Based on kernel version 4.16.1. Page generated on 2018-04-09 11:53 EST.
1 Note 2 ==== 3 4 This driver supersedes the NCT6775F and NCT6776F support in the W83627EHF 5 driver. 6 7 Kernel driver NCT6775 8 ===================== 9 10 Supported chips: 11 * Nuvoton NCT6102D/NCT6104D/NCT6106D 12 Prefix: 'nct6106' 13 Addresses scanned: ISA address retrieved from Super I/O registers 14 Datasheet: Available from the Nuvoton web site 15 * Nuvoton NCT5572D/NCT6771F/NCT6772F/NCT6775F/W83677HG-I 16 Prefix: 'nct6775' 17 Addresses scanned: ISA address retrieved from Super I/O registers 18 Datasheet: Available from Nuvoton upon request 19 * Nuvoton NCT5573D/NCT5577D/NCT6776D/NCT6776F 20 Prefix: 'nct6776' 21 Addresses scanned: ISA address retrieved from Super I/O registers 22 Datasheet: Available from Nuvoton upon request 23 * Nuvoton NCT5532D/NCT6779D 24 Prefix: 'nct6779' 25 Addresses scanned: ISA address retrieved from Super I/O registers 26 Datasheet: Available from Nuvoton upon request 27 * Nuvoton NCT6791D 28 Prefix: 'nct6791' 29 Addresses scanned: ISA address retrieved from Super I/O registers 30 Datasheet: Available from Nuvoton upon request 31 * Nuvoton NCT6792D 32 Prefix: 'nct6792' 33 Addresses scanned: ISA address retrieved from Super I/O registers 34 Datasheet: Available from Nuvoton upon request 35 * Nuvoton NCT6793D 36 Prefix: 'nct6793' 37 Addresses scanned: ISA address retrieved from Super I/O registers 38 Datasheet: Available from Nuvoton upon request 39 40 Authors: 41 Guenter Roeck <linux@roeck-us.net> 42 43 Description 44 ----------- 45 46 This driver implements support for the Nuvoton NCT6775F, NCT6776F, and NCT6779D 47 and compatible super I/O chips. 48 49 The chips support up to 25 temperature monitoring sources. Up to 6 of those are 50 direct temperature sensor inputs, the others are special sources such as PECI, 51 PCH, and SMBUS. Depending on the chip type, 2 to 6 of the temperature sources 52 can be monitored and compared against minimum, maximum, and critical 53 temperatures. The driver reports up to 10 of the temperatures to the user. 54 There are 4 to 5 fan rotation speed sensors, 8 to 15 analog voltage sensors, 55 one VID, alarms with beep warnings (control unimplemented), and some automatic 56 fan regulation strategies (plus manual fan control mode). 57 58 The temperature sensor sources on all chips are configurable. The configured 59 source for each of the temperature sensors is provided in tempX_label. 60 61 Temperatures are measured in degrees Celsius and measurement resolution is 62 either 1 degC or 0.5 degC, depending on the temperature source and 63 configuration. An alarm is triggered when the temperature gets higher than 64 the high limit; it stays on until the temperature falls below the hysteresis 65 value. Alarms are only supported for temp1 to temp6, depending on the chip type. 66 67 Fan rotation speeds are reported in RPM (rotations per minute). An alarm is 68 triggered if the rotation speed has dropped below a programmable limit. On 69 NCT6775F, fan readings can be divided by a programmable divider (1, 2, 4, 8, 70 16, 32, 64 or 128) to give the readings more range or accuracy; the other chips 71 do not have a fan speed divider. The driver sets the most suitable fan divisor 72 itself; specifically, it increases the divider value each time a fan speed 73 reading returns an invalid value, and it reduces it if the fan speed reading 74 is lower than optimal. Some fans might not be present because they share pins 75 with other functions. 76 77 Voltage sensors (also known as IN sensors) report their values in millivolts. 78 An alarm is triggered if the voltage has crossed a programmable minimum 79 or maximum limit. 80 81 The driver supports automatic fan control mode known as Thermal Cruise. 82 In this mode, the chip attempts to keep the measured temperature in a 83 predefined temperature range. If the temperature goes out of range, fan 84 is driven slower/faster to reach the predefined range again. 85 86 The mode works for fan1-fan5. 87 88 sysfs attributes 89 ---------------- 90 91 pwm[1-5] - this file stores PWM duty cycle or DC value (fan speed) in range: 92 0 (lowest speed) to 255 (full) 93 94 pwm[1-5]_enable - this file controls mode of fan/temperature control: 95 * 0 Fan control disabled (fans set to maximum speed) 96 * 1 Manual mode, write to pwm[0-5] any value 0-255 97 * 2 "Thermal Cruise" mode 98 * 3 "Fan Speed Cruise" mode 99 * 4 "Smart Fan III" mode (NCT6775F only) 100 * 5 "Smart Fan IV" mode 101 102 pwm[1-5]_mode - controls if output is PWM or DC level 103 * 0 DC output 104 * 1 PWM output 105 106 Common fan control attributes 107 ----------------------------- 108 109 pwm[1-5]_temp_sel Temperature source. Value is temperature sensor index. 110 For example, select '1' for temp1_input. 111 pwm[1-5]_weight_temp_sel 112 Secondary temperature source. Value is temperature 113 sensor index. For example, select '1' for temp1_input. 114 Set to 0 to disable secondary temperature control. 115 116 If secondary temperature functionality is enabled, it is controlled with the 117 following attributes. 118 119 pwm[1-5]_weight_duty_step 120 Duty step size. 121 pwm[1-5]_weight_temp_step 122 Temperature step size. With each step over 123 temp_step_base, the value of weight_duty_step is added 124 to the current pwm value. 125 pwm[1-5]_weight_temp_step_base 126 Temperature at which secondary temperature control kicks 127 in. 128 pwm[1-5]_weight_temp_step_tol 129 Temperature step tolerance. 130 131 Thermal Cruise mode (2) 132 ----------------------- 133 134 If the temperature is in the range defined by: 135 136 pwm[1-5]_target_temp Target temperature, unit millidegree Celsius 137 (range 0 - 127000) 138 pwm[1-5]_temp_tolerance 139 Target temperature tolerance, unit millidegree Celsius 140 141 there are no changes to fan speed. Once the temperature leaves the interval, fan 142 speed increases (if temperature is higher that desired) or decreases (if 143 temperature is lower than desired), using the following limits and time 144 intervals. 145 146 pwm[1-5]_start fan pwm start value (range 1 - 255), to start fan 147 when the temperature is above defined range. 148 pwm[1-5]_floor lowest fan pwm (range 0 - 255) if temperature is below 149 the defined range. If set to 0, the fan is expected to 150 stop if the temperature is below the defined range. 151 pwm[1-5]_step_up_time milliseconds before fan speed is increased 152 pwm[1-5]_step_down_time milliseconds before fan speed is decreased 153 pwm[1-5]_stop_time how many milliseconds must elapse to switch 154 corresponding fan off (when the temperature was below 155 defined range). 156 157 Speed Cruise mode (3) 158 --------------------- 159 160 This modes tries to keep the fan speed constant. 161 162 fan[1-5]_target Target fan speed 163 fan[1-5]_tolerance 164 Target speed tolerance 165 166 167 Untested; use at your own risk. 168 169 Smart Fan IV mode (5) 170 --------------------- 171 172 This mode offers multiple slopes to control the fan speed. The slopes can be 173 controlled by setting the pwm and temperature attributes. When the temperature 174 rises, the chip will calculate the DC/PWM output based on the current slope. 175 There are up to seven data points depending on the chip type. Subsequent data 176 points should be set to higher temperatures and higher pwm values to achieve 177 higher fan speeds with increasing temperature. The last data point reflects 178 critical temperature mode, in which the fans should run at full speed. 179 180 pwm[1-5]_auto_point[1-7]_pwm 181 pwm value to be set if temperature reaches matching 182 temperature range. 183 pwm[1-5]_auto_point[1-7]_temp 184 Temperature over which the matching pwm is enabled. 185 pwm[1-5]_temp_tolerance 186 Temperature tolerance, unit millidegree Celsius 187 pwm[1-5]_crit_temp_tolerance 188 Temperature tolerance for critical temperature, 189 unit millidegree Celsius 190 191 pwm[1-5]_step_up_time milliseconds before fan speed is increased 192 pwm[1-5]_step_down_time milliseconds before fan speed is decreased 193 194 Usage Notes 195 ----------- 196 197 On various ASUS boards with NCT6776F, it appears that CPUTIN is not really 198 connected to anything and floats, or that it is connected to some non-standard 199 temperature measurement device. As a result, the temperature reported on CPUTIN 200 will not reflect a usable value. It often reports unreasonably high 201 temperatures, and in some cases the reported temperature declines if the actual 202 temperature increases (similar to the raw PECI temperature value - see PECI 203 specification for details). CPUTIN should therefore be be ignored on ASUS 204 boards. The CPU temperature on ASUS boards is reported from PECI 0.