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authorMathieu Othacehe2018-07-20 19:34:26 +0200
committerJonathan Cameron2018-07-23 19:18:10 +0100
commit1c28799257bca28cd5ba715e33157500d6239333 (patch)
tree1526b438955ac2ddea5e12087a970aaab65b7874 /Documentation/ABI/testing/sysfs-bus-iio-isl29501
parentc73314e6ebb2651a70ca8a3ff08d4bd6b9f9ade1 (diff)
iio: light: isl29501: Add support for the ISL29501 ToF sensor.
This patch adds support for the ISL29501 Time of Flight sensor. Signed-off-by: Mathieu Othacehe <m.othacehe@gmail.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'Documentation/ABI/testing/sysfs-bus-iio-isl29501')
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+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.