4 This driver supercedes the NCT6775F and NCT6776F support in the W83627EHF
5 driver. It supports NCT6775F, NCT6776F, and NCT6779D.
7 Preliminary support for NCT6106D is available in the nct6106 git branch.
8 The code in this branch is untested.
10 The driver should be in shape for upstream integration, and has been submitted
11 to the lm-sensors mailing list for that purpose. Testing and review feedback
12 will be required for the driver to be actually integrated. If you use the latest
13 version of this driver, and/or if you can provide review feedback, please let
17 =======================
22 Addresses scanned: ISA address retrieved from Super I/O registers
23 Datasheet: Available from Nuvoton upon request
24 * Nuvoton NCT6775F/W83667HG-I
26 Addresses scanned: ISA address retrieved from Super I/O registers
27 Datasheet: Available from Nuvoton upon request
30 Addresses scanned: ISA address retrieved from Super I/O registers
31 Datasheet: Available from Nuvoton upon request
34 Addresses scanned: ISA address retrieved from Super I/O registers
35 Datasheet: Available from Nuvoton upon request
38 Guenter Roeck <linux@roeck-us.net>
43 This driver implements support for the Nuvoton NCT6106D, NCT6775F, NCT6776F,
44 and NCT6779D super I/O chips. We will refer to them collectively as Nuvoton
47 The chips implement up to 8 temperature sensors depending on the chip type and
48 configuration. Temperatures used to control fan speed are reported separately.
49 There are 4 to 5 fan rotation speed sensors, 8 to 15 analog voltage sensors,
50 one VID, alarms with beep warnings (control unimplemented), and some automatic
51 fan regulation strategies (plus manual fan control mode).
53 The temperature sensor sources on all chips are configurable. temp4 and higher
54 attributes are only reported if its temperature source differs from the
55 temperature sources of the already reported temperature sensors.
56 The configured source for each of the temperature sensors is provided
59 Temperatures are measured in degrees Celsius and measurement resolution is
60 either 1 degC or 0.5 degC, depending on the temperature source and
61 configuration. An alarm is triggered when the temperature gets higher than
62 the high limit; it stays on until the temperature falls below the hysteresis
63 value. Alarms are only supported for temp1, temp2, and temp3.
65 Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
66 triggered if the rotation speed has dropped below a programmable limit. Fan
67 readings can be divided by a programmable divider (1, 2, 4, 8, 16, 32, 64 or
68 128) to give the readings more range or accuracy. The driver sets the most
69 suitable fan divisor itself. Some fans might not be present because they
70 share pins with other functions.
72 Voltage sensors (also known as IN sensors) report their values in millivolts.
73 An alarm is triggered if the voltage has crossed a programmable minimum
76 The driver supports automatic fan control mode known as Thermal Cruise.
77 In this mode, the chip attempts to keep the measured temperature in a
78 predefined temperature range. If the temperature goes out of range, fan
79 is driven slower/faster to reach the predefined range again.
81 The mode works for fan1-fan5.
86 name - this is a standard hwmon device entry, it contains the name of
87 the device (see the prefix in the list of supported devices at
90 pwm[1-5] - this file stores PWM duty cycle or DC value (fan speed) in range:
91 0 (stop) to 255 (full)
93 pwm[1-5]_enable - this file controls mode of fan/temperature control:
94 * 0 Fan control disabled (fans set to maximum speed)
95 * 1 Manual mode, write to pwm file any value 0-255 (full speed)
96 * 2 "Thermal Cruise" mode
97 * 3 "Fan Speed Cruise" mode
98 * 4 "Smart Fan III" mode (NCT6775F only)
99 * 5 "Smart Fan IV" mode
101 pwm[1-5]_mode - controls if output is PWM or DC level
102 * 0 DC output (0 - 12v)
105 Common fan control attributes
106 -----------------------------
108 pwm[1-5]_temp_sel Temperature source. Value is temperature sensor index.
109 For example, select '1' for temp1_input.
110 pwm[1-5]_weight_temp_sel
111 Secondary temperature source. Value is temperature
112 sensor index. For example, select '1' for temp1_input.
113 pwm[1-5]_weight_enable Set to 1 to enable secondary temperature control.
115 If secondary temperature functionality is enabled, it is controlled with the
116 following attributes.
118 pwm[1-5]_weight_duty_step
120 pwm[1-5]_weight_temp_step
121 Temperature step size. With each step over
122 temp_step_base, the value of weight_duty_step is added
123 to the current pwm value.
124 pwm[1-5]_weight_temp_step_base
125 Temperature at which secondary temperature control kicks
127 pwm[1-5]_weight_temp_step_tol
128 Temperature step tolerance or hysteresis. This is a
132 Thermal Cruise mode (2)
133 -----------------------
135 If the temperature is in the range defined by:
137 pwm[1-5]_target Target temperature, unit millidegree Celsius
139 pwm[1-5]_auto_temp1_hyst
140 Hysteresis, unit millidegree Celsius
141 Hysteresis value is relative to pwm[1-5]_auto_temp1.
143 there are no changes to fan speed. Once the temperature leaves the interval,
144 fan speed increases (temp is higher) or decreases if lower than desired,
145 using the following steps and times.
147 pwm[1-5]_start_output fan pwm start value (range 1 - 255), to start fan
148 when the temperature is above defined range.
149 pwm[1-5]_stop_output lowest fan pwm (range 1 - 255) if temperature is below
151 pwm[1-5]_stop_output_enable
152 Set to 1 to enable pwm[1-5]_stop_output. If disabled
153 (set to 0), the fan will stop if the temperature is
154 below the defined range.
155 pwm[1-5]_step_up_time milliseconds [ms] before fan speed is increased
156 pwm[1-5]_step_down_time milliseconds [ms] before fan speed is decreased
157 pwm[1-5]_stop_time how many milliseconds [ms] must elapse to switch
158 corresponding fan off (when the temperature was below
161 Speed Cruise mode (3)
162 ---------------------
164 This modes tries to keep the fan speed constant.
165 Untested; use at your own risk.
167 Smart Fan IV mode (5)
168 ---------------------
170 The fan is regulated to maintain a target temperature. There are five data
171 points. Subsequent data points should be set to higher temperatures and higher
172 pwm values to achieve higher fan speeds with increasing temperature. The last
173 data point reflects critical temperature mode, in which the fans should run at
176 pwm[1-5]_auto_point[1-5]_pwm
177 pwm value to be set if temperature reaches matching
179 pwm[1-5]_auto_point[1-5]_temp
180 Temperature at which the matching pwm is enabled.
181 pwm[1-5]_step_up_time milliseconds [ms] before fan speed is increased
182 pwm[1-5]_step_down_time milliseconds [ms] before fan speed is decreased
183 pwm[1-5]_step_enable Set to 1 to enable fine grain speed control.
184 If disabled, pwm values will increase or decrease to
185 the values configured in the auto_point_pwm attributes.
186 If enabled, pwm values will be interpolated, resulting
187 in a more fine-grained fan control, resulting in a more
188 fine-grained fan control
194 On various ASUS boards with NCT6776F, it appears that CPUTIN is not really
195 connected to anything and floats, or that it is connected to some non-standard
196 temperature measurement device. As a result, the temperature reported on CPUTIN
197 will not reflect a usable value. It often reports unreasonably high
198 temperatures, and in some cases the reported temperature declines if the actual
199 temperature increases (similar to the raw PECI temperature value - see PECI
200 specification for details). CPUTIN should therefore be be ignored on ASUS
201 boards. The CPU temperature on ASUS boards is reported from PECI 0.