Root/Documentation/hwmon/adm1025

1Kernel driver adm1025
2=====================
3
4Supported chips:
5  * Analog Devices ADM1025, ADM1025A
6    Prefix: 'adm1025'
7    Addresses scanned: I2C 0x2c - 0x2e
8    Datasheet: Publicly available at the Analog Devices website
9  * Philips NE1619
10    Prefix: 'ne1619'
11    Addresses scanned: I2C 0x2c - 0x2d
12    Datasheet: Publicly available at the Philips website
13
14The NE1619 presents some differences with the original ADM1025:
15  * Only two possible addresses (0x2c - 0x2d).
16  * No temperature offset register, but we don't use it anyway.
17  * No INT mode for pin 16. We don't play with it anyway.
18
19Authors:
20        Chen-Yuan Wu <gwu@esoft.com>,
21        Jean Delvare <khali@linux-fr.org>
22
23Description
24-----------
25
26(This is from Analog Devices.) The ADM1025 is a complete system hardware
27monitor for microprocessor-based systems, providing measurement and limit
28comparison of various system parameters. Five voltage measurement inputs
29are provided, for monitoring +2.5V, +3.3V, +5V and +12V power supplies and
30the processor core voltage. The ADM1025 can monitor a sixth power-supply
31voltage by measuring its own VCC. One input (two pins) is dedicated to a
32remote temperature-sensing diode and an on-chip temperature sensor allows
33ambient temperature to be monitored.
34
35One specificity of this chip is that the pin 11 can be hardwired in two
36different manners. It can act as the +12V power-supply voltage analog
37input, or as the a fifth digital entry for the VID reading (bit 4). It's
38kind of strange since both are useful, and the reason for designing the
39chip that way is obscure at least to me. The bit 5 of the configuration
40register can be used to define how the chip is hardwired. Please note that
41it is not a choice you have to make as the user. The choice was already
42made by your motherboard's maker. If the configuration bit isn't set
43properly, you'll have a wrong +12V reading or a wrong VID reading. The way
44the driver handles that is to preserve this bit through the initialization
45process, assuming that the BIOS set it up properly beforehand. If it turns
46out not to be true in some cases, we'll provide a module parameter to force
47modes.
48
49This driver also supports the ADM1025A, which differs from the ADM1025
50only in that it has "open-drain VID inputs while the ADM1025 has on-chip
51100k pull-ups on the VID inputs". It doesn't make any difference for us.
52

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