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>

1 files changed, 74 insertions, 0 deletions

diff --git a/Documentation/hwmon/thmc50 b/Documentation/hwmon/thmc50
new file mode 100644
index 000000000000..9639ca93d559
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+++ b/Documentation/hwmon/thmc50
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+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.
+