Kernel driver nct7904

Supported chip:

• Nuvoton NCT7904D

  Prefix: nct7904

  Addresses: I2C 0x2d, 0x2e

  Datasheet: Publicly available at Nuvoton website

  http://www.nuvoton.com/

Author: Vadim V. Vlasov <vvlasov@dev.rtsoft.ru>

Description

The NCT7904D is a hardware monitor supporting up to 20 voltage sensors, internal temperature sensor, Intel PECI and AMD SB-TSI CPU temperature interface, up to 12 fan tachometer inputs, up to 4 fan control channels with SmartFan.

Sysfs entries

Currently, the driver supports only the following features:

in[1-20]_input	Input voltage measurements (mV)
fan[1-12]_input	Fan tachometer measurements (rpm)
temp1_input	Local temperature (1/1000 degree, 0.125 degree resolution)
temp[2-9]_input	CPU temperatures (1/1000 degree, 0.125 degree resolution)
pwm[1-4]_enable	R/W, 1/2 for manual or SmartFan mode Setting SmartFan mode is supported only if it has been previously configured by BIOS (or configuration EEPROM)
pwm[1-4]	R/O in SmartFan mode, R/W in manual control mode

The driver checks sensor control registers and does not export the sensors that are not enabled. Anyway, a sensor that is enabled may actually be not connected and thus provide zero readings.

Limitations

The following features are not supported in current version:

• SmartFan control

• Watchdog

• GPIO

• external temperature sensors

• SMI

• min/max values

• many other…