2_int_ioctl_func_1
*)
164 find_ioctl(d
->u
.slave
, cmd
,
165 (v4l2_int_ioctl_func
*)&no_such_ioctl_1
))(d
, arg
);