[PATCH v2 1/7] media: uvcvideo: Allow custom control mapping

[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.

Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 drivers/media/usb/uvc/uvc_ctrl.c | 10 +++++++++-
 drivers/media/usb/uvc/uvcvideo.h |  5 +++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index e59a463c2761..44ec185a8c8b 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -2360,7 +2360,7 @@ static int uvc_ctrl_add_info(struct uvc_device *dev, struct uvc_control *ctrl,
 /*
  * Add a control mapping to a given control.
  */
-static int __uvc_ctrl_add_mapping(struct uvc_video_chain *chain,
+static int __uvc_ctrl_add_mapping_to_list(struct uvc_video_chain *chain,
 	struct uvc_control *ctrl, const struct uvc_control_mapping *mapping)
 {
 	struct uvc_control_mapping *map;
@@ -2434,6 +2434,14 @@ static int __uvc_ctrl_add_mapping(struct uvc_video_chain *chain,
 	return -ENOMEM;
 }
 
+static int __uvc_ctrl_add_mapping(struct uvc_video_chain *chain,
+	struct uvc_control *ctrl, const struct uvc_control_mapping *mapping)
+{
+	if (mapping && mapping->add_mapping)
+		return mapping->add_mapping(chain, ctrl, mapping);
+	return __uvc_ctrl_add_mapping_to_list(chain, ctrl, mapping);
+}
+
 int uvc_ctrl_add_mapping(struct uvc_video_chain *chain,
 	const struct uvc_control_mapping *mapping)
 {
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index 6fb0a78b1b00..fa0396dd5b35 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -84,7 +84,9 @@
 
 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
@@ -123,6 +125,9 @@ struct uvc_control_mapping {
 	s32 master_manual;
 	u32 slave_ids[2];
 
+	int (*add_mapping)(struct uvc_video_chain *chain,
+			   struct uvc_control *ctrl,
+			   const struct uvc_control_mapping *mapping);
 	s32 (*get)(struct uvc_control_mapping *mapping, u8 query,
 		   const u8 *data);
 	void (*set)(struct uvc_control_mapping *mapping, s32 value,

-- 
2.45.2.505.gda0bf45e8d-goog