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author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-03 22:09:43 +0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-03 22:09:43 +0400 |
commit | f456205265a61f1d649f8378eceaa163850cba4e (patch) | |
tree | c974aafac8fad9bf1322f2ec66aaf01d01adfaf8 /Documentation/hwmon/emc1403 | |
parent | 8f5759aeb88a47448cd92ab55a016d013b154a98 (diff) | |
parent | 9d311eddf3565ed0e05b3cb5a22db41fa74d9d86 (diff) | |
download | linux-f456205265a61f1d649f8378eceaa163850cba4e.tar.xz |
Merge tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging into next
Pull hwmon updates from Guenter Roeck:
"New driver for NCT6683D
New chip support to existing drivers:
- add support for STTS2004 and AT30TSE004 to jc42 driver
- add support for EMC1402/EMC1412/EMC1422 to emc1403 driver
Other notable changes:
- document hwmon kernel API
- convert jc42, lm70, lm75, lm77, lm83, lm92, max1619, tmp421, and
tmp102 drivers to use new hwmon API functions
- replace function macros in lm80, lm92, and jc42 drivers with real
code
- convert emc1403 driver to use regmap, add support for additional
attributes, and add device IDs for EMC1412, EMC1413, and EMC1414
- various additional cleanup and minor bug fixes in several drivers"
* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging: (60 commits)
hwmon: (nct6775) Fix probe unwind paths to properly unregister platform devices
hwmon: (nct6683) Fix probe unwind paths to properly unregister platform devices
hwmon: (ultra45_env) Introduce managed version of kzalloc
hwmon: Driver for NCT6683D
hwmon: (lm80) Rearrange code to avoid forward declarations
hwmon: (lm80) Convert fan display function macros into functions
hwmon: (lm80) Convert voltage display function macros into functions
hwmon: (lm80) Convert temperature display function macros into functions
hwmon: (lm80) Normalize all temperature values to 16 bit
hwmon: (lm80) Simplify TEMP_FROM_REG
hwmon: (lm83) Convert to use devm_hwmon_device_register_with_groups
hwmon: (lm83) Rearange code to avoid forward declarations
hwmon: (lm83) Drop FSF address
hwmon: (max1619) Convert to use devm_hwmon_device_register_with_groups
hwmon: (max1619) Drop function macros
hwmon: (max1619) Rearrange code to avoid forward declarations
hwmon: (max1619) Drop FSF address
hwmon: (max1619) Fix critical alarm display
hwmon: (jc42) Add support for STTS2004 and AT30TSE004
hwmon: (jc42) Convert function macros into functions
...
Diffstat (limited to 'Documentation/hwmon/emc1403')
-rw-r--r-- | Documentation/hwmon/emc1403 | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/Documentation/hwmon/emc1403 b/Documentation/hwmon/emc1403 new file mode 100644 index 000000000000..a869b0ef6a9d --- /dev/null +++ b/Documentation/hwmon/emc1403 @@ -0,0 +1,59 @@ +Kernel driver emc1403 +===================== + +Supported chips: + * SMSC / Microchip EMC1402, EMC1412 + Addresses scanned: I2C 0x18, 0x1c, 0x29, 0x4c, 0x4d, 0x5c + Prefix: 'emc1402' + Datasheets: + http://ww1.microchip.com/downloads/en/DeviceDoc/1412.pdf + http://ww1.microchip.com/downloads/en/DeviceDoc/1402.pdf + * SMSC / Microchip EMC1403, EMC1404, EMC1413, EMC1414 + Addresses scanned: I2C 0x18, 0x29, 0x4c, 0x4d + Prefix: 'emc1403', 'emc1404' + Datasheets: + http://ww1.microchip.com/downloads/en/DeviceDoc/1403_1404.pdf + http://ww1.microchip.com/downloads/en/DeviceDoc/1413_1414.pdf + * SMSC / Microchip EMC1422 + Addresses scanned: I2C 0x4c + Prefix: 'emc1422' + Datasheet: + http://ww1.microchip.com/downloads/en/DeviceDoc/1422.pdf + * SMSC / Microchip EMC1423, EMC1424 + Addresses scanned: I2C 0x4c + Prefix: 'emc1423', 'emc1424' + Datasheet: + http://ww1.microchip.com/downloads/en/DeviceDoc/1423_1424.pdf + +Author: + Kalhan Trisal <kalhan.trisal@intel.com + + +Description +----------- + +The Standard Microsystems Corporation (SMSC) / Microchip EMC14xx chips +contain up to four temperature sensors. EMC14x2 support two sensors +(one internal, one external). EMC14x3 support three sensors (one internal, +two external), and EMC14x4 support four sensors (one internal, three +external). + +The chips implement three limits for each sensor: low (tempX_min), high +(tempX_max) and critical (tempX_crit.) The chips also implement an +hysteresis mechanism which applies to all limits. The relative difference +is stored in a single register on the chip, which means that the relative +difference between the limit and its hysteresis is always the same for +all three limits. + +This implementation detail implies the following: +* When setting a limit, its hysteresis will automatically follow, the + difference staying unchanged. For example, if the old critical limit + was 80 degrees C, and the hysteresis was 75 degrees C, and you change + the critical limit to 90 degrees C, then the hysteresis will + automatically change to 85 degrees C. +* The hysteresis values can't be set independently. We decided to make + only temp1_crit_hyst writable, while all other hysteresis attributes + are read-only. Setting temp1_crit_hyst writes the difference between + temp1_crit_hyst and temp1_crit into the chip, and the same relative + hysteresis applies automatically to all other limits. +* The limits should be set before the hysteresis. |