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