Documentation/hwmon/vt1211.rst

10     Addresses scanned: none, address read from Super-I/O config space
24 -----------------
29 			configuration for channels 1-5.
30 			Legal values are in the range of 0-31. Bit 0 maps to
36 			Override the BIOS default temperature interrupt mode.
40 			long as the temperature stays above the hysteresis
47 -----------
49 The VIA VT1211 Super-I/O chip includes complete hardware monitoring
50 capabilities. It monitors 2 dedicated temperature sensor inputs (temp1 and
51 temp2), 1 dedicated voltage (in5) and 2 fans. Additionally, the chip
52 implements 5 universal input channels (UCH1-5) that can be individually
53 programmed to either monitor a voltage or a temperature.
55 This chip also provides manual and automatic control of fan speeds (according
60 connected to the PWM outputs of the VT1211 :-().
80 ------------------
82 Voltages are sampled by an 8-bit ADC with a LSB of ~10mV. The supported input
91 implementation :-) You will have to find documentation for your own
99 VccP          ---    ---    1.0       1400 mV [1]_
108 .. [2] R1 and R2 for 3.3V (int) are internal to the VT1211 chip and the driver
115 Temperature Monitoring
116 ----------------------
118 Temperatures are reported in millidegree Celsius. Each measured temperature
120 hysteresis value with each temperature below which the temperature has to drop
125 All temperature channels except temp2 are external. Temp2 is the VT1211
127 returns the temperature in millidegree Celsius. For the external channels
128 temp1 and temp3-temp7, scaling depends on the board implementation and needs
131 Temp1 is an Intel-type thermal diode which requires the following formula to
134 compute temp1 (@-Offset)/Gain, (@*Gain)+Offset
145 VIA C3 Ezra-T   73.869   0.9528
152 Temp3-temp7 support NTC thermistors. For these channels, the driver returns
153 the voltages as seen at the individual pins of UCH1-UCH5. The voltage at the
162   Rth = Ro * exp(B * (1 / T - 1 / To))   (To is 298.15K (25C) and Ro is the
168   compute tempx 1 / (1 / 298.15 - (` (2200 / @ - 1)) / 3435) - 273.15,
169 		2200 / (1 + (^ (3435 / 298.15 - 3435 / (273.15 + @))))
173 -----------------
176 fans. Writing a 2 to any of the two pwm[1-2]_enable sysfs nodes will put the
181 Each PWM has 4 associated distinct output duty-cycles: full, high, low and
182 off. Full and off are internally hard-wired to 255 (100%) and 0 (0%),
184 pwm[1-2]_auto_point[2-3]_pwm. Each PWM output can be associated with a
185 different thermal input but - and here's the weird part - only one set of
186 thermal thresholds exist that controls both PWMs output duty-cycles. The
187 thermal thresholds are accessible via pwm[1-2]_auto_point[1-4]_temp. Note
190 the first set pwm1_auto_point[1-4]_temp is writable, the second set is
191 read-only).
194 PWM Auto Point             PWM Output Duty-Cycle
196 pwm[1-2]_auto_point4_pwm   full speed duty-cycle (hard-wired to 255)
197 pwm[1-2]_auto_point3_pwm   high speed duty-cycle
198 pwm[1-2]_auto_point2_pwm   low speed duty-cycle
199 pwm[1-2]_auto_point1_pwm   off duty-cycle (hard-wired to 0)
203 Temp Auto Point             Thermal Threshold
205 pwm[1-2]_auto_point4_temp   full speed temp
206 pwm[1-2]_auto_point3_temp   high speed temp
207 pwm[1-2]_auto_point2_temp   low speed temp
208 pwm[1-2]_auto_point1_temp   off temp
212 PWM output duty-cycle based on the input temperature:
215 Thermal Threshold   Output Duty-Cycle       Output Duty-Cycle
218 -                   full speed duty-cycle   full speed duty-cycle
220 -		    high speed duty-cycle   full speed duty-cycle
222 -		    low speed duty-cycle    high speed duty-cycle
224 -		    off duty-cycle          low speed duty-cycle