uvc_entity.c

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/*
 *      uvc_entity.c  --  USB Video Class driver
 *
 *      Copyright (C) 2005-2011
 *          Laurent Pinchart ([email protected])
 *
 *      This program is free software; you can redistribute it and/or modify
 *      it under the terms of the GNU General Public License as published by
 *      the Free Software Foundation; either version 2 of the License, or
 *      (at your option) any later version.
 *
 */

#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/videodev2.h>

#include <media/v4l2-common.h>

#include "uvcvideo.h"

/* ------------------------------------------------------------------------
 * Video subdevices registration and unregistration
 */

static int uvc_mc_register_entity(struct uvc_video_chain *chain,
    struct uvc_entity *entity)
{
    const u32 flags = MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE;
    struct media_entity *sink;
    unsigned int i;
    int ret;

    sink = (UVC_ENTITY_TYPE(entity) == UVC_TT_STREAMING)
         ? (entity->vdev ? &entity->vdev->entity : NULL)
         : &entity->subdev.entity;
    if (sink == NULL)
        return 0;

    for (i = 0; i < entity->num_pads; ++i) {
        struct media_entity *source;
        struct uvc_entity *remote;
        u8 remote_pad;

        if (!(entity->pads[i].flags & MEDIA_PAD_FL_SINK))
            continue;

        remote = uvc_entity_by_id(chain->dev, entity->baSourceID[i]);
        if (remote == NULL)
            return -EINVAL;

        source = (UVC_ENTITY_TYPE(remote) == UVC_TT_STREAMING)
               ? (remote->vdev ? &remote->vdev->entity : NULL)
               : &remote->subdev.entity;
        if (source == NULL)
            continue;

        remote_pad = remote->num_pads - 1;
        ret = media_entity_create_link(source, remote_pad,
                           sink, i, flags);
        if (ret < 0)
            return ret;
    }

    if (UVC_ENTITY_TYPE(entity) == UVC_TT_STREAMING)
        return 0;

    return v4l2_device_register_subdev(&chain->dev->vdev, &entity->subdev);
}

static struct v4l2_subdev_ops uvc_subdev_ops = {
};

void uvc_mc_cleanup_entity(struct uvc_entity *entity)
{
    if (UVC_ENTITY_TYPE(entity) != UVC_TT_STREAMING)
        media_entity_cleanup(&entity->subdev.entity);
    else if (entity->vdev != NULL)
        media_entity_cleanup(&entity->vdev->entity);
}

static int uvc_mc_init_entity(struct uvc_entity *entity)
{
    int ret;

    if (UVC_ENTITY_TYPE(entity) != UVC_TT_STREAMING) {
        v4l2_subdev_init(&entity->subdev, &uvc_subdev_ops);
        strlcpy(entity->subdev.name, entity->name,
            sizeof(entity->subdev.name));

        ret = media_entity_init(&entity->subdev.entity,
                    entity->num_pads, entity->pads, 0);
    } else if (entity->vdev != NULL) {
        ret = media_entity_init(&entity->vdev->entity,
                    entity->num_pads, entity->pads, 0);
    } else
        ret = 0;

    return ret;
}

int uvc_mc_register_entities(struct uvc_video_chain *chain)
{
    struct uvc_entity *entity;
    int ret;

    list_for_each_entry(entity, &chain->entities, chain) {
        ret = uvc_mc_init_entity(entity);
        if (ret < 0) {
            uvc_printk(KERN_INFO, "Failed to initialize entity for "
                   "entity %u\n", entity->id);
            return ret;
        }
    }

    list_for_each_entry(entity, &chain->entities, chain) {
        ret = uvc_mc_register_entity(chain, entity);
        if (ret < 0) {
            uvc_printk(KERN_INFO, "Failed to register entity for "
                   "entity %u\n", entity->id);
            return ret;
        }
    }

    return 0;
}