[v3,1/6] media: uvcvideo: Allow custom control mapping

Message ID 20240616231350.6787-2-laurent.pinchart@ideasonboard.com (mailing list archive)
State Accepted
Delegated to: Laurent Pinchart
Headers
Series media: uvc: Probe PLF limits at start-up |

Commit Message

Laurent Pinchart June 16, 2024, 11:13 p.m. UTC
  From: Ricardo Ribalda <ribalda@chromium.org>

Some advanced controls might not be completely implemented by vendors.

If the controls are a enumeration, UVC does not gives a way to probe
what is implemented and what is not.

Let's create a new callback function where heuristics can be implemented
to detect what is implemented and what not and update the control
mapping accordingly.

Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
Changes since v2:

- Replace .add_mapping() with .filter_mapping()
- Modify the filtering logic: mappings whose filter function return NULL
  as skipped
---
 drivers/media/usb/uvc/uvc_ctrl.c | 7 +++++++
 drivers/media/usb/uvc/uvcvideo.h | 5 +++++
 2 files changed, 12 insertions(+)
  

Patch

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 4b685f883e4d..bc30af516afd 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -2652,6 +2652,13 @@  static void uvc_ctrl_init_ctrl(struct uvc_video_chain *chain,
 	for (i = 0; i < ARRAY_SIZE(uvc_ctrl_mappings); ++i) {
 		const struct uvc_control_mapping *mapping = &uvc_ctrl_mappings[i];
 
+		/* Let the device provide a custom mapping. */
+		if (mapping->filter_mapping) {
+			mapping = mapping->filter_mapping(chain, ctrl);
+			if (!mapping)
+				continue;
+		}
+
 		if (uvc_entity_match_guid(ctrl->entity, mapping->entity) &&
 		    ctrl->info.selector == mapping->selector)
 			__uvc_ctrl_add_mapping(chain, ctrl, mapping);
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index e5b12717016f..93b421918d3b 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -87,7 +87,9 @@ 
 
 struct gpio_desc;
 struct sg_table;
+struct uvc_control;
 struct uvc_device;
+struct uvc_video_chain;
 
 /*
  * TODO: Put the most frequently accessed fields at the beginning of
@@ -126,6 +128,9 @@  struct uvc_control_mapping {
 	s32 master_manual;
 	u32 slave_ids[2];
 
+	const struct uvc_control_mapping *(*filter_mapping)
+				(struct uvc_video_chain *chain,
+				struct uvc_control *ctrl);
 	s32 (*get)(struct uvc_control_mapping *mapping, u8 query,
 		   const u8 *data);
 	void (*set)(struct uvc_control_mapping *mapping, s32 value,