mirror of https://gitee.com/openkylin/linux.git
66 lines
2.5 KiB
Plaintext
66 lines
2.5 KiB
Plaintext
|
Kernel driver lm75
|
||
|
|
==================
|
||
|
|
|
||
|
|
Supported chips:
|
||
|
|
* National Semiconductor LM75
|
||
|
|
Prefix: 'lm75'
|
||
|
|
Addresses scanned: I2C 0x48 - 0x4f
|
||
|
|
Datasheet: Publicly available at the National Semiconductor website
|
||
|
|
http://www.national.com/
|
||
|
|
* Dallas Semiconductor DS75
|
||
|
|
Prefix: 'lm75'
|
||
|
|
Addresses scanned: I2C 0x48 - 0x4f
|
||
|
|
Datasheet: Publicly available at the Dallas Semiconductor website
|
||
|
|
http://www.maxim-ic.com/
|
||
|
|
* Dallas Semiconductor DS1775
|
||
|
|
Prefix: 'lm75'
|
||
|
|
Addresses scanned: I2C 0x48 - 0x4f
|
||
|
|
Datasheet: Publicly available at the Dallas Semiconductor website
|
||
|
|
http://www.maxim-ic.com/
|
||
|
|
* Maxim MAX6625, MAX6626
|
||
|
|
Prefix: 'lm75'
|
||
|
|
Addresses scanned: I2C 0x48 - 0x4b
|
||
|
|
Datasheet: Publicly available at the Maxim website
|
||
|
|
http://www.maxim-ic.com/
|
||
|
|
* Microchip (TelCom) TCN75
|
||
|
|
Prefix: 'lm75'
|
||
|
|
Addresses scanned: I2C 0x48 - 0x4f
|
||
|
|
Datasheet: Publicly available at the Microchip website
|
||
|
|
http://www.microchip.com/
|
||
|
|
|
||
|
|
Author: Frodo Looijaard <frodol@dds.nl>
|
||
|
|
|
||
|
|
Description
|
||
|
|
-----------
|
||
|
|
|
||
|
|
The LM75 implements one temperature sensor. Limits can be set through the
|
||
|
|
Overtemperature Shutdown register and Hysteresis register. Each value can be
|
||
|
|
set and read to half-degree accuracy.
|
||
|
|
An alarm is issued (usually to a connected LM78) when the temperature
|
||
|
|
gets higher then the Overtemperature Shutdown value; it stays on until
|
||
|
|
the temperature falls below the Hysteresis value.
|
||
|
|
All temperatures are in degrees Celsius, and are guaranteed within a
|
||
|
|
range of -55 to +125 degrees.
|
||
|
|
|
||
|
|
The LM75 only updates its values each 1.5 seconds; reading it more often
|
||
|
|
will do no harm, but will return 'old' values.
|
||
|
|
|
||
|
|
The LM75 is usually used in combination with LM78-like chips, to measure
|
||
|
|
the temperature of the processor(s).
|
||
|
|
|
||
|
|
The DS75, DS1775, MAX6625, and MAX6626 are supported as well.
|
||
|
|
They are not distinguished from an LM75. While most of these chips
|
||
|
|
have three additional bits of accuracy (12 vs. 9 for the LM75),
|
||
|
|
the additional bits are not supported. Not only that, but these chips will
|
||
|
|
not be detected if not in 9-bit precision mode (use the force parameter if
|
||
|
|
needed).
|
||
|
|
|
||
|
|
The TCN75 is supported as well, and is not distinguished from an LM75.
|
||
|
|
|
||
|
|
The LM75 is essentially an industry standard; there may be other
|
||
|
|
LM75 clones not listed here, with or without various enhancements,
|
||
|
|
that are supported.
|
||
|
|
|
||
|
|
The LM77 is not supported, contrary to what we pretended for a long time.
|
||
|
|
Both chips are simply not compatible, value encoding differs.
|