[PATCH v9 11/11] media: uvcvideo: document UVC v1.5 ROI

[Yunke Cao <yunkec@google.com>]

Added documentation of V4L2_CID_UVC_REGION_OF_INTEREST_RECT and
V4L2_CID_UVC_REGION_OF_INTEREST_AUTO.

Signed-off-by: Yunke Cao <yunkec@google.com>
Reviewed-by: Ricardo Ribalda <ribalda@chromium.org>
---
Changelog since v8:
- No change.
Changelog since v7:
- Fix documentation for automatic exposure based on comment in v7.

Some descriptions for some V4L2_UVC_REGION_OF_INTEREST_AUTO_* are vague because
I copied these options from the UVC spec.

 .../userspace-api/media/drivers/uvcvideo.rst  | 62 +++++++++++++++++++
 1 file changed, 62 insertions(+)

diff --git a/Documentation/userspace-api/media/drivers/uvcvideo.rst b/Documentation/userspace-api/media/drivers/uvcvideo.rst
index aab4304e6bb5..3dc062221f8b 100644
--- a/Documentation/userspace-api/media/drivers/uvcvideo.rst
+++ b/Documentation/userspace-api/media/drivers/uvcvideo.rst
@@ -181,6 +181,7 @@ Argument: struct uvc_xu_control_mapping
 	UVC_CTRL_DATA_TYPE_BOOLEAN	Boolean
 	UVC_CTRL_DATA_TYPE_ENUM		Enumeration
 	UVC_CTRL_DATA_TYPE_BITMASK	Bitmask
+	UVC_CTRL_DATA_TYPE_RECT		Rectangular area
 
 
 UVCIOC_CTRL_QUERY - Query a UVC XU control
@@ -255,3 +256,64 @@ Argument: struct uvc_xu_control_query
 	__u8	query		Request code to send to the device
 	__u16	size		Control data size (in bytes)
 	__u8	*data		Control value
+
+
+Driver-specific V4L2 controls
+-----------------------------
+
+The uvcvideo driver implements the following UVC-specific controls:
+
+``V4L2_CID_UVC_REGION_OF_INTEREST_RECT (struct)``
+	This control determines the region of interest (ROI). ROI is a
+	rectangular area represented by a struct :c:type:`v4l2_rect`. The
+	rectangle is in global sensor coordinates and pixel units. It is
+	independent of the field of view, not impacted by any cropping or
+	scaling.
+
+	Use ``V4L2_CTRL_WHICH_MIN_VAL`` and ``V4L2_CTRL_WHICH_MAX_VAL`` to query
+	the range of rectangle sizes. The left/top coordinates of a minimum or
+	maximum rectangle are always 0. For example, a device can have a minimum
+	ROI rectangle of 1x1@0x0 and a maximum of 640x480@0x0.
+
+	Setting a ROI allows the camera to optimize the capture for the region.
+	The value of ``V4L2_CID_REGION_OF_INTEREST_AUTO`` control determines
+	the detailed behavior.
+
+
+``V4L2_CID_UVC_REGION_OF_INTEREST_AUTO (bitmask)``
+	This determines which, if any, on board features should track to the
+	Region of Interest specified by the current value of
+	``V4L2_CID_UVD__REGION_OF_INTEREST_RECT``.
+
+	Max value is a mask indicating all supported Auto Controls.
+
+.. flat-table::
+    :header-rows:  0
+    :stub-columns: 0
+
+    * - ``V4L2_UVC_REGION_OF_INTEREST_AUTO_EXPOSURE``
+      - Setting this to true causes automatic exposure to track the region of
+	interest instead of the whole image.
+    * - ``V4L2_UVC_REGION_OF_INTEREST_AUTO_IRIS``
+      - Setting this to true causes automatic iris to track the region of
+	interest instead of the whole image.
+    * - ``V4L2_UVC_REGION_OF_INTEREST_AUTO_WHITE_BALANCE``
+      - Setting this to true causes automatic white balance to track the region
+	of interest instead of the whole image.
+    * - ``V4L2_UVC_REGION_OF_INTEREST_AUTO_FOCUS``
+      - Setting this to true causes automatic focus adjustment to track the
+	region of interest instead of the whole image.
+    * - ``V4L2_UVC_REGION_OF_INTEREST_AUTO_FACE_DETECT``
+      - Setting this to true causes automatic face detection to track the
+	region of interest instead of the whole image.
+    * - ``V4L2_UVC_REGION_OF_INTEREST_AUTO_DETECT_AND_TRACK``
+      - Setting this to true enables automatic face detection and tracking. The
+	current value of ``V4L2_CID_REGION_OF_INTEREST_RECT`` may be updated by
+	the driver.
+    * - ``V4L2_UVC_REGION_OF_INTEREST_AUTO_IMAGE_STABILIZATION``
+      - Setting this to true enables automatic image stabilization. The
+	current value of ``V4L2_CID_REGION_OF_INTEREST_RECT`` may be updated by
+	the driver.
+    * - ``V4L2_UVC_REGION_OF_INTEREST_AUTO_HIGHER_QUALITY``
+      - Setting this to true enables automatically capture the specified region
+	with higher quality if possible.
-- 
2.38.0.135.g90850a2211-goog