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Commit | Line | Data |
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9de2e2e8 GR |
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: | |
b6e6dd8e GR |
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 | |
2c7fd30d | 15 | * Nuvoton NCT5572D/NCT6771F/NCT6772F/NCT6775F/W83677HG-I |
9de2e2e8 GR |
16 | Prefix: 'nct6775' |
17 | Addresses scanned: ISA address retrieved from Super I/O registers | |
18 | Datasheet: Available from Nuvoton upon request | |
b6e6dd8e | 19 | * Nuvoton NCT5573D/NCT5577D/NCT6776D/NCT6776F |
9de2e2e8 GR |
20 | Prefix: 'nct6776' |
21 | Addresses scanned: ISA address retrieved from Super I/O registers | |
22 | Datasheet: Available from Nuvoton upon request | |
2c7fd30d | 23 | * Nuvoton NCT5532D/NCT6779D |
9de2e2e8 GR |
24 | Prefix: 'nct6779' |
25 | Addresses scanned: ISA address retrieved from Super I/O registers | |
26 | Datasheet: Available from Nuvoton upon request | |
b6e6dd8e GR |
27 | * Nuvoton NCT6791D |
28 | Prefix: 'nct6791' | |
29 | Addresses scanned: ISA address retrieved from Super I/O registers | |
30 | Datasheet: Available from Nuvoton upon request | |
8aefb93f GR |
31 | * Nuvoton NCT6792D |
32 | Prefix: 'nct6792' | |
33 | Addresses scanned: ISA address retrieved from Super I/O registers | |
34 | Datasheet: Available from Nuvoton upon request | |
9de2e2e8 GR |
35 | |
36 | Authors: | |
37 | Guenter Roeck <linux@roeck-us.net> | |
38 | ||
39 | Description | |
40 | ----------- | |
41 | ||
42 | This driver implements support for the Nuvoton NCT6775F, NCT6776F, and NCT6779D | |
2c7fd30d | 43 | and compatible super I/O chips. |
9de2e2e8 GR |
44 | |
45 | The chips support up to 25 temperature monitoring sources. Up to 6 of those are | |
46 | direct temperature sensor inputs, the others are special sources such as PECI, | |
47 | PCH, and SMBUS. Depending on the chip type, 2 to 6 of the temperature sources | |
48 | can be monitored and compared against minimum, maximum, and critical | |
49 | temperatures. The driver reports up to 10 of the temperatures to the user. | |
50 | There are 4 to 5 fan rotation speed sensors, 8 to 15 analog voltage sensors, | |
51 | one VID, alarms with beep warnings (control unimplemented), and some automatic | |
52 | fan regulation strategies (plus manual fan control mode). | |
53 | ||
54 | The temperature sensor sources on all chips are configurable. The configured | |
55 | source for each of the temperature sensors is provided in tempX_label. | |
56 | ||
57 | Temperatures are measured in degrees Celsius and measurement resolution is | |
58 | either 1 degC or 0.5 degC, depending on the temperature source and | |
59 | configuration. An alarm is triggered when the temperature gets higher than | |
60 | the high limit; it stays on until the temperature falls below the hysteresis | |
61 | value. Alarms are only supported for temp1 to temp6, depending on the chip type. | |
62 | ||
63 | Fan rotation speeds are reported in RPM (rotations per minute). An alarm is | |
64 | triggered if the rotation speed has dropped below a programmable limit. On | |
65 | NCT6775F, fan readings can be divided by a programmable divider (1, 2, 4, 8, | |
66 | 16, 32, 64 or 128) to give the readings more range or accuracy; the other chips | |
67 | do not have a fan speed divider. The driver sets the most suitable fan divisor | |
1c65dc36 GR |
68 | itself; specifically, it increases the divider value each time a fan speed |
69 | reading returns an invalid value, and it reduces it if the fan speed reading | |
70 | is lower than optimal. Some fans might not be present because they share pins | |
9de2e2e8 GR |
71 | with other functions. |
72 | ||
73 | Voltage sensors (also known as IN sensors) report their values in millivolts. | |
74 | An alarm is triggered if the voltage has crossed a programmable minimum | |
75 | or maximum limit. | |
76 | ||
77 | The driver supports automatic fan control mode known as Thermal Cruise. | |
78 | In this mode, the chip attempts to keep the measured temperature in a | |
79 | predefined temperature range. If the temperature goes out of range, fan | |
80 | is driven slower/faster to reach the predefined range again. | |
81 | ||
82 | The mode works for fan1-fan5. | |
83 | ||
77eb5b37 GR |
84 | sysfs attributes |
85 | ---------------- | |
86 | ||
87 | pwm[1-5] - this file stores PWM duty cycle or DC value (fan speed) in range: | |
88 | 0 (lowest speed) to 255 (full) | |
89 | ||
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[0-5] any value 0-255 | |
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 | |
97 | ||
98 | pwm[1-5]_mode - controls if output is PWM or DC level | |
99 | * 0 DC output | |
100 | * 1 PWM output | |
101 | ||
cdcaeceb GR |
102 | Common fan control attributes |
103 | ----------------------------- | |
104 | ||
105 | pwm[1-5]_temp_sel Temperature source. Value is temperature sensor index. | |
106 | For example, select '1' for temp1_input. | |
bbd8decd GR |
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 | Set to 0 to disable secondary temperature control. | |
111 | ||
112 | If secondary temperature functionality is enabled, it is controlled with the | |
113 | following attributes. | |
114 | ||
115 | pwm[1-5]_weight_duty_step | |
116 | Duty step size. | |
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 | |
123 | in. | |
124 | pwm[1-5]_weight_temp_step_tol | |
125 | Temperature step tolerance. | |
cdcaeceb GR |
126 | |
127 | Thermal Cruise mode (2) | |
128 | ----------------------- | |
129 | ||
130 | If the temperature is in the range defined by: | |
131 | ||
132 | pwm[1-5]_target_temp Target temperature, unit millidegree Celsius | |
133 | (range 0 - 127000) | |
134 | pwm[1-5]_temp_tolerance | |
135 | Target temperature tolerance, unit millidegree Celsius | |
136 | ||
137 | there are no changes to fan speed. Once the temperature leaves the interval, fan | |
138 | speed increases (if temperature is higher that desired) or decreases (if | |
139 | temperature is lower than desired), using the following limits and time | |
140 | intervals. | |
141 | ||
142 | pwm[1-5]_start fan pwm start value (range 1 - 255), to start fan | |
143 | when the temperature is above defined range. | |
144 | pwm[1-5]_floor lowest fan pwm (range 0 - 255) if temperature is below | |
145 | the defined range. If set to 0, the fan is expected to | |
146 | stop if the temperature is below the defined range. | |
147 | pwm[1-5]_step_up_time milliseconds before fan speed is increased | |
148 | pwm[1-5]_step_down_time milliseconds before fan speed is decreased | |
149 | pwm[1-5]_stop_time how many milliseconds must elapse to switch | |
150 | corresponding fan off (when the temperature was below | |
151 | defined range). | |
152 | ||
153 | Speed Cruise mode (3) | |
154 | --------------------- | |
155 | ||
156 | This modes tries to keep the fan speed constant. | |
157 | ||
158 | fan[1-5]_target Target fan speed | |
159 | fan[1-5]_tolerance | |
160 | Target speed tolerance | |
161 | ||
162 | ||
163 | Untested; use at your own risk. | |
164 | ||
165 | Smart Fan IV mode (5) | |
166 | --------------------- | |
167 | ||
168 | This mode offers multiple slopes to control the fan speed. The slopes can be | |
169 | controlled by setting the pwm and temperature attributes. When the temperature | |
170 | rises, the chip will calculate the DC/PWM output based on the current slope. | |
171 | There are up to seven data points depending on the chip type. Subsequent data | |
172 | points should be set to higher temperatures and higher pwm values to achieve | |
173 | higher fan speeds with increasing temperature. The last data point reflects | |
174 | critical temperature mode, in which the fans should run at full speed. | |
175 | ||
176 | pwm[1-5]_auto_point[1-7]_pwm | |
177 | pwm value to be set if temperature reaches matching | |
178 | temperature range. | |
179 | pwm[1-5]_auto_point[1-7]_temp | |
180 | Temperature over which the matching pwm is enabled. | |
181 | pwm[1-5]_temp_tolerance | |
182 | Temperature tolerance, unit millidegree Celsius | |
183 | pwm[1-5]_crit_temp_tolerance | |
184 | Temperature tolerance for critical temperature, | |
185 | unit millidegree Celsius | |
186 | ||
187 | pwm[1-5]_step_up_time milliseconds before fan speed is increased | |
188 | pwm[1-5]_step_down_time milliseconds before fan speed is decreased | |
189 | ||
9de2e2e8 GR |
190 | Usage Notes |
191 | ----------- | |
192 | ||
193 | On various ASUS boards with NCT6776F, it appears that CPUTIN is not really | |
194 | connected to anything and floats, or that it is connected to some non-standard | |
195 | temperature measurement device. As a result, the temperature reported on CPUTIN | |
196 | will not reflect a usable value. It often reports unreasonably high | |
197 | temperatures, and in some cases the reported temperature declines if the actual | |
198 | temperature increases (similar to the raw PECI temperature value - see PECI | |
199 | specification for details). CPUTIN should therefore be be ignored on ASUS | |
200 | boards. The CPU temperature on ASUS boards is reported from PECI 0. |