superio/ite/it8623e: initialize the PWM fan controller

Copies the common/env_ctrl support code from the it8728f driver.

Tested on an ASUS AM1I-A using Linux 4.16.7-gentoo as payload,
and booting userspace without a kexec call.

Prior to this change, an error was given during boot:

it87 it87.656: Detected broken BIOS defaults, disabling PWM interface

After this change, the message is gone, and PWM fan control works
through the /sys/class/hwmon interface.

Change-Id: Id97c4ec19562e7c78308c5afe6ff7c938922c9e7
Signed-off-by: Kevin Cody-Little <>
Reviewed-by: Felix Held <>
Reviewed-by: Nico Huber <>
Reviewed-by: Kyösti Mälkki <>
Reviewed-by: Paul Menzel <>
Tested-by: build bot (Jenkins) <>
3 files changed