[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 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 sd->of_node == 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;

	/* 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;

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