diff options
Diffstat (limited to 'Documentation/hwmon/vt1211')
| -rw-r--r-- | Documentation/hwmon/vt1211 | 84 |
1 files changed, 52 insertions, 32 deletions
diff --git a/Documentation/hwmon/vt1211 b/Documentation/hwmon/vt1211 index 77fa633b97a8..ddbcde7dd642 100644 --- a/Documentation/hwmon/vt1211 +++ b/Documentation/hwmon/vt1211 @@ -2,9 +2,13 @@ Kernel driver vt1211 ==================== Supported chips: + * VIA VT1211 + Prefix: 'vt1211' + Addresses scanned: none, address read from Super-I/O config space + Datasheet: Provided by VIA upon request and under NDA Authors: Juerg Haefliger <juergh@gmail.com> @@ -19,14 +23,17 @@ technical support. Module Parameters ----------------- -* uch_config: int Override the BIOS default universal channel (UCH) + +* uch_config: int + Override the BIOS default universal channel (UCH) configuration for channels 1-5. Legal values are in the range of 0-31. Bit 0 maps to UCH1, bit 1 maps to UCH2 and so on. Setting a bit to 1 enables the thermal input of that particular UCH and setting a bit to 0 enables the voltage input. -* int_mode: int Override the BIOS default temperature interrupt mode. +* int_mode: int + Override the BIOS default temperature interrupt mode. The only possible value is 0 which forces interrupt mode 0. In this mode, any pending interrupt is cleared when the status register is read but is regenerated as @@ -55,8 +62,9 @@ connected to the PWM outputs of the VT1211 :-(). The following table shows the relationship between the vt1211 inputs and the sysfs nodes. +=============== ============== =========== ================================ Sensor Voltage Mode Temp Mode Default Use (from the datasheet) ------- ------------ --------- -------------------------------- +=============== ============== =========== ================================ Reading 1 temp1 Intel thermal diode Reading 3 temp2 Internal thermal diode UCH1/Reading2 in0 temp3 NTC type thermistor @@ -65,6 +73,7 @@ UCH3 in2 temp5 VccP (processor core) UCH4 in3 temp6 +5V UCH5 in4 temp7 +12V +3.3V in5 Internal VCC (+3.3V) +=============== ============== =========== ================================ Voltage Monitoring @@ -82,19 +91,22 @@ follows. And this is of course totally dependent on the actual board implementation :-) You will have to find documentation for your own motherboard and edit sensors.conf accordingly. - Expected +============= ====== ====== ========= ============ + Expected Voltage R1 R2 Divider Raw Value ------------------------------------------------ +============= ====== ====== ========= ============ +2.5V 2K 10K 1.2 2083 mV -VccP --- --- 1.0 1400 mV (1) +VccP --- --- 1.0 1400 mV [1]_ +5V 14K 10K 2.4 2083 mV +12V 47K 10K 5.7 2105 mV -+3.3V (int) 2K 3.4K 1.588 3300 mV (2) ++3.3V (int) 2K 3.4K 1.588 3300 mV [2]_ +3.3V (ext) 6.8K 10K 1.68 1964 mV +============= ====== ====== ========= ============ + +.. [1] Depending on the CPU (1.4V is for a VIA C3 Nehemiah). -(1) Depending on the CPU (1.4V is for a VIA C3 Nehemiah). -(2) R1 and R2 for 3.3V (int) are internal to the VT1211 chip and the driver - performs the scaling and returns the properly scaled voltage value. +.. [2] R1 and R2 for 3.3V (int) are internal to the VT1211 chip and the driver + performs the scaling and returns the properly scaled voltage value. Each measured voltage has an associated low and high limit which triggers an alarm when crossed. @@ -124,35 +136,37 @@ compute temp1 (@-Offset)/Gain, (@*Gain)+Offset According to the VIA VT1211 BIOS porting guide, the following gain and offset values should be used: +=============== ======== =========== Diode Type Offset Gain ----------- ------ ---- +=============== ======== =========== Intel CPU 88.638 0.9528 - 65.000 0.9686 *) + 65.000 0.9686 [3]_ VIA C3 Ezra 83.869 0.9528 VIA C3 Ezra-T 73.869 0.9528 +=============== ======== =========== -*) This is the formula from the lm_sensors 2.10.0 sensors.conf file. I don't -know where it comes from or how it was derived, it's just listed here for -completeness. +.. [3] This is the formula from the lm_sensors 2.10.0 sensors.conf file. I don't + know where it comes from or how it was derived, it's just listed here for + completeness. Temp3-temp7 support NTC thermistors. For these channels, the driver returns the voltages as seen at the individual pins of UCH1-UCH5. The voltage at the pin (Vpin) is formed by a voltage divider made of the thermistor (Rth) and a -scaling resistor (Rs): +scaling resistor (Rs):: -Vpin = 2200 * Rth / (Rs + Rth) (2200 is the ADC max limit of 2200 mV) + Vpin = 2200 * Rth / (Rs + Rth) (2200 is the ADC max limit of 2200 mV) The equation for the thermistor is as follows (google it if you want to know -more about it): +more about it):: -Rth = Ro * exp(B * (1 / T - 1 / To)) (To is 298.15K (25C) and Ro is the - nominal resistance at 25C) + Rth = Ro * exp(B * (1 / T - 1 / To)) (To is 298.15K (25C) and Ro is the + nominal resistance at 25C) Mingling the above two equations and assuming Rs = Ro and B = 3435 yields the -following formula for sensors.conf: +following formula for sensors.conf:: -compute tempx 1 / (1 / 298.15 - (` (2200 / @ - 1)) / 3435) - 273.15, - 2200 / (1 + (^ (3435 / 298.15 - 3435 / (273.15 + @)))) + compute tempx 1 / (1 / 298.15 - (` (2200 / @ - 1)) / 3435) - 273.15, + 2200 / (1 + (^ (3435 / 298.15 - 3435 / (273.15 + @)))) Fan Speed Control @@ -176,31 +190,37 @@ registers in the VT1211 and programming one set is sufficient (actually only the first set pwm1_auto_point[1-4]_temp is writable, the second set is read-only). +========================== ========================================= PWM Auto Point PWM Output Duty-Cycle ------------------------------------------------- +========================== ========================================= pwm[1-2]_auto_point4_pwm full speed duty-cycle (hard-wired to 255) pwm[1-2]_auto_point3_pwm high speed duty-cycle pwm[1-2]_auto_point2_pwm low speed duty-cycle pwm[1-2]_auto_point1_pwm off duty-cycle (hard-wired to 0) +========================== ========================================= +========================== ================= Temp Auto Point Thermal Threshold ---------------------------------------------- +========================== ================= pwm[1-2]_auto_point4_temp full speed temp pwm[1-2]_auto_point3_temp high speed temp pwm[1-2]_auto_point2_temp low speed temp pwm[1-2]_auto_point1_temp off temp +========================== ================= Long story short, the controller implements the following algorithm to set the PWM output duty-cycle based on the input temperature: -Thermal Threshold Output Duty-Cycle - (Rising Temp) (Falling Temp) ----------------------------------------------------------- - full speed duty-cycle full speed duty-cycle +=================== ======================= ======================== +Thermal Threshold Output Duty-Cycle Output Duty-Cycle + (Rising Temp) (Falling Temp) +=================== ======================= ======================== +- full speed duty-cycle full speed duty-cycle full speed temp - high speed duty-cycle full speed duty-cycle +- high speed duty-cycle full speed duty-cycle high speed temp - low speed duty-cycle high speed duty-cycle +- low speed duty-cycle high speed duty-cycle low speed temp - off duty-cycle low speed duty-cycle +- off duty-cycle low speed duty-cycle off temp +=================== ======================= ======================== |