| Kernel driver w83627ehf |
| ======================= |
| |
| Supported chips: |
| * Winbond W83627EHF/EHG/DHG (ISA access ONLY) |
| Prefix: 'w83627ehf' |
| Addresses scanned: ISA address retrieved from Super I/O registers |
| Datasheet: |
| http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/W83627EHF_%20W83627EHGb.pdf |
| DHG datasheet confidential. |
| |
| Authors: |
| Jean Delvare <khali@linux-fr.org> |
| Yuan Mu (Winbond) |
| Rudolf Marek <r.marek@assembler.cz> |
| David Hubbard <david.c.hubbard@gmail.com> |
| |
| Description |
| ----------- |
| |
| This driver implements support for the Winbond W83627EHF, W83627EHG, and |
| W83627DHG super I/O chips. We will refer to them collectively as Winbond chips. |
| |
| The chips implement three temperature sensors, five fan rotation |
| speed sensors, ten analog voltage sensors (only nine for the 627DHG), alarms |
| with beep warnings (control unimplemented), and some automatic fan regulation |
| strategies (plus manual fan control mode). |
| |
| Temperatures are measured in degrees Celsius and measurement resolution is 1 |
| degC for temp1 and 0.5 degC for temp2 and temp3. An alarm is triggered when |
| the temperature gets higher than high limit; it stays on until the temperature |
| falls below the hysteresis value. |
| |
| 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 (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" and for the W83627DHG it is set to "w83627dhg" |
| |
| 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 |
| |
| 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. |
