diff options
Diffstat (limited to 'kernel/Documentation/hwmon/w83627ehf')
| -rw-r--r-- | kernel/Documentation/hwmon/w83627ehf | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/kernel/Documentation/hwmon/w83627ehf b/kernel/Documentation/hwmon/w83627ehf new file mode 100644 index 000000000..735c42a85 --- /dev/null +++ b/kernel/Documentation/hwmon/w83627ehf @@ -0,0 +1,190 @@ +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 W83627UHG + Prefix: 'w83627uhg' + Addresses scanned: ISA address retrieved from Super I/O registers + Datasheet: available from www.nuvoton.com + * 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 <jdelvare@suse.de> + 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, W83627UHG, W83667HG, W83667HG-B, W83667HG-I +(NCT6775F), and NCT6776F super I/O chips. We will refer to them collectively +as Winbond chips. + +The chips implement 3 to 4 temperature sensors (9 for NCT6775F and NCT6776F), +2 to 5 fan rotation speed sensors, 8 to 10 analog voltage sensors, one VID +(except for 627UHG), 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 (not on 627UHG) +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, it contains the name of + the device (see the prefix in the list of supported devices at + the top of this file) + +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). +pwm[1-4]_start_output-minimum fan speed (range 1 - 255) when spinning up +pwm[1-4]_step_output- rate of fan speed change (1 - 255) +pwm[1-4]_stop_output- minimum fan speed (range 1 - 255) when spinning down +pwm[1-4]_max_output - maximum fan speed (range 1 - 255), when the temperature + is above defined range. + +Note: last six 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. |