Description¶

SMSC SCH5627 Super I/O chips include complete hardware monitoringcapabilities. They can monitor up to 5 voltages, 4 fans and 8 temperatures.

In addition, the SCH5627 exports data describing which temperature sensorsaffect the speed of each fan. Setting pwmX_auto_channels_temp to 0 forcesthe corresponding fan to full speed until another value is written.

The SMSC SCH5627 hardware monitoring part also contains an integratedwatchdog. In order for this watchdog to function some motherboard specificinitialization most be done by the BIOS, so if the watchdog is not enabledby the BIOS the sch5627 driver will not register a watchdog device.

The hardware monitoring part of the SMSC SCH5627 is accessed by talkingthrough an embedded microcontroller. An application note describing theprotocol for communicating with the microcontroller is available uponrequest. Please mail me if you want a copy.

Controlling fan speed¶

The SCH5627 allows for partially controlling the fan speed. If a temperaturechannel exceeds tempX_max, all fans are forced to maximum speed. The same is nottrue for tempX_crit, presumably some other measures to cool down the system aretake in this case.In which way the value of fanX_min affects the fan speed is currently unknown.