4 This driver supercedes the NCT6775F and NCT6776F support in the W83627EHF
5 driver. It supports NCT6106D, NCT6775F, NCT6776F, and NCT6779D.
7 The driver should be in shape for upstream integration, and has been submitted
8 to the lm-sensors mailing list for that purpose. Testing and review feedback
9 will be required for the driver to be actually integrated. If you use the latest
10 version of this driver, and/or if you can provide review feedback, please let
14 =======================
17 * Nuvoton NCT6102D/NCT6104D/NCT6106D
19 Addresses scanned: ISA address retrieved from Super I/O registers
20 Datasheet: Available from Nuvoton upon request
21 * Nuvoton NCT6775F/W83667HG-I
23 Addresses scanned: ISA address retrieved from Super I/O registers
24 Datasheet: Available from Nuvoton upon request
27 Addresses scanned: ISA address retrieved from Super I/O registers
28 Datasheet: Available from Nuvoton upon request
31 Addresses scanned: ISA address retrieved from Super I/O registers
32 Datasheet: Available from Nuvoton upon request
35 Guenter Roeck <linux@roeck-us.net>
40 This driver implements support for the Nuvoton NCT6106D, NCT6775F, NCT6776F,
41 and NCT6779D super I/O chips. We will refer to them collectively as Nuvoton
44 The chips implement up to 8 temperature sensors depending on the chip type and
45 configuration. Temperatures used to control fan speed are reported separately.
46 There are 4 to 5 fan rotation speed sensors, 8 to 15 analog voltage sensors,
47 one VID, alarms with beep warnings (control unimplemented), and some automatic
48 fan regulation strategies (plus manual fan control mode).
50 The temperature sensor sources on all chips are configurable. temp4 and higher
51 attributes are only reported if its temperature source differs from the
52 temperature sources of the already reported temperature sensors.
53 The configured source for each of the temperature sensors is provided
56 Temperatures are measured in degrees Celsius and measurement resolution is
57 either 1 degC or 0.5 degC, depending on the temperature source and
58 configuration. An alarm is triggered when the temperature gets higher than
59 the high limit; it stays on until the temperature falls below the hysteresis
60 value. Alarms are only supported for temp1, temp2, and temp3.
62 Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
63 triggered if the rotation speed has dropped below a programmable limit. Fan
64 readings can be divided by a programmable divider (1, 2, 4, 8, 16, 32, 64 or
65 128) to give the readings more range or accuracy. The driver sets the most
66 suitable fan divisor itself. Some fans might not be present because they
67 share pins with other functions.
69 Voltage sensors (also known as IN sensors) report their values in millivolts.
70 An alarm is triggered if the voltage has crossed a programmable minimum
73 The driver supports automatic fan control mode known as Thermal Cruise.
74 In this mode, the chip attempts to keep the measured temperature in a
75 predefined temperature range. If the temperature goes out of range, fan
76 is driven slower/faster to reach the predefined range again.
78 The mode works for fan1-fan5.
83 name - this is a standard hwmon device entry, it contains the name of
84 the device (see the prefix in the list of supported devices at
87 pwm[1-5] - this file stores PWM duty cycle or DC value (fan speed) in range:
88 0 (stop) to 255 (full)
90 pwm[1-5]_enable - this file controls mode of fan/temperature control:
91 * 0 Fan control disabled (fans set to maximum speed)
92 * 1 Manual mode, write to pwm file any value 0-255 (full speed)
93 * 2 "Thermal Cruise" mode
94 * 3 "Fan Speed Cruise" mode
95 * 4 "Smart Fan III" mode (NCT6775F only)
96 * 5 "Smart Fan IV" mode
98 pwm[1-5]_mode - controls if output is PWM or DC level
99 * 0 DC output (0 - 12v)
102 Common fan control attributes
103 -----------------------------
105 pwm[1-5]_temp_sel Temperature source. Value is temperature sensor index.
106 For example, select '1' for temp1_input.
107 pwm[1-5]_weight_temp_sel
108 Secondary temperature source. Value is temperature
109 sensor index. For example, select '1' for temp1_input.
110 pwm[1-5]_weight_enable Set to 1 to enable secondary temperature control.
112 If secondary temperature functionality is enabled, it is controlled with the
113 following attributes.
115 pwm[1-5]_weight_duty_step
117 pwm[1-5]_weight_temp_step
118 Temperature step size. With each step over
119 temp_step_base, the value of weight_duty_step is added
120 to the current pwm value.
121 pwm[1-5]_weight_temp_step_base
122 Temperature at which secondary temperature control kicks
124 pwm[1-5]_weight_temp_step_tol
125 Temperature step tolerance or hysteresis. This is a
129 Thermal Cruise mode (2)
130 -----------------------
132 If the temperature is in the range defined by:
134 pwm[1-5]_target Target temperature, unit millidegree Celsius
136 pwm[1-5]_auto_temp1_hyst
137 Hysteresis, unit millidegree Celsius
138 Hysteresis value is relative to pwm[1-5]_auto_temp1.
140 there are no changes to fan speed. Once the temperature leaves the interval,
141 fan speed increases (temp is higher) or decreases if lower than desired,
142 using the following steps and times.
144 pwm[1-5]_start_output fan pwm start value (range 1 - 255), to start fan
145 when the temperature is above defined range.
146 pwm[1-5]_stop_output lowest fan pwm (range 1 - 255) if temperature is below
148 pwm[1-5]_stop_output_enable
149 Set to 1 to enable pwm[1-5]_stop_output. If disabled
150 (set to 0), the fan will stop if the temperature is
151 below the defined range.
152 pwm[1-5]_step_up_time milliseconds [ms] before fan speed is increased
153 pwm[1-5]_step_down_time milliseconds [ms] before fan speed is decreased
154 pwm[1-5]_stop_time how many milliseconds [ms] must elapse to switch
155 corresponding fan off (when the temperature was below
158 Speed Cruise mode (3)
159 ---------------------
161 This modes tries to keep the fan speed constant.
162 Untested; use at your own risk.
164 Smart Fan IV mode (5)
165 ---------------------
167 The fan is regulated to maintain a target temperature. There are five data
168 points. Subsequent data points should be set to higher temperatures and higher
169 pwm values to achieve higher fan speeds with increasing temperature. The last
170 data point reflects critical temperature mode, in which the fans should run at
173 pwm[1-5]_auto_point[1-5]_pwm
174 pwm value to be set if temperature reaches matching
176 pwm[1-5]_auto_point[1-5]_temp
177 Temperature at which the matching pwm is enabled.
178 pwm[1-5]_step_up_time milliseconds [ms] before fan speed is increased
179 pwm[1-5]_step_down_time milliseconds [ms] before fan speed is decreased
180 pwm[1-5]_step_enable Set to 1 to enable fine grain speed control.
181 If disabled, pwm values will increase or decrease to
182 the values configured in the auto_point_pwm attributes.
183 If enabled, pwm values will be interpolated, resulting
184 in a more fine-grained fan control, resulting in a more
185 fine-grained fan control
191 On various ASUS boards with NCT6776F, it appears that CPUTIN is not really
192 connected to anything and floats, or that it is connected to some non-standard
193 temperature measurement device. As a result, the temperature reported on CPUTIN
194 will not reflect a usable value. It often reports unreasonably high
195 temperatures, and in some cases the reported temperature declines if the actual
196 temperature increases (similar to the raw PECI temperature value - see PECI
197 specification for details). CPUTIN should therefore be be ignored on ASUS
198 boards. The CPU temperature on ASUS boards is reported from PECI 0.