[PATCH v2 1/3] iio: Add in_illumincance vectors in different color spaces

[Gwendal Grignou]

Define 2 spaces for defining color coming from color sensors:
RGB and XYZ: Both are in lux.
RGB is the raw output from sensors (Red, Green and Blue channels), in
addition to the existing clear channel (C).
The RGBC vector goes through a matrix transformation to produce the XYZ
vector. Y is illumincance, and XY caries the chromaticity information.
The matrix is model specific, as the color sensor can be behing a glass
that can filter some wavelengths.

Signed-off-by: Gwendal Grignou <gwendal@xxxxxxxxxxxx>
---
New in v2.

 Documentation/ABI/testing/sysfs-bus-iio | 27 +++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index d3e53a6d8331b..256db6e63a25e 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -1309,6 +1309,33 @@ Description:
 		Illuminance measurement, units after application of scale
 		and offset are lux.
 
+What:		/sys/.../iio:deviceX/in_illuminance_red_raw
+What:		/sys/.../iio:deviceX/in_illuminance_green_raw
+What:		/sys/.../iio:deviceX/in_illuminance_blue_raw
+KernelVersion:	5.7
+Contact:	linux-iio@xxxxxxxxxxxxxxx
+Description:
+		Illuminance measuremed in red, green or blue channels, units
+		after application of scale and offset are lux.
+
+What:		/sys/.../iio:deviceX/in_illuminance_x_raw
+What:		/sys/.../iio:deviceX/in_illuminance_y_raw
+What:		/sys/.../iio:deviceX/in_illuminance_z_raw
+KernelVersion:	5.7
+Contact:	linux-iio@xxxxxxxxxxxxxxx
+Description:
+		lluminance measured in the CIE 1931 color space (XYZ).
+		in_illuminance_y_raw is a measure of the brightness, and is
+		identical in_illuminance_raw.
+		in_illuminance_x_raw and in_illuminance_z_raw carry chromacity
+		information.
+		in_illuminance_x,y,z_raw are be obtained from the sensor color
+		channels using color matching functions that may be device
+		specific.
+		Units after application of scale and offset are lux.
+		The measurments can be used to represent colors in the CIE
+		xyY color space
+
 What:		/sys/.../iio:deviceX/in_intensityY_raw
 What:		/sys/.../iio:deviceX/in_intensityY_ir_raw
 What:		/sys/.../iio:deviceX/in_intensityY_both_raw
-- 
2.26.2.526.g744177e7f7-goog