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