linux/drivers/media/media-device.c
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   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
  36static int media_device_open(struct file *filp)
  37{
  38        return 0;
  39}
  40
  41static int media_device_close(struct file *filp)
  42{
  43        return 0;
  44}
  45
  46static 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
  67static 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
  89static 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
 119static 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
 127static 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
 177static 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
 215static 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
 254static 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
 265static 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
 273static DEVICE_ATTR(model, S_IRUGO, show_model, NULL);
 274
 275/* -----------------------------------------------------------------------------
 276 * Registration/unregistration
 277 */
 278
 279static 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 */
 293int __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}
 321EXPORT_SYMBOL_GPL(media_device_register);
 322
 323/**
 324 * media_device_unregister - unregister a media device
 325 * @mdev:       The media device
 326 *
 327 */
 328void 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}
 339EXPORT_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 */
 346int __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}
 363EXPORT_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 */
 372void 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}
 384EXPORT_SYMBOL_GPL(media_device_unregister_entity);
 385
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