1Kernel driver emc1403
2=====================
3
4Supported chips:
5
6  * SMSC / Microchip EMC1402, EMC1412
7
8    Addresses scanned: I2C 0x18, 0x1c, 0x29, 0x4c, 0x4d, 0x5c
9
10    Prefix: 'emc1402'
11
12    Datasheets:
13
14	- http://ww1.microchip.com/downloads/en/DeviceDoc/1412.pdf
15	- http://ww1.microchip.com/downloads/en/DeviceDoc/1402.pdf
16
17  * SMSC / Microchip EMC1403, EMC1404, EMC1413, EMC1414
18
19    Addresses scanned: I2C 0x18, 0x29, 0x4c, 0x4d
20
21    Prefix: 'emc1403', 'emc1404'
22
23    Datasheets:
24
25	- http://ww1.microchip.com/downloads/en/DeviceDoc/1403_1404.pdf
26	- http://ww1.microchip.com/downloads/en/DeviceDoc/1413_1414.pdf
27
28  * SMSC / Microchip EMC1422
29
30    Addresses scanned: I2C 0x4c
31
32    Prefix: 'emc1422'
33
34    Datasheet:
35
36	- http://ww1.microchip.com/downloads/en/DeviceDoc/1422.pdf
37
38  * SMSC / Microchip EMC1423, EMC1424
39
40    Addresses scanned: I2C 0x4c
41
42    Prefix: 'emc1423', 'emc1424'
43
44    Datasheet:
45
46	- http://ww1.microchip.com/downloads/en/DeviceDoc/1423_1424.pdf
47
48Author:
49    Kalhan Trisal <kalhan.trisal@intel.com
50
51
52Description
53-----------
54
55The Standard Microsystems Corporation (SMSC) / Microchip EMC14xx chips
56contain up to four temperature sensors. EMC14x2 support two sensors
57(one internal, one external). EMC14x3 support three sensors (one internal,
58two external), and EMC14x4 support four sensors (one internal, three
59external).
60
61The chips implement three limits for each sensor: low (tempX_min), high
62(tempX_max) and critical (tempX_crit.) The chips also implement an
63hysteresis mechanism which applies to all limits. The relative difference
64is stored in a single register on the chip, which means that the relative
65difference between the limit and its hysteresis is always the same for
66all three limits.
67
68This implementation detail implies the following:
69
70* When setting a limit, its hysteresis will automatically follow, the
71  difference staying unchanged. For example, if the old critical limit
72  was 80 degrees C, and the hysteresis was 75 degrees C, and you change
73  the critical limit to 90 degrees C, then the hysteresis will
74  automatically change to 85 degrees C.
75* The hysteresis values can't be set independently. We decided to make
76  only temp1_crit_hyst writable, while all other hysteresis attributes
77  are read-only. Setting temp1_crit_hyst writes the difference between
78  temp1_crit_hyst and temp1_crit into the chip, and the same relative
79  hysteresis applies automatically to all other limits.
80* The limits should be set before the hysteresis.
81