realtek: add hasivo-mcu sensor driver
Add a temperature/fan sensor (hwmon) driver for the Hasivo / Horaco
management MCU as a second child of the hasivo MCU MFD (alongside the
watchdog). It exposes the CPU and system temperatures and a 3-state fan
control (auto / force-on / force-off), read/written through the parent's
shared syscon regmap.
The register protocol was reverse-engineered from the stock 'imi' firmware
and verified on hardware. The fan-status register (0xFB) reflects the MCU's
effective drive state, not actual rotation (a blocked fan still reads
force-on), so no fanN_alarm is exposed. pwm1 echoes the commanded state so
a write reads back consistently, and falls back to the live drive state in
automatic mode. The register map is shared across boards.
Signed-off-by: Carlo Szelinsky <github@szelinsky.de>
Link: https://github.com/openwrt/openwrt/pull/23762
Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>
projects / thirdparty / openwrt.git / commit
