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-rw-r--r--Documentation/hwmon/vt121184
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
+=================== ======================= ========================