1Kernel driver lm75
2==================
3
4Supported chips:
5  * National Semiconductor LM75
6    Prefix: 'lm75'
7    Addresses scanned: I2C 0x48 - 0x4f
8    Datasheet: Publicly available at the National Semiconductor website
9               http://www.national.com/
10  * National Semiconductor LM75A
11    Prefix: 'lm75a'
12    Addresses scanned: I2C 0x48 - 0x4f
13    Datasheet: Publicly available at the National Semiconductor website
14               http://www.national.com/
15  * Dallas Semiconductor (now Maxim) DS75, DS1775, DS7505
16    Prefixes: 'ds75', 'ds1775', 'ds7505'
17    Addresses scanned: none
18    Datasheet: Publicly available at the Maxim website
19               http://www.maximintegrated.com/
20  * Maxim MAX6625, MAX6626
21    Prefixes: 'max6625', 'max6626'
22    Addresses scanned: none
23    Datasheet: Publicly available at the Maxim website
24               http://www.maxim-ic.com/
25  * Microchip (TelCom) TCN75
26    Prefix: 'tcn75'
27    Addresses scanned: none
28    Datasheet: Publicly available at the Microchip website
29               http://www.microchip.com/
30  * Microchip MCP9800, MCP9801, MCP9802, MCP9803
31    Prefix: 'mcp980x'
32    Addresses scanned: none
33    Datasheet: Publicly available at the Microchip website
34               http://www.microchip.com/
35  * Analog Devices ADT75
36    Prefix: 'adt75'
37    Addresses scanned: none
38    Datasheet: Publicly available at the Analog Devices website
39               http://www.analog.com/adt75
40  * ST Microelectronics STDS75
41    Prefix: 'stds75'
42    Addresses scanned: none
43    Datasheet: Publicly available at the ST website
44               http://www.st.com/internet/analog/product/121769.jsp
45  * Texas Instruments TMP100, TMP101, TMP105, TMP112, TMP75, TMP175, TMP275
46    Prefixes: 'tmp100', 'tmp101', 'tmp105', 'tmp112', 'tmp175', 'tmp75', 'tmp275'
47    Addresses scanned: none
48    Datasheet: Publicly available at the Texas Instruments website
49               http://www.ti.com/product/tmp100
50               http://www.ti.com/product/tmp101
51               http://www.ti.com/product/tmp105
52               http://www.ti.com/product/tmp112
53               http://www.ti.com/product/tmp75
54               http://www.ti.com/product/tmp175
55               http://www.ti.com/product/tmp275
56  * NXP LM75B
57    Prefix: 'lm75b'
58    Addresses scanned: none
59    Datasheet: Publicly available at the NXP website
60               http://www.nxp.com/documents/data_sheet/LM75B.pdf
61
62Author: Frodo Looijaard <frodol@dds.nl>
63
64Description
65-----------
66
67The LM75 implements one temperature sensor. Limits can be set through the
68Overtemperature Shutdown register and Hysteresis register. Each value can be
69set and read to half-degree accuracy.
70An alarm is issued (usually to a connected LM78) when the temperature
71gets higher then the Overtemperature Shutdown value; it stays on until
72the temperature falls below the Hysteresis value.
73All temperatures are in degrees Celsius, and are guaranteed within a
74range of -55 to +125 degrees.
75
76The driver caches the values for a period varying between 1 second for the
77slowest chips and 125 ms for the fastest chips; reading it more often
78will do no harm, but will return 'old' values.
79
80The original LM75 was typically used in combination with LM78-like chips
81on PC motherboards, to measure the temperature of the processor(s). Clones
82are now used in various embedded designs.
83
84The LM75 is essentially an industry standard; there may be other
85LM75 clones not listed here, with or without various enhancements,
86that are supported. The clones are not detected by the driver, unless
87they reproduce the exact register tricks of the original LM75, and must
88therefore be instantiated explicitly. Higher resolution up to 12-bit
89is supported by this driver, other specific enhancements are not.
90
91The LM77 is not supported, contrary to what we pretended for a long time.
92Both chips are simply not compatible, value encoding differs.
93