The current implementation always sets the voltage before enabling,
even if the current voltage is in the allowed range.
This has some side effects, i.e. for PMIC regulators that are
pre-programmed for a specific value but allow voltage changes during
runtime. The side effect being that the regulator will always be reset
to the lower value of the voltage range at init.
Another usecase would be when a bootloader sets a specific voltage then
loads an application that uses the same driver.
The proposed fix is to evaluate the current voltage and try to bring
the actual voltage in range if the current voltage is not valid
according to the min/max constraints.
Tested on custom SAMD20 board with a custom RK816 PMIC driver.
Signed-off-by: Ionut Catalin Pavel <iocapa@iocapa.com>
867c254801