|  | Kernel driver w83627ehf | 
|  | ======================= | 
|  |  | 
|  | Supported chips: | 
|  | * Winbond W83627EHF/EHG (ISA access ONLY) | 
|  | Prefix: 'w83627ehf' | 
|  | Addresses scanned: ISA address retrieved from Super I/O registers | 
|  | Datasheet: not available | 
|  | * Winbond W83627DHG | 
|  | Prefix: 'w83627dhg' | 
|  | Addresses scanned: ISA address retrieved from Super I/O registers | 
|  | Datasheet: not available | 
|  | * Winbond W83627DHG-P | 
|  | Prefix: 'w83627dhg' | 
|  | Addresses scanned: ISA address retrieved from Super I/O registers | 
|  | Datasheet: not available | 
|  | * Winbond W83667HG | 
|  | Prefix: 'w83667hg' | 
|  | Addresses scanned: ISA address retrieved from Super I/O registers | 
|  | Datasheet: not available | 
|  | * Winbond W83667HG-B | 
|  | Prefix: 'w83667hg' | 
|  | 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 | 
|  |  | 
|  | Authors: | 
|  | Jean Delvare <khali@linux-fr.org> | 
|  | Yuan Mu (Winbond) | 
|  | Rudolf Marek <r.marek@assembler.cz> | 
|  | David Hubbard <david.c.hubbard@gmail.com> | 
|  | Gong Jun <JGong@nuvoton.com> | 
|  |  | 
|  | Description | 
|  | ----------- | 
|  |  | 
|  | This driver implements support for the Winbond W83627EHF, W83627EHG, | 
|  | W83627DHG, W83627DHG-P, W83667HG, W83667HG-B, W83667HG-I (NCT6775F), | 
|  | and NCT6776F super I/O chips. We will refer to them collectively as | 
|  | Winbond chips. | 
|  |  | 
|  | The chips implement three temperature sensors (up to four for 667HG-B, and nine | 
|  | for NCT6775F and NCT6776F), five fan rotation speed sensors, ten analog voltage | 
|  | sensors (only nine for the 627DHG), one VID (6 pins for the 627EHF/EHG, 8 pins | 
|  | for the 627DHG and 667HG), alarms with beep warnings (control unimplemented), | 
|  | and some automatic fan regulation strategies (plus manual fan control mode). | 
|  |  | 
|  | The temperature sensor sources on W82677HG-B, NCT6775F, and NCT6776F 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 1 | 
|  | degC for temp1 and and 0.5 degC for temp2 and temp3. For temp4 and higher, | 
|  | resolution is 1 degC for W83667HG-B and 0.0 degC for NCT6775F and NCT6776F. | 
|  | An alarm is triggered when the temperature gets higher than 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-fan4. Mapping of temperatures to pwm outputs is as | 
|  | follows: | 
|  |  | 
|  | temp1 -> pwm1 | 
|  | temp2 -> pwm2 | 
|  | temp3 -> pwm3 | 
|  | prog  -> pwm4 (not on 667HG and 667HG-B; the programmable setting is not | 
|  | supported by the driver) | 
|  |  | 
|  | /sys files | 
|  | ---------- | 
|  |  | 
|  | name - this is a standard hwmon device entry. For the W83627EHF and W83627EHG, | 
|  | it is set to "w83627ehf", for the W83627DHG it is set to "w83627dhg", | 
|  | for the W83667HG and W83667HG-B it is set to "w83667hg", for NCT6775F it | 
|  | is set to "nct6775", and for NCT6776F it is set to "nct6776". | 
|  |  | 
|  | pwm[1-4] - this file stores PWM duty cycle or DC value (fan speed) in range: | 
|  | 0 (stop) to 255 (full) | 
|  |  | 
|  | pwm[1-4]_enable - this file controls mode of fan/temperature control: | 
|  | * 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 | 
|  | * 5 "Smart Fan IV" mode | 
|  |  | 
|  | SmartFan III mode is not supported on NCT6776F. | 
|  |  | 
|  | SmartFan IV mode is configurable only if it was configured at system | 
|  | startup, and is only supported for W83677HG-B, NCT6775F, and NCT6776F. | 
|  | SmartFan IV operational parameters can not be configured at this time, | 
|  | and the various pwm attributes are not used in SmartFan IV mode. | 
|  | The attributes can be written to, which is useful if you plan to | 
|  | configure the system for a different pwm mode. However, the information | 
|  | returned when reading pwm attributes is unrelated to SmartFan IV | 
|  | operation. | 
|  |  | 
|  | pwm[1-4]_mode - controls if output is PWM or DC level | 
|  | * 0 DC output (0 - 12v) | 
|  | * 1 PWM output | 
|  |  | 
|  | Thermal Cruise mode | 
|  | ------------------- | 
|  |  | 
|  | If the temperature is in the range defined by: | 
|  |  | 
|  | pwm[1-4]_target    - set target temperature, unit millidegree Celsius | 
|  | (range 0 - 127000) | 
|  | pwm[1-4]_tolerance - tolerance, unit millidegree Celsius (range 0 - 15000) | 
|  |  | 
|  | 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. | 
|  | There are defined steps and times, but not exported by the driver yet. | 
|  |  | 
|  | pwm[1-4]_min_output - minimum fan speed (range 1 - 255), when the temperature | 
|  | is below defined range. | 
|  | pwm[1-4]_stop_time  - how many milliseconds [ms] must elapse to switch | 
|  | corresponding fan off. (when the temperature was below | 
|  | defined range). | 
|  |  | 
|  | Note: last two functions are influenced by other control bits, not yet exported | 
|  | by the driver, so a change might not have any effect. | 
|  |  | 
|  | Implementation Details | 
|  | ---------------------- | 
|  |  | 
|  | Future driver development should bear in mind that the following registers have | 
|  | different functions on the 627EHF and the 627DHG. Some registers also have | 
|  | different power-on default values, but BIOS should already be loading | 
|  | appropriate defaults. Note that bank selection must be performed as is currently | 
|  | done in the driver for all register addresses. | 
|  |  | 
|  | 0x49:  only on DHG, selects temperature source for AUX fan, CPU fan0 | 
|  | 0x4a:  not completely documented for the EHF and the DHG documentation assigns | 
|  | different behavior to bits 7 and 6, including extending the temperature | 
|  | input selection to SmartFan I, not just SmartFan III. Testing on the EHF | 
|  | will reveal whether they are compatible or not. | 
|  |  | 
|  | 0x58:  Chip ID: 0xa1=EHF 0xc1=DHG | 
|  | 0x5e:  only on DHG, has bits to enable "current mode" temperature detection and | 
|  | critical temperature protection | 
|  | 0x45b: only on EHF, bit 3, vin4 alarm (EHF supports 10 inputs, only 9 on DHG) | 
|  | 0x552: only on EHF, vin4 | 
|  | 0x558: only on EHF, vin4 high limit | 
|  | 0x559: only on EHF, vin4 low limit | 
|  | 0x6b:  only on DHG, SYS fan critical temperature | 
|  | 0x6c:  only on DHG, CPU fan0 critical temperature | 
|  | 0x6d:  only on DHG, AUX fan critical temperature | 
|  | 0x6e:  only on DHG, CPU fan1 critical temperature | 
|  |  | 
|  | 0x50-0x55 and 0x650-0x657 are marked "Test Register" for the EHF, but "Reserved | 
|  | Register" for the DHG | 
|  |  | 
|  | The DHG also supports PECI, where the DHG queries Intel CPU temperatures, and | 
|  | the ICH8 southbridge gets that data via PECI from the DHG, so that the | 
|  | southbridge drives the fans. And the DHG supports SST, a one-wire serial bus. | 
|  |  | 
|  | The DHG-P has an additional automatic fan speed control mode named Smart Fan | 
|  | (TM) III+. This mode is not yet supported by the driver. |