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/compat.h>
  24 #include <linux/export.h>
  25 #include <linux/ioctl.h>
  26 #include <linux/media.h>
  27 #include <linux/types.h>
  28
  29 #include <media/media-device.h>
  30 #include <media/media-devnode.h>
  31 #include <media/media-entity.h>
  32
  33 /* -----------------------------------------------------------------------------
  34  * Userspace API
  35  */
  36
  37 static int media_device_open(struct file *filp)
  38 {
  39         return 0;
  40 }
  41
  42 static int media_device_close(struct file *filp)
  43 {
  44         return 0;
  45 }
  46
  47 static int media_device_get_info(struct media_device *dev,
  48                                  struct media_device_info __user *__info)
  49 {
  50         struct media_device_info info;
  51
  52         memset(&info, 0, sizeof(info));
  53
  54         strlcpy(info.driver, dev->dev->driver->name, sizeof(info.driver));
  55         strlcpy(info.model, dev->model, sizeof(info.model));
  56         strlcpy(info.serial, dev->serial, sizeof(info.serial));
  57         strlcpy(info.bus_info, dev->bus_info, sizeof(info.bus_info));
  58
  59         info.media_version = MEDIA_API_VERSION;
  60         info.hw_revision = dev->hw_revision;
  61         info.driver_version = dev->driver_version;
  62
  63         if (copy_to_user(__info, &info, sizeof(*__info)))
  64                 return -EFAULT;
  65         return 0;
  66 }
  67
  68 static struct media_entity *find_entity(struct media_device *mdev, u32 id)
  69 {
  70         struct media_entity *entity;
  71         int next = id & MEDIA_ENT_ID_FLAG_NEXT;
  72
  73         id &= ~MEDIA_ENT_ID_FLAG_NEXT;
  74
  75         spin_lock(&mdev->lock);
  76
  77         media_device_for_each_entity(entity, mdev) {
  78                 if ((entity->id == id && !next) ||
  79                     (entity->id > id && next)) {
  80                         spin_unlock(&mdev->lock);
  81                         return entity;
  82                 }
  83         }
  84
  85         spin_unlock(&mdev->lock);
  86
  87         return NULL;
  88 }
  89
  90 static long media_device_enum_entities(struct media_device *mdev,
  91                                        struct media_entity_desc __user *uent)
  92 {
  93         struct media_entity *ent;
  94         struct media_entity_desc u_ent;
  95
  96         if (copy_from_user(&u_ent.id, &uent->id, sizeof(u_ent.id)))
  97                 return -EFAULT;
  98
  99         ent = find_entity(mdev, u_ent.id);
 100
 101         if (ent == NULL)
 102                 return -EINVAL;
 103
 104         u_ent.id = ent->id;
 105         if (ent->name) {
 106                 strncpy(u_ent.name, ent->name, sizeof(u_ent.name));
 107                 u_ent.name[sizeof(u_ent.name) - 1] = '\0';
 108         } else {
 109                 memset(u_ent.name, 0, sizeof(u_ent.name));
 110         }
 111         u_ent.type = ent->type;
 112         u_ent.revision = ent->revision;
 113         u_ent.flags = ent->flags;
 114         u_ent.group_id = ent->group_id;
 115         u_ent.pads = ent->num_pads;
 116         u_ent.links = ent->num_links - ent->num_backlinks;
 117         memcpy(&u_ent.raw, &ent->info, sizeof(ent->info));
 118         if (copy_to_user(uent, &u_ent, sizeof(u_ent)))
 119                 return -EFAULT;
 120         return 0;
 121 }
 122
 123 static void media_device_kpad_to_upad(const struct media_pad *kpad,
 124                                       struct media_pad_desc *upad)
 125 {
 126         upad->entity = kpad->entity->id;
 127         upad->index = kpad->index;
 128         upad->flags = kpad->flags;
 129 }
 130
 131 static long __media_device_enum_links(struct media_device *mdev,
 132                                       struct media_links_enum *links)
 133 {
 134         struct media_entity *entity;
 135
 136         entity = find_entity(mdev, links->entity);
 137         if (entity == NULL)
 138                 return -EINVAL;
 139
 140         if (links->pads) {
 141                 unsigned int p;
 142
 143                 for (p = 0; p < entity->num_pads; p++) {
 144                         struct media_pad_desc pad;
 145                         media_device_kpad_to_upad(&entity->pads[p], &pad);
 146                         if (copy_to_user(&links->pads[p], &pad, sizeof(pad)))
 147                                 return -EFAULT;
 148                 }
 149         }
 150
 151         if (links->links) {
 152                 struct media_link_desc __user *ulink;
 153                 unsigned int l;
 154
 155                 for (l = 0, ulink = links->links; l < entity->num_links; l++) {
 156                         struct media_link_desc link;
 157
 158                         /* Ignore backlinks. */
 159                         if (entity->links[l].source->entity != entity)
 160                                 continue;
 161
 162                         media_device_kpad_to_upad(entity->links[l].source,
 163                                                   &link.source);
 164                         media_device_kpad_to_upad(entity->links[l].sink,
 165                                                   &link.sink);
 166                         link.flags = entity->links[l].flags;
 167                         if (copy_to_user(ulink, &link, sizeof(*ulink)))
 168                                 return -EFAULT;
 169                         ulink++;
 170                 }
 171         }
 172
 173         return 0;
 174 }
 175
 176 static long media_device_enum_links(struct media_device *mdev,
 177                                     struct media_links_enum __user *ulinks)
 178 {
 179         struct media_links_enum links;
 180         int rval;
 181
 182         if (copy_from_user(&links, ulinks, sizeof(links)))
 183                 return -EFAULT;
 184
 185         rval = __media_device_enum_links(mdev, &links);
 186         if (rval < 0)
 187                 return rval;
 188
 189         if (copy_to_user(ulinks, &links, sizeof(*ulinks)))
 190                 return -EFAULT;
 191
 192         return 0;
 193 }
 194
 195 static long media_device_setup_link(struct media_device *mdev,
 196                                     struct media_link_desc __user *_ulink)
 197 {
 198         struct media_link *link = NULL;
 199         struct media_link_desc ulink;
 200         struct media_entity *source;
 201         struct media_entity *sink;
 202         int ret;
 203
 204         if (copy_from_user(&ulink, _ulink, sizeof(ulink)))
 205                 return -EFAULT;
 206
 207         /* Find the source and sink entities and link.
 208          */
 209         source = find_entity(mdev, ulink.source.entity);
 210         sink = find_entity(mdev, ulink.sink.entity);
 211
 212         if (source == NULL || sink == NULL)
 213                 return -EINVAL;
 214
 215         if (ulink.source.index >= source->num_pads ||
 216             ulink.sink.index >= sink->num_pads)
 217                 return -EINVAL;
 218
 219         link = media_entity_find_link(&source->pads[ulink.source.index],
 220                                       &sink->pads[ulink.sink.index]);
 221         if (link == NULL)
 222                 return -EINVAL;
 223
 224         /* Setup the link on both entities. */
 225         ret = __media_entity_setup_link(link, ulink.flags);
 226
 227         if (copy_to_user(_ulink, &ulink, sizeof(ulink)))
 228                 return -EFAULT;
 229
 230         return ret;
 231 }
 232
 233 static long media_device_ioctl(struct file *filp, unsigned int cmd,
 234                                unsigned long arg)
 235 {
 236         struct media_devnode *devnode = media_devnode_data(filp);
 237         struct media_device *dev = to_media_device(devnode);
 238         long ret;
 239
 240         switch (cmd) {
 241         case MEDIA_IOC_DEVICE_INFO:
 242                 ret = media_device_get_info(dev,
 243                                 (struct media_device_info __user *)arg);
 244                 break;
 245
 246         case MEDIA_IOC_ENUM_ENTITIES:
 247                 ret = media_device_enum_entities(dev,
 248                                 (struct media_entity_desc __user *)arg);
 249                 break;
 250
 251         case MEDIA_IOC_ENUM_LINKS:
 252                 mutex_lock(&dev->graph_mutex);
 253                 ret = media_device_enum_links(dev,
 254                                 (struct media_links_enum __user *)arg);
 255                 mutex_unlock(&dev->graph_mutex);
 256                 break;
 257
 258         case MEDIA_IOC_SETUP_LINK:
 259                 mutex_lock(&dev->graph_mutex);
 260                 ret = media_device_setup_link(dev,
 261                                 (struct media_link_desc __user *)arg);
 262                 mutex_unlock(&dev->graph_mutex);
 263                 break;
 264
 265         default:
 266                 ret = -ENOIOCTLCMD;
 267         }
 268
 269         return ret;
 270 }
 271
 272 #ifdef CONFIG_COMPAT
 273
 274 struct media_links_enum32 {
 275         __u32 entity;
 276         compat_uptr_t pads; /* struct media_pad_desc * */
 277         compat_uptr_t links; /* struct media_link_desc * */
 278         __u32 reserved[4];
 279 };
 280
 281 static long media_device_enum_links32(struct media_device *mdev,
 282                                       struct media_links_enum32 __user *ulinks)
 283 {
 284         struct media_links_enum links;
 285         compat_uptr_t pads_ptr, links_ptr;
 286
 287         memset(&links, 0, sizeof(links));
 288
 289         if (get_user(links.entity, &ulinks->entity)
 290             || get_user(pads_ptr, &ulinks->pads)
 291             || get_user(links_ptr, &ulinks->links))
 292                 return -EFAULT;
 293
 294         links.pads = compat_ptr(pads_ptr);
 295         links.links = compat_ptr(links_ptr);
 296
 297         return __media_device_enum_links(mdev, &links);
 298 }
 299
 300 #define MEDIA_IOC_ENUM_LINKS32          _IOWR('|', 0x02, struct media_links_enum32)
 301
 302 static long media_device_compat_ioctl(struct file *filp, unsigned int cmd,
 303                                       unsigned long arg)
 304 {
 305         struct media_devnode *devnode = media_devnode_data(filp);
 306         struct media_device *dev = to_media_device(devnode);
 307         long ret;
 308
 309         switch (cmd) {
 310         case MEDIA_IOC_DEVICE_INFO:
 311         case MEDIA_IOC_ENUM_ENTITIES:
 312         case MEDIA_IOC_SETUP_LINK:
 313                 return media_device_ioctl(filp, cmd, arg);
 314
 315         case MEDIA_IOC_ENUM_LINKS32:
 316                 mutex_lock(&dev->graph_mutex);
 317                 ret = media_device_enum_links32(dev,
 318                                 (struct media_links_enum32 __user *)arg);
 319                 mutex_unlock(&dev->graph_mutex);
 320                 break;
 321
 322         default:
 323                 ret = -ENOIOCTLCMD;
 324         }
 325
 326         return ret;
 327 }
 328 #endif /* CONFIG_COMPAT */
 329
 330 static const struct media_file_operations media_device_fops = {
 331         .owner = THIS_MODULE,
 332         .open = media_device_open,
 333         .ioctl = media_device_ioctl,
 334 #ifdef CONFIG_COMPAT
 335         .compat_ioctl = media_device_compat_ioctl,
 336 #endif /* CONFIG_COMPAT */
 337         .release = media_device_close,
 338 };
 339
 340 /* -----------------------------------------------------------------------------
 341  * sysfs
 342  */
 343
 344 static ssize_t show_model(struct device *cd,
 345                           struct device_attribute *attr, char *buf)
 346 {
 347         struct media_device *mdev = to_media_device(to_media_devnode(cd));
 348
 349         return sprintf(buf, "%.*s\n", (int)sizeof(mdev->model), mdev->model);
 350 }
 351
 352 static DEVICE_ATTR(model, S_IRUGO, show_model, NULL);
 353
 354 /* -----------------------------------------------------------------------------
 355  * Registration/unregistration
 356  */
 357
 358 static void media_device_release(struct media_devnode *mdev)
 359 {
 360 }
 361
 362 /**
 363  * media_device_register - register a media device
 364  * @mdev:       The media device
 365  *
 366  * The caller is responsible for initializing the media device before
 367  * registration. The following fields must be set:
 368  *
 369  * - dev must point to the parent device
 370  * - model must be filled with the device model name
 371  */
 372 int __must_check media_device_register(struct media_device *mdev)
 373 {
 374         int ret;
 375
 376         if (WARN_ON(mdev->dev == NULL || mdev->model[0] == 0))
 377                 return -EINVAL;
 378
 379         mdev->entity_id = 1;
 380         INIT_LIST_HEAD(&mdev->entities);
 381         spin_lock_init(&mdev->lock);
 382         mutex_init(&mdev->graph_mutex);
 383
 384         /* Register the device node. */
 385         mdev->devnode.fops = &media_device_fops;
 386         mdev->devnode.parent = mdev->dev;
 387         mdev->devnode.release = media_device_release;
 388         ret = media_devnode_register(&mdev->devnode);
 389         if (ret < 0)
 390                 return ret;
 391
 392         ret = device_create_file(&mdev->devnode.dev, &dev_attr_model);
 393         if (ret < 0) {
 394                 media_devnode_unregister(&mdev->devnode);
 395                 return ret;
 396         }
 397
 398         return 0;
 399 }
 400 EXPORT_SYMBOL_GPL(media_device_register);
 401
 402 /**
 403  * media_device_unregister - unregister a media device
 404  * @mdev:       The media device
 405  *
 406  */
 407 void media_device_unregister(struct media_device *mdev)
 408 {
 409         struct media_entity *entity;
 410         struct media_entity *next;
 411
 412         list_for_each_entry_safe(entity, next, &mdev->entities, list)
 413                 media_device_unregister_entity(entity);
 414
 415         device_remove_file(&mdev->devnode.dev, &dev_attr_model);
 416         media_devnode_unregister(&mdev->devnode);
 417 }
 418 EXPORT_SYMBOL_GPL(media_device_unregister);
 419
 420 /**
 421  * media_device_register_entity - Register an entity with a media device
 422  * @mdev:       The media device
 423  * @entity:     The entity
 424  */
 425 int __must_check media_device_register_entity(struct media_device *mdev,
 426                                               struct media_entity *entity)
 427 {
 428         /* Warn if we apparently re-register an entity */
 429         WARN_ON(entity->parent != NULL);
 430         entity->parent = mdev;
 431
 432         spin_lock(&mdev->lock);
 433         if (entity->id == 0)
 434                 entity->id = mdev->entity_id++;
 435         else
 436                 mdev->entity_id = max(entity->id + 1, mdev->entity_id);
 437         list_add_tail(&entity->list, &mdev->entities);
 438         spin_unlock(&mdev->lock);
 439
 440         return 0;
 441 }
 442 EXPORT_SYMBOL_GPL(media_device_register_entity);
 443
 444 /**
 445  * media_device_unregister_entity - Unregister an entity
 446  * @entity:     The entity
 447  *
 448  * If the entity has never been registered this function will return
 449  * immediately.
 450  */
 451 void media_device_unregister_entity(struct media_entity *entity)
 452 {
 453         struct media_device *mdev = entity->parent;
 454
 455         if (mdev == NULL)
 456                 return;
 457
 458         spin_lock(&mdev->lock);
 459         list_del(&entity->list);
 460         spin_unlock(&mdev->lock);
 461         entity->parent = NULL;
 462 }
 463 EXPORT_SYMBOL_GPL(media_device_unregister_entity);