xref: /linux/drivers/media/usb/uvc/uvc_entity.c (revision 827634added7f38b7d724cab1dccdb2b004c13c3)
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 }
129