Kernel driver `vt1211.o' ========================= Status: Beta. Supported chips: * Via VT1211 Super I/O Controller Addresses scanned: none, address read from Super I/O config space Authors: Mark D. Studebaker Module Parameters ----------------- force_addr=0xaddr Set the I/O base address. Useful for boards that don't set the address in the BIOS. Don't use this unless the driver complains that the base address is not set. Example: 'modprobe vt1211 force_addr=0x680' Description ----------- The Via VT1211 Super I/O chip contains voltage/temperature monitoring and PWM control circuitry for two fans. We define the sensors as follows. Somewhat convoluted to minimize changes from via686a. Sensor Voltage Mode Temp Mode uch_config bit -------- ------------ --------- -------------- Reading 1 temp3 Reading 3 temp1 UCH1/Reading2 in0 temp2 0x04 (4) UCH2 in1 temp4 0x08 (8) UCH3 in2 temp5 0x10 (16) UCH4 in3 temp6 0x20 (32) UCH5 in4 temp7 0x40 (64) 3.3V in5 As noted above, 5 of the sensors are "universal channels" and can be set for either voltage or temperature. Set the uch_config bit (in /proc) to 0 for voltage and 1 for temperature. Voltages will read 0 if set for temperature. Temperatures will read a really low number if set for voltage. Fan rotation speeds are reported in RPM (rotations per minute). An alarm is triggered if the rotation speed has dropped below a programmable limit. Fan readings can be divided by a programmable divider (1, 2, 4 or 8) to give the readings more range or accuracy. Not all RPM values can accurately be represented, so some rounding is done. With a divider of 2, the lowest representable value is around 2600 RPM. PWM values are from 0 to 255. The first value in the /proc entry is the pwm value; the second is the enable (0 or 1). If an alarm triggers, it will remain triggered until the hardware register is read at least once. This means that the cause for the alarm may already have disappeared! Note that in the current implementation, all hardware registers are read whenever any data is read (unless it is less than 1.5 seconds since the last update). This means that you can easily miss once-only alarms. ********************** The lm_sensors project gratefully acknowledges the support of Via in the development of this driver.