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Diffstat (limited to 'Documentation/i2c/chips/adm1025')
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diff --git a/Documentation/i2c/chips/adm1025 b/Documentation/i2c/chips/adm1025 new file mode 100644 index 00000000000..39d2b781b5d --- /dev/null +++ b/Documentation/i2c/chips/adm1025 @@ -0,0 +1,51 @@ +Kernel driver adm1025 +===================== + +Supported chips: + * Analog Devices ADM1025, ADM1025A + Prefix: 'adm1025' + Addresses scanned: I2C 0x2c - 0x2e + Datasheet: Publicly available at the Analog Devices website + * Philips NE1619 + Prefix: 'ne1619' + Addresses scanned: I2C 0x2c - 0x2d + Datasheet: Publicly available at the Philips website + +The NE1619 presents some differences with the original ADM1025: + * Only two possible addresses (0x2c - 0x2d). + * No temperature offset register, but we don't use it anyway. + * No INT mode for pin 16. We don't play with it anyway. + +Authors: + Chen-Yuan Wu <gwu@esoft.com>, + Jean Delvare <khali@linux-fr.org> + +Description +----------- + +(This is from Analog Devices.) The ADM1025 is a complete system hardware +monitor for microprocessor-based systems, providing measurement and limit +comparison of various system parameters. Five voltage measurement inputs +are provided, for monitoring +2.5V, +3.3V, +5V and +12V power supplies and +the processor core voltage. The ADM1025 can monitor a sixth power-supply +voltage by measuring its own VCC. One input (two pins) is dedicated to a +remote temperature-sensing diode and an on-chip temperature sensor allows +ambient temperature to be monitored. + +One specificity of this chip is that the pin 11 can be hardwired in two +different manners. It can act as the +12V power-supply voltage analog +input, or as the a fifth digital entry for the VID reading (bit 4). It's +kind of strange since both are useful, and the reason for designing the +chip that way is obscure at least to me. The bit 5 of the configuration +register can be used to define how the chip is hardwired. Please note that +it is not a choice you have to make as the user. The choice was already +made by your motherboard's maker. If the configuration bit isn't set +properly, you'll have a wrong +12V reading or a wrong VID reading. The way +the driver handles that is to preserve this bit through the initialization +process, assuming that the BIOS set it up properly beforehand. If it turns +out not to be true in some cases, we'll provide a module parameter to force +modes. + +This driver also supports the ADM1025A, which differs from the ADM1025 +only in that it has "open-drain VID inputs while the ADM1025 has on-chip +100k pull-ups on the VID inputs". It doesn't make any difference for us. |