xref: /openbmc/linux/drivers/media/usb/uvc/uvc_entity.c (revision e3d786a3)
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 const 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 		strscpy(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 }
129