60 lines
2.4 KiB
Plaintext
60 lines
2.4 KiB
Plaintext
|
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.
|