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 2007-07-18 17:59:15 -03:00 committed by Mauro Carvalho Chehab
parent bbf25010f1
commit 9b5d0f1e6d
3 changed files with 366 additions and 1 deletions

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@ -11,7 +11,8 @@ tuner-$(CONFIG_TUNER_TEA5761) += tea5761.o
msp3400-objs := msp3400-driver.o msp3400-kthreads.o
obj-$(CONFIG_VIDEO_DEV) += videodev.o v4l2-common.o compat_ioctl32.o
obj-$(CONFIG_VIDEO_DEV) += videodev.o v4l2-common.o compat_ioctl32.o \
v4l2-int-device.o
ifeq ($(CONFIG_VIDEO_V4L1_COMPAT),y)
obj-$(CONFIG_VIDEO_DEV) += v4l1-compat.o

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@ -0,0 +1,154 @@
/*
* 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;
}
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);
}
static int no_such_ioctl(struct v4l2_int_device *d)
{
return -EINVAL;
}
/* Adapted from search_extable in extable.c. */
static v4l2_int_ioctl_func *find_ioctl(struct v4l2_int_slave *slave, int cmd)
{
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;
}
int v4l2_int_ioctl_0(struct v4l2_int_device *d, int cmd)
{
return ((v4l2_int_ioctl_func_0 *)find_ioctl(d->u.slave, cmd))(d);
}
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))(d, arg);
}

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@ -0,0 +1,210 @@
/*
* include/media/v4l2-int-device.h
*
* 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
*/
#ifndef V4L2_INT_DEVICE_H
#define V4L2_INT_DEVICE_H
#include <linux/module.h>
#include <media/v4l2-common.h>
#define V4L2NAMESIZE 32
enum v4l2_int_type {
v4l2_int_type_master = 1,
v4l2_int_type_slave
};
enum v4l2_int_ioctl_num {
/*
*
* "Proper" V4L ioctls, as in struct video_device.
*
*/
vidioc_int_enum_fmt_cap_num = 1,
vidioc_int_g_fmt_cap_num,
vidioc_int_s_fmt_cap_num,
vidioc_int_try_fmt_cap_num,
vidioc_int_queryctrl_num,
vidioc_int_g_ctrl_num,
vidioc_int_s_ctrl_num,
vidioc_int_g_parm_num,
vidioc_int_s_parm_num,
/*
*
* Strictly internal ioctls.
*
*/
/* Initialise the device when slave attaches to the master. */
vidioc_int_dev_init_num = 1000,
/* Delinitialise the device at slave detach. */
vidioc_int_dev_exit_num,
/* Set device power state: 0 is off, non-zero is on. */
vidioc_int_s_power_num,
/* Get parallel interface clock speed for current settings. */
vidioc_int_g_ext_clk_num,
/*
* Tell what the parallel interface clock speed actually is.
*/
vidioc_int_s_ext_clk_num,
/* Does the slave need to be reset after VIDIOC_DQBUF? */
vidioc_int_g_needs_reset_num,
/*
*
* VIDIOC_INT_* ioctls.
*
*/
/* VIDIOC_INT_RESET */
vidioc_int_reset_num,
/* VIDIOC_INT_INIT */
vidioc_int_init_num,
/* VIDIOC_INT_G_CHIP_IDENT */
vidioc_int_g_chip_ident_num,
/*
*
* Start of private ioctls.
*
*/
vidioc_int_priv_start_num = 2000,
};
struct v4l2_int_device;
struct v4l2_int_master {
int (*attach)(struct v4l2_int_device *master,
struct v4l2_int_device *slave);
void (*detach)(struct v4l2_int_device *master);
};
typedef int (v4l2_int_ioctl_func)(struct v4l2_int_device *);
typedef int (v4l2_int_ioctl_func_0)(struct v4l2_int_device *);
typedef int (v4l2_int_ioctl_func_1)(struct v4l2_int_device *, void *);
struct v4l2_int_ioctl_desc {
int num;
v4l2_int_ioctl_func *func;
};
struct v4l2_int_slave {
/* Don't touch master. */
struct v4l2_int_device *master;
char attach_to[V4L2NAMESIZE];
int num_ioctls;
struct v4l2_int_ioctl_desc *ioctls;
};
struct v4l2_int_device {
/* Don't touch head. */
struct list_head head;
struct module *module;
char name[V4L2NAMESIZE];
enum v4l2_int_type type;
union {
struct v4l2_int_master *master;
struct v4l2_int_slave *slave;
} u;
void *priv;
};
int v4l2_int_device_register(struct v4l2_int_device *d);
void v4l2_int_device_unregister(struct v4l2_int_device *d);
int v4l2_int_ioctl_0(struct v4l2_int_device *d, int cmd);
int v4l2_int_ioctl_1(struct v4l2_int_device *d, int cmd, void *arg);
/*
*
* IOCTL wrapper functions for better type checking.
*
*/
#define V4L2_INT_WRAPPER_0(name) \
static inline int vidioc_int_##name(struct v4l2_int_device *d) \
{ \
return v4l2_int_ioctl_0(d, vidioc_int_##name##_num); \
} \
\
static inline struct v4l2_int_ioctl_desc \
vidioc_int_##name##_cb(int (*func) \
(struct v4l2_int_device *)) \
{ \
struct v4l2_int_ioctl_desc desc; \
\
desc.num = vidioc_int_##name##_num; \
desc.func = (v4l2_int_ioctl_func *)func; \
\
return desc; \
}
#define V4L2_INT_WRAPPER_1(name, arg_type, asterisk) \
static inline int vidioc_int_##name(struct v4l2_int_device *d, \
arg_type asterisk arg) \
{ \
return v4l2_int_ioctl_1(d, vidioc_int_##name##_num, \
(void *)arg); \
} \
\
static inline struct v4l2_int_ioctl_desc \
vidioc_int_##name##_cb(int (*func) \
(struct v4l2_int_device *, \
arg_type asterisk)) \
{ \
struct v4l2_int_ioctl_desc desc; \
\
desc.num = vidioc_int_##name##_num; \
desc.func = (v4l2_int_ioctl_func *)func; \
\
return desc; \
}
V4L2_INT_WRAPPER_1(enum_fmt_cap, struct v4l2_fmtdesc, *);
V4L2_INT_WRAPPER_1(g_fmt_cap, struct v4l2_format, *);
V4L2_INT_WRAPPER_1(s_fmt_cap, struct v4l2_format, *);
V4L2_INT_WRAPPER_1(try_fmt_cap, struct v4l2_format, *);
V4L2_INT_WRAPPER_1(queryctrl, struct v4l2_queryctrl, *);
V4L2_INT_WRAPPER_1(g_ctrl, struct v4l2_control, *);
V4L2_INT_WRAPPER_1(s_ctrl, struct v4l2_control, *);
V4L2_INT_WRAPPER_1(g_parm, struct v4l2_streamparm, *);
V4L2_INT_WRAPPER_1(s_parm, struct v4l2_streamparm, *);
V4L2_INT_WRAPPER_0(dev_init);
V4L2_INT_WRAPPER_0(dev_exit);
V4L2_INT_WRAPPER_1(s_power, int, );
V4L2_INT_WRAPPER_1(s_ext_clk, u32, );
V4L2_INT_WRAPPER_1(g_ext_clk, u32, *);
V4L2_INT_WRAPPER_1(g_needs_reset, void, *);
V4L2_INT_WRAPPER_0(reset);
V4L2_INT_WRAPPER_0(init);
V4L2_INT_WRAPPER_1(g_chip_ident, int, *);
#endif