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 /* ------------------------------------------------------------------------
  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 media_entity *sink;
  31         unsigned int i;
  32         int ret;
  33
  34         sink = (UVC_ENTITY_TYPE(entity) == UVC_TT_STREAMING)
  35              ? (entity->vdev ? &entity->vdev->entity : NULL)
  36              : &entity->subdev.entity;
  37         if (sink == NULL)
  38                 return 0;
  39
  40         for (i = 0; i < entity->num_pads; ++i) {
  41                 struct media_entity *source;
  42                 struct uvc_entity *remote;
  43                 u8 remote_pad;
  44
  45                 if (!(entity->pads[i].flags & MEDIA_PAD_FL_SINK))
  46                         continue;
  47
  48                 remote = uvc_entity_by_id(chain->dev, entity->baSourceID[i]);
  49                 if (remote == NULL)
  50                         return -EINVAL;
  51
  52                 source = (UVC_ENTITY_TYPE(remote) == UVC_TT_STREAMING)
  53                        ? (remote->vdev ? &remote->vdev->entity : NULL)
  54                        : &remote->subdev.entity;
  55                 if (source == NULL)
  56                         continue;
  57
  58                 remote_pad = remote->num_pads - 1;
  59                 ret = media_entity_create_link(source, remote_pad,
  60                                                sink, i, flags);
  61                 if (ret < 0)
  62                         return ret;
  63         }
  64
  65         if (UVC_ENTITY_TYPE(entity) == UVC_TT_STREAMING)
  66                 return 0;
  67
  68         return v4l2_device_register_subdev(&chain->dev->vdev, &entity->subdev);
  69 }
  70
  71 static struct v4l2_subdev_ops uvc_subdev_ops = {
  72 };
  73
  74 void uvc_mc_cleanup_entity(struct uvc_entity *entity)
  75 {
  76         if (UVC_ENTITY_TYPE(entity) != UVC_TT_STREAMING)
  77                 media_entity_cleanup(&entity->subdev.entity);
  78         else if (entity->vdev != NULL)
  79                 media_entity_cleanup(&entity->vdev->entity);
  80 }
  81
  82 static int uvc_mc_init_entity(struct uvc_entity *entity)
  83 {
  84         int ret;
  85
  86         if (UVC_ENTITY_TYPE(entity) != UVC_TT_STREAMING) {
  87                 v4l2_subdev_init(&entity->subdev, &uvc_subdev_ops);
  88                 strlcpy(entity->subdev.name, entity->name,
  89                         sizeof(entity->subdev.name));
  90
  91                 ret = media_entity_init(&entity->subdev.entity,
  92                                         entity->num_pads, entity->pads, 0);
  93         } else if (entity->vdev != NULL) {
  94                 ret = media_entity_init(&entity->vdev->entity,
  95                                         entity->num_pads, entity->pads, 0);
  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(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_register_entity(chain, entity);
 120                 if (ret < 0) {
 121                         uvc_printk(KERN_INFO, "Failed to register entity for "
 122                                    "entity %u\n", entity->id);
 123                         return ret;
 124                 }
 125         }
 126
 127         return 0;
 128 }