[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / media / video / v4l2-int-device.c

/*
 * 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);

void v4l2_int_device_try_attach_all(void)
{
	struct v4l2_int_device *m, *s;

	list_for_each_entry(m, &int_list, head) {
		if (m->type != v4l2_int_type_master)
			continue;

		list_for_each_entry(s, &int_list, 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;

			s->u.slave->master = m;
			if (m->u.master->attach(s)) {
				s->u.slave->master = NULL;
				module_put(m->module);
				continue;
			}
		}
	}
}
EXPORT_SYMBOL_GPL(v4l2_int_device_try_attach_all);

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 -ENOIOCTLCMD;
}

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);
}
EXPORT_SYMBOL_GPL(v4l2_int_ioctl_0);

static int no_such_ioctl_1(struct v4l2_int_device *d, void *arg)
{
	return -ENOIOCTLCMD;
}

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);
}
EXPORT_SYMBOL_GPL(v4l2_int_ioctl_1);

MODULE_LICENSE("GPL");
Commit	Line	Data
9b5d0f1e SA	1	/*
	2	* drivers/media/video/v4l2-int-device.c
	3	*
	4	* V4L2 internal ioctl interface.
	5	*
	6	* Copyright (C) 2007 Nokia Corporation.
	7	*
	8	* Contact: Sakari Ailus <sakari.ailus@nokia.com>
	9	*
	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.
	13	*
	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.
	18	*
	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
	22	* 02110-1301 USA
	23	*/
	24
	25	#include <linux/kernel.h>
	26	#include <linux/list.h>
	27	#include <linux/sort.h>
	28	#include <linux/string.h>
	29
	30	#include <media/v4l2-int-device.h>
	31
	32	static DEFINE_MUTEX(mutex);
	33	static LIST_HEAD(int_list);
	34
36499e52	35	void v4l2_int_device_try_attach_all(void)
9b5d0f1e	36	{
a991f44b	37	struct v4l2_int_device m, s;
9b5d0f1e	38
a991f44b	39	list_for_each_entry(m, &int_list, head) {
9b5d0f1e SA	40	if (m->type != v4l2_int_type_master)
	41	continue;
	42
a991f44b	43	list_for_each_entry(s, &int_list, head) {
9b5d0f1e SA	44	if (s->type != v4l2_int_type_slave)
	45	continue;
	46
	47	/* Slave is connected? */
	48	if (s->u.slave->master)
	49	continue;
	50
	51	/* Slave wants to attach to master? */
	52	if (s->u.slave->attach_to[0] != 0
	53	&& strncmp(m->name, s->u.slave->attach_to,
	54	V4L2NAMESIZE))
	55	continue;
	56
	57	if (!try_module_get(m->module))
	58	continue;
	59
2c94a674 SA	60	s->u.slave->master = m;
	61	if (m->u.master->attach(s)) {
	62	s->u.slave->master = NULL;
9b5d0f1e SA	63	module_put(m->module);
	64	continue;
	65	}
9b5d0f1e SA	66	}
	67	}
	68	}
36499e52	69	EXPORT_SYMBOL_GPL(v4l2_int_device_try_attach_all);
9b5d0f1e SA	70
	71	static int ioctl_sort_cmp(const void a, const void b)
	72	{
	73	const struct v4l2_int_ioctl_desc d1 = a, d2 = b;
	74
	75	if (d1->num > d2->num)
	76	return 1;
	77
	78	if (d1->num < d2->num)
	79	return -1;
	80
	81	return 0;
	82	}
	83
	84	int v4l2_int_device_register(struct v4l2_int_device *d)
	85	{
	86	if (d->type == v4l2_int_type_slave)
	87	sort(d->u.slave->ioctls, d->u.slave->num_ioctls,
	88	sizeof(struct v4l2_int_ioctl_desc),
	89	&ioctl_sort_cmp, NULL);
	90	mutex_lock(&mutex);
	91	list_add(&d->head, &int_list);
	92	v4l2_int_device_try_attach_all();
	93	mutex_unlock(&mutex);
	94
	95	return 0;
	96	}
261efd12	97	EXPORT_SYMBOL_GPL(v4l2_int_device_register);
9b5d0f1e SA	98
	99	void v4l2_int_device_unregister(struct v4l2_int_device *d)
	100	{
	101	mutex_lock(&mutex);
	102	list_del(&d->head);
	103	if (d->type == v4l2_int_type_slave
	104	&& d->u.slave->master != NULL) {
	105	d->u.slave->master->u.master->detach(d);
	106	module_put(d->u.slave->master->module);
	107	d->u.slave->master = NULL;
	108	}
	109	mutex_unlock(&mutex);
	110	}
261efd12	111	EXPORT_SYMBOL_GPL(v4l2_int_device_unregister);
9b5d0f1e	112
9b5d0f1e	113	/* Adapted from search_extable in extable.c. */
63116feb SA	114	static v4l2_int_ioctl_func find_ioctl(struct v4l2_int_slave slave, int cmd,
63116feb SA	115	v4l2_int_ioctl_func *no_such_ioctl)
9b5d0f1e SA	116	{
	117	const struct v4l2_int_ioctl_desc *first = slave->ioctls;
	118	const struct v4l2_int_ioctl_desc *last =
	119	first + slave->num_ioctls - 1;
	120
	121	while (first <= last) {
	122	const struct v4l2_int_ioctl_desc *mid;
	123
	124	mid = (last - first) / 2 + first;
	125
	126	if (mid->num < cmd)
	127	first = mid + 1;
	128	else if (mid->num > cmd)
	129	last = mid - 1;
	130	else
	131	return mid->func;
	132	}
	133
63116feb SA	134	return no_such_ioctl;
	135	}
	136
	137	static int no_such_ioctl_0(struct v4l2_int_device *d)
	138	{
61c310dc	139	return -ENOIOCTLCMD;
9b5d0f1e SA	140	}
	141
	142	int v4l2_int_ioctl_0(struct v4l2_int_device *d, int cmd)
	143	{
63116feb SA	144	return ((v4l2_int_ioctl_func_0 *)
63116feb SA	145	find_ioctl(d->u.slave, cmd,
098c645e	146	(v4l2_int_ioctl_func *)no_such_ioctl_0))(d);
63116feb	147	}
36499e52	148	EXPORT_SYMBOL_GPL(v4l2_int_ioctl_0);
63116feb SA	149
	150	static int no_such_ioctl_1(struct v4l2_int_device d, void arg)
	151	{
61c310dc	152	return -ENOIOCTLCMD;
9b5d0f1e SA	153	}
	154
	155	int v4l2_int_ioctl_1(struct v4l2_int_device d, int cmd, void arg)
	156	{
63116feb SA	157	return ((v4l2_int_ioctl_func_1 *)
63116feb SA	158	find_ioctl(d->u.slave, cmd,
098c645e	159	(v4l2_int_ioctl_func *)no_such_ioctl_1))(d, arg);
9b5d0f1e	160	}
36499e52	161	EXPORT_SYMBOL_GPL(v4l2_int_ioctl_1);
19ac111c AB	162
19ac111c AB	163	MODULE_LICENSE("GPL");