drivers/media/usb/uvc/uvc_entity.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      uvc_entity.c  --  USB Video Class driver
   4  *
   5  *      Copyright (C) 2005-2011
   6  *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/list.h>
  11 #include <linux/videodev2.h>
  12
  13 #include <media/v4l2-common.h>
  14
  15 #include "uvcvideo.h"
  16
  17 static int uvc_mc_create_links(struct uvc_video_chain *chain,
  18                                     struct uvc_entity *entity)
  19 {
  20         const u32 flags = MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE;
  21         struct media_entity *sink;
  22         unsigned int i;
  23         int ret;
  24
  25         sink = (UVC_ENTITY_TYPE(entity) == UVC_TT_STREAMING)
  26              ? (entity->vdev ? &entity->vdev->entity : NULL)
  27              : &entity->subdev.entity;
  28         if (sink == NULL)
  29                 return 0;
  30
  31         for (i = 0; i < entity->num_pads; ++i) {
  32                 struct media_entity *source;
  33                 struct uvc_entity *remote;
  34                 u8 remote_pad;
  35
  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                 source = (UVC_ENTITY_TYPE(remote) == UVC_TT_STREAMING)
  44                        ? (remote->vdev ? &remote->vdev->entity : NULL)
  45                        : &remote->subdev.entity;
  46                 if (source == NULL)
  47                         continue;
  48
  49                 remote_pad = remote->num_pads - 1;
  50                 ret = media_create_pad_link(source, remote_pad,
  51                                                sink, i, flags);
  52                 if (ret < 0)
  53                         return ret;
  54         }
  55
  56         return 0;
  57 }
  58
  59 static const struct v4l2_subdev_ops uvc_subdev_ops = {
  60 };
  61
  62 void uvc_mc_cleanup_entity(struct uvc_entity *entity)
  63 {
  64         if (UVC_ENTITY_TYPE(entity) != UVC_TT_STREAMING)
  65                 media_entity_cleanup(&entity->subdev.entity);
  66         else if (entity->vdev != NULL)
  67                 media_entity_cleanup(&entity->vdev->entity);
  68 }
  69
  70 static int uvc_mc_init_entity(struct uvc_video_chain *chain,
  71                               struct uvc_entity *entity)
  72 {
  73         int ret;
  74
  75         if (UVC_ENTITY_TYPE(entity) != UVC_TT_STREAMING) {
  76                 v4l2_subdev_init(&entity->subdev, &uvc_subdev_ops);
  77                 strscpy(entity->subdev.name, entity->name,
  78                         sizeof(entity->subdev.name));
  79
  80                 ret = media_entity_pads_init(&entity->subdev.entity,
  81                                         entity->num_pads, entity->pads);
  82
  83                 if (ret < 0)
  84                         return ret;
  85
  86                 ret = v4l2_device_register_subdev(&chain->dev->vdev,
  87                                                   &entity->subdev);
  88         } else if (entity->vdev != NULL) {
  89                 ret = media_entity_pads_init(&entity->vdev->entity,
  90                                         entity->num_pads, entity->pads);
  91                 if (entity->flags & UVC_ENTITY_FLAG_DEFAULT)
  92                         entity->vdev->entity.flags |= MEDIA_ENT_FL_DEFAULT;
  93         } else
  94                 ret = 0;
  95
  96         return ret;
  97 }
  98
  99 int uvc_mc_register_entities(struct uvc_video_chain *chain)
 100 {
 101         struct uvc_entity *entity;
 102         int ret;
 103
 104         list_for_each_entry(entity, &chain->entities, chain) {
 105                 ret = uvc_mc_init_entity(chain, entity);
 106                 if (ret < 0) {
 107                         uvc_printk(KERN_INFO, "Failed to initialize entity for "
 108                                    "entity %u\n", entity->id);
 109                         return ret;
 110                 }
 111         }
 112
 113         list_for_each_entry(entity, &chain->entities, chain) {
 114                 ret = uvc_mc_create_links(chain, entity);
 115                 if (ret < 0) {
 116                         uvc_printk(KERN_INFO, "Failed to create links for "
 117                                    "entity %u\n", entity->id);
 118                         return ret;
 119                 }
 120         }
 121
 122         return 0;
 123 }