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/*
* drivers/media/video/v4l2-int-device.c
*
* V4L2 internal ioctl interface.
*
* Copyright (C) 2007 Nokia Corporation.
*
* Contact: Sakari Ailus <sakari.ailus@nokia.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*/
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/sort.h>
#include <linux/string.h>
#include <media/v4l2-int-device.h>
static DEFINE_MUTEX(mutex);
static LIST_HEAD(int_list);
static void v4l2_int_device_try_attach_all(void)
{
struct list_head *head_master;
list_for_each(head_master, &int_list) {
struct list_head *head_slave;
struct v4l2_int_device *m =
list_entry(head_master, struct v4l2_int_device, head);
if (m->type != v4l2_int_type_master)
continue;
list_for_each(head_slave, &int_list) {
struct v4l2_int_device *s =
list_entry(head_slave,
struct v4l2_int_device, head);
if (s->type != v4l2_int_type_slave)
continue;
/* Slave is connected? */
if (s->u.slave->master)
continue;
/* Slave wants to attach to master? */
if (s->u.slave->attach_to[0] != 0
&& strncmp(m->name, s->u.slave->attach_to,
V4L2NAMESIZE))
continue;
if (!try_module_get(m->module))
continue;
if (m->u.master->attach(m, s)) {
module_put(m->module);
continue;
}
s->u.slave->master = m;
}
}
}
static int ioctl_sort_cmp(const void *a, const void *b)
{
const struct v4l2_int_ioctl_desc *d1 = a, *d2 = b;
if (d1->num > d2->num)
return 1;
if (d1->num < d2->num)
return -1;
return 0;
}
int v4l2_int_device_register(struct v4l2_int_device *d)
{
if (d->type == v4l2_int_type_slave)
sort(d->u.slave->ioctls, d->u.slave->num_ioctls,
sizeof(struct v4l2_int_ioctl_desc),
&ioctl_sort_cmp, NULL);
mutex_lock(&mutex);
list_add(&d->head, &int_list);
v4l2_int_device_try_attach_all();
mutex_unlock(&mutex);
return 0;
}
EXPORT_SYMBOL_GPL(v4l2_int_device_register);
void v4l2_int_device_unregister(struct v4l2_int_device *d)
{
mutex_lock(&mutex);
list_del(&d->head);
if (d->type == v4l2_int_type_slave
&& d->u.slave->master != NULL) {
d->u.slave->master->u.master->detach(d);
module_put(d->u.slave->master->module);
d->u.slave->master = NULL;
}
mutex_unlock(&mutex);
}
EXPORT_SYMBOL_GPL(v4l2_int_device_unregister);
/* Adapted from search_extable in extable.c. */
static v4l2_int_ioctl_func *find_ioctl(struct v4l2_int_slave *slave, int cmd,
v4l2_int_ioctl_func *no_such_ioctl)
{
const struct v4l2_int_ioctl_desc *first = slave->ioctls;
const struct v4l2_int_ioctl_desc *last =
first + slave->num_ioctls - 1;
while (first <= last) {
const struct v4l2_int_ioctl_desc *mid;
mid = (last - first) / 2 + first;
if (mid->num < cmd)
first = mid + 1;
else if (mid->num > cmd)
last = mid - 1;
else
return mid->func;
}
return no_such_ioctl;
}
static int no_such_ioctl_0(struct v4l2_int_device *d)
{
return -EINVAL;
}
int v4l2_int_ioctl_0(struct v4l2_int_device *d, int cmd)
{
return ((v4l2_int_ioctl_func_0 *)
find_ioctl(d->u.slave, cmd,
(v4l2_int_ioctl_func *)no_such_ioctl_0))(d);
}
static int no_such_ioctl_1(struct v4l2_int_device *d, void *arg)
{
return -EINVAL;
}
int v4l2_int_ioctl_1(struct v4l2_int_device *d, int cmd, void *arg)
{
return ((v4l2_int_ioctl_func_1 *)
find_ioctl(d->u.slave, cmd,
(v4l2_int_ioctl_func *)no_such_ioctl_1))(d, arg);
}
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