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
 146                         memset(&pad, 0, sizeof(pad));
 147                         media_device_kpad_to_upad(&entity->pads[p], &pad);
 148                         if (copy_to_user(&links->pads[p], &pad, sizeof(pad)))
 149                                 return -EFAULT;
 150                 }
 151         }
 152
 153         if (links->links) {
 154                 struct media_link_desc __user *ulink;
 155                 unsigned int l;
 156
 157                 for (l = 0, ulink = links->links; l < entity->num_links; l++) {
 158                         struct media_link_desc link;
 159
 160                         /* Ignore backlinks. */
 161                         if (entity->links[l].source->entity != entity)
 162                                 continue;
 163
 164                         memset(&link, 0, sizeof(link));
 165                         media_device_kpad_to_upad(entity->links[l].source,
 166                                                   &link.source);
 167                         media_device_kpad_to_upad(entity->links[l].sink,
 168                                                   &link.sink);
 169                         link.flags = entity->links[l].flags;
 170                         if (copy_to_user(ulink, &link, sizeof(*ulink)))
 171                                 return -EFAULT;
 172                         ulink++;
 173                 }
 174         }
 175
 176         return 0;
 177 }
 178
 179 static long media_device_enum_links(struct media_device *mdev,
 180                                     struct media_links_enum __user *ulinks)
 181 {
 182         struct media_links_enum links;
 183         int rval;
 184
 185         if (copy_from_user(&links, ulinks, sizeof(links)))
 186                 return -EFAULT;
 187
 188         rval = __media_device_enum_links(mdev, &links);
 189         if (rval < 0)
 190                 return rval;
 191
 192         if (copy_to_user(ulinks, &links, sizeof(*ulinks)))
 193                 return -EFAULT;
 194
 195         return 0;
 196 }
 197
 198 static long media_device_setup_link(struct media_device *mdev,
 199                                     struct media_link_desc __user *_ulink)
 200 {
 201         struct media_link *link = NULL;
 202         struct media_link_desc ulink;
 203         struct media_entity *source;
 204         struct media_entity *sink;
 205         int ret;
 206
 207         if (copy_from_user(&ulink, _ulink, sizeof(ulink)))
 208                 return -EFAULT;
 209
 210         /* Find the source and sink entities and link.
 211          */
 212         source = find_entity(mdev, ulink.source.entity);
 213         sink = find_entity(mdev, ulink.sink.entity);
 214
 215         if (source == NULL || sink == NULL)
 216                 return -EINVAL;
 217
 218         if (ulink.source.index >= source->num_pads ||
 219             ulink.sink.index >= sink->num_pads)
 220                 return -EINVAL;
 221
 222         link = media_entity_find_link(&source->pads[ulink.source.index],
 223                                       &sink->pads[ulink.sink.index]);
 224         if (link == NULL)
 225                 return -EINVAL;
 226
 227         /* Setup the link on both entities. */
 228         ret = __media_entity_setup_link(link, ulink.flags);
 229
 230         if (copy_to_user(_ulink, &ulink, sizeof(ulink)))
 231                 return -EFAULT;
 232
 233         return ret;
 234 }
 235
 236 static long media_device_ioctl(struct file *filp, unsigned int cmd,
 237                                unsigned long arg)
 238 {
 239         struct media_devnode *devnode = media_devnode_data(filp);
 240         struct media_device *dev = to_media_device(devnode);
 241         long ret;
 242
 243         switch (cmd) {
 244         case MEDIA_IOC_DEVICE_INFO:
 245                 ret = media_device_get_info(dev,
 246                                 (struct media_device_info __user *)arg);
 247                 break;
 248
 249         case MEDIA_IOC_ENUM_ENTITIES:
 250                 ret = media_device_enum_entities(dev,
 251                                 (struct media_entity_desc __user *)arg);
 252                 break;
 253
 254         case MEDIA_IOC_ENUM_LINKS:
 255                 mutex_lock(&dev->graph_mutex);
 256                 ret = media_device_enum_links(dev,
 257                                 (struct media_links_enum __user *)arg);
 258                 mutex_unlock(&dev->graph_mutex);
 259                 break;
 260
 261         case MEDIA_IOC_SETUP_LINK:
 262                 mutex_lock(&dev->graph_mutex);
 263                 ret = media_device_setup_link(dev,
 264                                 (struct media_link_desc __user *)arg);
 265                 mutex_unlock(&dev->graph_mutex);
 266                 break;
 267
 268         default:
 269                 ret = -ENOIOCTLCMD;
 270         }
 271
 272         return ret;
 273 }
 274
 275 #ifdef CONFIG_COMPAT
 276
 277 struct media_links_enum32 {
 278         __u32 entity;
 279         compat_uptr_t pads; /* struct media_pad_desc * */
 280         compat_uptr_t links; /* struct media_link_desc * */
 281         __u32 reserved[4];
 282 };
 283
 284 static long media_device_enum_links32(struct media_device *mdev,
 285                                       struct media_links_enum32 __user *ulinks)
 286 {
 287         struct media_links_enum links;
 288         compat_uptr_t pads_ptr, links_ptr;
 289
 290         memset(&links, 0, sizeof(links));
 291
 292         if (get_user(links.entity, &ulinks->entity)
 293             || get_user(pads_ptr, &ulinks->pads)
 294             || get_user(links_ptr, &ulinks->links))
 295                 return -EFAULT;
 296
 297         links.pads = compat_ptr(pads_ptr);
 298         links.links = compat_ptr(links_ptr);
 299
 300         return __media_device_enum_links(mdev, &links);
 301 }
 302
 303 #define MEDIA_IOC_ENUM_LINKS32          _IOWR('|', 0x02, struct media_links_enum32)
 304
 305 static long media_device_compat_ioctl(struct file *filp, unsigned int cmd,
 306                                       unsigned long arg)
 307 {
 308         struct media_devnode *devnode = media_devnode_data(filp);
 309         struct media_device *dev = to_media_device(devnode);
 310         long ret;
 311
 312         switch (cmd) {
 313         case MEDIA_IOC_DEVICE_INFO:
 314         case MEDIA_IOC_ENUM_ENTITIES:
 315         case MEDIA_IOC_SETUP_LINK:
 316                 return media_device_ioctl(filp, cmd, arg);
 317
 318         case MEDIA_IOC_ENUM_LINKS32:
 319                 mutex_lock(&dev->graph_mutex);
 320                 ret = media_device_enum_links32(dev,
 321                                 (struct media_links_enum32 __user *)arg);
 322                 mutex_unlock(&dev->graph_mutex);
 323                 break;
 324
 325         default:
 326                 ret = -ENOIOCTLCMD;
 327         }
 328
 329         return ret;
 330 }
 331 #endif /* CONFIG_COMPAT */
 332
 333 static const struct media_file_operations media_device_fops = {
 334         .owner = THIS_MODULE,
 335         .open = media_device_open,
 336         .ioctl = media_device_ioctl,
 337 #ifdef CONFIG_COMPAT
 338         .compat_ioctl = media_device_compat_ioctl,
 339 #endif /* CONFIG_COMPAT */
 340         .release = media_device_close,
 341 };
 342
 343 /* -----------------------------------------------------------------------------
 344  * sysfs
 345  */
 346
 347 static ssize_t show_model(struct device *cd,
 348                           struct device_attribute *attr, char *buf)
 349 {
 350         struct media_device *mdev = to_media_device(to_media_devnode(cd));
 351
 352         return sprintf(buf, "%.*s\n", (int)sizeof(mdev->model), mdev->model);
 353 }
 354
 355 static DEVICE_ATTR(model, S_IRUGO, show_model, NULL);
 356
 357 /* -----------------------------------------------------------------------------
 358  * Registration/unregistration
 359  */
 360
 361 static void media_device_release(struct media_devnode *mdev)
 362 {
 363 }
 364
 365 /**
 366  * media_device_register - register a media device
 367  * @mdev:       The media device
 368  *
 369  * The caller is responsible for initializing the media device before
 370  * registration. The following fields must be set:
 371  *
 372  * - dev must point to the parent device
 373  * - model must be filled with the device model name
 374  */
 375 int __must_check media_device_register(struct media_device *mdev)
 376 {
 377         int ret;
 378
 379         if (WARN_ON(mdev->dev == NULL || mdev->model[0] == 0))
 380                 return -EINVAL;
 381
 382         mdev->entity_id = 1;
 383         INIT_LIST_HEAD(&mdev->entities);
 384         spin_lock_init(&mdev->lock);
 385         mutex_init(&mdev->graph_mutex);
 386
 387         /* Register the device node. */
 388         mdev->devnode.fops = &media_device_fops;
 389         mdev->devnode.parent = mdev->dev;
 390         mdev->devnode.release = media_device_release;
 391         ret = media_devnode_register(&mdev->devnode);
 392         if (ret < 0)
 393                 return ret;
 394
 395         ret = device_create_file(&mdev->devnode.dev, &dev_attr_model);
 396         if (ret < 0) {
 397                 media_devnode_unregister(&mdev->devnode);
 398                 return ret;
 399         }
 400
 401         return 0;
 402 }
 403 EXPORT_SYMBOL_GPL(media_device_register);
 404
 405 /**
 406  * media_device_unregister - unregister a media device
 407  * @mdev:       The media device
 408  *
 409  */
 410 void media_device_unregister(struct media_device *mdev)
 411 {
 412         struct media_entity *entity;
 413         struct media_entity *next;
 414
 415         list_for_each_entry_safe(entity, next, &mdev->entities, list)
 416                 media_device_unregister_entity(entity);
 417
 418         device_remove_file(&mdev->devnode.dev, &dev_attr_model);
 419         media_devnode_unregister(&mdev->devnode);
 420 }
 421 EXPORT_SYMBOL_GPL(media_device_unregister);
 422
 423 /**
 424  * media_device_register_entity - Register an entity with a media device
 425  * @mdev:       The media device
 426  * @entity:     The entity
 427  */
 428 int __must_check media_device_register_entity(struct media_device *mdev,
 429                                               struct media_entity *entity)
 430 {
 431         /* Warn if we apparently re-register an entity */
 432         WARN_ON(entity->parent != NULL);
 433         entity->parent = mdev;
 434
 435         spin_lock(&mdev->lock);
 436         if (entity->id == 0)
 437                 entity->id = mdev->entity_id++;
 438         else
 439                 mdev->entity_id = max(entity->id + 1, mdev->entity_id);
 440         list_add_tail(&entity->list, &mdev->entities);
 441         spin_unlock(&mdev->lock);
 442
 443         return 0;
 444 }
 445 EXPORT_SYMBOL_GPL(media_device_register_entity);
 446
 447 /**
 448  * media_device_unregister_entity - Unregister an entity
 449  * @entity:     The entity
 450  *
 451  * If the entity has never been registered this function will return
 452  * immediately.
 453  */
 454 void media_device_unregister_entity(struct media_entity *entity)
 455 {
 456         struct media_device *mdev = entity->parent;
 457
 458         if (mdev == NULL)
 459                 return;
 460
 461         spin_lock(&mdev->lock);
 462         list_del(&entity->list);
 463         spin_unlock(&mdev->lock);
 464         entity->parent = NULL;
 465 }
 466 EXPORT_SYMBOL_GPL(media_device_unregister_entity);