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         memcpy(&u_ent.raw, &ent->info, sizeof(ent->info));
 112         if (copy_to_user(uent, &u_ent, sizeof(u_ent)))
 113                 return -EFAULT;
 114         return 0;
 115 }
 116
 117 static void media_device_kpad_to_upad(const struct media_pad *kpad,
 118                                       struct media_pad_desc *upad)
 119 {
 120         upad->entity = kpad->entity->id;
 121         upad->index = kpad->index;
 122         upad->flags = kpad->flags;
 123 }
 124
 125 static long media_device_enum_links(struct media_device *mdev,
 126                                     struct media_links_enum __user *ulinks)
 127 {
 128         struct media_entity *entity;
 129         struct media_links_enum links;
 130
 131         if (copy_from_user(&links, ulinks, sizeof(links)))
 132                 return -EFAULT;
 133
 134         entity = find_entity(mdev, links.entity);
 135         if (entity == NULL)
 136                 return -EINVAL;
 137
 138         if (links.pads) {
 139                 unsigned int p;
 140
 141                 for (p = 0; p < entity->num_pads; p++) {
 142                         struct media_pad_desc pad;
 143                         media_device_kpad_to_upad(&entity->pads[p], &pad);
 144                         if (copy_to_user(&links.pads[p], &pad, sizeof(pad)))
 145                                 return -EFAULT;
 146                 }
 147         }
 148
 149         if (links.links) {
 150                 struct media_link_desc __user *ulink;
 151                 unsigned int l;
 152
 153                 for (l = 0, ulink = links.links; l < entity->num_links; l++) {
 154                         struct media_link_desc link;
 155
 156                         /* Ignore backlinks. */
 157                         if (entity->links[l].source->entity != entity)
 158                                 continue;
 159
 160                         media_device_kpad_to_upad(entity->links[l].source,
 161                                                   &link.source);
 162                         media_device_kpad_to_upad(entity->links[l].sink,
 163                                                   &link.sink);
 164                         link.flags = entity->links[l].flags;
 165                         if (copy_to_user(ulink, &link, sizeof(*ulink)))
 166                                 return -EFAULT;
 167                         ulink++;
 168                 }
 169         }
 170         if (copy_to_user(ulinks, &links, sizeof(*ulinks)))
 171                 return -EFAULT;
 172         return 0;
 173 }
 174
 175 static long media_device_setup_link(struct media_device *mdev,
 176                                     struct media_link_desc __user *_ulink)
 177 {
 178         struct media_link *link = NULL;
 179         struct media_link_desc ulink;
 180         struct media_entity *source;
 181         struct media_entity *sink;
 182         int ret;
 183
 184         if (copy_from_user(&ulink, _ulink, sizeof(ulink)))
 185                 return -EFAULT;
 186
 187         /* Find the source and sink entities and link.
 188          */
 189         source = find_entity(mdev, ulink.source.entity);
 190         sink = find_entity(mdev, ulink.sink.entity);
 191
 192         if (source == NULL || sink == NULL)
 193                 return -EINVAL;
 194
 195         if (ulink.source.index >= source->num_pads ||
 196             ulink.sink.index >= sink->num_pads)
 197                 return -EINVAL;
 198
 199         link = media_entity_find_link(&source->pads[ulink.source.index],
 200                                       &sink->pads[ulink.sink.index]);
 201         if (link == NULL)
 202                 return -EINVAL;
 203
 204         /* Setup the link on both entities. */
 205         ret = __media_entity_setup_link(link, ulink.flags);
 206
 207         if (copy_to_user(_ulink, &ulink, sizeof(ulink)))
 208                 return -EFAULT;
 209
 210         return ret;
 211 }
 212
 213 static long media_device_ioctl(struct file *filp, unsigned int cmd,
 214                                unsigned long arg)
 215 {
 216         struct media_devnode *devnode = media_devnode_data(filp);
 217         struct media_device *dev = to_media_device(devnode);
 218         long ret;
 219
 220         switch (cmd) {
 221         case MEDIA_IOC_DEVICE_INFO:
 222                 ret = media_device_get_info(dev,
 223                                 (struct media_device_info __user *)arg);
 224                 break;
 225
 226         case MEDIA_IOC_ENUM_ENTITIES:
 227                 ret = media_device_enum_entities(dev,
 228                                 (struct media_entity_desc __user *)arg);
 229                 break;
 230
 231         case MEDIA_IOC_ENUM_LINKS:
 232                 mutex_lock(&dev->graph_mutex);
 233                 ret = media_device_enum_links(dev,
 234                                 (struct media_links_enum __user *)arg);
 235                 mutex_unlock(&dev->graph_mutex);
 236                 break;
 237
 238         case MEDIA_IOC_SETUP_LINK:
 239                 mutex_lock(&dev->graph_mutex);
 240                 ret = media_device_setup_link(dev,
 241                                 (struct media_link_desc __user *)arg);
 242                 mutex_unlock(&dev->graph_mutex);
 243                 break;
 244
 245         default:
 246                 ret = -ENOIOCTLCMD;
 247         }
 248
 249         return ret;
 250 }
 251
 252 static const struct media_file_operations media_device_fops = {
 253         .owner = THIS_MODULE,
 254         .open = media_device_open,
 255         .ioctl = media_device_ioctl,
 256         .release = media_device_close,
 257 };
 258
 259 /* -----------------------------------------------------------------------------
 260  * sysfs
 261  */
 262
 263 static ssize_t show_model(struct device *cd,
 264                           struct device_attribute *attr, char *buf)
 265 {
 266         struct media_device *mdev = to_media_device(to_media_devnode(cd));
 267
 268         return sprintf(buf, "%.*s\n", (int)sizeof(mdev->model), mdev->model);
 269 }
 270
 271 static DEVICE_ATTR(model, S_IRUGO, show_model, NULL);
 272
 273 /* -----------------------------------------------------------------------------
 274  * Registration/unregistration
 275  */
 276
 277 static void media_device_release(struct media_devnode *mdev)
 278 {
 279 }
 280
 281 /**
 282  * media_device_register - register a media device
 283  * @mdev:       The media device
 284  *
 285  * The caller is responsible for initializing the media device before
 286  * registration. The following fields must be set:
 287  *
 288  * - dev must point to the parent device
 289  * - model must be filled with the device model name
 290  */
 291 int __must_check media_device_register(struct media_device *mdev)
 292 {
 293         int ret;
 294
 295         if (WARN_ON(mdev->dev == NULL || mdev->model[0] == 0))
 296                 return -EINVAL;
 297
 298         mdev->entity_id = 1;
 299         INIT_LIST_HEAD(&mdev->entities);
 300         spin_lock_init(&mdev->lock);
 301         mutex_init(&mdev->graph_mutex);
 302
 303         /* Register the device node. */
 304         mdev->devnode.fops = &media_device_fops;
 305         mdev->devnode.parent = mdev->dev;
 306         mdev->devnode.release = media_device_release;
 307         ret = media_devnode_register(&mdev->devnode);
 308         if (ret < 0)
 309                 return ret;
 310
 311         ret = device_create_file(&mdev->devnode.dev, &dev_attr_model);
 312         if (ret < 0) {
 313                 media_devnode_unregister(&mdev->devnode);
 314                 return ret;
 315         }
 316
 317         return 0;
 318 }
 319 EXPORT_SYMBOL_GPL(media_device_register);
 320
 321 /**
 322  * media_device_unregister - unregister a media device
 323  * @mdev:       The media device
 324  *
 325  */
 326 void media_device_unregister(struct media_device *mdev)
 327 {
 328         struct media_entity *entity;
 329         struct media_entity *next;
 330
 331         list_for_each_entry_safe(entity, next, &mdev->entities, list)
 332                 media_device_unregister_entity(entity);
 333
 334         device_remove_file(&mdev->devnode.dev, &dev_attr_model);
 335         media_devnode_unregister(&mdev->devnode);
 336 }
 337 EXPORT_SYMBOL_GPL(media_device_unregister);
 338
 339 /**
 340  * media_device_register_entity - Register an entity with a media device
 341  * @mdev:       The media device
 342  * @entity:     The entity
 343  */
 344 int __must_check media_device_register_entity(struct media_device *mdev,
 345                                               struct media_entity *entity)
 346 {
 347         /* Warn if we apparently re-register an entity */
 348         WARN_ON(entity->parent != NULL);
 349         entity->parent = mdev;
 350
 351         spin_lock(&mdev->lock);
 352         if (entity->id == 0)
 353                 entity->id = mdev->entity_id++;
 354         else
 355                 mdev->entity_id = max(entity->id + 1, mdev->entity_id);
 356         list_add_tail(&entity->list, &mdev->entities);
 357         spin_unlock(&mdev->lock);
 358
 359         return 0;
 360 }
 361 EXPORT_SYMBOL_GPL(media_device_register_entity);
 362
 363 /**
 364  * media_device_unregister_entity - Unregister an entity
 365  * @entity:     The entity
 366  *
 367  * If the entity has never been registered this function will return
 368  * immediately.
 369  */
 370 void media_device_unregister_entity(struct media_entity *entity)
 371 {
 372         struct media_device *mdev = entity->parent;
 373
 374         if (mdev == NULL)
 375                 return;
 376
 377         spin_lock(&mdev->lock);
 378         list_del(&entity->list);
 379         spin_unlock(&mdev->lock);
 380         entity->parent = NULL;
 381 }
 382 EXPORT_SYMBOL_GPL(media_device_unregister_entity);