thmc50.rst (2671B)
1Kernel driver thmc50 2===================== 3 4Supported chips: 5 6 * Analog Devices ADM1022 7 8 Prefix: 'adm1022' 9 10 Addresses scanned: I2C 0x2c - 0x2e 11 12 Datasheet: http://www.analog.com/en/prod/0,2877,ADM1022,00.html 13 14 * Texas Instruments THMC50 15 16 Prefix: 'thmc50' 17 18 Addresses scanned: I2C 0x2c - 0x2e 19 20 Datasheet: https://www.ti.com/ 21 22 23Author: Krzysztof Helt <krzysztof.h1@wp.pl> 24 25This driver was derived from the 2.4 kernel thmc50.c source file. 26 27Credits: 28 29 thmc50.c (2.4 kernel): 30 31 - Frodo Looijaard <frodol@dds.nl> 32 - Philip Edelbrock <phil@netroedge.com> 33 34Module Parameters 35----------------- 36 37* adm1022_temp3: short array 38 List of adapter,address pairs to force chips into ADM1022 mode with 39 second remote temperature. This does not work for original THMC50 chips. 40 41Description 42----------- 43 44The THMC50 implements: an internal temperature sensor, support for an 45external diode-type temperature sensor (compatible w/ the diode sensor inside 46many processors), and a controllable fan/analog_out DAC. For the temperature 47sensors, limits can be set through the appropriate Overtemperature Shutdown 48register and Hysteresis register. Each value can be set and read to half-degree 49accuracy. An alarm is issued (usually to a connected LM78) when the 50temperature gets higher then the Overtemperature Shutdown value; it stays on 51until the temperature falls below the Hysteresis value. All temperatures are in 52degrees Celsius, and are guaranteed within a range of -55 to +125 degrees. 53 54The THMC50 only updates its values each 1.5 seconds; reading it more often 55will do no harm, but will return 'old' values. 56 57The THMC50 is usually used in combination with LM78-like chips, to measure 58the temperature of the processor(s). 59 60The ADM1022 works the same as THMC50 but it is faster (5 Hz instead of 611 Hz for THMC50). It can be also put in a new mode to handle additional 62remote temperature sensor. The driver use the mode set by BIOS by default. 63 64In case the BIOS is broken and the mode is set incorrectly, you can force 65the mode with additional remote temperature with adm1022_temp3 parameter. 66A typical symptom of wrong setting is a fan forced to full speed. 67 68Driver Features 69--------------- 70 71The driver provides up to three temperatures: 72 73temp1 74 - internal 75temp2 76 - remote 77temp3 78 - 2nd remote only for ADM1022 79 80pwm1 81 - fan speed (0 = stop, 255 = full) 82pwm1_mode 83 - always 0 (DC mode) 84 85The value of 0 for pwm1 also forces FAN_OFF signal from the chip, 86so it stops fans even if the value 0 into the ANALOG_OUT register does not. 87 88The driver was tested on Compaq AP550 with two ADM1022 chips (one works 89in the temp3 mode), five temperature readings and two fans.