diff options
author | Krzysztof Helt <krzysztof.h1@wp.pl> | 2007-07-08 20:43:00 (GMT) |
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committer | Mark M. Hoffman <mhoffman@lightlink.com> | 2007-07-31 01:02:59 (GMT) |
commit | add77c64ca8b00dae5dc0a6be9eb89f1514d21ea (patch) | |
tree | 91f998c9c203d877cce43cf0c08d05848d624973 /Documentation/hwmon/thmc50 | |
parent | 80ba80a9bf25d251237694c3fcee850a73324532 (diff) | |
download | linux-fsl-qoriq-add77c64ca8b00dae5dc0a6be9eb89f1514d21ea.tar.xz |
hwmon: add support for THMC50 and ADM1022
This patch adds support for THMC50 and ADM1022 hardware monitoring chips.
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>
Diffstat (limited to 'Documentation/hwmon/thmc50')
-rw-r--r-- | Documentation/hwmon/thmc50 | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/Documentation/hwmon/thmc50 b/Documentation/hwmon/thmc50 new file mode 100644 index 0000000..9639ca9 --- /dev/null +++ b/Documentation/hwmon/thmc50 @@ -0,0 +1,74 @@ +Kernel driver thmc50 +===================== + +Supported chips: + * Analog Devices ADM1022 + Prefix: 'adm1022' + Addresses scanned: I2C 0x2c - 0x2e + Datasheet: http://www.analog.com/en/prod/0,2877,ADM1022,00.html + * Texas Instruments THMC50 + Prefix: 'thmc50' + Addresses scanned: I2C 0x2c - 0x2e + Datasheet: http://focus.ti.com/docs/prod/folders/print/thmc50.html + +Author: Krzysztof Helt <krzysztof.h1@wp.pl> + +This driver was derived from the 2.4 kernel thmc50.c source file. + +Credits: + thmc50.c (2.4 kernel): + Frodo Looijaard <frodol@dds.nl> + Philip Edelbrock <phil@netroedge.com> + +Module Parameters +----------------- + +* adm1022_temp3: short array + List of adapter,address pairs to force chips into ADM1022 mode with + second remote temperature. This does not work for original THMC50 chips. + +Description +----------- + +The THMC50 implements: an internal temperature sensor, support for an +external diode-type temperature sensor (compatible w/ the diode sensor inside +many processors), and a controllable fan/analog_out DAC. For the temperature +sensors, limits can be set through the appropriate Overtemperature Shutdown +register and Hysteresis register. Each value can be set and read to half-degree +accuracy. An alarm is issued (usually to a connected LM78) when the +temperature gets higher then the Overtemperature Shutdown value; it stays on +until the temperature falls below the Hysteresis value. All temperatures are in +degrees Celsius, and are guaranteed within a range of -55 to +125 degrees. + +The THMC50 only updates its values each 1.5 seconds; reading it more often +will do no harm, but will return 'old' values. + +The THMC50 is usually used in combination with LM78-like chips, to measure +the temperature of the processor(s). + +The ADM1022 works the same as THMC50 but it is faster (5 Hz instead of +1 Hz for THMC50). It can be also put in a new mode to handle additional +remote temperature sensor. The driver use the mode set by BIOS by default. + +In case the BIOS is broken and the mode is set incorrectly, you can force +the mode with additional remote temperature with adm1022_temp3 parameter. +A typical symptom of wrong setting is a fan forced to full speed. + +Driver Features +--------------- + +The driver provides up to three temperatures: + +temp1 -- internal +temp2 -- remote +temp3 -- 2nd remote only for ADM1022 + +pwm1 -- fan speed (0 = stop, 255 = full) +pwm1_mode -- always 0 (DC mode) + +The value of 0 for pwm1 also forces FAN_OFF signal from the chip, +so it stops fans even if the value 0 into the ANALOG_OUT register does not. + +The driver was tested on Compaq AP550 with two ADM1022 chips (one works +in the temp3 mode), five temperature readings and two fans. + |