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

Gwendal Grignou
2020-05-06T23:03:39Z

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@chromium.org>
---
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@vger.kernel.org
+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@vger.kernel.org
+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