[PATCH v5 5/7] media: v4l2: add support for the subdev CSC API for hsv_enc on mediabus

[Dafna Hirschfeld]

Add the flag V4L2_SUBDEV_MBUS_CODE_CSC_HSV_ENC that drivers
can set when enumerating the supported mediabus formats
on subdevices to indicate that the userspace can ask to
set the 'hsv_enc'. The patch also replaces the 'ycbcr_enc'
field in 'struct v4l2_mbus_framefmt' with a union that
includes 'hsv_enc'

Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld at collabora.com>
---
 .../media/v4l/subdev-formats.rst              | 33 +++++++++++++++----
 include/uapi/linux/v4l2-mediabus.h            |  8 ++++-
 include/uapi/linux/v4l2-subdev.h              |  1 +
 3 files changed, 34 insertions(+), 8 deletions(-)

diff --git a/Documentation/userspace-api/media/v4l/subdev-formats.rst b/Documentation/userspace-api/media/v4l/subdev-formats.rst
index 7362ee0b1e96..dddc38191547 100644
--- a/Documentation/userspace-api/media/v4l/subdev-formats.rst
+++ b/Documentation/userspace-api/media/v4l/subdev-formats.rst
@@ -51,7 +51,9 @@ Media Bus Formats
 	The driver indicates that colorspace conversion is supported by setting
 	the flag V4L2_SUBDEV_MBUS_CODE_CSC_COLORSPACE in the corresponding struct
 	:c:type:`v4l2_subdev_mbus_code_enum` during enumeration.
-	See :ref:`colorspaces`.
+	See :ref:`v4l2-subdev-mbus-code-flags`.
+    * - union {
+      - (anonymous)
     * - __u16
       - ``ycbcr_enc``
       - Y'CbCr encoding, from enum :c:type:`v4l2_ycbcr_encoding`.
@@ -67,7 +69,23 @@ Media Bus Formats
 	V4L2_SUBDEV_MBUS_CODE_CSC_YCBCR_ENC in the corresponding struct
 	:c:type:`v4l2_subdev_mbus_code_enum` during enumeration.
 	See :ref:`v4l2-subdev-mbus-code-flags`.
-
+    * - __u16
+      - ``hsv_enc``
+      - HSV encoding, from enum :c:type:`v4l2_hsv_encoding`.
+        This information supplements the ``colorspace`` and must be set by
+	the driver for capture streams and by the application for output
+	streams, see :ref:`colorspaces`. If the application sets the
+	flag ``V4L2_MBUS_FRAMEFMT_SET_CSC`` then the application can set
+	this field for a capture stream to request a specific HSV encoding
+	for the media bus data. If the driver cannot handle requested
+	conversion, it will return another supported encoding.
+	This field is ignored for Y'CbCr media bus formats. The driver indicates
+	that hsv_enc conversion is supported by setting the flag
+	V4L2_SUBDEV_MBUS_CODE_CSC_HSV_ENC in the corresponding struct
+	:c:type:`v4l2_subdev_mbus_code_enum` during enumeration.
+	See :ref:`v4l2-subdev-mbus-code-flags`
+    * - }
+      -
     * - __u16
       - ``quantization``
       - Quantization range, from enum :c:type:`v4l2_quantization`.
@@ -123,11 +141,12 @@ Media Bus Formats
 	ignored for output streams. If set, then request the subdevice to do
 	colorspace conversion from the received colorspace to the requested
 	colorspace values. If colorimetry field (``colorspace``, ``ycbcr_enc``,
-	``quantization`` or ``xfer_func``) is set to 0, then that colorimetry
-	setting will remain unchanged from what was received. So to change the
-	quantization, only the ``quantization`` field shall be set to non-zero values
-	(``V4L2_QUANTIZATION_FULL_RANGE`` or ``V4L2_QUANTIZATION_LIM_RANGE``)
-	and all other colorimetry fields shall be set to 0.
+	''hsv_enc``, ``quantization`` or ``xfer_func``) is set to 0, then that
+	colorimetry setting will remain unchanged from what was received. So to
+	change the quantization, only the ``quantization`` field shall be set to
+	non-zero values (``V4L2_QUANTIZATION_FULL_RANGE`` or
+	``V4L2_QUANTIZATION_LIM_RANGE``) and all other colorimetry fields shall
+	be set to 0.
 
 	To check which conversions are supported by the hardware for the current
 	media bus frame format, see :ref:`v4l2-subdev-mbus-code-flags`.
diff --git a/include/uapi/linux/v4l2-mediabus.h b/include/uapi/linux/v4l2-mediabus.h
index 3b7d692b4015..d0bc8df18ad5 100644
--- a/include/uapi/linux/v4l2-mediabus.h
+++ b/include/uapi/linux/v4l2-mediabus.h
@@ -26,6 +26,7 @@
  * @field:	used interlacing type (from enum v4l2_field)
  * @colorspace:	colorspace of the data (from enum v4l2_colorspace)
  * @ycbcr_enc:	YCbCr encoding of the data (from enum v4l2_ycbcr_encoding)
+ * @hsv_enc:	HSV encoding of the data (from enum v4l2_hsv_encoding)
  * @quantization: quantization of the data (from enum v4l2_quantization)
  * @xfer_func:  transfer function of the data (from enum v4l2_xfer_func)
  * @reserved2:  two reserved bytes that can be later used
@@ -38,7 +39,12 @@ struct v4l2_mbus_framefmt {
 	__u32			code;
 	__u32			field;
 	__u32			colorspace;
-	__u16			ycbcr_enc;
+	union {
+		/* enum v4l2_ycbcr_encoding */
+		__u16			ycbcr_enc;
+		/* enum v4l2_hsv_encoding */
+		__u16			hsv_enc;
+	};
 	__u16			quantization;
 	__u16			xfer_func;
 	__u16			reserved2;
diff --git a/include/uapi/linux/v4l2-subdev.h b/include/uapi/linux/v4l2-subdev.h
index c20aa9a89864..08e25a961d15 100644
--- a/include/uapi/linux/v4l2-subdev.h
+++ b/include/uapi/linux/v4l2-subdev.h
@@ -67,6 +67,7 @@ struct v4l2_subdev_crop {
 
 #define V4L2_SUBDEV_MBUS_CODE_CSC_COLORSPACE	0x00000001
 #define V4L2_SUBDEV_MBUS_CODE_CSC_YCBCR_ENC	0x00000002
+#define V4L2_SUBDEV_MBUS_CODE_CSC_HSV_ENC	V4L2_SUBDEV_MBUS_CODE_CSC_YCBCR_ENC
 #define V4L2_SUBDEV_MBUS_CODE_CSC_QUANTIZATION	0x00000004
 #define V4L2_SUBDEV_MBUS_CODE_CSC_XFER_FUNC	0x00000008
 /**
-- 
2.17.1