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authorJean Delvare <khali@linux-fr.org>2005-07-02 12:52:48 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2005-07-11 17:47:41 -0400
commitede7fbdf526c314850c9f32dd8da1753bf8d0ad5 (patch)
tree2f1fefa6f6df58f5c27bf98bd7df0908e97e44ef /Documentation/hwmon/lm90
parent8d5d45fb14680326f833295f2316a4ec5e357220 (diff)
[PATCH] I2C: Move hwmon drivers (3/3)
Part 3: Move the drivers documentation, plus two general documentation files. Note that the patch "adds trailing whitespace", because it does move the files as-is, and some files happen to have trailing whitespace. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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1Kernel driver lm90
2==================
3
4Supported chips:
5 * National Semiconductor LM90
6 Prefix: 'lm90'
7 Addresses scanned: I2C 0x4c
8 Datasheet: Publicly available at the National Semiconductor website
9 http://www.national.com/pf/LM/LM90.html
10 * National Semiconductor LM89
11 Prefix: 'lm99'
12 Addresses scanned: I2C 0x4c and 0x4d
13 Datasheet: Publicly available at the National Semiconductor website
14 http://www.national.com/pf/LM/LM89.html
15 * National Semiconductor LM99
16 Prefix: 'lm99'
17 Addresses scanned: I2C 0x4c and 0x4d
18 Datasheet: Publicly available at the National Semiconductor website
19 http://www.national.com/pf/LM/LM99.html
20 * National Semiconductor LM86
21 Prefix: 'lm86'
22 Addresses scanned: I2C 0x4c
23 Datasheet: Publicly available at the National Semiconductor website
24 http://www.national.com/pf/LM/LM86.html
25 * Analog Devices ADM1032
26 Prefix: 'adm1032'
27 Addresses scanned: I2C 0x4c
28 Datasheet: Publicly available at the Analog Devices website
29 http://products.analog.com/products/info.asp?product=ADM1032
30 * Analog Devices ADT7461
31 Prefix: 'adt7461'
32 Addresses scanned: I2C 0x4c
33 Datasheet: Publicly available at the Analog Devices website
34 http://products.analog.com/products/info.asp?product=ADT7461
35 Note: Only if in ADM1032 compatibility mode
36 * Maxim MAX6657
37 Prefix: 'max6657'
38 Addresses scanned: I2C 0x4c
39 Datasheet: Publicly available at the Maxim website
40 http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2578
41 * Maxim MAX6658
42 Prefix: 'max6657'
43 Addresses scanned: I2C 0x4c
44 Datasheet: Publicly available at the Maxim website
45 http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2578
46 * Maxim MAX6659
47 Prefix: 'max6657'
48 Addresses scanned: I2C 0x4c, 0x4d (unsupported 0x4e)
49 Datasheet: Publicly available at the Maxim website
50 http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2578
51
52
53Author: Jean Delvare <khali@linux-fr.org>
54
55
56Description
57-----------
58
59The LM90 is a digital temperature sensor. It senses its own temperature as
60well as the temperature of up to one external diode. It is compatible
61with many other devices such as the LM86, the LM89, the LM99, the ADM1032,
62the MAX6657, MAX6658 and the MAX6659 all of which are supported by this driver.
63Note that there is no easy way to differentiate between the last three
64variants. The extra address and features of the MAX6659 are not supported by
65this driver. Additionally, the ADT7461 is supported if found in ADM1032
66compatibility mode.
67
68The specificity of this family of chipsets over the ADM1021/LM84
69family is that it features critical limits with hysteresis, and an
70increased resolution of the remote temperature measurement.
71
72The different chipsets of the family are not strictly identical, although
73very similar. This driver doesn't handle any specific feature for now,
74but could if there ever was a need for it. For reference, here comes a
75non-exhaustive list of specific features:
76
77LM90:
78 * Filter and alert configuration register at 0xBF.
79 * ALERT is triggered by temperatures over critical limits.
80
81LM86 and LM89:
82 * Same as LM90
83 * Better external channel accuracy
84
85LM99:
86 * Same as LM89
87 * External temperature shifted by 16 degrees down
88
89ADM1032:
90 * Consecutive alert register at 0x22.
91 * Conversion averaging.
92 * Up to 64 conversions/s.
93 * ALERT is triggered by open remote sensor.
94
95ADT7461
96 * Extended temperature range (breaks compatibility)
97 * Lower resolution for remote temperature
98
99MAX6657 and MAX6658:
100 * Remote sensor type selection
101
102MAX6659
103 * Selectable address
104 * Second critical temperature limit
105 * Remote sensor type selection
106
107All temperature values are given in degrees Celsius. Resolution
108is 1.0 degree for the local temperature, 0.125 degree for the remote
109temperature.
110
111Each sensor has its own high and low limits, plus a critical limit.
112Additionally, there is a relative hysteresis value common to both critical
113values. To make life easier to user-space applications, two absolute values
114are exported, one for each channel, but these values are of course linked.
115Only the local hysteresis can be set from user-space, and the same delta
116applies to the remote hysteresis.
117
118The lm90 driver will not update its values more frequently than every
119other second; reading them more often will do no harm, but will return
120'old' values.
121