Userspace applications can now discover the UVC device topology using
the media controller API.
Signed-off-by: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
Index: v4l-dvb-mc/linux/drivers/media/video/uvc/uvc_driver.c
===================================================================
--- v4l-dvb-mc.orig/linux/drivers/media/video/uvc/uvc_driver.c
+++ v4l-dvb-mc/linux/drivers/media/video/uvc/uvc_driver.c
@@ -762,9 +762,12 @@ static struct uvc_entity *uvc_alloc_enti
struct uvc_entity *entity;
unsigned int num_inputs;
unsigned int size;
+ unsigned int i;
+ extra_size = ALIGN(extra_size, sizeof(*entity->pads));
num_inputs = (type & UVC_TERM_OUTPUT) ? num_pads : num_pads - 1;
- size = sizeof(*entity) + extra_size + num_inputs;
+ size = sizeof(*entity) + extra_size + sizeof(*entity->pads) * num_pads
+ + num_inputs;
entity = kzalloc(size, GFP_KERNEL);
if (entity == NULL)
return NULL;
@@ -772,8 +775,17 @@ static struct uvc_entity *uvc_alloc_enti
entity->id = id;
entity->type = type;
+ entity->num_links = 0;
+ entity->num_pads = num_pads;
+ entity->pads = ((void *)(entity + 1)) + extra_size;
+
+ for (i = 0; i < num_inputs; ++i)
+ entity->pads[i].type = V4L2_PAD_TYPE_INPUT;
+ if (!UVC_ENTITY_IS_OTERM(entity))
+ entity->pads[num_pads-1].type = V4L2_PAD_TYPE_OUTPUT;
+
entity->bNrInPins = num_inputs;
- entity->baSourceID = ((__u8 *)entity) + sizeof(*entity) + extra_size;
+ entity->baSourceID = (__u8 *)(&entity->pads[num_pads]);
return entity;
}
@@ -1158,6 +1170,77 @@ next_descriptor:
}
/* ------------------------------------------------------------------------
+ * Video subdevices registration and unregistration
+ */
+
+static int uvc_mc_register_subdev(struct uvc_video_chain *chain,
+ struct uvc_entity *entity)
+{
+ const u32 flags = V4L2_LINK_FLAG_ACTIVE | V4L2_LINK_FLAG_PERMANENT;
+ struct uvc_entity *remote;
+ unsigned int i;
+ u8 remote_pad;
+ int ret;
+
+ for (i = 0; i < entity->num_pads; ++i) {
+ if (entity->pads[i].type != V4L2_PAD_TYPE_INPUT)
+ continue;
+
+ remote = uvc_entity_by_id(chain->dev, entity->baSourceID[i]);
+ if (remote == NULL)
+ return -EINVAL;
+
+ remote_pad = remote->num_pads - 1;
+ ret = v4l2_entity_connect(&remote->subdev.entity, remote_pad,
+ &entity->subdev.entity, i, flags);
+ if (ret < 0)
+ return ret;
+ }
+
+ return v4l2_device_register_subdev(&chain->dev->vdev, &entity->subdev);
+}
+
+static struct v4l2_subdev_ops uvc_subdev_ops = {
+};
+
+static int uvc_mc_init_subdev(struct uvc_video_chain *chain,
+ struct uvc_entity *entity)
+{
+ v4l2_subdev_init(&entity->subdev, &uvc_subdev_ops);
+ snprintf(entity->subdev.name, sizeof(entity->subdev.name), "uvc-%u",
+ entity->id);
+
+ return v4l2_entity_init(&entity->subdev.entity, entity->num_pads,
+ entity->pads, 0);
+}
+
+static int uvc_mc_register_subdevs(struct uvc_video_chain *chain)
+{
+ struct uvc_entity *entity;
+ int ret;
+
+ list_for_each_entry(entity, &chain->entities, chain) {
+ ret = uvc_mc_init_subdev(chain, entity);
+ if (ret < 0) {
+ uvc_printk(KERN_INFO, "Failed to initialize subdev for "
+ "entity %u\n", entity->id);
+ return ret;
+ }
+ }
+
+ list_for_each_entry(entity, &chain->entities, chain) {
+ ret = uvc_mc_register_subdev(chain, entity);
+ if (ret < 0) {
+ uvc_printk(KERN_INFO, "Failed to register subdev for "
+ "entity %u\n", entity->id);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+/* ------------------------------------------------------------------------
* UVC device scan
*/
@@ -1708,6 +1791,12 @@ static int uvc_register_chains(struct uv
ret = uvc_register_terms(dev, chain);
if (ret < 0)
return ret;
+
+ ret = uvc_mc_register_subdevs(chain);
+ if (ret < 0) {
+ uvc_printk(KERN_INFO, "Failed to register subdevs "
+ "(%d).\n", ret);
+ }
}
return 0;
Index: v4l-dvb-mc/linux/drivers/media/video/uvc/uvcvideo.h
===================================================================
--- v4l-dvb-mc.orig/linux/drivers/media/video/uvc/uvcvideo.h
+++ v4l-dvb-mc/linux/drivers/media/video/uvc/uvcvideo.h
@@ -278,6 +278,12 @@ struct uvc_entity {
__u16 type;
char name[64];
+ /* Media controller-related fields. */
+ struct v4l2_subdev subdev;
+ unsigned int num_pads;
+ unsigned int num_links;
+ struct v4l2_entity_pad *pads;
+
union {
struct {
__u16 wObjectiveFocalLengthMin;
--
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