[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)
{
	struct i2c_client *client = i2c_verify_client(dev);
	return client &&
		asd->bus_type == V4L2_ASYNC_BUS_I2C &&
		asd->match.i2c.adapter_id == client->adapter->nr &&
		asd->match.i2c.address == client->addr;
}

static bool match_platform(struct device *dev, struct v4l2_async_subdev *asd)
{
	return asd->bus_type == V4L2_ASYNC_BUS_PLATFORM &&
		!strcmp(asd->match.platform.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->bus_type) {
		case V4L2_ASYNC_BUS_CUSTOM:
			match = asd->match.custom.match;
			if (!match)
				/* Match always */
				return asd;
			break;
		case V4L2_ASYNC_BUS_PLATFORM:
			match = match_platform;
			break;
		case V4L2_ASYNC_BUS_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->bus_type) {
		case V4L2_ASYNC_BUS_CUSTOM:
		case V4L2_ASYNC_BUS_PLATFORM:
		case V4L2_ASYNC_BUS_I2C:
			break;
		default:
			dev_err(notifier->v4l2_dev ? notifier->v4l2_dev->dev : NULL,
				"Invalid bus-type %u on %p\n",
				asd->bus_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	{
	27	struct i2c_client *client = i2c_verify_client(dev);
	28	return client &&
	29	asd->bus_type == V4L2_ASYNC_BUS_I2C &&
	30	asd->match.i2c.adapter_id == client->adapter->nr &&
	31	asd->match.i2c.address == client->addr;
	32	}
	33
	34	static bool match_platform(struct device dev, struct v4l2_async_subdev asd)
	35	{
	36	return asd->bus_type == V4L2_ASYNC_BUS_PLATFORM &&
	37	!strcmp(asd->match.platform.name, dev_name(dev));
	38	}
	39
	40	static LIST_HEAD(subdev_list);
	41	static LIST_HEAD(notifier_list);
	42	static DEFINE_MUTEX(list_lock);
	43
	44	static struct v4l2_async_subdev v4l2_async_belongs(struct v4l2_async_notifier notifier,
	45	struct v4l2_async_subdev_list *asdl)
	46	{
	47	struct v4l2_subdev *sd = v4l2_async_to_subdev(asdl);
	48	struct v4l2_async_subdev *asd;
	49	bool (match)(struct device ,
	50	struct v4l2_async_subdev *);
	51
	52	list_for_each_entry(asd, &notifier->waiting, list) {
	53	/* bus_type has been verified valid before */
	54	switch (asd->bus_type) {
	55	case V4L2_ASYNC_BUS_CUSTOM:
	56	match = asd->match.custom.match;
	57	if (!match)
	58	/* Match always */
	59	return asd;
	60	break;
	61	case V4L2_ASYNC_BUS_PLATFORM:
	62	match = match_platform;
	63	break;
	64	case V4L2_ASYNC_BUS_I2C:
65	match = match_i2c;
66	break;
67	default:
68	/* Cannot happen, unless someone breaks us */
69	WARN_ON(true);
70	return NULL;
71	}
72
73	/* match cannot be NULL here */
74	if (match(sd->dev, asd))
75	return asd;
76	}
77
78	return NULL;
79	}
80
81	static int v4l2_async_test_notify(struct v4l2_async_notifier *notifier,
82	struct v4l2_async_subdev_list *asdl,
83	struct v4l2_async_subdev *asd)
84	{
85	struct v4l2_subdev *sd = v4l2_async_to_subdev(asdl);
86	int ret;
87
88	/* Remove from the waiting list */
89	list_del(&asd->list);
90	asdl->asd = asd;
91	asdl->notifier = notifier;
92
93	if (notifier->bound) {
94	ret = notifier->bound(notifier, sd, asd);
95	if (ret < 0)
96	return ret;
97	}
98	/* Move from the global subdevice list to notifier's done */
99	list_move(&asdl->list, &notifier->done);
100
101	ret = v4l2_device_register_subdev(notifier->v4l2_dev, sd);
102	if (ret < 0) {
103	if (notifier->unbind)
104	notifier->unbind(notifier, sd, asd);
105	return ret;
106	}
107
108	if (list_empty(&notifier->waiting) && notifier->complete)
109	return notifier->complete(notifier);
110
111	return 0;
112	}
113
114	static void v4l2_async_cleanup(struct v4l2_async_subdev_list *asdl)
115	{
116	struct v4l2_subdev *sd = v4l2_async_to_subdev(asdl);
117
118	v4l2_device_unregister_subdev(sd);
119	/* Subdevice driver will reprobe and put asdl back onto the list */
120	list_del_init(&asdl->list);
121	asdl->asd = NULL;
122	sd->dev = NULL;
123	}
124
125	int v4l2_async_notifier_register(struct v4l2_device *v4l2_dev,
126	struct v4l2_async_notifier *notifier)
127	{
128	struct v4l2_async_subdev_list asdl, tmp;
129	struct v4l2_async_subdev *asd;
130	int i;
131
132	if (!notifier->num_subdevs \|\| notifier->num_subdevs > V4L2_MAX_SUBDEVS)
133	return -EINVAL;
134
135	notifier->v4l2_dev = v4l2_dev;
136	INIT_LIST_HEAD(&notifier->waiting);
137	INIT_LIST_HEAD(&notifier->done);
138
139	for (i = 0; i < notifier->num_subdevs; i++) {
140	asd = notifier->subdev[i];
141
142	switch (asd->bus_type) {
143	case V4L2_ASYNC_BUS_CUSTOM:
144	case V4L2_ASYNC_BUS_PLATFORM:
145	case V4L2_ASYNC_BUS_I2C:
146	break;
147	default:
148	dev_err(notifier->v4l2_dev ? notifier->v4l2_dev->dev : NULL,
149	"Invalid bus-type %u on %p\n",
150	asd->bus_type, asd);
151	return -EINVAL;
152	}
153	list_add_tail(&asd->list, &notifier->waiting);
154	}
155
156	mutex_lock(&list_lock);
157
158	/* Keep also completed notifiers on the list */
159	list_add(&notifier->list, &notifier_list);
160
161	list_for_each_entry_safe(asdl, tmp, &subdev_list, list) {
162	int ret;
163
164	asd = v4l2_async_belongs(notifier, asdl);
165	if (!asd)
166	continue;
167
168	ret = v4l2_async_test_notify(notifier, asdl, asd);
169	if (ret < 0) {
170	mutex_unlock(&list_lock);
171	return ret;
172	}
173	}
174
175	mutex_unlock(&list_lock);
176
177	return 0;
178	}
179	EXPORT_SYMBOL(v4l2_async_notifier_register);
180
181	void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier)
182	{
183	struct v4l2_async_subdev_list asdl, tmp;
184	unsigned int notif_n_subdev = notifier->num_subdevs;
185	unsigned int n_subdev = min(notif_n_subdev, V4L2_MAX_SUBDEVS);
186	struct device *dev[n_subdev];
187	int i = 0;
188
189	mutex_lock(&list_lock);
190
191	list_del(&notifier->list);
192
193	list_for_each_entry_safe(asdl, tmp, &notifier->done, list) {
194	struct v4l2_subdev *sd = v4l2_async_to_subdev(asdl);
195
196	dev[i] = get_device(sd->dev);
197
198	v4l2_async_cleanup(asdl);
199
200	/* If we handled USB devices, we'd have to lock the parent too */
201	device_release_driver(dev[i++]);
202
203	if (notifier->unbind)
204	notifier->unbind(notifier, sd, sd->asdl.asd);
205	}
206
207	mutex_unlock(&list_lock);
208
209	while (i--) {
210	struct device *d = dev[i];
211
212	if (d && device_attach(d) < 0) {
213	const char *name = "(none)";
214	int lock = device_trylock(d);
215
216	if (lock && d->driver)
217	name = d->driver->name;
218	dev_err(d, "Failed to re-probe to %s\n", name);
219	if (lock)
220	device_unlock(d);
221	}
222	put_device(d);
223	}
224	/*
225	* Don't care about the waiting list, it is initialised and populated
226	* upon notifier registration.
227	*/
228	}
229	EXPORT_SYMBOL(v4l2_async_notifier_unregister);
230
231	int v4l2_async_register_subdev(struct v4l2_subdev *sd)
232	{
233	struct v4l2_async_subdev_list *asdl = &sd->asdl;
234	struct v4l2_async_notifier *notifier;
235
236	mutex_lock(&list_lock);
237
238	INIT_LIST_HEAD(&asdl->list);
239
240	list_for_each_entry(notifier, &notifier_list, list) {
241	struct v4l2_async_subdev *asd = v4l2_async_belongs(notifier, asdl);
242	if (asd) {
243	int ret = v4l2_async_test_notify(notifier, asdl, asd);
244	mutex_unlock(&list_lock);
245	return ret;
246	}
247	}
248
249	/* None matched, wait for hot-plugging */
250	list_add(&asdl->list, &subdev_list);
251
252	mutex_unlock(&list_lock);
253
254	return 0;
255	}
256	EXPORT_SYMBOL(v4l2_async_register_subdev);
257
258	void v4l2_async_unregister_subdev(struct v4l2_subdev *sd)
259	{
260	struct v4l2_async_subdev_list *asdl = &sd->asdl;
261	struct v4l2_async_notifier *notifier = asdl->notifier;
262
263	if (!asdl->asd) {
264	if (!list_empty(&asdl->list))
265	v4l2_async_cleanup(asdl);
266	return;
267	}
268
269	mutex_lock(&list_lock);
270
271	list_add(&asdl->asd->list, &notifier->waiting);
272
273	v4l2_async_cleanup(asdl);
274
275	if (notifier->unbind)
276	notifier->unbind(notifier, sd, sd->asdl.asd);
277
278	mutex_unlock(&list_lock);
279	}
280	EXPORT_SYMBOL(v4l2_async_unregister_subdev);