hwmon: (pmbus/isl68137) add support for voltage divider on Vout

Some applications require Vout to be higher than the detectable voltage
range of the Vsense pin for a given rail. In such applications, a voltage
divider may be placed between Vout and the Vsense pin, but this results
in erroneous telemetry being read back from the part. This change adds
support for a voltage divider to be defined in the devicetree for a (or
multiple) specific rail(s) for a supported digital multiphase device and
for the applicable Vout telemetry to be scaled based on the voltage
divider configuration.

This change copies the implementation of the vout-voltage-divider
devicetree property defined in the maxim,max20730 bindings schema since
it is the best fit for the use case of scaling hwmon PMBus telemetry. The
generic voltage-divider property used by many iio drivers was determined
to be a poor fit because that schema is tied directly to iio and the
isl68137 driver is not an iio driver.

Signed-off-by: Grant Peltier <grantpeltier93@gmail.com>
Message-ID: <8c2d048f87282bcf66313afbf5e923d8fc17b4d7.1731439797.git.grantpeltier93@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
1 file changed