[deliverable/linux.git] / drivers / media / v4l2-core / v4l2-async.c

/*
 * V4L2 asynchronous subdevice registration API
 *
 * Copyright (C) 2012-2013, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
 *
 * 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.
 */

#include <linux/device.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/types.h>

#include <media/v4l2-async.h>
#include <media/v4l2-device.h>
#include <media/v4l2-subdev.h>

static bool match_i2c(struct device *dev, struct v4l2_async_subdev *asd)
{
#if IS_ENABLED(CONFIG_I2C)
	struct i2c_client *client = i2c_verify_client(dev);
	return client &&
		asd->match.i2c.adapter_id == client->adapter->nr &&
		asd->match.i2c.address == client->addr;
#else
	return false;
#endif
}

static bool match_devname(struct device *dev, struct v4l2_async_subdev *asd)
{
	return !strcmp(asd->match.device_name.name, dev_name(dev));
}

static bool match_of(struct device *dev, struct v4l2_async_subdev *asd)
{
	return dev->of_node == asd->match.of.node;
}

static LIST_HEAD(subdev_list);
static LIST_HEAD(notifier_list);
static DEFINE_MUTEX(list_lock);

static struct v4l2_async_subdev *v4l2_async_belongs(struct v4l2_async_notifier *notifier,
						    struct v4l2_subdev *sd)
{
	struct v4l2_async_subdev *asd;
	bool (*match)(struct device *, struct v4l2_async_subdev *);

	list_for_each_entry(asd, &notifier->waiting, list) {
		/* bus_type has been verified valid before */
		switch (asd->match_type) {
		case V4L2_ASYNC_MATCH_CUSTOM:
			match = asd->match.custom.match;
			if (!match)
				/* Match always */
				return asd;
			break;
		case V4L2_ASYNC_MATCH_DEVNAME:
			match = match_devname;
			break;
		case V4L2_ASYNC_MATCH_I2C:
			match = match_i2c;
			break;
		case V4L2_ASYNC_MATCH_OF:
			match = match_of;
			break;
		default:
			/* Cannot happen, unless someone breaks us */
			WARN_ON(true);
			return NULL;
		}

		/* match cannot be NULL here */
		if (match(sd->dev, asd))
			return asd;
	}

	return NULL;
}

static int v4l2_async_test_notify(struct v4l2_async_notifier *notifier,
				  struct v4l2_subdev *sd,
				  struct v4l2_async_subdev *asd)
{
	int ret;

	/* Remove from the waiting list */
	list_del(&asd->list);
	sd->asd = asd;
	sd->notifier = notifier;

	if (notifier->bound) {
		ret = notifier->bound(notifier, sd, asd);
		if (ret < 0)
			return ret;
	}
	/* Move from the global subdevice list to notifier's done */
	list_move(&sd->async_list, &notifier->done);

	ret = v4l2_device_register_subdev(notifier->v4l2_dev, sd);
	if (ret < 0) {
		if (notifier->unbind)
			notifier->unbind(notifier, sd, asd);
		return ret;
	}

	if (list_empty(&notifier->waiting) && notifier->complete)
		return notifier->complete(notifier);

	return 0;
}

static void v4l2_async_cleanup(struct v4l2_subdev *sd)
{
	v4l2_device_unregister_subdev(sd);
	/* Subdevice driver will reprobe and put the subdev back onto the list */
	list_del_init(&sd->async_list);
	sd->asd = NULL;
	sd->dev = NULL;
}

int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
				 struct v4l2_async_notifier *notifier)
{
	struct v4l2_subdev *sd, *tmp;
	struct v4l2_async_subdev *asd;
	int i;

	if (!notifier->num_subdevs || notifier->num_subdevs > V4L2_MAX_SUBDEVS)
		return -EINVAL;

	notifier->v4l2_dev = v4l2_dev;
	INIT_LIST_HEAD(&notifier->waiting);
	INIT_LIST_HEAD(&notifier->done);

	for (i = 0; i < notifier->num_subdevs; i++) {
		asd = notifier->subdevs[i];

		switch (asd->match_type) {
		case V4L2_ASYNC_MATCH_CUSTOM:
		case V4L2_ASYNC_MATCH_DEVNAME:
		case V4L2_ASYNC_MATCH_I2C:
		case V4L2_ASYNC_MATCH_OF:
			break;
		default:
			dev_err(notifier->v4l2_dev ? notifier->v4l2_dev->dev : NULL,
				"Invalid match type %u on %p\n",
				asd->match_type, asd);
			return -EINVAL;
		}
		list_add_tail(&asd->list, &notifier->waiting);
	}

	mutex_lock(&list_lock);

	/* Keep also completed notifiers on the list */
	list_add(&notifier->list, &notifier_list);

	list_for_each_entry_safe(sd, tmp, &subdev_list, async_list) {
		int ret;

		asd = v4l2_async_belongs(notifier, sd);
		if (!asd)
			continue;

		ret = v4l2_async_test_notify(notifier, sd, asd);
		if (ret < 0) {
			mutex_unlock(&list_lock);
			return ret;
		}
	}

	mutex_unlock(&list_lock);

	return 0;
}
EXPORT_SYMBOL(v4l2_async_notifier_register);

void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
{
	struct v4l2_subdev *sd, *tmp;
	unsigned int notif_n_subdev = notifier->num_subdevs;
	unsigned int n_subdev = min(notif_n_subdev, V4L2_MAX_SUBDEVS);
	struct device **dev;
	int i = 0;

	if (!notifier->v4l2_dev)
		return;

	dev = kmalloc(n_subdev * sizeof(*dev), GFP_KERNEL);
	if (!dev) {
		dev_err(notifier->v4l2_dev->dev,
			"Failed to allocate device cache!\n");
	}

	mutex_lock(&list_lock);

	list_del(&notifier->list);

	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
		struct device *d;

		d = get_device(sd->dev);

		v4l2_async_cleanup(sd);

		/* If we handled USB devices, we'd have to lock the parent too */
		device_release_driver(d);

		if (notifier->unbind)
			notifier->unbind(notifier, sd, sd->asd);

		/*
		 * Store device at the device cache, in order to call
		 * put_device() on the final step
		 */
		if (dev)
			dev[i++] = d;
		else
			put_device(d);
	}

	mutex_unlock(&list_lock);

	/*
	 * Call device_attach() to reprobe devices
	 *
	 * NOTE: If dev allocation fails, i is 0, and the whole loop won't be
	 * executed.
	 */
	while (i--) {
		struct device *d = dev[i];

		if (d && device_attach(d) < 0) {
			const char *name = "(none)";
			int lock = device_trylock(d);

			if (lock && d->driver)
				name = d->driver->name;
			dev_err(d, "Failed to re-probe to %s\n", name);
			if (lock)
				device_unlock(d);
		}
		put_device(d);
	}
	kfree(dev);

	notifier->v4l2_dev = NULL;

	/*
	 * Don't care about the waiting list, it is initialised and populated
	 * upon notifier registration.
	 */
}
EXPORT_SYMBOL(v4l2_async_notifier_unregister);

int v4l2_async_register_subdev(struct v4l2_subdev *sd)
{
	struct v4l2_async_notifier *notifier;

	mutex_lock(&list_lock);

	INIT_LIST_HEAD(&sd->async_list);

	list_for_each_entry(notifier, &notifier_list, list) {
		struct v4l2_async_subdev *asd = v4l2_async_belongs(notifier, sd);
		if (asd) {
			int ret = v4l2_async_test_notify(notifier, sd, asd);
			mutex_unlock(&list_lock);
			return ret;
		}
	}

	/* None matched, wait for hot-plugging */
	list_add(&sd->async_list, &subdev_list);

	mutex_unlock(&list_lock);

	return 0;
}
EXPORT_SYMBOL(v4l2_async_register_subdev);

void v4l2_async_unregister_subdev(struct v4l2_subdev *sd)
{
	struct v4l2_async_notifier *notifier = sd->notifier;

	if (!sd->asd) {
		if (!list_empty(&sd->async_list))
			v4l2_async_cleanup(sd);
		return;
	}

	mutex_lock(&list_lock);

	list_add(&sd->asd->list, &notifier->waiting);

	v4l2_async_cleanup(sd);

	if (notifier->unbind)
		notifier->unbind(notifier, sd, sd->asd);

	mutex_unlock(&list_lock);
}
EXPORT_SYMBOL(v4l2_async_unregister_subdev);
Commit	Line	Data
e9e31049 GL	1	/*
	2	* V4L2 asynchronous subdevice registration API
	3	*
	4	* Copyright (C) 2012-2013, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*/
	10
	11	#include <linux/device.h>
	12	#include <linux/err.h>
	13	#include <linux/i2c.h>
	14	#include <linux/list.h>
	15	#include <linux/module.h>
	16	#include <linux/mutex.h>
	17	#include <linux/platform_device.h>
	18	#include <linux/slab.h>
	19	#include <linux/types.h>
	20
	21	#include <media/v4l2-async.h>
	22	#include <media/v4l2-device.h>
	23	#include <media/v4l2-subdev.h>
	24
	25	static bool match_i2c(struct device dev, struct v4l2_async_subdev asd)
	26	{
fe05e141	27	#if IS_ENABLED(CONFIG_I2C)
e9e31049 GL	28	struct i2c_client *client = i2c_verify_client(dev);
e9e31049 GL	29	return client &&
e9e31049 GL	30	asd->match.i2c.adapter_id == client->adapter->nr &&
e9e31049 GL	31	asd->match.i2c.address == client->addr;
fe05e141 GL	32	#else
	33	return false;
	34	#endif
e9e31049 GL	35	}
e9e31049 GL	36
cfca7644	37	static bool match_devname(struct device dev, struct v4l2_async_subdev asd)
e9e31049	38	{
cfca7644	39	return !strcmp(asd->match.device_name.name, dev_name(dev));
e9e31049 GL	40	}
e9e31049 GL	41
e7359f8e SN	42	static bool match_of(struct device dev, struct v4l2_async_subdev asd)
	43	{
	44	return dev->of_node == asd->match.of.node;
	45	}
	46
e9e31049 GL	47	static LIST_HEAD(subdev_list);
	48	static LIST_HEAD(notifier_list);
	49	static DEFINE_MUTEX(list_lock);
	50
	51	static struct v4l2_async_subdev v4l2_async_belongs(struct v4l2_async_notifier notifier,
b426b3a6	52	struct v4l2_subdev *sd)
e9e31049	53	{
e9e31049	54	struct v4l2_async_subdev *asd;
b426b3a6	55	bool (match)(struct device , struct v4l2_async_subdev *);
e9e31049 GL	56
	57	list_for_each_entry(asd, &notifier->waiting, list) {
	58	/* bus_type has been verified valid before */
cfca7644 SN	59	switch (asd->match_type) {
cfca7644 SN	60	case V4L2_ASYNC_MATCH_CUSTOM:
e9e31049 GL	61	match = asd->match.custom.match;
	62	if (!match)
	63	/* Match always */
	64	return asd;
	65	break;
cfca7644 SN	66	case V4L2_ASYNC_MATCH_DEVNAME:
cfca7644 SN	67	match = match_devname;
e9e31049	68	break;
cfca7644	69	case V4L2_ASYNC_MATCH_I2C:
e9e31049 GL	70	match = match_i2c;
e9e31049 GL	71	break;
e7359f8e SN	72	case V4L2_ASYNC_MATCH_OF:
	73	match = match_of;
	74	break;
e9e31049 GL	75	default:
	76	/* Cannot happen, unless someone breaks us */
	77	WARN_ON(true);
	78	return NULL;
	79	}
	80
	81	/* match cannot be NULL here */
	82	if (match(sd->dev, asd))
	83	return asd;
	84	}
	85
	86	return NULL;
	87	}
	88
	89	static int v4l2_async_test_notify(struct v4l2_async_notifier *notifier,
b426b3a6	90	struct v4l2_subdev *sd,
e9e31049 GL	91	struct v4l2_async_subdev *asd)
e9e31049 GL	92	{
e9e31049 GL	93	int ret;
	94
	95	/* Remove from the waiting list */
	96	list_del(&asd->list);
b426b3a6 SN	97	sd->asd = asd;
b426b3a6 SN	98	sd->notifier = notifier;
e9e31049 GL	99
	100	if (notifier->bound) {
	101	ret = notifier->bound(notifier, sd, asd);
	102	if (ret < 0)
	103	return ret;
	104	}
	105	/* Move from the global subdevice list to notifier's done */
b426b3a6	106	list_move(&sd->async_list, &notifier->done);
e9e31049 GL	107
	108	ret = v4l2_device_register_subdev(notifier->v4l2_dev, sd);
	109	if (ret < 0) {
	110	if (notifier->unbind)
	111	notifier->unbind(notifier, sd, asd);
	112	return ret;
	113	}
	114
	115	if (list_empty(&notifier->waiting) && notifier->complete)
	116	return notifier->complete(notifier);
	117
	118	return 0;
	119	}
	120
b426b3a6	121	static void v4l2_async_cleanup(struct v4l2_subdev *sd)
e9e31049	122	{
e9e31049	123	v4l2_device_unregister_subdev(sd);
b426b3a6 SN	124	/* Subdevice driver will reprobe and put the subdev back onto the list */
	125	list_del_init(&sd->async_list);
	126	sd->asd = NULL;
e9e31049 GL	127	sd->dev = NULL;
	128	}
	129
	130	int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
	131	struct v4l2_async_notifier *notifier)
	132	{
b426b3a6	133	struct v4l2_subdev sd, tmp;
e9e31049 GL	134	struct v4l2_async_subdev *asd;
	135	int i;
	136
	137	if (!notifier->num_subdevs \|\| notifier->num_subdevs > V4L2_MAX_SUBDEVS)
	138	return -EINVAL;
	139
	140	notifier->v4l2_dev = v4l2_dev;
	141	INIT_LIST_HEAD(&notifier->waiting);
	142	INIT_LIST_HEAD(&notifier->done);
	143
	144	for (i = 0; i < notifier->num_subdevs; i++) {
e8419d08	145	asd = notifier->subdevs[i];
e9e31049	146
cfca7644 SN	147	switch (asd->match_type) {
	148	case V4L2_ASYNC_MATCH_CUSTOM:
	149	case V4L2_ASYNC_MATCH_DEVNAME:
	150	case V4L2_ASYNC_MATCH_I2C:
e7359f8e	151	case V4L2_ASYNC_MATCH_OF:
e9e31049 GL	152	break;
	153	default:
	154	dev_err(notifier->v4l2_dev ? notifier->v4l2_dev->dev : NULL,
cfca7644 SN	155	"Invalid match type %u on %p\n",
cfca7644 SN	156	asd->match_type, asd);
e9e31049 GL	157	return -EINVAL;
	158	}
	159	list_add_tail(&asd->list, &notifier->waiting);
	160	}
	161
	162	mutex_lock(&list_lock);
	163
	164	/* Keep also completed notifiers on the list */
	165	list_add(&notifier->list, &notifier_list);
	166
b426b3a6	167	list_for_each_entry_safe(sd, tmp, &subdev_list, async_list) {
e9e31049 GL	168	int ret;
e9e31049 GL	169
b426b3a6	170	asd = v4l2_async_belongs(notifier, sd);
e9e31049 GL	171	if (!asd)
	172	continue;
	173
b426b3a6	174	ret = v4l2_async_test_notify(notifier, sd, asd);
e9e31049 GL	175	if (ret < 0) {
	176	mutex_unlock(&list_lock);
	177	return ret;
	178	}
	179	}
	180
	181	mutex_unlock(&list_lock);
	182
	183	return 0;
	184	}
	185	EXPORT_SYMBOL(v4l2_async_notifier_register);
	186
	187	void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
	188	{
b426b3a6	189	struct v4l2_subdev sd, tmp;
e9e31049 GL	190	unsigned int notif_n_subdev = notifier->num_subdevs;
e9e31049 GL	191	unsigned int n_subdev = min(notif_n_subdev, V4L2_MAX_SUBDEVS);
24e9a47e	192	struct device **dev;
e9e31049 GL	193	int i = 0;
e9e31049 GL	194
8e3fbfee LP	195	if (!notifier->v4l2_dev)
	196	return;
	197
24e9a47e MCC	198	dev = kmalloc(n_subdev * sizeof(*dev), GFP_KERNEL);
	199	if (!dev) {
	200	dev_err(notifier->v4l2_dev->dev,
	201	"Failed to allocate device cache!\n");
	202	}
	203
e9e31049 GL	204	mutex_lock(&list_lock);
	205
	206	list_del(&notifier->list);
	207
ceedcc4e	208	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
24e9a47e MCC	209	struct device *d;
	210
	211	d = get_device(sd->dev);
e9e31049	212
b426b3a6	213	v4l2_async_cleanup(sd);
e9e31049 GL	214
e9e31049 GL	215	/* If we handled USB devices, we'd have to lock the parent too */
24e9a47e	216	device_release_driver(d);
e9e31049 GL	217
e9e31049 GL	218	if (notifier->unbind)
b426b3a6	219	notifier->unbind(notifier, sd, sd->asd);
24e9a47e MCC	220
	221	/*
	222	* Store device at the device cache, in order to call
	223	* put_device() on the final step
	224	*/
	225	if (dev)
	226	dev[i++] = d;
	227	else
	228	put_device(d);
e9e31049 GL	229	}
	230
	231	mutex_unlock(&list_lock);
	232
24e9a47e MCC	233	/*
	234	* Call device_attach() to reprobe devices
	235	*
	236	* NOTE: If dev allocation fails, i is 0, and the whole loop won't be
	237	* executed.
	238	*/
e9e31049 GL	239	while (i--) {
	240	struct device *d = dev[i];
	241
	242	if (d && device_attach(d) < 0) {
	243	const char *name = "(none)";
	244	int lock = device_trylock(d);
	245
	246	if (lock && d->driver)
	247	name = d->driver->name;
	248	dev_err(d, "Failed to re-probe to %s\n", name);
	249	if (lock)
	250	device_unlock(d);
	251	}
	252	put_device(d);
	253	}
24e9a47e	254	kfree(dev);
8e3fbfee LP	255
	256	notifier->v4l2_dev = NULL;
	257
e9e31049 GL	258	/*
	259	* Don't care about the waiting list, it is initialised and populated
	260	* upon notifier registration.
	261	*/
	262	}
	263	EXPORT_SYMBOL(v4l2_async_notifier_unregister);
	264
	265	int v4l2_async_register_subdev(struct v4l2_subdev *sd)
	266	{
e9e31049 GL	267	struct v4l2_async_notifier *notifier;
	268
	269	mutex_lock(&list_lock);
	270
b426b3a6	271	INIT_LIST_HEAD(&sd->async_list);
e9e31049 GL	272
e9e31049 GL	273	list_for_each_entry(notifier, &notifier_list, list) {
b426b3a6	274	struct v4l2_async_subdev *asd = v4l2_async_belongs(notifier, sd);
e9e31049	275	if (asd) {
b426b3a6	276	int ret = v4l2_async_test_notify(notifier, sd, asd);
e9e31049 GL	277	mutex_unlock(&list_lock);
	278	return ret;
	279	}
	280	}
	281
	282	/* None matched, wait for hot-plugging */
b426b3a6	283	list_add(&sd->async_list, &subdev_list);
e9e31049 GL	284
	285	mutex_unlock(&list_lock);
	286
	287	return 0;
	288	}
	289	EXPORT_SYMBOL(v4l2_async_register_subdev);
	290
	291	void v4l2_async_unregister_subdev(struct v4l2_subdev *sd)
	292	{
b426b3a6	293	struct v4l2_async_notifier *notifier = sd->notifier;
e9e31049	294
b426b3a6 SN	295	if (!sd->asd) {
	296	if (!list_empty(&sd->async_list))
	297	v4l2_async_cleanup(sd);
e9e31049 GL	298	return;
	299	}
	300
	301	mutex_lock(&list_lock);
	302
b426b3a6	303	list_add(&sd->asd->list, &notifier->waiting);
e9e31049	304
b426b3a6	305	v4l2_async_cleanup(sd);
e9e31049 GL	306
e9e31049 GL	307	if (notifier->unbind)
b426b3a6	308	notifier->unbind(notifier, sd, sd->asd);
e9e31049 GL	309
	310	mutex_unlock(&list_lock);
	311	}
	312	EXPORT_SYMBOL(v4l2_async_unregister_subdev);