drivers/media/usb/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 static int uvc_mc_create_links(struct uvc_video_chain *chain,
  23                                     struct uvc_entity *entity)
  24 {
  25         const u32 flags = MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE;
  26         struct media_entity *sink;
  27         unsigned int i;
  28         int ret;
  29
  30         sink = (UVC_ENTITY_TYPE(entity) == UVC_TT_STREAMING)
  31              ? (entity->vdev ? &entity->vdev->entity : NULL)
  32              : &entity->subdev.entity;
  33         if (sink == NULL)
  34                 return 0;
  35
  36         for (i = 0; i < entity->num_pads; ++i) {
  37                 struct media_entity *source;
  38                 struct uvc_entity *remote;
  39                 u8 remote_pad;
  40
  41                 if (!(entity->pads[i].flags & MEDIA_PAD_FL_SINK))
  42                         continue;
  43
  44                 remote = uvc_entity_by_id(chain->dev, entity->baSourceID[i]);
  45                 if (remote == NULL)
  46                         return -EINVAL;
  47
  48                 source = (UVC_ENTITY_TYPE(remote) == UVC_TT_STREAMING)
  49                        ? (remote->vdev ? &remote->vdev->entity : NULL)
  50                        : &remote->subdev.entity;
  51                 if (source == NULL)
  52                         continue;
  53
  54                 remote_pad = remote->num_pads - 1;
  55                 ret = media_create_pad_link(source, remote_pad,
  56                                                sink, i, flags);
  57                 if (ret < 0)
  58                         return ret;
  59         }
  60
  61         return 0;
  62 }
  63
  64 static struct v4l2_subdev_ops uvc_subdev_ops = {
  65 };
  66
  67 void uvc_mc_cleanup_entity(struct uvc_entity *entity)
  68 {
  69         if (UVC_ENTITY_TYPE(entity) != UVC_TT_STREAMING)
  70                 media_entity_cleanup(&entity->subdev.entity);
  71         else if (entity->vdev != NULL)
  72                 media_entity_cleanup(&entity->vdev->entity);
  73 }
  74
  75 static int uvc_mc_init_entity(struct uvc_video_chain *chain,
  76                               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_pads_init(&entity->subdev.entity,
  86                                         entity->num_pads, entity->pads);
  87
  88                 if (ret < 0)
  89                         return ret;
  90
  91                 ret = v4l2_device_register_subdev(&chain->dev->vdev,
  92                                                   &entity->subdev);
  93         } else if (entity->vdev != NULL) {
  94                 ret = media_entity_pads_init(&entity->vdev->entity,
  95                                         entity->num_pads, entity->pads);
  96                 if (entity->flags & UVC_ENTITY_FLAG_DEFAULT)
  97                         entity->vdev->entity.flags |= MEDIA_ENT_FL_DEFAULT;
  98         } else
  99                 ret = 0;
 100
 101         return ret;
 102 }
 103
 104 int uvc_mc_register_entities(struct uvc_video_chain *chain)
 105 {
 106         struct uvc_entity *entity;
 107         int ret;
 108
 109         list_for_each_entry(entity, &chain->entities, chain) {
 110                 ret = uvc_mc_init_entity(chain, entity);
 111                 if (ret < 0) {
 112                         uvc_printk(KERN_INFO, "Failed to initialize entity for "
 113                                    "entity %u\n", entity->id);
 114                         return ret;
 115                 }
 116         }
 117
 118         list_for_each_entry(entity, &chain->entities, chain) {
 119                 ret = uvc_mc_create_links(chain, entity);
 120                 if (ret < 0) {
 121                         uvc_printk(KERN_INFO, "Failed to create links for "
 122                                    "entity %u\n", entity->id);
 123                         return ret;
 124                 }
 125         }
 126
 127         return 0;
 128 }