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review.evervolv.com / android_kernel_htc_msm8960 / 426343ef34fac426e619176c84cb2e263b9ed23d / . / Documentation / hwmon / lm75
blob: c91a1d15fa28ae62aca3796ab89e15de3fdd0f5a [file] [log] [blame]
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +0000[diff] [blame]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/
Len Sorensen05e82fe2011-03-21 17:59:36 +0100[diff] [blame]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/
Jean Delvare426343e2011-10-13 17:15:11 -0400[diff] [blame^]15 * Dallas Semiconductor DS75, DS1775
16 Prefixes: 'ds75', 'ds1775'
17 Addresses scanned: none
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +0000[diff] [blame]18 Datasheet: Publicly available at the Dallas Semiconductor website
19 http://www.maxim-ic.com/
20 * Maxim MAX6625, MAX6626
Jean Delvare426343e2011-10-13 17:15:11 -0400[diff] [blame^]21 Prefixes: 'max6625', 'max6626'
22 Addresses scanned: none
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +0000[diff] [blame]23 Datasheet: Publicly available at the Maxim website
24 http://www.maxim-ic.com/
25 * Microchip (TelCom) TCN75
26 Prefix: 'lm75'
Jean Delvare426343e2011-10-13 17:15:11 -0400[diff] [blame^]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
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +0000[diff] [blame]33 Datasheet: Publicly available at the Microchip website
34 http://www.microchip.com/
Michael Henneriche96f9d82011-10-13 04:43:31 -0400[diff] [blame]35 * Analog Devices ADT75
36 Prefix: 'adt75'
Jean Delvare426343e2011-10-13 17:15:11 -0400[diff] [blame^]37 Addresses scanned: none
Michael Henneriche96f9d82011-10-13 04:43:31 -0400[diff] [blame]38 Datasheet: Publicly available at the Analog Devices website
39 http://www.analog.com/adt75
Jean Delvare426343e2011-10-13 17:15:11 -0400[diff] [blame^]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, TMP75, TMP175, TMP275
46 Prefixes: 'tmp100', 'tmp101', 'tmp105', '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/tmp75
53 http://www.ti.com/product/tmp175
54 http://www.ti.com/product/tmp275
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +0000[diff] [blame]55
56Author: Frodo Looijaard <frodol@dds.nl>
57
58Description
59-----------
60
61The LM75 implements one temperature sensor. Limits can be set through the
62Overtemperature Shutdown register and Hysteresis register. Each value can be
63set and read to half-degree accuracy.
64An alarm is issued (usually to a connected LM78) when the temperature
65gets higher then the Overtemperature Shutdown value; it stays on until
66the temperature falls below the Hysteresis value.
67All temperatures are in degrees Celsius, and are guaranteed within a
68range of -55 to +125 degrees.
69
70The LM75 only updates its values each 1.5 seconds; reading it more often
71will do no harm, but will return 'old' values.
72
Jean Delvare426343e2011-10-13 17:15:11 -0400[diff] [blame^]73The original LM75 was typically used in combination with LM78-like chips
74on PC motherboards, to measure the temperature of the processor(s). Clones
75are now used in various embedded designs.
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +0000[diff] [blame]76
77The LM75 is essentially an industry standard; there may be other
78LM75 clones not listed here, with or without various enhancements,
Jean Delvare426343e2011-10-13 17:15:11 -0400[diff] [blame^]79that are supported. The clones are not detected by the driver, unless
80they reproduce the exact register tricks of the original LM75, and must
81therefore be instantiated explicitly. The specific enhancements (such as
82higher resolution) are not currently supported by the driver.
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +0000[diff] [blame]83
84The LM77 is not supported, contrary to what we pretended for a long time.
85Both chips are simply not compatible, value encoding differs.