[linux-2.6-block.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 v4l2_subdev *sd, struct v4l2_async_subdev *asd)
{
#if IS_ENABLED(CONFIG_I2C)
	struct i2c_client *client = i2c_verify_client(sd->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 v4l2_subdev *sd,
			  struct v4l2_async_subdev *asd)
{
	return !strcmp(asd->match.device_name.name, dev_name(sd->dev));
}

static bool match_of(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
{
	return !of_node_cmp(of_node_full_name(sd->of_node),
			    of_node_full_name(asd->match.of.node));
}

static bool match_custom(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
{
	if (!asd->match.custom.match)
		/* Match always */
		return true;

	return asd->match.custom.match(sd->dev, asd);
}

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)
{
	bool (*match)(struct v4l2_subdev *, struct v4l2_async_subdev *);
	struct v4l2_async_subdev *asd;

	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 = match_custom;
			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, 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;

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

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

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

	/* Move from the global subdevice list to notifier's done */
	list_move(&sd->async_list, &notifier->done);

	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);

	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;
		}
	}

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

	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_array(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;

	/*
	 * No reference taken. The reference is held by the device
	 * (struct v4l2_subdev.dev), and async sub-device does not
	 * exist independently of the device at any point of time.
	 */
	if (!sd->of_node && sd->dev)
		sd->of_node = sd->dev->of_node;

	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
86217651	25	static bool match_i2c(struct v4l2_subdev sd, struct v4l2_async_subdev asd)
e9e31049	26	{
fe05e141	27	#if IS_ENABLED(CONFIG_I2C)
86217651	28	struct i2c_client *client = i2c_verify_client(sd->dev);
e9e31049	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
86217651 SA	37	static bool match_devname(struct v4l2_subdev *sd,
86217651 SA	38	struct v4l2_async_subdev *asd)
e9e31049	39	{
86217651	40	return !strcmp(asd->match.device_name.name, dev_name(sd->dev));
e9e31049 GL	41	}
e9e31049 GL	42
86217651	43	static bool match_of(struct v4l2_subdev sd, struct v4l2_async_subdev asd)
e7359f8e	44	{
d2180e0c JM	45	return !of_node_cmp(of_node_full_name(sd->of_node),
d2180e0c JM	46	of_node_full_name(asd->match.of.node));
86217651 SA	47	}
	48
	49	static bool match_custom(struct v4l2_subdev sd, struct v4l2_async_subdev asd)
	50	{
	51	if (!asd->match.custom.match)
	52	/* Match always */
	53	return true;
	54
	55	return asd->match.custom.match(sd->dev, asd);
e7359f8e SN	56	}
e7359f8e SN	57
e9e31049 GL	58	static LIST_HEAD(subdev_list);
	59	static LIST_HEAD(notifier_list);
	60	static DEFINE_MUTEX(list_lock);
	61
	62	static struct v4l2_async_subdev v4l2_async_belongs(struct v4l2_async_notifier notifier,
b426b3a6	63	struct v4l2_subdev *sd)
e9e31049	64	{
86217651	65	bool (match)(struct v4l2_subdev , struct v4l2_async_subdev *);
e9e31049	66	struct v4l2_async_subdev *asd;
e9e31049 GL	67
	68	list_for_each_entry(asd, &notifier->waiting, list) {
	69	/* bus_type has been verified valid before */
cfca7644 SN	70	switch (asd->match_type) {
cfca7644 SN	71	case V4L2_ASYNC_MATCH_CUSTOM:
86217651	72	match = match_custom;
e9e31049	73	break;
cfca7644 SN	74	case V4L2_ASYNC_MATCH_DEVNAME:
cfca7644 SN	75	match = match_devname;
e9e31049	76	break;
cfca7644	77	case V4L2_ASYNC_MATCH_I2C:
e9e31049 GL	78	match = match_i2c;
e9e31049 GL	79	break;
e7359f8e SN	80	case V4L2_ASYNC_MATCH_OF:
	81	match = match_of;
	82	break;
e9e31049 GL	83	default:
	84	/* Cannot happen, unless someone breaks us */
	85	WARN_ON(true);
	86	return NULL;
	87	}
	88
	89	/* match cannot be NULL here */
86217651	90	if (match(sd, asd))
e9e31049 GL	91	return asd;
	92	}
	93
	94	return NULL;
	95	}
	96
	97	static int v4l2_async_test_notify(struct v4l2_async_notifier *notifier,
b426b3a6	98	struct v4l2_subdev *sd,
e9e31049 GL	99	struct v4l2_async_subdev *asd)
e9e31049 GL	100	{
e9e31049 GL	101	int ret;
e9e31049 GL	102
e9e31049 GL	103	if (notifier->bound) {
	104	ret = notifier->bound(notifier, sd, asd);
	105	if (ret < 0)
	106	return ret;
	107	}
e9e31049 GL	108
	109	ret = v4l2_device_register_subdev(notifier->v4l2_dev, sd);
	110	if (ret < 0) {
	111	if (notifier->unbind)
	112	notifier->unbind(notifier, sd, asd);
	113	return ret;
	114	}
	115
47b037a0 TT	116	/* Remove from the waiting list */
	117	list_del(&asd->list);
	118	sd->asd = asd;
	119	sd->notifier = notifier;
	120
	121	/* Move from the global subdevice list to notifier's done */
	122	list_move(&sd->async_list, &notifier->done);
	123
e9e31049 GL	124	if (list_empty(&notifier->waiting) && notifier->complete)
	125	return notifier->complete(notifier);
	126
	127	return 0;
	128	}
	129
b426b3a6	130	static void v4l2_async_cleanup(struct v4l2_subdev *sd)
e9e31049	131	{
e9e31049	132	v4l2_device_unregister_subdev(sd);
b426b3a6 SN	133	/* Subdevice driver will reprobe and put the subdev back onto the list */
	134	list_del_init(&sd->async_list);
	135	sd->asd = NULL;
e9e31049 GL	136	sd->dev = NULL;
	137	}
	138
	139	int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
	140	struct v4l2_async_notifier *notifier)
	141	{
b426b3a6	142	struct v4l2_subdev sd, tmp;
e9e31049 GL	143	struct v4l2_async_subdev *asd;
	144	int i;
	145
	146	if (!notifier->num_subdevs \|\| notifier->num_subdevs > V4L2_MAX_SUBDEVS)
	147	return -EINVAL;
	148
	149	notifier->v4l2_dev = v4l2_dev;
	150	INIT_LIST_HEAD(&notifier->waiting);
	151	INIT_LIST_HEAD(&notifier->done);
	152
	153	for (i = 0; i < notifier->num_subdevs; i++) {
e8419d08	154	asd = notifier->subdevs[i];
e9e31049	155
cfca7644 SN	156	switch (asd->match_type) {
	157	case V4L2_ASYNC_MATCH_CUSTOM:
	158	case V4L2_ASYNC_MATCH_DEVNAME:
	159	case V4L2_ASYNC_MATCH_I2C:
e7359f8e	160	case V4L2_ASYNC_MATCH_OF:
e9e31049 GL	161	break;
	162	default:
	163	dev_err(notifier->v4l2_dev ? notifier->v4l2_dev->dev : NULL,
cfca7644 SN	164	"Invalid match type %u on %p\n",
cfca7644 SN	165	asd->match_type, asd);
e9e31049 GL	166	return -EINVAL;
	167	}
	168	list_add_tail(&asd->list, &notifier->waiting);
	169	}
	170
	171	mutex_lock(&list_lock);
	172
b426b3a6	173	list_for_each_entry_safe(sd, tmp, &subdev_list, async_list) {
e9e31049 GL	174	int ret;
e9e31049 GL	175
b426b3a6	176	asd = v4l2_async_belongs(notifier, sd);
e9e31049 GL	177	if (!asd)
	178	continue;
	179
b426b3a6	180	ret = v4l2_async_test_notify(notifier, sd, asd);
e9e31049 GL	181	if (ret < 0) {
	182	mutex_unlock(&list_lock);
	183	return ret;
	184	}
	185	}
	186
47b037a0 TT	187	/* Keep also completed notifiers on the list */
	188	list_add(&notifier->list, &notifier_list);
	189
e9e31049 GL	190	mutex_unlock(&list_lock);
	191
	192	return 0;
	193	}
	194	EXPORT_SYMBOL(v4l2_async_notifier_register);
	195
	196	void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
	197	{
b426b3a6	198	struct v4l2_subdev sd, tmp;
e9e31049 GL	199	unsigned int notif_n_subdev = notifier->num_subdevs;
e9e31049 GL	200	unsigned int n_subdev = min(notif_n_subdev, V4L2_MAX_SUBDEVS);
24e9a47e	201	struct device **dev;
e9e31049 GL	202	int i = 0;
e9e31049 GL	203
8e3fbfee LP	204	if (!notifier->v4l2_dev)
	205	return;
	206
f9e9c066	207	dev = kmalloc_array(n_subdev, sizeof(*dev), GFP_KERNEL);
24e9a47e MCC	208	if (!dev) {
	209	dev_err(notifier->v4l2_dev->dev,
	210	"Failed to allocate device cache!\n");
	211	}
	212
e9e31049 GL	213	mutex_lock(&list_lock);
	214
	215	list_del(&notifier->list);
	216
ceedcc4e	217	list_for_each_entry_safe(sd, tmp, &notifier->done, async_list) {
24e9a47e MCC	218	struct device *d;
	219
	220	d = get_device(sd->dev);
e9e31049	221
b426b3a6	222	v4l2_async_cleanup(sd);
e9e31049 GL	223
e9e31049 GL	224	/* If we handled USB devices, we'd have to lock the parent too */
24e9a47e	225	device_release_driver(d);
e9e31049 GL	226
e9e31049 GL	227	if (notifier->unbind)
b426b3a6	228	notifier->unbind(notifier, sd, sd->asd);
24e9a47e MCC	229
	230	/*
	231	* Store device at the device cache, in order to call
	232	* put_device() on the final step
	233	*/
	234	if (dev)
	235	dev[i++] = d;
	236	else
	237	put_device(d);
e9e31049 GL	238	}
	239
	240	mutex_unlock(&list_lock);
	241
24e9a47e MCC	242	/*
	243	* Call device_attach() to reprobe devices
	244	*
	245	* NOTE: If dev allocation fails, i is 0, and the whole loop won't be
	246	* executed.
	247	*/
e9e31049 GL	248	while (i--) {
	249	struct device *d = dev[i];
	250
	251	if (d && device_attach(d) < 0) {
	252	const char *name = "(none)";
	253	int lock = device_trylock(d);
	254
	255	if (lock && d->driver)
	256	name = d->driver->name;
	257	dev_err(d, "Failed to re-probe to %s\n", name);
	258	if (lock)
	259	device_unlock(d);
	260	}
	261	put_device(d);
	262	}
24e9a47e	263	kfree(dev);
8e3fbfee LP	264
	265	notifier->v4l2_dev = NULL;
	266
e9e31049 GL	267	/*
	268	* Don't care about the waiting list, it is initialised and populated
	269	* upon notifier registration.
	270	*/
	271	}
	272	EXPORT_SYMBOL(v4l2_async_notifier_unregister);
	273
	274	int v4l2_async_register_subdev(struct v4l2_subdev *sd)
	275	{
e9e31049 GL	276	struct v4l2_async_notifier *notifier;
e9e31049 GL	277
86217651 SA	278	/*
	279	* No reference taken. The reference is held by the device
	280	* (struct v4l2_subdev.dev), and async sub-device does not
	281	* exist independently of the device at any point of time.
	282	*/
	283	if (!sd->of_node && sd->dev)
	284	sd->of_node = sd->dev->of_node;
	285
e9e31049 GL	286	mutex_lock(&list_lock);
e9e31049 GL	287
b426b3a6	288	INIT_LIST_HEAD(&sd->async_list);
e9e31049 GL	289
e9e31049 GL	290	list_for_each_entry(notifier, &notifier_list, list) {
b426b3a6	291	struct v4l2_async_subdev *asd = v4l2_async_belongs(notifier, sd);
e9e31049	292	if (asd) {
b426b3a6	293	int ret = v4l2_async_test_notify(notifier, sd, asd);
e9e31049 GL	294	mutex_unlock(&list_lock);
	295	return ret;
	296	}
	297	}
	298
	299	/* None matched, wait for hot-plugging */
b426b3a6	300	list_add(&sd->async_list, &subdev_list);
e9e31049 GL	301
	302	mutex_unlock(&list_lock);
	303
	304	return 0;
	305	}
	306	EXPORT_SYMBOL(v4l2_async_register_subdev);
	307
	308	void v4l2_async_unregister_subdev(struct v4l2_subdev *sd)
	309	{
b426b3a6	310	struct v4l2_async_notifier *notifier = sd->notifier;
e9e31049	311
b426b3a6 SN	312	if (!sd->asd) {
	313	if (!list_empty(&sd->async_list))
	314	v4l2_async_cleanup(sd);
e9e31049 GL	315	return;
	316	}
	317
	318	mutex_lock(&list_lock);
	319
b426b3a6	320	list_add(&sd->asd->list, &notifier->waiting);
e9e31049	321
b426b3a6	322	v4l2_async_cleanup(sd);
e9e31049 GL	323
e9e31049 GL	324	if (notifier->unbind)
b426b3a6	325	notifier->unbind(notifier, sd, sd->asd);
e9e31049 GL	326
	327	mutex_unlock(&list_lock);
	328	}
	329	EXPORT_SYMBOL(v4l2_async_unregister_subdev);