|  | Kernel driver adm1021 | 
|  | ===================== | 
|  |  | 
|  | Supported chips: | 
|  | * Analog Devices ADM1021 | 
|  | Prefix: 'adm1021' | 
|  | Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e | 
|  | Datasheet: Publicly available at the Analog Devices website | 
|  | * Analog Devices ADM1021A/ADM1023 | 
|  | Prefix: 'adm1023' | 
|  | Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e | 
|  | Datasheet: Publicly available at the Analog Devices website | 
|  | * Genesys Logic GL523SM | 
|  | Prefix: 'gl523sm' | 
|  | Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e | 
|  | Datasheet: | 
|  | * Maxim MAX1617 | 
|  | Prefix: 'max1617' | 
|  | Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e | 
|  | Datasheet: Publicly available at the Maxim website | 
|  | * Maxim MAX1617A | 
|  | Prefix: 'max1617a' | 
|  | Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e | 
|  | Datasheet: Publicly available at the Maxim website | 
|  | * National Semiconductor LM84 | 
|  | Prefix: 'lm84' | 
|  | Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e | 
|  | Datasheet: Publicly available at the National Semiconductor website | 
|  | * Philips NE1617 | 
|  | Prefix: 'max1617' (probably detected as a max1617) | 
|  | Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e | 
|  | Datasheet: Publicly available at the Philips website | 
|  | * Philips NE1617A | 
|  | Prefix: 'max1617' (probably detected as a max1617) | 
|  | Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e | 
|  | Datasheet: Publicly available at the Philips website | 
|  | * TI THMC10 | 
|  | Prefix: 'thmc10' | 
|  | Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e | 
|  | Datasheet: Publicly available at the TI website | 
|  | * Onsemi MC1066 | 
|  | Prefix: 'mc1066' | 
|  | Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e | 
|  | Datasheet: Publicly available at the Onsemi website | 
|  |  | 
|  |  | 
|  | Authors: | 
|  | Frodo Looijaard <frodol@dds.nl>, | 
|  | Philip Edelbrock <phil@netroedge.com> | 
|  |  | 
|  | Module Parameters | 
|  | ----------------- | 
|  |  | 
|  | * read_only: int | 
|  | Don't set any values, read only mode | 
|  |  | 
|  |  | 
|  | Description | 
|  | ----------- | 
|  |  | 
|  | The chips supported by this driver are very similar. The Maxim MAX1617 is | 
|  | the oldest; it has the problem that it is not very well detectable. The | 
|  | MAX1617A solves that. The ADM1021 is a straight clone of the MAX1617A. | 
|  | Ditto for the THMC10. From here on, we will refer to all these chips as | 
|  | ADM1021-clones. | 
|  |  | 
|  | The ADM1021 and MAX1617A reports a die code, which is a sort of revision | 
|  | code. This can help us pinpoint problems; it is not very useful | 
|  | otherwise. | 
|  |  | 
|  | ADM1021-clones implement two temperature sensors. One of them is internal, | 
|  | and measures the temperature of the chip itself; the other is external and | 
|  | is realised in the form of a transistor-like device. A special alarm | 
|  | indicates whether the remote sensor is connected. | 
|  |  | 
|  | Each sensor has its own low and high limits. When they are crossed, the | 
|  | corresponding alarm is set and remains on as long as the temperature stays | 
|  | out of range. Temperatures are measured in degrees Celsius. Measurements | 
|  | are possible between -65 and +127 degrees, with a resolution of one degree. | 
|  |  | 
|  | If an alarm triggers, it will remain triggered until the hardware register | 
|  | is read at least once. This means that the cause for the alarm may already | 
|  | have disappeared! | 
|  |  | 
|  | This driver only updates its values each 1.5 seconds; reading it more often | 
|  | will do no harm, but will return 'old' values. It is possible to make | 
|  | ADM1021-clones do faster measurements, but there is really no good reason | 
|  | for that. | 
|  |  | 
|  |  | 
|  | Netburst-based Xeon support | 
|  | --------------------------- | 
|  |  | 
|  | Some Xeon processors based on the Netburst (early Pentium 4, from 2001 to | 
|  | 2003) microarchitecture had real MAX1617, ADM1021, or compatible chips | 
|  | within them, with two temperature sensors. Other Xeon processors of this | 
|  | era (with 400 MHz FSB) had chips with only one temperature sensor. | 
|  |  | 
|  | If you have such an old Xeon, and you get two valid temperatures when | 
|  | loading the adm1021 module, then things are good. | 
|  |  | 
|  | If nothing happens when loading the adm1021 module, and you are certain | 
|  | that your specific Xeon processor model includes compatible sensors, you | 
|  | will have to explicitly instantiate the sensor chips from user-space. See | 
|  | method 4 in Documentation/i2c/instantiating-devices. Possible slave | 
|  | addresses are 0x18, 0x1a, 0x29, 0x2b, 0x4c, or 0x4e. It is likely that | 
|  | only temp2 will be correct and temp1 will have to be ignored. | 
|  |  | 
|  | Previous generations of the Xeon processor (based on Pentium II/III) | 
|  | didn't have these sensors. Next generations of Xeon processors (533 MHz | 
|  | FSB and faster) lost them, until the Core-based generation which | 
|  | introduced integrated digital thermal sensors. These are supported by | 
|  | the coretemp driver. |