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                 struct media_entity *source;
  37                 struct media_entity *sink;
  38
  39                 if (!(entity->pads[i].flags & MEDIA_PAD_FL_SINK))
  40                         continue;
  41
  42                 remote = uvc_entity_by_id(chain->dev, entity->baSourceID[i]);
  43                 if (remote == NULL)
  44                         return -EINVAL;
  45
  46                 source = (UVC_ENTITY_TYPE(remote) == UVC_TT_STREAMING)
  47                        ? &remote->vdev->entity : &remote->subdev.entity;
  48                 sink = (UVC_ENTITY_TYPE(entity) == UVC_TT_STREAMING)
  49                      ? &entity->vdev->entity : &entity->subdev.entity;
  50
  51                 remote_pad = remote->num_pads - 1;
  52                 ret = media_entity_create_link(source, remote_pad,
  53                                                sink, i, flags);
  54                 if (ret < 0)
  55                         return ret;
  56         }
  57
  58         if (UVC_ENTITY_TYPE(entity) != UVC_TT_STREAMING)
  59                 ret = v4l2_device_register_subdev(&chain->dev->vdev,
  60                                                   &entity->subdev);
  61
  62         return ret;
  63 }
  64
  65 static struct v4l2_subdev_ops uvc_subdev_ops = {
  66 };
  67
  68 void uvc_mc_cleanup_entity(struct uvc_entity *entity)
  69 {
  70         if (UVC_ENTITY_TYPE(entity) != UVC_TT_STREAMING)
  71                 media_entity_cleanup(&entity->subdev.entity);
  72         else if (entity->vdev != NULL)
  73                 media_entity_cleanup(&entity->vdev->entity);
  74 }
  75
  76 static int uvc_mc_init_entity(struct uvc_entity *entity)
  77 {
  78         int ret;
  79
  80         if (UVC_ENTITY_TYPE(entity) != UVC_TT_STREAMING) {
  81                 v4l2_subdev_init(&entity->subdev, &uvc_subdev_ops);
  82                 strlcpy(entity->subdev.name, entity->name,
  83                         sizeof(entity->subdev.name));
  84
  85                 ret = media_entity_init(&entity->subdev.entity,
  86                                         entity->num_pads, entity->pads, 0);
  87         } else
  88                 ret = media_entity_init(&entity->vdev->entity,
  89                                         entity->num_pads, entity->pads, 0);
  90
  91         return ret;
  92 }
  93
  94 int uvc_mc_register_entities(struct uvc_video_chain *chain)
  95 {
  96         struct uvc_entity *entity;
  97         int ret;
  98
  99         list_for_each_entry(entity, &chain->entities, chain) {
 100                 ret = uvc_mc_init_entity(entity);
 101                 if (ret < 0) {
 102                         uvc_printk(KERN_INFO, "Failed to initialize entity for "
 103                                    "entity %u\n", entity->id);
 104                         return ret;
 105                 }
 106         }
 107
 108         list_for_each_entry(entity, &chain->entities, chain) {
 109                 ret = uvc_mc_register_entity(chain, entity);
 110                 if (ret < 0) {
 111                         uvc_printk(KERN_INFO, "Failed to register entity for "
 112                                    "entity %u\n", entity->id);
 113                         return ret;
 114                 }
 115         }
 116
 117         return 0;
 118 }