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authorLinus Torvalds <torvalds@linux-foundation.org>2019-05-06 19:56:51 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-05-06 19:56:51 -0700
commit7aefd944f038c7469571adb37769cb6f3924ecfa (patch)
treef0a8dc23633b6bbbc4f0bff932f332e847fb6c1b /Documentation/hwmon/thmc50.rst
parentMerge branch 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip (diff)
parenthwmon: (lm75) Add support for TMP75B (diff)
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Merge tag 'hwmon-for-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging
Pull hwmon updates from Guenter Roeck: - Add driver for Intersil ISL68137 PWM Controller - Add driver for Lochnagar 2 - Add driver for Infineon IR38064 Voltage Regulator - Add support for TMP75B to lm75 driver - Convert documentation to ReST format - Use request_muxed_region for Super-IO accesses in several drivers - Add 'samples' attribute to ABI, and start using it - Add support for custom sysfs attributes to pmbus drivers (used in ISL68137 driver) - Introduce HWMON_CHANNEL_INFO macro - Automated changes: - Use permission specific [SENSOR_][DEVICE_]ATTR variants - Fix build warnings due to unused of_device_id structures - Use HWMON_CHANNEL_INFO macro - Various minor improvements and fixes * tag 'hwmon-for-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging: (125 commits) hwmon: (lm75) Add support for TMP75B dt-bindings: hwmon: Add tmp75b to lm75.txt hwmon: (s3c) Use dev_get_drvdata() hwmon: (max6650) Drop call to thermal_cdev_update docs: hwmon: remove the extension from .rst files docs: hwmon: convert three docs to ReST format hwmon: (max6650) add thermal cooling device capability hwmon: (ina3221) Add voltage conversion time settings hwmon: (ina3221) Do not read-back to cache reg_config docs: hwmon: Add an index file and rename docs to *.rst docs: hwmon: convert remaining files to ReST format docs: hwmon: misc files: convert to ReST format docs: hwmon: pmbus files: convert to ReST format docs: hwmon: k8temp, w83793: convert to ReST format docs: hwmon: da9052, da9055: convert to ReST format docs: hwmon: wm831x, wm8350: convert to ReST format docs: hwmon: dme1737, vt1211: convert to ReST format docs: hwmon: ads1015: convert to ReST format docs: hwmon: asc7621: convert to ReST format docs: hwmon: ibmpowernv: convert to ReST format ...
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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://www.ti.com/
+
+
+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.