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