This patch adds a compensation phase to improve the accuracy of ADC
measurement. This is the built-in function through input half of the
reference voltage to get the ADC offset.
Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
Link: https://lore.kernel.org/r/20210922081520.30580-10-billy_tsai@aspeedtech.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>