linux/linux-5.4.31/Documentation/ABI/testing/sysfs-bus-iio-isl29501

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2024-01-30 10:43:28 +00:00
What: /sys/bus/iio/devices/iio:deviceX/in_proximity0_agc_gain
What: /sys/bus/iio/devices/iio:deviceX/in_proximity0_agc_gain_bias
KernelVersion: 4.18
Contact: linux-iio@vger.kernel.org
Description:
This sensor has an automatic gain control (agc) loop
which sets the analog signal levels at an optimum
level by controlling programmable gain amplifiers. The
criteria for optimal gain is determined by the sensor.
Return the actual gain value as an integer in [0; 65536]
range when read from.
The agc gain read when measuring crosstalk shall be
written into in_proximity0_agc_gain_bias.
What: /sys/bus/iio/devices/iio:deviceX/in_proximity0_calib_phase_temp_a
What: /sys/bus/iio/devices/iio:deviceX/in_proximity0_calib_phase_temp_b
What: /sys/bus/iio/devices/iio:deviceX/in_proximity0_calib_phase_light_a
What: /sys/bus/iio/devices/iio:deviceX/in_proximity0_calib_phase_light_b
KernelVersion: 4.18
Contact: linux-iio@vger.kernel.org
Description:
The sensor is able to perform correction of distance
measurements due to changing temperature and ambient
light conditions. It can be programmed to correct for
a second order error polynomial.
Phase data has to be collected when temperature and
ambient light are modulated independently.
Then a least squares curve fit to a second order
polynomial has to be generated from the data. The
resultant curves have the form ax^2 + bx + c.
From those two curves, a and b coefficients shall be
stored in in_proximity0_calib_phase_temp_a and
in_proximity0_calib_phase_temp_b for temperature and
in in_proximity0_calib_phase_light_a and
in_proximity0_calib_phase_light_b for ambient light.
Those values must be integer in [0; 8355840] range.
Finally, the c constant is set by the sensor
internally.
The value stored in sensor is displayed when read from.