Kernel driver `lm78.o' Prefixes: lm78 (LM78, I2C and ISA) lm78-j (LM78-J, I2C and ISA) lm79 (LM79, I2C and ISA) This driver implements support for the National Semiconductor LM78, LM78-J and LM79. They are described as `Microprocessor System Hardware Monitors'. There is almost no difference between these three chips. Functionally, the LM78 and LM78-J are exactly identical. The LM79 has one more VID line, which is used to report the lower voltages newer Pentium processors use. From now on, LM7* means either of these three types. The LM7* implements one temperatur sensor, three FAN rotation speed sensors, seven voltage sensors, VID lines, alarms, and some miscellaneous stuff. Temperatures are measured in degrees Celcius. An alarm is triggered once when the Overtemperature Shutdown limit is crossed; it is triggered again as soon as it drops below the Hysteris value. A more useful behaviour can be found by setting the Hysteris value to +127 degrees Celcius; in this case, alarms are issued during all the time when the actual temperature \ is above the Overtemperature Shutdown value. 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. This is imporatant because some FANs report only one 'tick' each rotation, while others report two - making all readings twice as high. Not all RPM values can accurately be represented, so some rounding is done. Voltage sensors (also known as IN sensors) report their values in volts. An alarm is triggered if the voltage has crossed a programmable minimum or maximum limit. Note that minimum in this case always means 'closest to zero'; this is important for negative voltage measurements. The VID lines encode the core voltage value: the voltage level your processor should work with. This is hardcoded by the mainboard and/or processor itself. It is a value in volts. In addition to the alarms described above, there are a couple of additional ones. There is a BTI alarm, which gets triggered when an external chip has crossed its limits. Usually, this is connected to all LM75 chips; if at least one crosses its limits, this bit gets set. The CHAS alarm triggers if your computer case is open. The FIFO alarms should never trigger; it indicates an internal error. The SMI_IN alarm indicates some other chip has triggered an SMI interrupt. As we do not use SMI interrupts at all, this condition usually indicates there is a problem with some other device. 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 LM7* only updates its values each 1.5 seconds; reading it more often will do no harm, but will return 'old' values. /proc and sysctl interface files: * alarms (LM78_SYSCTL_ALARMS) A single number (R,0) which indicates which alarms are currently triggered. It is a logical OR of the following bit values: LM78_ALARM_BTI, LM78_ALARM_CHAS, LM78_ALARM_FIFO, LM78_ALARM_SMI_IN, LM78_ALARMS_IN[0-6], LM78_ALARM_FAN[1-3], LM78_ALARM_TEMP * fan[1-3] (LM78_SYSCTL_FAN[1-3]) The Fan Low Limit (RW,0) and Current Fan Reading (R,0). * fan_div (LM78_SYSCTL_FAN_DIV) The FAN1 Scaling Factor (RW,0), FAN2 Scaling Factor (RW,0) and FAN3 Scaling Factor (RW,0). * in[0-6] (LM78_SYSCTL_IN[0-6]) The Voltage Low Limit (RW,2), Voltage High Limit (RW,2) and Current Voltage Reading (R,2). * temp The Overtemperature Shutdown Value (RW,1), Hysteris Value (RW,1) and Current Temperature (R,1). * vid The Core Voltage Value (R,2). configuration file features: NAME LABEL CLASS COMPUTE CLASS RW alarms: R fan1: R fan1_div: fan1 RW fan1_min: fan1 RW fan2: R fan2_div: fan2 RW fan2_min: fan2 RW fan3: R fan3_div: fan3 R fan3_min: fan3 RW in0: R in0_max: in0 in0 RW in0_min: in0 in0 RW in1: R in1_max: in1 in1 RW in1_min: in1 in1 RW in2: R in2_max: in2 in2 RW in2_min: in2 in2 RW in3: R in3_max: in3 in3 RW in3_min: in3 in3 RW in4: R in4_max: in4 in4 RW in4_min: in4 in4 RW in5: R in5_max: in5 in5 RW in5_min: in5 in5 RW in6: R in6_max: in6 in6 RW in6_min: in6 in6 RW temp: R temp_hyst: temp temp RW temp_over: temp temp RW vid: R