[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 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_async_subdev_list *asdl)
{
	struct v4l2_subdev *sd = v4l2_async_to_subdev(asdl);
	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;
		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_async_subdev_list *asdl,
				  struct v4l2_async_subdev *asd)
{
	struct v4l2_subdev *sd = v4l2_async_to_subdev(asdl);
	int ret;

	/* Remove from the waiting list */
	list_del(&asd->list);
	asdl->asd = asd;
	asdl->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(&asdl->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_async_subdev_list *asdl)
{
	struct v4l2_subdev *sd = v4l2_async_to_subdev(asdl);

	v4l2_device_unregister_subdev(sd);
	/* Subdevice driver will reprobe and put asdl back onto the list */
	list_del_init(&asdl->list);
	asdl->asd = NULL;
	sd->dev = NULL;
}

int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
				 struct v4l2_async_notifier *notifier)
{
	struct v4l2_async_subdev_list *asdl, *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->subdev[i];

		switch (asd->match_type) {
		case V4L2_ASYNC_MATCH_CUSTOM:
		case V4L2_ASYNC_MATCH_DEVNAME:
		case V4L2_ASYNC_MATCH_I2C:
			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(asdl, tmp, &subdev_list, list) {
		int ret;

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

		ret = v4l2_async_test_notify(notifier, asdl, 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_async_subdev_list *asdl, *tmp;
	unsigned int notif_n_subdev = notifier->num_subdevs;
	unsigned int n_subdev = min(notif_n_subdev, V4L2_MAX_SUBDEVS);
	struct device *dev[n_subdev];
	int i = 0;

	mutex_lock(&list_lock);

	list_del(&notifier->list);

	list_for_each_entry_safe(asdl, tmp, &notifier->done, list) {
		struct v4l2_subdev *sd = v4l2_async_to_subdev(asdl);

		dev[i] = get_device(sd->dev);

		v4l2_async_cleanup(asdl);

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

		if (notifier->unbind)
			notifier->unbind(notifier, sd, sd->asdl.asd);
	}

	mutex_unlock(&list_lock);

	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);
	}
	/*
	 * 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_subdev_list *asdl = &sd->asdl;
	struct v4l2_async_notifier *notifier;

	mutex_lock(&list_lock);

	INIT_LIST_HEAD(&asdl->list);

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

	/* None matched, wait for hot-plugging */
	list_add(&asdl->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_subdev_list *asdl = &sd->asdl;
	struct v4l2_async_notifier *notifier = asdl->notifier;

	if (!asdl->asd) {
		if (!list_empty(&asdl->list))
			v4l2_async_cleanup(asdl);
		return;
	}

	mutex_lock(&list_lock);

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

	v4l2_async_cleanup(asdl);

	if (notifier->unbind)
		notifier->unbind(notifier, sd, sd->asdl.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	}
	41
	42	static LIST_HEAD(subdev_list);
	43	static LIST_HEAD(notifier_list);
	44	static DEFINE_MUTEX(list_lock);
	45
	46	static struct v4l2_async_subdev v4l2_async_belongs(struct v4l2_async_notifier notifier,
	47	struct v4l2_async_subdev_list *asdl)
	48	{
	49	struct v4l2_subdev *sd = v4l2_async_to_subdev(asdl);
	50	struct v4l2_async_subdev *asd;
	51	bool (match)(struct device ,
	52	struct v4l2_async_subdev *);
	53
	54	list_for_each_entry(asd, &notifier->waiting, list) {
	55	/* bus_type has been verified valid before */
cfca7644 SN	56	switch (asd->match_type) {
cfca7644 SN	57	case V4L2_ASYNC_MATCH_CUSTOM:
e9e31049 GL	58	match = asd->match.custom.match;
	59	if (!match)
	60	/* Match always */
	61	return asd;
	62	break;
cfca7644 SN	63	case V4L2_ASYNC_MATCH_DEVNAME:
cfca7644 SN	64	match = match_devname;
e9e31049	65	break;
cfca7644	66	case V4L2_ASYNC_MATCH_I2C:
e9e31049 GL	67	match = match_i2c;
	68	break;
	69	default:
	70	/* Cannot happen, unless someone breaks us */
	71	WARN_ON(true);
	72	return NULL;
	73	}
	74
	75	/* match cannot be NULL here */
	76	if (match(sd->dev, asd))
	77	return asd;
	78	}
	79
	80	return NULL;
	81	}
	82
	83	static int v4l2_async_test_notify(struct v4l2_async_notifier *notifier,
	84	struct v4l2_async_subdev_list *asdl,
	85	struct v4l2_async_subdev *asd)
	86	{
	87	struct v4l2_subdev *sd = v4l2_async_to_subdev(asdl);
	88	int ret;
	89
	90	/* Remove from the waiting list */
	91	list_del(&asd->list);
	92	asdl->asd = asd;
	93	asdl->notifier = notifier;
	94
	95	if (notifier->bound) {
	96	ret = notifier->bound(notifier, sd, asd);
	97	if (ret < 0)
	98	return ret;
	99	}
	100	/* Move from the global subdevice list to notifier's done */
	101	list_move(&asdl->list, &notifier->done);
	102
	103	ret = v4l2_device_register_subdev(notifier->v4l2_dev, sd);
	104	if (ret < 0) {
	105	if (notifier->unbind)
	106	notifier->unbind(notifier, sd, asd);
	107	return ret;
	108	}
	109
	110	if (list_empty(&notifier->waiting) && notifier->complete)
	111	return notifier->complete(notifier);
	112
	113	return 0;
	114	}
	115
	116	static void v4l2_async_cleanup(struct v4l2_async_subdev_list *asdl)
	117	{
	118	struct v4l2_subdev *sd = v4l2_async_to_subdev(asdl);
	119
	120	v4l2_device_unregister_subdev(sd);
	121	/* Subdevice driver will reprobe and put asdl back onto the list */
	122	list_del_init(&asdl->list);
	123	asdl->asd = NULL;
	124	sd->dev = NULL;
	125	}
	126
	127	int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
	128	struct v4l2_async_notifier *notifier)
	129	{
	130	struct v4l2_async_subdev_list asdl, tmp;
131	struct v4l2_async_subdev *asd;
132	int i;
133
134	if (!notifier->num_subdevs \|\| notifier->num_subdevs > V4L2_MAX_SUBDEVS)
135	return -EINVAL;
136
137	notifier->v4l2_dev = v4l2_dev;
138	INIT_LIST_HEAD(&notifier->waiting);
139	INIT_LIST_HEAD(&notifier->done);
140
141	for (i = 0; i < notifier->num_subdevs; i++) {
142	asd = notifier->subdev[i];
143
cfca7644 SN	144	switch (asd->match_type) {
	145	case V4L2_ASYNC_MATCH_CUSTOM:
	146	case V4L2_ASYNC_MATCH_DEVNAME:
	147	case V4L2_ASYNC_MATCH_I2C:
e9e31049 GL	148	break;
	149	default:
	150	dev_err(notifier->v4l2_dev ? notifier->v4l2_dev->dev : NULL,
cfca7644 SN	151	"Invalid match type %u on %p\n",
cfca7644 SN	152	asd->match_type, asd);
e9e31049 GL	153	return -EINVAL;
	154	}
	155	list_add_tail(&asd->list, &notifier->waiting);
	156	}
	157
	158	mutex_lock(&list_lock);
	159
	160	/* Keep also completed notifiers on the list */
	161	list_add(&notifier->list, &notifier_list);
	162
	163	list_for_each_entry_safe(asdl, tmp, &subdev_list, list) {
	164	int ret;
	165
	166	asd = v4l2_async_belongs(notifier, asdl);
	167	if (!asd)
	168	continue;
	169
	170	ret = v4l2_async_test_notify(notifier, asdl, asd);
	171	if (ret < 0) {
	172	mutex_unlock(&list_lock);
	173	return ret;
	174	}
	175	}
	176
	177	mutex_unlock(&list_lock);
	178
	179	return 0;
	180	}
	181	EXPORT_SYMBOL(v4l2_async_notifier_register);
	182
	183	void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
	184	{
	185	struct v4l2_async_subdev_list asdl, tmp;
	186	unsigned int notif_n_subdev = notifier->num_subdevs;
	187	unsigned int n_subdev = min(notif_n_subdev, V4L2_MAX_SUBDEVS);
	188	struct device *dev[n_subdev];
	189	int i = 0;
	190
	191	mutex_lock(&list_lock);
	192
	193	list_del(&notifier->list);
	194
	195	list_for_each_entry_safe(asdl, tmp, &notifier->done, list) {
	196	struct v4l2_subdev *sd = v4l2_async_to_subdev(asdl);
	197
	198	dev[i] = get_device(sd->dev);
	199
	200	v4l2_async_cleanup(asdl);
	201
	202	/* If we handled USB devices, we'd have to lock the parent too */
	203	device_release_driver(dev[i++]);
	204
	205	if (notifier->unbind)
	206	notifier->unbind(notifier, sd, sd->asdl.asd);
	207	}
	208
	209	mutex_unlock(&list_lock);
	210
	211	while (i--) {
	212	struct device *d = dev[i];
	213
	214	if (d && device_attach(d) < 0) {
	215	const char *name = "(none)";
	216	int lock = device_trylock(d);
217
218	if (lock && d->driver)
219	name = d->driver->name;
220	dev_err(d, "Failed to re-probe to %s\n", name);
221	if (lock)
222	device_unlock(d);
223	}
224	put_device(d);
225	}
226	/*
227	* Don't care about the waiting list, it is initialised and populated
228	* upon notifier registration.
229	*/
230	}
231	EXPORT_SYMBOL(v4l2_async_notifier_unregister);
232
233	int v4l2_async_register_subdev(struct v4l2_subdev *sd)
234	{
235	struct v4l2_async_subdev_list *asdl = &sd->asdl;
236	struct v4l2_async_notifier *notifier;
237
238	mutex_lock(&list_lock);
239
240	INIT_LIST_HEAD(&asdl->list);
241
242	list_for_each_entry(notifier, &notifier_list, list) {
243	struct v4l2_async_subdev *asd = v4l2_async_belongs(notifier, asdl);
244	if (asd) {
245	int ret = v4l2_async_test_notify(notifier, asdl, asd);
246	mutex_unlock(&list_lock);
247	return ret;
248	}
249	}
250
251	/* None matched, wait for hot-plugging */
252	list_add(&asdl->list, &subdev_list);
253
254	mutex_unlock(&list_lock);
255
256	return 0;
257	}
258	EXPORT_SYMBOL(v4l2_async_register_subdev);
259
260	void v4l2_async_unregister_subdev(struct v4l2_subdev *sd)
261	{
262	struct v4l2_async_subdev_list *asdl = &sd->asdl;
263	struct v4l2_async_notifier *notifier = asdl->notifier;
264
265	if (!asdl->asd) {
266	if (!list_empty(&asdl->list))
267	v4l2_async_cleanup(asdl);
268	return;
269	}
270
271	mutex_lock(&list_lock);
272
273	list_add(&asdl->asd->list, &notifier->waiting);
274
275	v4l2_async_cleanup(asdl);
276
277	if (notifier->unbind)
278	notifier->unbind(notifier, sd, sd->asdl.asd);
279
280	mutex_unlock(&list_lock);
281	}
282	EXPORT_SYMBOL(v4l2_async_unregister_subdev);