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         memset(&u_ent, 0, sizeof(u_ent));
  97         if (copy_from_user(&u_ent.id, &uent->id, sizeof(u_ent.id)))
  98                 return -EFAULT;
  99
 100         ent = find_entity(mdev, u_ent.id);
 101
 102         if (ent == NULL)
 103                 return -EINVAL;
 104
 105         u_ent.id = ent->id;
 106         if (ent->name) {
 107                 strncpy(u_ent.name, ent->name, sizeof(u_ent.name));
 108                 u_ent.name[sizeof(u_ent.name) - 1] = '\0';
 109         }
 110         u_ent.type = ent->type;
 111         u_ent.revision = ent->revision;
 112         u_ent.flags = ent->flags;
 113         u_ent.group_id = ent->group_id;
 114         u_ent.pads = ent->num_pads;
 115         u_ent.links = ent->num_links - ent->num_backlinks;
 116         memcpy(&u_ent.raw, &ent->info, sizeof(ent->info));
 117         if (copy_to_user(uent, &u_ent, sizeof(u_ent)))
 118                 return -EFAULT;
 119         return 0;
 120 }
 121
 122 static void media_device_kpad_to_upad(const struct media_pad *kpad,
 123                                       struct media_pad_desc *upad)
 124 {
 125         upad->entity = kpad->entity->id;
 126         upad->index = kpad->index;
 127         upad->flags = kpad->flags;
 128 }
 129
 130 static long __media_device_enum_links(struct media_device *mdev,
 131                                       struct media_links_enum *links)
 132 {
 133         struct media_entity *entity;
 134
 135         entity = find_entity(mdev, links->entity);
 136         if (entity == NULL)
 137                 return -EINVAL;
 138
 139         if (links->pads) {
 140                 unsigned int p;
 141
 142                 for (p = 0; p < entity->num_pads; p++) {
 143                         struct media_pad_desc pad;
 144
 145                         memset(&pad, 0, sizeof(pad));
 146                         media_device_kpad_to_upad(&entity->pads[p], &pad);
 147                         if (copy_to_user(&links->pads[p], &pad, sizeof(pad)))
 148                                 return -EFAULT;
 149                 }
 150         }
 151
 152         if (links->links) {
 153                 struct media_link_desc __user *ulink;
 154                 unsigned int l;
 155
 156                 for (l = 0, ulink = links->links; l < entity->num_links; l++) {
 157                         struct media_link_desc link;
 158
 159                         /* Ignore backlinks. */
 160                         if (entity->links[l].source->entity != entity)
 161                                 continue;
 162
 163                         memset(&link, 0, sizeof(link));
 164                         media_device_kpad_to_upad(entity->links[l].source,
 165                                                   &link.source);
 166                         media_device_kpad_to_upad(entity->links[l].sink,
 167                                                   &link.sink);
 168                         link.flags = entity->links[l].flags;
 169                         if (copy_to_user(ulink, &link, sizeof(*ulink)))
 170                                 return -EFAULT;
 171                         ulink++;
 172                 }
 173         }
 174
 175         return 0;
 176 }
 177
 178 static long media_device_enum_links(struct media_device *mdev,
 179                                     struct media_links_enum __user *ulinks)
 180 {
 181         struct media_links_enum links;
 182         int rval;
 183
 184         if (copy_from_user(&links, ulinks, sizeof(links)))
 185                 return -EFAULT;
 186
 187         rval = __media_device_enum_links(mdev, &links);
 188         if (rval < 0)
 189                 return rval;
 190
 191         if (copy_to_user(ulinks, &links, sizeof(*ulinks)))
 192                 return -EFAULT;
 193
 194         return 0;
 195 }
 196
 197 static long media_device_setup_link(struct media_device *mdev,
 198                                     struct media_link_desc __user *_ulink)
 199 {
 200         struct media_link *link = NULL;
 201         struct media_link_desc ulink;
 202         struct media_entity *source;
 203         struct media_entity *sink;
 204         int ret;
 205
 206         if (copy_from_user(&ulink, _ulink, sizeof(ulink)))
 207                 return -EFAULT;
 208
 209         /* Find the source and sink entities and link.
 210          */
 211         source = find_entity(mdev, ulink.source.entity);
 212         sink = find_entity(mdev, ulink.sink.entity);
 213
 214         if (source == NULL || sink == NULL)
 215                 return -EINVAL;
 216
 217         if (ulink.source.index >= source->num_pads ||
 218             ulink.sink.index >= sink->num_pads)
 219                 return -EINVAL;
 220
 221         link = media_entity_find_link(&source->pads[ulink.source.index],
 222                                       &sink->pads[ulink.sink.index]);
 223         if (link == NULL)
 224                 return -EINVAL;
 225
 226         /* Setup the link on both entities. */
 227         ret = __media_entity_setup_link(link, ulink.flags);
 228
 229         if (copy_to_user(_ulink, &ulink, sizeof(ulink)))
 230                 return -EFAULT;
 231
 232         return ret;
 233 }
 234
 235 static long media_device_ioctl(struct file *filp, unsigned int cmd,
 236                                unsigned long arg)
 237 {
 238         struct media_devnode *devnode = media_devnode_data(filp);
 239         struct media_device *dev = to_media_device(devnode);
 240         long ret;
 241
 242         switch (cmd) {
 243         case MEDIA_IOC_DEVICE_INFO:
 244                 ret = media_device_get_info(dev,
 245                                 (struct media_device_info __user *)arg);
 246                 break;
 247
 248         case MEDIA_IOC_ENUM_ENTITIES:
 249                 ret = media_device_enum_entities(dev,
 250                                 (struct media_entity_desc __user *)arg);
 251                 break;
 252
 253         case MEDIA_IOC_ENUM_LINKS:
 254                 mutex_lock(&dev->graph_mutex);
 255                 ret = media_device_enum_links(dev,
 256                                 (struct media_links_enum __user *)arg);
 257                 mutex_unlock(&dev->graph_mutex);
 258                 break;
 259
 260         case MEDIA_IOC_SETUP_LINK:
 261                 mutex_lock(&dev->graph_mutex);
 262                 ret = media_device_setup_link(dev,
 263                                 (struct media_link_desc __user *)arg);
 264                 mutex_unlock(&dev->graph_mutex);
 265                 break;
 266
 267         default:
 268                 ret = -ENOIOCTLCMD;
 269         }
 270
 271         return ret;
 272 }
 273
 274 #ifdef CONFIG_COMPAT
 275
 276 struct media_links_enum32 {
 277         __u32 entity;
 278         compat_uptr_t pads; /* struct media_pad_desc * */
 279         compat_uptr_t links; /* struct media_link_desc * */
 280         __u32 reserved[4];
 281 };
 282
 283 static long media_device_enum_links32(struct media_device *mdev,
 284                                       struct media_links_enum32 __user *ulinks)
 285 {
 286         struct media_links_enum links;
 287         compat_uptr_t pads_ptr, links_ptr;
 288
 289         memset(&links, 0, sizeof(links));
 290
 291         if (get_user(links.entity, &ulinks->entity)
 292             || get_user(pads_ptr, &ulinks->pads)
 293             || get_user(links_ptr, &ulinks->links))
 294                 return -EFAULT;
 295
 296         links.pads = compat_ptr(pads_ptr);
 297         links.links = compat_ptr(links_ptr);
 298
 299         return __media_device_enum_links(mdev, &links);
 300 }
 301
 302 #define MEDIA_IOC_ENUM_LINKS32          _IOWR('|', 0x02, struct media_links_enum32)
 303
 304 static long media_device_compat_ioctl(struct file *filp, unsigned int cmd,
 305                                       unsigned long arg)
 306 {
 307         struct media_devnode *devnode = media_devnode_data(filp);
 308         struct media_device *dev = to_media_device(devnode);
 309         long ret;
 310
 311         switch (cmd) {
 312         case MEDIA_IOC_DEVICE_INFO:
 313         case MEDIA_IOC_ENUM_ENTITIES:
 314         case MEDIA_IOC_SETUP_LINK:
 315                 return media_device_ioctl(filp, cmd, arg);
 316
 317         case MEDIA_IOC_ENUM_LINKS32:
 318                 mutex_lock(&dev->graph_mutex);
 319                 ret = media_device_enum_links32(dev,
 320                                 (struct media_links_enum32 __user *)arg);
 321                 mutex_unlock(&dev->graph_mutex);
 322                 break;
 323
 324         default:
 325                 ret = -ENOIOCTLCMD;
 326         }
 327
 328         return ret;
 329 }
 330 #endif /* CONFIG_COMPAT */
 331
 332 static const struct media_file_operations media_device_fops = {
 333         .owner = THIS_MODULE,
 334         .open = media_device_open,
 335         .ioctl = media_device_ioctl,
 336 #ifdef CONFIG_COMPAT
 337         .compat_ioctl = media_device_compat_ioctl,
 338 #endif /* CONFIG_COMPAT */
 339         .release = media_device_close,
 340 };
 341
 342 /* -----------------------------------------------------------------------------
 343  * sysfs
 344  */
 345
 346 static ssize_t show_model(struct device *cd,
 347                           struct device_attribute *attr, char *buf)
 348 {
 349         struct media_device *mdev = to_media_device(to_media_devnode(cd));
 350
 351         return sprintf(buf, "%.*s\n", (int)sizeof(mdev->model), mdev->model);
 352 }
 353
 354 static DEVICE_ATTR(model, S_IRUGO, show_model, NULL);
 355
 356 /* -----------------------------------------------------------------------------
 357  * Registration/unregistration
 358  */
 359
 360 static void media_device_release(struct media_devnode *mdev)
 361 {
 362 }
 363
 364 /**
 365  * media_device_register - register a media device
 366  * @mdev:       The media device
 367  *
 368  * The caller is responsible for initializing the media device before
 369  * registration. The following fields must be set:
 370  *
 371  * - dev must point to the parent device
 372  * - model must be filled with the device model name
 373  */
 374 int __must_check media_device_register(struct media_device *mdev)
 375 {
 376         int ret;
 377
 378         if (WARN_ON(mdev->dev == NULL || mdev->model[0] == 0))
 379                 return -EINVAL;
 380
 381         mdev->entity_id = 1;
 382         INIT_LIST_HEAD(&mdev->entities);
 383         spin_lock_init(&mdev->lock);
 384         mutex_init(&mdev->graph_mutex);
 385
 386         /* Register the device node. */
 387         mdev->devnode.fops = &media_device_fops;
 388         mdev->devnode.parent = mdev->dev;
 389         mdev->devnode.release = media_device_release;
 390         ret = media_devnode_register(&mdev->devnode);
 391         if (ret < 0)
 392                 return ret;
 393
 394         ret = device_create_file(&mdev->devnode.dev, &dev_attr_model);
 395         if (ret < 0) {
 396                 media_devnode_unregister(&mdev->devnode);
 397                 return ret;
 398         }
 399
 400         return 0;
 401 }
 402 EXPORT_SYMBOL_GPL(media_device_register);
 403
 404 /**
 405  * media_device_unregister - unregister a media device
 406  * @mdev:       The media device
 407  *
 408  */
 409 void media_device_unregister(struct media_device *mdev)
 410 {
 411         struct media_entity *entity;
 412         struct media_entity *next;
 413
 414         list_for_each_entry_safe(entity, next, &mdev->entities, list)
 415                 media_device_unregister_entity(entity);
 416
 417         device_remove_file(&mdev->devnode.dev, &dev_attr_model);
 418         media_devnode_unregister(&mdev->devnode);
 419 }
 420 EXPORT_SYMBOL_GPL(media_device_unregister);
 421
 422 /**
 423  * media_device_register_entity - Register an entity with a media device
 424  * @mdev:       The media device
 425  * @entity:     The entity
 426  */
 427 int __must_check media_device_register_entity(struct media_device *mdev,
 428                                               struct media_entity *entity)
 429 {
 430         /* Warn if we apparently re-register an entity */
 431         WARN_ON(entity->parent != NULL);
 432         entity->parent = mdev;
 433
 434         spin_lock(&mdev->lock);
 435         if (entity->id == 0)
 436                 entity->id = mdev->entity_id++;
 437         else
 438                 mdev->entity_id = max(entity->id + 1, mdev->entity_id);
 439         list_add_tail(&entity->list, &mdev->entities);
 440         spin_unlock(&mdev->lock);
 441
 442         return 0;
 443 }
 444 EXPORT_SYMBOL_GPL(media_device_register_entity);
 445
 446 /**
 447  * media_device_unregister_entity - Unregister an entity
 448  * @entity:     The entity
 449  *
 450  * If the entity has never been registered this function will return
 451  * immediately.
 452  */
 453 void media_device_unregister_entity(struct media_entity *entity)
 454 {
 455         struct media_device *mdev = entity->parent;
 456
 457         if (mdev == NULL)
 458                 return;
 459
 460         spin_lock(&mdev->lock);
 461         list_del(&entity->list);
 462         spin_unlock(&mdev->lock);
 463         entity->parent = NULL;
 464 }
 465 EXPORT_SYMBOL_GPL(media_device_unregister_entity);