The implementation makes use of the new fan control virtual registers
exposed by the pmbus core. It mixes use of the default implementations
with some overrides via the read/write handlers to handle FAN_COMMAND_1
on the MAX31785, whose definition breaks the value range into various
control bands dependent on RPM or PWM mode.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>