xref: /openbmc/linux/drivers/media/usb/uvc/uvc_entity.c (revision b830f94f)
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 }
124