|  | 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... |