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1 | Kernel driver adm1025 | ||
2 | ===================== | ||
3 | |||
4 | Supported 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 | |||
14 | The 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 | |||
19 | Authors: | ||
20 | Chen-Yuan Wu <gwu@esoft.com>, | ||
21 | Jean Delvare <khali@linux-fr.org> | ||
22 | |||
23 | Description | ||
24 | ----------- | ||
25 | |||
26 | (This is from Analog Devices.) The ADM1025 is a complete system hardware | ||
27 | monitor for microprocessor-based systems, providing measurement and limit | ||
28 | comparison of various system parameters. Five voltage measurement inputs | ||
29 | are provided, for monitoring +2.5V, +3.3V, +5V and +12V power supplies and | ||
30 | the processor core voltage. The ADM1025 can monitor a sixth power-supply | ||
31 | voltage by measuring its own VCC. One input (two pins) is dedicated to a | ||
32 | remote temperature-sensing diode and an on-chip temperature sensor allows | ||
33 | ambient temperature to be monitored. | ||
34 | |||
35 | One specificity of this chip is that the pin 11 can be hardwired in two | ||
36 | different manners. It can act as the +12V power-supply voltage analog | ||
37 | input, or as the a fifth digital entry for the VID reading (bit 4). It's | ||
38 | kind of strange since both are useful, and the reason for designing the | ||
39 | chip that way is obscure at least to me. The bit 5 of the configuration | ||
40 | register can be used to define how the chip is hardwired. Please note that | ||
41 | it is not a choice you have to make as the user. The choice was already | ||
42 | made by your motherboard's maker. If the configuration bit isn't set | ||
43 | properly, you'll have a wrong +12V reading or a wrong VID reading. The way | ||
44 | the driver handles that is to preserve this bit through the initialization | ||
45 | process, assuming that the BIOS set it up properly beforehand. If it turns | ||
46 | out not to be true in some cases, we'll provide a module parameter to force | ||
47 | modes. | ||
48 | |||
49 | This driver also supports the ADM1025A, which differs from the ADM1025 | ||
50 | only in that it has "open-drain VID inputs while the ADM1025 has on-chip | ||
51 | 100k pull-ups on the VID inputs". It doesn't make any difference for us. | ||