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gerrit-public.fairphone.software / kernel / msm-4.9 / 253aab0597d9e16014888639f801ff89df6949c3 / . / Documentation / hwmon / lm75
blob: ac95edfcd907ccddcf2f7be7cf34944b0895ea94 [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 Delvare3fbc81e2013-05-04 14:49:36 +0200[diff] [blame]15 * Dallas Semiconductor (now Maxim) DS75, DS1775, DS7505
16 Prefixes: 'ds75', 'ds1775', 'ds7505'
Jean Delvare426343e2011-10-13 17:15:11 -0400[diff] [blame]17 Addresses scanned: none
Jean Delvare3fbc81e2013-05-04 14:49:36 +0200[diff] [blame]18 Datasheet: Publicly available at the Maxim website
19 http://www.maximintegrated.com/
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +0000[diff] [blame]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
Jean Delvare25eba812013-03-18 21:19:49 +0100[diff] [blame]26 Prefix: 'tcn75'
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
Ben Gardner9c32e812015-10-07 21:55:20 -0500[diff] [blame]45 * Texas Instruments TMP100, TMP101, TMP105, TMP112, TMP75, TMP75C, TMP175, TMP275
46 Prefixes: 'tmp100', 'tmp101', 'tmp105', 'tmp112', 'tmp175', 'tmp75', 'tmp75c', 'tmp275'
Jean Delvare426343e2011-10-13 17:15:11 -0400[diff] [blame]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
Frans Klaverc83959f2014-06-26 11:21:11 +0200[diff] [blame]52 http://www.ti.com/product/tmp112
Jean Delvare426343e2011-10-13 17:15:11 -0400[diff] [blame]53 http://www.ti.com/product/tmp75
Ben Gardner9c32e812015-10-07 21:55:20 -0500[diff] [blame]54 http://www.ti.com/product/tmp75c
Jean Delvare426343e2011-10-13 17:15:11 -0400[diff] [blame]55 http://www.ti.com/product/tmp175
56 http://www.ti.com/product/tmp275
Michael Thalmeier799fc602014-11-18 17:08:04 +0100[diff] [blame]57 * NXP LM75B
58 Prefix: 'lm75b'
59 Addresses scanned: none
60 Datasheet: Publicly available at the NXP website
61 http://www.nxp.com/documents/data_sheet/LM75B.pdf
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +0000[diff] [blame]62
63Author: Frodo Looijaard <frodol@dds.nl>
64
65Description
66-----------
67
68The LM75 implements one temperature sensor. Limits can be set through the
69Overtemperature Shutdown register and Hysteresis register. Each value can be
70set and read to half-degree accuracy.
71An alarm is issued (usually to a connected LM78) when the temperature
72gets higher then the Overtemperature Shutdown value; it stays on until
73the temperature falls below the Hysteresis value.
74All temperatures are in degrees Celsius, and are guaranteed within a
75range of -55 to +125 degrees.
76
Jean Delvare0cd2c722013-05-04 14:49:36 +0200[diff] [blame]77The driver caches the values for a period varying between 1 second for the
78slowest chips and 125 ms for the fastest chips; reading it more often
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +0000[diff] [blame]79will do no harm, but will return 'old' values.
80
Jean Delvare426343e2011-10-13 17:15:11 -0400[diff] [blame]81The original LM75 was typically used in combination with LM78-like chips
82on PC motherboards, to measure the temperature of the processor(s). Clones
83are now used in various embedded designs.
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +0000[diff] [blame]84
85The LM75 is essentially an industry standard; there may be other
86LM75 clones not listed here, with or without various enhancements,
Jean Delvare426343e2011-10-13 17:15:11 -0400[diff] [blame]87that are supported. The clones are not detected by the driver, unless
88they reproduce the exact register tricks of the original LM75, and must
Jean Delvare0cd2c722013-05-04 14:49:36 +0200[diff] [blame]89therefore be instantiated explicitly. Higher resolution up to 12-bit
90is supported by this driver, other specific enhancements are not.
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +0000[diff] [blame]91
92The LM77 is not supported, contrary to what we pretended for a long time.
93Both chips are simply not compatible, value encoding differs.