V4L/DVB (5862): V4L: Add internal ioctl-like interface.
This patch adds an internal ioctl-like interface which can be used in situations where a single Video4Linux device is implemented by multiple device drivers. One master device controls one or more slave devices. The slaves provide Video4Linux ioctl-like interface for the use of the master. Only a handful of ioctls are implemented at the moment. More can (and should) be added as more functionality is required. Signed-off-by: Sakari Ailus <sakari.ailus@nokia.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
This commit is contained in:
Sakari Ailus
Mauro Carvalho Chehab
parent
bbf25010f1
commit
9b5d0f1e6d
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@ -11,7 +11,8 @@ tuner-$(CONFIG_TUNER_TEA5761) += tea5761.o
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msp3400-objs := msp3400-driver.o msp3400-kthreads.o
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obj-$(CONFIG_VIDEO_DEV) += videodev.o v4l2-common.o compat_ioctl32.o
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obj-$(CONFIG_VIDEO_DEV) += videodev.o v4l2-common.o compat_ioctl32.o \
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v4l2-int-device.o
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ifeq ($(CONFIG_VIDEO_V4L1_COMPAT),y)
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obj-$(CONFIG_VIDEO_DEV) += v4l1-compat.o
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@ -0,0 +1,154 @@
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/*
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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 list_head *head_master;
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list_for_each(head_master, &int_list) {
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struct list_head *head_slave;
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struct v4l2_int_device *m =
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list_entry(head_master, struct v4l2_int_device, head);
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if (m->type != v4l2_int_type_master)
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continue;
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list_for_each(head_slave, &int_list) {
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struct v4l2_int_device *s =
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list_entry(head_slave,
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struct v4l2_int_device, 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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if (m->u.master->attach(m, s)) {
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module_put(m->module);
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continue;
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}
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s->u.slave->master = m;
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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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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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static int no_such_ioctl(struct v4l2_int_device *d)
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{
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return -EINVAL;
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}
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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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{
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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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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 *)find_ioctl(d->u.slave, cmd))(d);
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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 *)find_ioctl(d->u.slave, cmd))(d, arg);
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}
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@ -0,0 +1,210 @@
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/*
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* include/media/v4l2-int-device.h
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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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#ifndef V4L2_INT_DEVICE_H
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#define V4L2_INT_DEVICE_H
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#include <linux/module.h>
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#include <media/v4l2-common.h>
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#define V4L2NAMESIZE 32
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enum v4l2_int_type {
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v4l2_int_type_master = 1,
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v4l2_int_type_slave
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};
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enum v4l2_int_ioctl_num {
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/*
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*
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* "Proper" V4L ioctls, as in struct video_device.
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*
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*/
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vidioc_int_enum_fmt_cap_num = 1,
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vidioc_int_g_fmt_cap_num,
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vidioc_int_s_fmt_cap_num,
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vidioc_int_try_fmt_cap_num,
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vidioc_int_queryctrl_num,
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vidioc_int_g_ctrl_num,
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vidioc_int_s_ctrl_num,
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vidioc_int_g_parm_num,
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vidioc_int_s_parm_num,
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/*
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*
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* Strictly internal ioctls.
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*
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*/
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/* Initialise the device when slave attaches to the master. */
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vidioc_int_dev_init_num = 1000,
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/* Delinitialise the device at slave detach. */
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vidioc_int_dev_exit_num,
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/* Set device power state: 0 is off, non-zero is on. */
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vidioc_int_s_power_num,
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/* Get parallel interface clock speed for current settings. */
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vidioc_int_g_ext_clk_num,
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/*
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* Tell what the parallel interface clock speed actually is.
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*/
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vidioc_int_s_ext_clk_num,
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/* Does the slave need to be reset after VIDIOC_DQBUF? */
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vidioc_int_g_needs_reset_num,
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/*
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*
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* VIDIOC_INT_* ioctls.
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*
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*/
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/* VIDIOC_INT_RESET */
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vidioc_int_reset_num,
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/* VIDIOC_INT_INIT */
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vidioc_int_init_num,
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/* VIDIOC_INT_G_CHIP_IDENT */
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vidioc_int_g_chip_ident_num,
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/*
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*
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* Start of private ioctls.
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*
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*/
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vidioc_int_priv_start_num = 2000,
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};
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struct v4l2_int_device;
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struct v4l2_int_master {
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int (*attach)(struct v4l2_int_device *master,
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struct v4l2_int_device *slave);
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void (*detach)(struct v4l2_int_device *master);
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};
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typedef int (v4l2_int_ioctl_func)(struct v4l2_int_device *);
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typedef int (v4l2_int_ioctl_func_0)(struct v4l2_int_device *);
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typedef int (v4l2_int_ioctl_func_1)(struct v4l2_int_device *, void *);
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struct v4l2_int_ioctl_desc {
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int num;
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v4l2_int_ioctl_func *func;
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};
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struct v4l2_int_slave {
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/* Don't touch master. */
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struct v4l2_int_device *master;
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char attach_to[V4L2NAMESIZE];
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int num_ioctls;
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struct v4l2_int_ioctl_desc *ioctls;
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};
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struct v4l2_int_device {
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/* Don't touch head. */
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struct list_head head;
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struct module *module;
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char name[V4L2NAMESIZE];
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enum v4l2_int_type type;
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union {
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struct v4l2_int_master *master;
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struct v4l2_int_slave *slave;
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} u;
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void *priv;
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};
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int v4l2_int_device_register(struct v4l2_int_device *d);
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void v4l2_int_device_unregister(struct v4l2_int_device *d);
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int v4l2_int_ioctl_0(struct v4l2_int_device *d, int cmd);
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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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*
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* IOCTL wrapper functions for better type checking.
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*
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*/
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#define V4L2_INT_WRAPPER_0(name) \
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static inline int vidioc_int_##name(struct v4l2_int_device *d) \
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{ \
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return v4l2_int_ioctl_0(d, vidioc_int_##name##_num); \
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} \
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\
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static inline struct v4l2_int_ioctl_desc \
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vidioc_int_##name##_cb(int (*func) \
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(struct v4l2_int_device *)) \
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{ \
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struct v4l2_int_ioctl_desc desc; \
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\
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desc.num = vidioc_int_##name##_num; \
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desc.func = (v4l2_int_ioctl_func *)func; \
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\
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return desc; \
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}
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#define V4L2_INT_WRAPPER_1(name, arg_type, asterisk) \
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static inline int vidioc_int_##name(struct v4l2_int_device *d, \
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arg_type asterisk arg) \
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{ \
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return v4l2_int_ioctl_1(d, vidioc_int_##name##_num, \
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(void *)arg); \
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} \
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\
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static inline struct v4l2_int_ioctl_desc \
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vidioc_int_##name##_cb(int (*func) \
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(struct v4l2_int_device *, \
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arg_type asterisk)) \
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{ \
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struct v4l2_int_ioctl_desc desc; \
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\
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desc.num = vidioc_int_##name##_num; \
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desc.func = (v4l2_int_ioctl_func *)func; \
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\
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return desc; \
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}
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V4L2_INT_WRAPPER_1(enum_fmt_cap, struct v4l2_fmtdesc, *);
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V4L2_INT_WRAPPER_1(g_fmt_cap, struct v4l2_format, *);
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V4L2_INT_WRAPPER_1(s_fmt_cap, struct v4l2_format, *);
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V4L2_INT_WRAPPER_1(try_fmt_cap, struct v4l2_format, *);
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V4L2_INT_WRAPPER_1(queryctrl, struct v4l2_queryctrl, *);
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V4L2_INT_WRAPPER_1(g_ctrl, struct v4l2_control, *);
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V4L2_INT_WRAPPER_1(s_ctrl, struct v4l2_control, *);
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V4L2_INT_WRAPPER_1(g_parm, struct v4l2_streamparm, *);
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V4L2_INT_WRAPPER_1(s_parm, struct v4l2_streamparm, *);
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V4L2_INT_WRAPPER_0(dev_init);
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V4L2_INT_WRAPPER_0(dev_exit);
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V4L2_INT_WRAPPER_1(s_power, int, );
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V4L2_INT_WRAPPER_1(s_ext_clk, u32, );
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V4L2_INT_WRAPPER_1(g_ext_clk, u32, *);
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V4L2_INT_WRAPPER_1(g_needs_reset, void, *);
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V4L2_INT_WRAPPER_0(reset);
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V4L2_INT_WRAPPER_0(init);
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V4L2_INT_WRAPPER_1(g_chip_ident, int, *);
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#endif
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