Kernel driver sch5627

Supported chips:

• SMSC SCH5627

  Prefix: ‘sch5627’

  Addresses scanned: none, address read from Super I/O config space

  Datasheet: Application Note available upon request

Author: Hans de Goede <hdegoede@redhat.com>

Description

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

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

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

The hardware monitoring part of the SMSC SCH5627 is accessed by talking through an embedded microcontroller. An application note describing the protocol for communicating with the microcontroller is available upon request. Please mail me if you want a copy.

Controlling fan speed

The SCH5627 allows for partially controlling the fan speed. If a temperature channel excedes tempX_max, all fans are forced to maximum speed. The same is not true for tempX_crit, presumably some other measures to cool down the system are take in this case. In which way the value of fanX_min affects the fan speed is currently unknown.