media: v4l2-ctrls: Add RGB color effects control

Add V4L2_COLORFX_SET_RGB color effects control, V4L2_CID_COLORFX_RGB
for RGB color setting.

with two mirror changes:
- change 0xFFFFFF to 0xffffff
- fix comments 2^24 to 2^24 - 1

[hverkuil: dropped spaces around + with V4L2_CID_BASE for consistency]

Signed-off-by: Dillon Min <dillon.minfei@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Documentation/userspace-api/media/v4l/control.rst

@@ -242,8 +242,17 @@ Control IDs
     * - ``V4L2_COLORFX_SET_CBCR``
       - The Cb and Cr chroma components are replaced by fixed coefficients
 	determined by ``V4L2_CID_COLORFX_CBCR`` control.
+    * - ``V4L2_COLORFX_SET_RGB``
+      - The RGB components are replaced by the fixed RGB components determined
+        by ``V4L2_CID_COLORFX_RGB`` control.
 
 
+``V4L2_CID_COLORFX_RGB`` ``(integer)``
+    Determines the Red, Green, and Blue coefficients for
+    ``V4L2_COLORFX_SET_RGB`` color effect.
+    Bits [7:0] of the supplied 32 bit value are interpreted as Blue component,
+    bits [15:8] as Green component, bits [23:16] as Red component, and
+    bits [31:24] must be zero.
 
 ``V4L2_CID_COLORFX_CBCR`` ``(integer)``
     Determines the Cb and Cr coefficients for ``V4L2_COLORFX_SET_CBCR``

drivers/media/v4l2-core/v4l2-ctrls-defs.c

@@ -785,6 +785,7 @@ const char *v4l2_ctrl_get_name(u32 id)
 	case V4L2_CID_MIN_BUFFERS_FOR_OUTPUT:	return "Min Number of Output Buffers";
 	case V4L2_CID_ALPHA_COMPONENT:		return "Alpha Component";
 	case V4L2_CID_COLORFX_CBCR:		return "Color Effects, CbCr";
+	case V4L2_CID_COLORFX_RGB:              return "Color Effects, RGB";
 
 	/*
 	 * Codec controls
@@ -1394,11 +1395,12 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
 		*min = *max = *step = *def = 0;
 		break;
 	case V4L2_CID_BG_COLOR:
+	case V4L2_CID_COLORFX_RGB:
 		*type = V4L2_CTRL_TYPE_INTEGER;
 		*step = 1;
 		*min = 0;
-		/* Max is calculated as RGB888 that is 2^24 */
-		*max = 0xFFFFFF;
+		/* Max is calculated as RGB888 that is 2^24 - 1 */
+		*max = 0xffffff;
 		break;
 	case V4L2_CID_COLORFX_CBCR:
 		*type = V4L2_CTRL_TYPE_INTEGER;

include/uapi/linux/v4l2-controls.h

@@ -128,6 +128,7 @@ enum v4l2_colorfx {
 	V4L2_COLORFX_SOLARIZATION		= 13,
 	V4L2_COLORFX_ANTIQUE			= 14,
 	V4L2_COLORFX_SET_CBCR			= 15,
+	V4L2_COLORFX_SET_RGB			= 16,
 };
 #define V4L2_CID_AUTOBRIGHTNESS			(V4L2_CID_BASE+32)
 #define V4L2_CID_BAND_STOP_FILTER		(V4L2_CID_BASE+33)
@@ -145,9 +146,10 @@ enum v4l2_colorfx {
 
 #define V4L2_CID_ALPHA_COMPONENT		(V4L2_CID_BASE+41)
 #define V4L2_CID_COLORFX_CBCR			(V4L2_CID_BASE+42)
+#define V4L2_CID_COLORFX_RGB			(V4L2_CID_BASE+43)
 
 /* last CID + 1 */
-#define V4L2_CID_LASTP1                         (V4L2_CID_BASE+43)
+#define V4L2_CID_LASTP1                         (V4L2_CID_BASE+44)
 
 /* USER-class private control IDs */