linux/drivers/media/media-device.c
<<
>>
Prefs
   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
  37static int media_device_open(struct file *filp)
  38{
  39        return 0;
  40}
  41
  42static int media_device_close(struct file *filp)
  43{
  44        return 0;
  45}
  46
  47static 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
  68static 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
  90static 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        if (copy_from_user(&u_ent.id, &uent->id, sizeof(u_ent.id)))
  97                return -EFAULT;
  98
  99        ent = find_entity(mdev, u_ent.id);
 100
 101        if (ent == NULL)
 102                return -EINVAL;
 103
 104        u_ent.id = ent->id;
 105        if (ent->name) {
 106                strncpy(u_ent.name, ent->name, sizeof(u_ent.name));
 107                u_ent.name[sizeof(u_ent.name) - 1] = '\0';
 108        } else {
 109                memset(u_ent.name, 0, sizeof(u_ent.name));
 110        }
 111        u_ent.type = ent->type;
 112        u_ent.revision = ent->revision;
 113        u_ent.flags = ent->flags;
 114        u_ent.group_id = ent->group_id;
 115        u_ent.pads = ent->num_pads;
 116        u_ent.links = ent->num_links - ent->num_backlinks;
 117        memcpy(&u_ent.raw, &ent->info, sizeof(ent->info));
 118        if (copy_to_user(uent, &u_ent, sizeof(u_ent)))
 119                return -EFAULT;
 120        return 0;
 121}
 122
 123static void media_device_kpad_to_upad(const struct media_pad *kpad,
 124                                      struct media_pad_desc *upad)
 125{
 126        upad->entity = kpad->entity->id;
 127        upad->index = kpad->index;
 128        upad->flags = kpad->flags;
 129}
 130
 131static long __media_device_enum_links(struct media_device *mdev,
 132                                      struct media_links_enum *links)
 133{
 134        struct media_entity *entity;
 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
 146                        memset(&pad, 0, sizeof(pad));
 147                        media_device_kpad_to_upad(&entity->pads[p], &pad);
 148                        if (copy_to_user(&links->pads[p], &pad, sizeof(pad)))
 149                                return -EFAULT;
 150                }
 151        }
 152
 153        if (links->links) {
 154                struct media_link_desc __user *ulink;
 155                unsigned int l;
 156
 157                for (l = 0, ulink = links->links; l < entity->num_links; l++) {
 158                        struct media_link_desc link;
 159
 160                        /* Ignore backlinks. */
 161                        if (entity->links[l].source->entity != entity)
 162                                continue;
 163
 164                        memset(&link, 0, sizeof(link));
 165                        media_device_kpad_to_upad(entity->links[l].source,
 166                                                  &link.source);
 167                        media_device_kpad_to_upad(entity->links[l].sink,
 168                                                  &link.sink);
 169                        link.flags = entity->links[l].flags;
 170                        if (copy_to_user(ulink, &link, sizeof(*ulink)))
 171                                return -EFAULT;
 172                        ulink++;
 173                }
 174        }
 175
 176        return 0;
 177}
 178
 179static long media_device_enum_links(struct media_device *mdev,
 180                                    struct media_links_enum __user *ulinks)
 181{
 182        struct media_links_enum links;
 183        int rval;
 184
 185        if (copy_from_user(&links, ulinks, sizeof(links)))
 186                return -EFAULT;
 187
 188        rval = __media_device_enum_links(mdev, &links);
 189        if (rval < 0)
 190                return rval;
 191
 192        if (copy_to_user(ulinks, &links, sizeof(*ulinks)))
 193                return -EFAULT;
 194
 195        return 0;
 196}
 197
 198static long media_device_setup_link(struct media_device *mdev,
 199                                    struct media_link_desc __user *_ulink)
 200{
 201        struct media_link *link = NULL;
 202        struct media_link_desc ulink;
 203        struct media_entity *source;
 204        struct media_entity *sink;
 205        int ret;
 206
 207        if (copy_from_user(&ulink, _ulink, sizeof(ulink)))
 208                return -EFAULT;
 209
 210        /* Find the source and sink entities and link.
 211         */
 212        source = find_entity(mdev, ulink.source.entity);
 213        sink = find_entity(mdev, ulink.sink.entity);
 214
 215        if (source == NULL || sink == NULL)
 216                return -EINVAL;
 217
 218        if (ulink.source.index >= source->num_pads ||
 219            ulink.sink.index >= sink->num_pads)
 220                return -EINVAL;
 221
 222        link = media_entity_find_link(&source->pads[ulink.source.index],
 223                                      &sink->pads[ulink.sink.index]);
 224        if (link == NULL)
 225                return -EINVAL;
 226
 227        /* Setup the link on both entities. */
 228        ret = __media_entity_setup_link(link, ulink.flags);
 229
 230        if (copy_to_user(_ulink, &ulink, sizeof(ulink)))
 231                return -EFAULT;
 232
 233        return ret;
 234}
 235
 236static long media_device_ioctl(struct file *filp, unsigned int cmd,
 237                               unsigned long arg)
 238{
 239        struct media_devnode *devnode = media_devnode_data(filp);
 240        struct media_device *dev = to_media_device(devnode);
 241        long ret;
 242
 243        switch (cmd) {
 244        case MEDIA_IOC_DEVICE_INFO:
 245                ret = media_device_get_info(dev,
 246                                (struct media_device_info __user *)arg);
 247                break;
 248
 249        case MEDIA_IOC_ENUM_ENTITIES:
 250                ret = media_device_enum_entities(dev,
 251                                (struct media_entity_desc __user *)arg);
 252                break;
 253
 254        case MEDIA_IOC_ENUM_LINKS:
 255                mutex_lock(&dev->graph_mutex);
 256                ret = media_device_enum_links(dev,
 257                                (struct media_links_enum __user *)arg);
 258                mutex_unlock(&dev->graph_mutex);
 259                break;
 260
 261        case MEDIA_IOC_SETUP_LINK:
 262                mutex_lock(&dev->graph_mutex);
 263                ret = media_device_setup_link(dev,
 264                                (struct media_link_desc __user *)arg);
 265                mutex_unlock(&dev->graph_mutex);
 266                break;
 267
 268        default:
 269                ret = -ENOIOCTLCMD;
 270        }
 271
 272        return ret;
 273}
 274
 275#ifdef CONFIG_COMPAT
 276
 277struct media_links_enum32 {
 278        __u32 entity;
 279        compat_uptr_t pads; /* struct media_pad_desc * */
 280        compat_uptr_t links; /* struct media_link_desc * */
 281        __u32 reserved[4];
 282};
 283
 284static long media_device_enum_links32(struct media_device *mdev,
 285                                      struct media_links_enum32 __user *ulinks)
 286{
 287        struct media_links_enum links;
 288        compat_uptr_t pads_ptr, links_ptr;
 289
 290        memset(&links, 0, sizeof(links));
 291
 292        if (get_user(links.entity, &ulinks->entity)
 293            || get_user(pads_ptr, &ulinks->pads)
 294            || get_user(links_ptr, &ulinks->links))
 295                return -EFAULT;
 296
 297        links.pads = compat_ptr(pads_ptr);
 298        links.links = compat_ptr(links_ptr);
 299
 300        return __media_device_enum_links(mdev, &links);
 301}
 302
 303#define MEDIA_IOC_ENUM_LINKS32          _IOWR('|', 0x02, struct media_links_enum32)
 304
 305static long media_device_compat_ioctl(struct file *filp, unsigned int cmd,
 306                                      unsigned long arg)
 307{
 308        struct media_devnode *devnode = media_devnode_data(filp);
 309        struct media_device *dev = to_media_device(devnode);
 310        long ret;
 311
 312        switch (cmd) {
 313        case MEDIA_IOC_DEVICE_INFO:
 314        case MEDIA_IOC_ENUM_ENTITIES:
 315        case MEDIA_IOC_SETUP_LINK:
 316                return media_device_ioctl(filp, cmd, arg);
 317
 318        case MEDIA_IOC_ENUM_LINKS32:
 319                mutex_lock(&dev->graph_mutex);
 320                ret = media_device_enum_links32(dev,
 321                                (struct media_links_enum32 __user *)arg);
 322                mutex_unlock(&dev->graph_mutex);
 323                break;
 324
 325        default:
 326                ret = -ENOIOCTLCMD;
 327        }
 328
 329        return ret;
 330}
 331#endif /* CONFIG_COMPAT */
 332
 333static const struct media_file_operations media_device_fops = {
 334        .owner = THIS_MODULE,
 335        .open = media_device_open,
 336        .ioctl = media_device_ioctl,
 337#ifdef CONFIG_COMPAT
 338        .compat_ioctl = media_device_compat_ioctl,
 339#endif /* CONFIG_COMPAT */
 340        .release = media_device_close,
 341};
 342
 343/* -----------------------------------------------------------------------------
 344 * sysfs
 345 */
 346
 347static ssize_t show_model(struct device *cd,
 348                          struct device_attribute *attr, char *buf)
 349{
 350        struct media_device *mdev = to_media_device(to_media_devnode(cd));
 351
 352        return sprintf(buf, "%.*s\n", (int)sizeof(mdev->model), mdev->model);
 353}
 354
 355static DEVICE_ATTR(model, S_IRUGO, show_model, NULL);
 356
 357/* -----------------------------------------------------------------------------
 358 * Registration/unregistration
 359 */
 360
 361static void media_device_release(struct media_devnode *mdev)
 362{
 363}
 364
 365/**
 366 * media_device_register - register a media device
 367 * @mdev:       The media device
 368 *
 369 * The caller is responsible for initializing the media device before
 370 * registration. The following fields must be set:
 371 *
 372 * - dev must point to the parent device
 373 * - model must be filled with the device model name
 374 */
 375int __must_check media_device_register(struct media_device *mdev)
 376{
 377        int ret;
 378
 379        if (WARN_ON(mdev->dev == NULL || mdev->model[0] == 0))
 380                return -EINVAL;
 381
 382        mdev->entity_id = 1;
 383        INIT_LIST_HEAD(&mdev->entities);
 384        spin_lock_init(&mdev->lock);
 385        mutex_init(&mdev->graph_mutex);
 386
 387        /* Register the device node. */
 388        mdev->devnode.fops = &media_device_fops;
 389        mdev->devnode.parent = mdev->dev;
 390        mdev->devnode.release = media_device_release;
 391        ret = media_devnode_register(&mdev->devnode);
 392        if (ret < 0)
 393                return ret;
 394
 395        ret = device_create_file(&mdev->devnode.dev, &dev_attr_model);
 396        if (ret < 0) {
 397                media_devnode_unregister(&mdev->devnode);
 398                return ret;
 399        }
 400
 401        return 0;
 402}
 403EXPORT_SYMBOL_GPL(media_device_register);
 404
 405/**
 406 * media_device_unregister - unregister a media device
 407 * @mdev:       The media device
 408 *
 409 */
 410void media_device_unregister(struct media_device *mdev)
 411{
 412        struct media_entity *entity;
 413        struct media_entity *next;
 414
 415        list_for_each_entry_safe(entity, next, &mdev->entities, list)
 416                media_device_unregister_entity(entity);
 417
 418        device_remove_file(&mdev->devnode.dev, &dev_attr_model);
 419        media_devnode_unregister(&mdev->devnode);
 420}
 421EXPORT_SYMBOL_GPL(media_device_unregister);
 422
 423/**
 424 * media_device_register_entity - Register an entity with a media device
 425 * @mdev:       The media device
 426 * @entity:     The entity
 427 */
 428int __must_check media_device_register_entity(struct media_device *mdev,
 429                                              struct media_entity *entity)
 430{
 431        /* Warn if we apparently re-register an entity */
 432        WARN_ON(entity->parent != NULL);
 433        entity->parent = mdev;
 434
 435        spin_lock(&mdev->lock);
 436        if (entity->id == 0)
 437                entity->id = mdev->entity_id++;
 438        else
 439                mdev->entity_id = max(entity->id + 1, mdev->entity_id);
 440        list_add_tail(&entity->list, &mdev->entities);
 441        spin_unlock(&mdev->lock);
 442
 443        return 0;
 444}
 445EXPORT_SYMBOL_GPL(media_device_register_entity);
 446
 447/**
 448 * media_device_unregister_entity - Unregister an entity
 449 * @entity:     The entity
 450 *
 451 * If the entity has never been registered this function will return
 452 * immediately.
 453 */
 454void media_device_unregister_entity(struct media_entity *entity)
 455{
 456        struct media_device *mdev = entity->parent;
 457
 458        if (mdev == NULL)
 459                return;
 460
 461        spin_lock(&mdev->lock);
 462        list_del(&entity->list);
 463        spin_unlock(&mdev->lock);
 464        entity->parent = NULL;
 465}
 466EXPORT_SYMBOL_GPL(media_device_unregister_entity);
 467
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.