drivers/media/video/uvc/uvc_entity.c

   1 /*
   2  *      uvc_entity.c  --  USB Video Class driver
   3  *
   4  *      Copyright (C) 2005-2011
   5  *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
   6  *
   7  *      This program is free software; you can redistribute it and/or modify
   8  *      it under the terms of the GNU General Public License as published by
   9  *      the Free Software Foundation; either version 2 of the License, or
  10  *      (at your option) any later version.
  11  *
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/list.h>
  16 #include <linux/videodev2.h>
  17
  18 #include <media/v4l2-common.h>
  19
  20 #include "uvcvideo.h"
  21
  22 /* ------------------------------------------------------------------------
  23  * Video subdevices registration and unregistration
  24  */
  25
  26 static int uvc_mc_register_entity(struct uvc_video_chain *chain,
  27         struct uvc_entity *entity)
  28 {
  29         const u32 flags = MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE;
  30         struct uvc_entity *remote;
  31         unsigned int i;
  32         u8 remote_pad;
  33         int ret;
  34
  35         for (i = 0; i < entity->num_pads; ++i) {
  36                 if (!(entity->pads[i].flags & MEDIA_PAD_FL_SINK))
  37                         continue;
  38
  39                 remote = uvc_entity_by_id(chain->dev, entity->baSourceID[i]);
  40                 if (remote == NULL)
  41                         return -EINVAL;
  42
  43                 remote_pad = remote->num_pads - 1;
  44                 ret = media_entity_create_link(&remote->subdev.entity,
  45                                 remote_pad, &entity->subdev.entity, i, flags);
  46                 if (ret < 0)
  47                         return ret;
  48         }
  49
  50         return v4l2_device_register_subdev(&chain->dev->vdev, &entity->subdev);
  51 }
  52
  53 static struct v4l2_subdev_ops uvc_subdev_ops = {
  54 };
  55
  56 void uvc_mc_cleanup_entity(struct uvc_entity *entity)
  57 {
  58         media_entity_cleanup(&entity->subdev.entity);
  59 }
  60
  61 static int uvc_mc_init_entity(struct uvc_entity *entity)
  62 {
  63         v4l2_subdev_init(&entity->subdev, &uvc_subdev_ops);
  64         strlcpy(entity->subdev.name, entity->name, sizeof(entity->subdev.name));
  65
  66         return media_entity_init(&entity->subdev.entity, entity->num_pads,
  67                                  entity->pads, 0);
  68 }
  69
  70 int uvc_mc_register_entities(struct uvc_video_chain *chain)
  71 {
  72         struct uvc_entity *entity;
  73         int ret;
  74
  75         list_for_each_entry(entity, &chain->entities, chain) {
  76                 ret = uvc_mc_init_entity(entity);
  77                 if (ret < 0) {
  78                         uvc_printk(KERN_INFO, "Failed to initialize entity for "
  79                                    "entity %u\n", entity->id);
  80                         return ret;
  81                 }
  82         }
  83
  84         list_for_each_entry(entity, &chain->entities, chain) {
  85                 ret = uvc_mc_register_entity(chain, entity);
  86                 if (ret < 0) {
  87                         uvc_printk(KERN_INFO, "Failed to register entity for "
  88                                    "entity %u\n", entity->id);
  89                         return ret;
  90                 }
  91         }
  92
  93         return 0;
  94 }