1Kernel driver w83627ehf 2======================= 3 4Supported chips: 5 * Winbond W83627EHF/EHG (ISA access ONLY) 6 Prefix: 'w83627ehf' 7 Addresses scanned: ISA address retrieved from Super I/O registers 8 Datasheet: not available 9 * Winbond W83627DHG 10 Prefix: 'w83627dhg' 11 Addresses scanned: ISA address retrieved from Super I/O registers 12 Datasheet: not available 13 * Winbond W83627DHG-P 14 Prefix: 'w83627dhg' 15 Addresses scanned: ISA address retrieved from Super I/O registers 16 Datasheet: not available 17 * Winbond W83627UHG 18 Prefix: 'w83627uhg' 19 Addresses scanned: ISA address retrieved from Super I/O registers 20 Datasheet: available from www.nuvoton.com 21 * Winbond W83667HG 22 Prefix: 'w83667hg' 23 Addresses scanned: ISA address retrieved from Super I/O registers 24 Datasheet: not available 25 * Winbond W83667HG-B 26 Prefix: 'w83667hg' 27 Addresses scanned: ISA address retrieved from Super I/O registers 28 Datasheet: Available from Nuvoton upon request 29 * Nuvoton NCT6775F/W83667HG-I 30 Prefix: 'nct6775' 31 Addresses scanned: ISA address retrieved from Super I/O registers 32 Datasheet: Available from Nuvoton upon request 33 * Nuvoton NCT6776F 34 Prefix: 'nct6776' 35 Addresses scanned: ISA address retrieved from Super I/O registers 36 Datasheet: Available from Nuvoton upon request 37 38Authors: 39 Jean Delvare <khali@linux-fr.org> 40 Yuan Mu (Winbond) 41 Rudolf Marek <r.marek@assembler.cz> 42 David Hubbard <david.c.hubbard@gmail.com> 43 Gong Jun <JGong@nuvoton.com> 44 45Description 46----------- 47 48This driver implements support for the Winbond W83627EHF, W83627EHG, 49W83627DHG, W83627DHG-P, W83627UHG, W83667HG, W83667HG-B, W83667HG-I 50(NCT6775F), and NCT6776F super I/O chips. We will refer to them collectively 51as Winbond chips. 52 53The chips implement 3 to 4 temperature sensors (9 for NCT6775F and NCT6776F), 542 to 5 fan rotation speed sensors, 8 to 10 analog voltage sensors, one VID 55(except for 627UHG), alarms with beep warnings (control unimplemented), 56and some automatic fan regulation strategies (plus manual fan control mode). 57 58The temperature sensor sources on W82677HG-B, NCT6775F, and NCT6776F are 59configurable. temp4 and higher attributes are only reported if its temperature 60source differs from the temperature sources of the already reported temperature 61sensors. The configured source for each of the temperature sensors is provided 62in tempX_label. 63 64Temperatures are measured in degrees Celsius and measurement resolution is 1 65degC for temp1 and and 0.5 degC for temp2 and temp3. For temp4 and higher, 66resolution is 1 degC for W83667HG-B and 0.0 degC for NCT6775F and NCT6776F. 67An alarm is triggered when the temperature gets higher than high limit; 68it stays on until the temperature falls below the hysteresis value. 69Alarms are only supported for temp1, temp2, and temp3. 70 71Fan rotation speeds are reported in RPM (rotations per minute). An alarm is 72triggered if the rotation speed has dropped below a programmable limit. Fan 73readings can be divided by a programmable divider (1, 2, 4, 8, 16, 32, 64 or 74128) to give the readings more range or accuracy. The driver sets the most 75suitable fan divisor itself. Some fans might not be present because they 76share pins with other functions. 77 78Voltage sensors (also known as IN sensors) report their values in millivolts. 79An alarm is triggered if the voltage has crossed a programmable minimum 80or maximum limit. 81 82The driver supports automatic fan control mode known as Thermal Cruise. 83In this mode, the chip attempts to keep the measured temperature in a 84predefined temperature range. If the temperature goes out of range, fan 85is driven slower/faster to reach the predefined range again. 86 87The mode works for fan1-fan4. Mapping of temperatures to pwm outputs is as 88follows: 89 90temp1 -> pwm1 91temp2 -> pwm2 92temp3 -> pwm3 (not on 627UHG) 93prog -> pwm4 (not on 667HG and 667HG-B; the programmable setting is not 94 supported by the driver) 95 96/sys files 97---------- 98 99name - this is a standard hwmon device entry, it contains the name of 100 the device (see the prefix in the list of supported devices at 101 the top of this file) 102 103pwm[1-4] - this file stores PWM duty cycle or DC value (fan speed) in range: 104 0 (stop) to 255 (full) 105 106pwm[1-4]_enable - this file controls mode of fan/temperature control: 107 * 1 Manual mode, write to pwm file any value 0-255 (full speed) 108 * 2 "Thermal Cruise" mode 109 * 3 "Fan Speed Cruise" mode 110 * 4 "Smart Fan III" mode 111 * 5 "Smart Fan IV" mode 112 113 SmartFan III mode is not supported on NCT6776F. 114 115 SmartFan IV mode is configurable only if it was configured at system 116 startup, and is only supported for W83677HG-B, NCT6775F, and NCT6776F. 117 SmartFan IV operational parameters can not be configured at this time, 118 and the various pwm attributes are not used in SmartFan IV mode. 119 The attributes can be written to, which is useful if you plan to 120 configure the system for a different pwm mode. However, the information 121 returned when reading pwm attributes is unrelated to SmartFan IV 122 operation. 123 124pwm[1-4]_mode - controls if output is PWM or DC level 125 * 0 DC output (0 - 12v) 126 * 1 PWM output 127 128Thermal Cruise mode 129------------------- 130 131If the temperature is in the range defined by: 132 133pwm[1-4]_target - set target temperature, unit millidegree Celsius 134 (range 0 - 127000) 135pwm[1-4]_tolerance - tolerance, unit millidegree Celsius (range 0 - 15000) 136 137there are no changes to fan speed. Once the temperature leaves the interval, 138fan speed increases (temp is higher) or decreases if lower than desired. 139There are defined steps and times, but not exported by the driver yet. 140 141pwm[1-4]_min_output - minimum fan speed (range 1 - 255), when the temperature 142 is below defined range. 143pwm[1-4]_stop_time - how many milliseconds [ms] must elapse to switch 144 corresponding fan off. (when the temperature was below 145 defined range). 146pwm[1-4]_start_output-minimum fan speed (range 1 - 255) when spinning up 147pwm[1-4]_step_output- rate of fan speed change (1 - 255) 148pwm[1-4]_stop_output- minimum fan speed (range 1 - 255) when spinning down 149pwm[1-4]_max_output - maximum fan speed (range 1 - 255), when the temperature 150 is above defined range. 151 152Note: last six functions are influenced by other control bits, not yet exported 153 by the driver, so a change might not have any effect. 154 155Implementation Details 156---------------------- 157 158Future driver development should bear in mind that the following registers have 159different functions on the 627EHF and the 627DHG. Some registers also have 160different power-on default values, but BIOS should already be loading 161appropriate defaults. Note that bank selection must be performed as is currently 162done in the driver for all register addresses. 163 1640x49: only on DHG, selects temperature source for AUX fan, CPU fan0 1650x4a: not completely documented for the EHF and the DHG documentation assigns 166 different behavior to bits 7 and 6, including extending the temperature 167 input selection to SmartFan I, not just SmartFan III. Testing on the EHF 168 will reveal whether they are compatible or not. 169 1700x58: Chip ID: 0xa1=EHF 0xc1=DHG 1710x5e: only on DHG, has bits to enable "current mode" temperature detection and 172 critical temperature protection 1730x45b: only on EHF, bit 3, vin4 alarm (EHF supports 10 inputs, only 9 on DHG) 1740x552: only on EHF, vin4 1750x558: only on EHF, vin4 high limit 1760x559: only on EHF, vin4 low limit 1770x6b: only on DHG, SYS fan critical temperature 1780x6c: only on DHG, CPU fan0 critical temperature 1790x6d: only on DHG, AUX fan critical temperature 1800x6e: only on DHG, CPU fan1 critical temperature 181 1820x50-0x55 and 0x650-0x657 are marked "Test Register" for the EHF, but "Reserved 183 Register" for the DHG 184 185The DHG also supports PECI, where the DHG queries Intel CPU temperatures, and 186the ICH8 southbridge gets that data via PECI from the DHG, so that the 187southbridge drives the fans. And the DHG supports SST, a one-wire serial bus. 188 189The DHG-P has an additional automatic fan speed control mode named Smart Fan 190(TM) III+. This mode is not yet supported by the driver. 191