Note ==== This driver supercedes the NCT6775F and NCT6776F support in the W83627EHF driver. It supports NCT6106D, NCT6775F, NCT6776F, NCT6779D, NCT6791D, NCT6792D, NCT6793D, and NCT6795D. The driver is also available in the upstream kernel. This version is maintained for backward compatibility with older kernels. I am trying to keep it buildable for older kernels, but may miss a problem once in a while. If you have a problem compiling this driver with any kernel version 2.6.32 or later, please let me know. Kernel driver NCT6775 ======================= Supported chips: * Nuvoton NCT6102D/NCT6104D/NCT6106D Prefix: 'nct6106' Addresses scanned: ISA address retrieved from Super I/O registers Datasheet: Available from Nuvoton upon request * Nuvoton NCT6775F/W83667HG-I Prefix: 'nct6775' Addresses scanned: ISA address retrieved from Super I/O registers Datasheet: Available from Nuvoton upon request * Nuvoton NCT6776F Prefix: 'nct6776' Addresses scanned: ISA address retrieved from Super I/O registers Datasheet: Available from Nuvoton upon request * Nuvoton NCT6779D Prefix: 'nct6779' Addresses scanned: ISA address retrieved from Super I/O registers Datasheet: Available from Nuvoton upon request * Nuvoton NCT6791D Prefix: 'nct6791' Addresses scanned: ISA address retrieved from Super I/O registers Datasheet: Available from Nuvoton upon request * Nuvoton NCT6792D Prefix: 'nct6792' Addresses scanned: ISA address retrieved from Super I/O registers Datasheet: Available from Nuvoton upon request * Nuvoton NCT6793D Prefix: 'nct6793' Addresses scanned: ISA address retrieved from Super I/O registers Datasheet: Available from Nuvoton upon request * Nuvoton NCT6795D Prefix: 'nct6795' Addresses scanned: ISA address retrieved from Super I/O registers Datasheet: Available from Nuvoton upon request Authors: Guenter Roeck <linux@roeck-us.net> David Bartley <andareed@gmail.com> (NCT6791D support) Description ----------- This driver implements support for the Nuvoton NCT6106D, NCT6775F, NCT6776F, NCT6779D, NCT6791D, NCT6792D, NCT6793D, and NCT6795D super I/O chips. We will refer to them collectively as Nuvoton chips. The chips implement up to 8 temperature sensors depending on the chip type and configuration. Temperatures used to control fan speed are reported separately. There are 3 to 6 fan rotation speed sensors, 8 to 15 analog voltage sensors, one VID, alarms with beep warnings (control unimplemented), and some automatic fan regulation strategies (plus manual fan control mode). The temperature sensor sources on all chips are configurable. temp4 and higher attributes are only reported if its temperature source differs from the temperature sources of the already reported temperature sensors. The configured source for each of the temperature sensors is provided in tempX_label. Temperatures are measured in degrees Celsius and measurement resolution is either 1 degC or 0.5 degC, depending on the temperature source and configuration. An alarm is triggered when the temperature gets higher than the high limit; it stays on until the temperature falls below the hysteresis value. Alarms are only supported for temp1, temp2, and temp3. Fan rotation speeds are reported in RPM (rotations per minute). An alarm is triggered if the rotation speed has dropped below a programmable limit. Fan readings can be divided by a programmable divider (1, 2, 4, 8, 16, 32, 64 or 128) to give the readings more range or accuracy. The driver sets the most suitable fan divisor itself. Some fans might not be present because they share pins with other functions. Voltage sensors (also known as IN sensors) report their values in millivolts. An alarm is triggered if the voltage has crossed a programmable minimum or maximum limit. The driver supports automatic fan control mode known as Thermal Cruise. In this mode, the chip attempts to keep the measured temperature in a predefined temperature range. If the temperature goes out of range, fan is driven slower/faster to reach the predefined range again. The mode works for fan1-fan6. sysfs attributes ---------------- name - this is a standard hwmon device entry, it contains the name of the device (see the prefix in the list of supported devices at the top of this file) pwm[1-6] - this file stores PWM duty cycle or DC value (fan speed) in range: 0 (stop) to 255 (full) pwm[1-6]_enable - this file controls mode of fan/temperature control: * 0 Fan control disabled (fans set to maximum speed) * 1 Manual mode, write to pwm file any value 0-255 (full speed) * 2 "Thermal Cruise" mode * 3 "Fan Speed Cruise" mode * 4 "Smart Fan III" mode (NCT6775F only) * 5 "Smart Fan IV" mode pwm[1-6]_mode - controls if output is PWM or DC level * 0 DC output (0 - 12v) * 1 PWM output Common fan control attributes ----------------------------- pwm[1-6]_temp_sel Temperature source. Value is temperature sensor index. For example, select '1' for temp1_input. pwm[1-6]_weight_temp_sel Secondary temperature source. Value is temperature sensor index. For example, select '1' for temp1_input. pwm[1-6]_weight_enable Set to 1 to enable secondary temperature control. If secondary temperature functionality is enabled, it is controlled with the following attributes. pwm[1-6]_weight_duty_step Duty step size. pwm[1-6]_weight_temp_step Temperature step size. With each step over temp_step_base, the value of weight_duty_step is added to the current pwm value. pwm[1-6]_weight_temp_step_base Temperature at which secondary temperature control kicks in. pwm[1-6]_weight_temp_step_tol Temperature step tolerance or hysteresis. This is a relative value. Thermal Cruise mode (2) ----------------------- If the temperature is in the range defined by: pwm[1-6]_target Target temperature, unit millidegree Celsius (range 0 - 127000) pwm[1-6]_auto_temp1_hyst Hysteresis, unit millidegree Celsius Hysteresis value is relative to pwm[1-6]_auto_temp1. there are no changes to fan speed. Once the temperature leaves the interval, fan speed increases (temp is higher) or decreases if lower than desired, using the following steps and times. pwm[1-6]_start_output fan pwm start value (range 1 - 255), to start fan when the temperature is above defined range. pwm[1-6]_stop_output lowest fan pwm (range 1 - 255) if temperature is below the defined range. pwm[1-6]_stop_output_enable Set to 1 to enable pwm[1-6]_stop_output. If disabled (set to 0), the fan will stop if the temperature is below the defined range. pwm[1-6]_step_up_time milliseconds [ms] before fan speed is increased pwm[1-6]_step_down_time milliseconds [ms] before fan speed is decreased pwm[1-6]_stop_time how many milliseconds [ms] must elapse to switch corresponding fan off (when the temperature was below defined range). Speed Cruise mode (3) --------------------- This modes tries to keep the fan speed constant. Untested; use at your own risk. Smart Fan IV mode (5) --------------------- The fan is regulated to maintain a target temperature. There are five data points. Subsequent data points should be set to higher temperatures and higher pwm values to achieve higher fan speeds with increasing temperature. The last data point reflects critical temperature mode, in which the fans should run at full speed. pwm[1-6]_auto_point[1-6]_pwm pwm value to be set if temperature reaches matching temperature range. pwm[1-6]_auto_point[1-6]_temp Temperature at which the matching pwm is enabled. pwm[1-6]_step_up_time milliseconds [ms] before fan speed is increased pwm[1-6]_step_down_time milliseconds [ms] before fan speed is decreased Usage Notes ----------- On various ASUS boards with NCT6776F, it appears that CPUTIN is not really connected to anything and floats, or that it is connected to some non-standard temperature measurement device. As a result, the temperature reported on CPUTIN will not reflect a usable value. It often reports unreasonably high temperatures, and in some cases the reported temperature declines if the actual temperature increases (similar to the raw PECI temperature value - see PECI specification for details). CPUTIN should therefore be be ignored on ASUS boards. The CPU temperature on ASUS boards is reported from PECI 0. Also, there have been reports that not all fan speeds are reported on at least some ASUS boards. P9X79 WS is one example, where fan speed is only reported for two of the fans on the board. Note that ASUS does not support Linux on desktop boards (this appears to be official ASUS policy) and does not release board specifications, so there is nothing we can do to improve support for such boards unless we get board specifications or a detailed description on how to control the fans on the affected boards. Known Problems -------------- After a suspend/resume cycle, all fan control settings are restored to the BIOS defaults.