/drivers/media/media-device.c

  1/*
  2 * Media device
  3 *
  4 * Copyright (C) 2010 Nokia Corporation
  5 *
  6 * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
  7 *	     Sakari Ailus <sakari.ailus@iki.fi>
  8 *
  9 * This program is free software; you can redistribute it and/or modify
 10 * it under the terms of the GNU General Public License version 2 as
 11 * published by the Free Software Foundation.
 12 *
 13 * This program is distributed in the hope that it will be useful,
 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 16 * GNU General Public License for more details.
 17 *
 18 * You should have received a copy of the GNU General Public License
 19 * along with this program; if not, write to the Free Software
 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 21 */
 22
 23#include <linux/types.h>
 24#include <linux/ioctl.h>
 25#include <linux/media.h>
 26
 27#include <media/media-device.h>
 28#include <media/media-devnode.h>
 29#include <media/media-entity.h>
 30
 31/* -----------------------------------------------------------------------------
 32 * Userspace API
 33 */
 34
 35static int media_device_open(struct file *filp)
 36{
 37	return 0;
 38}
 39
 40static int media_device_close(struct file *filp)
 41{
 42	return 0;
 43}
 44
 45static int media_device_get_info(struct media_device *dev,
 46				 struct media_device_info __user *__info)
 47{
 48	struct media_device_info info;
 49
 50	memset(&info, 0, sizeof(info));
 51
 52	strlcpy(info.driver, dev->dev->driver->name, sizeof(info.driver));
 53	strlcpy(info.model, dev->model, sizeof(info.model));
 54	strlcpy(info.serial, dev->serial, sizeof(info.serial));
 55	strlcpy(info.bus_info, dev->bus_info, sizeof(info.bus_info));
 56
 57	info.media_version = MEDIA_API_VERSION;
 58	info.hw_revision = dev->hw_revision;
 59	info.driver_version = dev->driver_version;
 60
 61	return copy_to_user(__info, &info, sizeof(*__info));
 62}
 63
 64static struct media_entity *find_entity(struct media_device *mdev, u32 id)
 65{
 66	struct media_entity *entity;
 67	int next = id & MEDIA_ENT_ID_FLAG_NEXT;
 68
 69	id &= ~MEDIA_ENT_ID_FLAG_NEXT;
 70
 71	spin_lock(&mdev->lock);
 72
 73	media_device_for_each_entity(entity, mdev) {
 74		if ((entity->id == id && !next) ||
 75		    (entity->id > id && next)) {
 76			spin_unlock(&mdev->lock);
 77			return entity;
 78		}
 79	}
 80
 81	spin_unlock(&mdev->lock);
 82
 83	return NULL;
 84}
 85
 86static long media_device_enum_entities(struct media_device *mdev,
 87				       struct media_entity_desc __user *uent)
 88{
 89	struct media_entity *ent;
 90	struct media_entity_desc u_ent;
 91
 92	if (copy_from_user(&u_ent.id, &uent->id, sizeof(u_ent.id)))
 93		return -EFAULT;
 94
 95	ent = find_entity(mdev, u_ent.id);
 96
 97	if (ent == NULL)
 98		return -EINVAL;
 99
100	u_ent.id = ent->id;
101	u_ent.name[0] = '\0';
102	if (ent->name)
103		strlcpy(u_ent.name, ent->name, sizeof(u_ent.name));
104	u_ent.type = ent->type;
105	u_ent.revision = ent->revision;
106	u_ent.flags = ent->flags;
107	u_ent.group_id = ent->group_id;
108	u_ent.pads = ent->num_pads;
109	u_ent.links = ent->num_links - ent->num_backlinks;
110	u_ent.v4l.major = ent->v4l.major;
111	u_ent.v4l.minor = ent->v4l.minor;
112	if (copy_to_user(uent, &u_ent, sizeof(u_ent)))
113		return -EFAULT;
114	return 0;
115}
116
117static void media_device_kpad_to_upad(const struct media_pad *kpad,
118				      struct media_pad_desc *upad)
119{
120	upad->entity = kpad->entity->id;
121	upad->index = kpad->index;
122	upad->flags = kpad->flags;
123}
124
125static long media_device_enum_links(struct media_device *mdev,
126				    struct media_links_enum __user *ulinks)
127{
128	struct media_entity *entity;
129	struct media_links_enum links;
130
131	if (copy_from_user(&links, ulinks, sizeof(links)))
132		return -EFAULT;
133
134	entity = find_entity(mdev, links.entity);
135	if (entity == NULL)
136		return -EINVAL;
137
138	if (links.pads) {
139		unsigned int p;
140
141		for (p = 0; p < entity->num_pads; p++) {
142			struct media_pad_desc pad;
143			media_device_kpad_to_upad(&entity->pads[p], &pad);
144			if (copy_to_user(&links.pads[p], &pad, sizeof(pad)))
145				return -EFAULT;
146		}
147	}
148
149	if (links.links) {
150		struct media_link_desc __user *ulink;
151		unsigned int l;
152
153		for (l = 0, ulink = links.links; l < entity->num_links; l++) {
154			struct media_link_desc link;
155
156			/* Ignore backlinks. */
157			if (entity->links[l].source->entity != entity)
158				continue;
159
160			media_device_kpad_to_upad(entity->links[l].source,
161						  &link.source);
162			media_device_kpad_to_upad(entity->links[l].sink,
163						  &link.sink);
164			link.flags = entity->links[l].flags;
165			if (copy_to_user(ulink, &link, sizeof(*ulink)))
166				return -EFAULT;
167			ulink++;
168		}
169	}
170	if (copy_to_user(ulinks, &links, sizeof(*ulinks)))
171		return -EFAULT;
172	return 0;
173}
174
175static long media_device_setup_link(struct media_device *mdev,
176				    struct media_link_desc __user *_ulink)
177{
178	struct media_link *link = NULL;
179	struct media_link_desc ulink;
180	struct media_entity *source;
181	struct media_entity *sink;
182	int ret;
183
184	if (copy_from_user(&ulink, _ulink, sizeof(ulink)))
185		return -EFAULT;
186
187	/* Find the source and sink entities and link.
188	 */
189	source = find_entity(mdev, ulink.source.entity);
190	sink = find_entity(mdev, ulink.sink.entity);
191
192	if (source == NULL || sink == NULL)
193		return -EINVAL;
194
195	if (ulink.source.index >= source->num_pads ||
196	    ulink.sink.index >= sink->num_pads)
197		return -EINVAL;
198
199	link = media_entity_find_link(&source->pads[ulink.source.index],
200				      &sink->pads[ulink.sink.index]);
201	if (link == NULL)
202		return -EINVAL;
203
204	/* Setup the link on both entities. */
205	ret = __media_entity_setup_link(link, ulink.flags);
206
207	if (copy_to_user(_ulink, &ulink, sizeof(ulink)))
208		return -EFAULT;
209
210	return ret;
211}
212
213static long media_device_ioctl(struct file *filp, unsigned int cmd,
214			       unsigned long arg)
215{
216	struct media_devnode *devnode = media_devnode_data(filp);
217	struct media_device *dev = to_media_device(devnode);
218	long ret;
219
220	switch (cmd) {
221	case MEDIA_IOC_DEVICE_INFO:
222		ret = media_device_get_info(dev,
223				(struct media_device_info __user *)arg);
224		break;
225
226	case MEDIA_IOC_ENUM_ENTITIES:
227		ret = media_device_enum_entities(dev,
228				(struct media_entity_desc __user *)arg);
229		break;
230
231	case MEDIA_IOC_ENUM_LINKS:
232		mutex_lock(&dev->graph_mutex);
233		ret = media_device_enum_links(dev,
234				(struct media_links_enum __user *)arg);
235		mutex_unlock(&dev->graph_mutex);
236		break;
237
238	case MEDIA_IOC_SETUP_LINK:
239		mutex_lock(&dev->graph_mutex);
240		ret = media_device_setup_link(dev,
241				(struct media_link_desc __user *)arg);
242		mutex_unlock(&dev->graph_mutex);
243		break;
244
245	default:
246		ret = -ENOIOCTLCMD;
247	}
248
249	return ret;
250}
251
252static const struct media_file_operations media_device_fops = {
253	.owner = THIS_MODULE,
254	.open = media_device_open,
255	.ioctl = media_device_ioctl,
256	.release = media_device_close,
257};
258
259/* -----------------------------------------------------------------------------
260 * sysfs
261 */
262
263static ssize_t show_model(struct device *cd,
264			  struct device_attribute *attr, char *buf)
265{
266	struct media_device *mdev = to_media_device(to_media_devnode(cd));
267
268	return sprintf(buf, "%.*s\n", (int)sizeof(mdev->model), mdev->model);
269}
270
271static DEVICE_ATTR(model, S_IRUGO, show_model, NULL);
272
273/* -----------------------------------------------------------------------------
274 * Registration/unregistration
275 */
276
277static void media_device_release(struct media_devnode *mdev)
278{
279}
280
281/**
282 * media_device_register - register a media device
283 * @mdev:	The media device
284 *
285 * The caller is responsible for initializing the media device before
286 * registration. The following fields must be set:
287 *
288 * - dev must point to the parent device
289 * - model must be filled with the device model name
290 */
291int __must_check media_device_register(struct media_device *mdev)
292{
293	int ret;
294
295	if (WARN_ON(mdev->dev == NULL || mdev->model[0] == 0))
296		return -EINVAL;
297
298	mdev->entity_id = 1;
299	INIT_LIST_HEAD(&mdev->entities);
300	spin_lock_init(&mdev->lock);
301	mutex_init(&mdev->graph_mutex);
302
303	/* Register the device node. */
304	mdev->devnode.fops = &media_device_fops;
305	mdev->devnode.parent = mdev->dev;
306	mdev->devnode.release = media_device_release;
307	ret = media_devnode_register(&mdev->devnode);
308	if (ret < 0)
309		return ret;
310
311	ret = device_create_file(&mdev->devnode.dev, &dev_attr_model);
312	if (ret < 0) {
313		media_devnode_unregister(&mdev->devnode);
314		return ret;
315	}
316
317	return 0;
318}
319EXPORT_SYMBOL_GPL(media_device_register);
320
321/**
322 * media_device_unregister - unregister a media device
323 * @mdev:	The media device
324 *
325 */
326void media_device_unregister(struct media_device *mdev)
327{
328	struct media_entity *entity;
329	struct media_entity *next;
330
331	list_for_each_entry_safe(entity, next, &mdev->entities, list)
332		media_device_unregister_entity(entity);
333
334	device_remove_file(&mdev->devnode.dev, &dev_attr_model);
335	media_devnode_unregister(&mdev->devnode);
336}
337EXPORT_SYMBOL_GPL(media_device_unregister);
338
339/**
340 * media_device_register_entity - Register an entity with a media device
341 * @mdev:	The media device
342 * @entity:	The entity
343 */
344int __must_check media_device_register_entity(struct media_device *mdev,
345					      struct media_entity *entity)
346{
347	/* Warn if we apparently re-register an entity */
348	WARN_ON(entity->parent != NULL);
349	entity->parent = mdev;
350
351	spin_lock(&mdev->lock);
352	if (entity->id == 0)
353		entity->id = mdev->entity_id++;
354	else
355		mdev->entity_id = max(entity->id + 1, mdev->entity_id);
356	list_add_tail(&entity->list, &mdev->entities);
357	spin_unlock(&mdev->lock);
358
359	return 0;
360}
361EXPORT_SYMBOL_GPL(media_device_register_entity);
362
363/**
364 * media_device_unregister_entity - Unregister an entity
365 * @entity:	The entity
366 *
367 * If the entity has never been registered this function will return
368 * immediately.
369 */
370void media_device_unregister_entity(struct media_entity *entity)
371{
372	struct media_device *mdev = entity->parent;
373
374	if (mdev == NULL)
375		return;
376
377	spin_lock(&mdev->lock);
378	list_del(&entity->list);
379	spin_unlock(&mdev->lock);
380	entity->parent = NULL;
381}
382EXPORT_SYMBOL_GPL(media_device_unregister_entity);