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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/Documentation/hwmon/emc1403
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
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+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.