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