blob: 03d02bfb3df13a8f7f06859f8669de4a905bcc88 [file] [log] [blame]
R.Marek@sh.cvut.cz7f15b662005-05-26 12:42:19 +00001Kernel driver adm1021
2=====================
3
4Supported chips:
5 * Analog Devices ADM1021
6 Prefix: 'adm1021'
7 Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
8 Datasheet: Publicly available at the Analog Devices website
9 * Analog Devices ADM1021A/ADM1023
10 Prefix: 'adm1023'
11 Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
12 Datasheet: Publicly available at the Analog Devices website
13 * Genesys Logic GL523SM
14 Prefix: 'gl523sm'
15 Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
16 Datasheet:
17 * Intel Xeon Processor
18 Prefix: - any other - may require 'force_adm1021' parameter
19 Addresses scanned: none
20 Datasheet: Publicly available at Intel website
21 * Maxim MAX1617
22 Prefix: 'max1617'
23 Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
24 Datasheet: Publicly available at the Maxim website
25 * Maxim MAX1617A
26 Prefix: 'max1617a'
27 Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
28 Datasheet: Publicly available at the Maxim website
29 * National Semiconductor LM84
30 Prefix: 'lm84'
31 Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
32 Datasheet: Publicly available at the National Semiconductor website
33 * Philips NE1617
34 Prefix: 'max1617' (probably detected as a max1617)
35 Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
36 Datasheet: Publicly available at the Philips website
37 * Philips NE1617A
38 Prefix: 'max1617' (probably detected as a max1617)
39 Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
40 Datasheet: Publicly available at the Philips website
41 * TI THMC10
42 Prefix: 'thmc10'
43 Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
44 Datasheet: Publicly available at the TI website
45 * Onsemi MC1066
46 Prefix: 'mc1066'
47 Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
48 Datasheet: Publicly available at the Onsemi website
49
50
51Authors:
52 Frodo Looijaard <frodol@dds.nl>,
53 Philip Edelbrock <phil@netroedge.com>
54
55Module Parameters
56-----------------
57
58* read_only: int
59 Don't set any values, read only mode
60
61
62Description
63-----------
64
65The chips supported by this driver are very similar. The Maxim MAX1617 is
66the oldest; it has the problem that it is not very well detectable. The
67MAX1617A solves that. The ADM1021 is a straight clone of the MAX1617A.
68Ditto for the THMC10. From here on, we will refer to all these chips as
69ADM1021-clones.
70
71The ADM1021 and MAX1617A reports a die code, which is a sort of revision
72code. This can help us pinpoint problems; it is not very useful
73otherwise.
74
75ADM1021-clones implement two temperature sensors. One of them is internal,
76and measures the temperature of the chip itself; the other is external and
77is realised in the form of a transistor-like device. A special alarm
78indicates whether the remote sensor is connected.
79
80Each sensor has its own low and high limits. When they are crossed, the
81corresponding alarm is set and remains on as long as the temperature stays
82out of range. Temperatures are measured in degrees Celsius. Measurements
83are possible between -65 and +127 degrees, with a resolution of one degree.
84
85If an alarm triggers, it will remain triggered until the hardware register
86is read at least once. This means that the cause for the alarm may already
87have disappeared!
88
89This driver only updates its values each 1.5 seconds; reading it more often
90will do no harm, but will return 'old' values. It is possible to make
91ADM1021-clones do faster measurements, but there is really no good reason
92for that.
93
94Xeon support
95------------
96
97Some Xeon processors have real max1617, adm1021, or compatible chips
98within them, with two temperature sensors.
99
100Other Xeons have chips with only one sensor.
101
102If you have a Xeon, and the adm1021 module loads, and both temperatures
103appear valid, then things are good.
104
105If the adm1021 module doesn't load, you should try this:
106 modprobe adm1021 force_adm1021=BUS,ADDRESS
107 ADDRESS can only be 0x18, 0x1a, 0x29, 0x2b, 0x4c, or 0x4e.
108
109If you have dual Xeons you may have appear to have two separate
110adm1021-compatible chips, or two single-temperature sensors, at distinct
111addresses.