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        return copy_to_user(__info, &info, sizeof(*__info));
  63}
  64
  65static 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
  87static 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
 117static 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
 125static 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
 175static 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
 213static 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
 252static 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
 263static 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
 271static DEVICE_ATTR(model, S_IRUGO, show_model, NULL);
 272
 273/* -----------------------------------------------------------------------------
 274 * Registration/unregistration
 275 */
 276
 277static 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 */
 291int __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}
 319EXPORT_SYMBOL_GPL(media_device_register);
 320
 321/**
 322 * media_device_unregister - unregister a media device
 323 * @mdev:       The media device
 324 *
 325 */
 326void 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}
 337EXPORT_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 */
 344int __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}
 361EXPORT_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 */
 370void 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}
 382EXPORT_SYMBOL_GPL(media_device_unregister_entity);
 383
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