projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 7f15b664 RM |
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 <[email protected]>, | |
| 21 | Jean Delvare <[email protected]> | |
| 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. |