mirror of
https://github.com/torvalds/linux.git
synced 2025-11-04 10:40:15 +02:00
2e9a41bbc1
The STLM75 is a high-precision digital CMOS temperature sensor IC with a sigma-delta temperature-to-digital converter. The configuration register mapping is similar to existing lm75 but the sample rate is 150ms(max). Tested on real hardware and verified temperature readings are correct. Signed-off-by: Jagan Teki <jagan@amarulasolutions.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
98 lines
4.1 KiB
Text
98 lines
4.1 KiB
Text
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/
|
|
* National Semiconductor LM75A
|
|
Prefix: 'lm75a'
|
|
Addresses scanned: I2C 0x48 - 0x4f
|
|
Datasheet: Publicly available at the National Semiconductor website
|
|
http://www.national.com/
|
|
* Dallas Semiconductor (now Maxim) DS75, DS1775, DS7505
|
|
Prefixes: 'ds75', 'ds1775', 'ds7505'
|
|
Addresses scanned: none
|
|
Datasheet: Publicly available at the Maxim website
|
|
http://www.maximintegrated.com/
|
|
* Maxim MAX6625, MAX6626, MAX31725, MAX31726
|
|
Prefixes: 'max6625', 'max6626', 'max31725', 'max31726'
|
|
Addresses scanned: none
|
|
Datasheet: Publicly available at the Maxim website
|
|
http://www.maxim-ic.com/
|
|
* Microchip (TelCom) TCN75
|
|
Prefix: 'tcn75'
|
|
Addresses scanned: none
|
|
Datasheet: Publicly available at the Microchip website
|
|
http://www.microchip.com/
|
|
* Microchip MCP9800, MCP9801, MCP9802, MCP9803
|
|
Prefix: 'mcp980x'
|
|
Addresses scanned: none
|
|
Datasheet: Publicly available at the Microchip website
|
|
http://www.microchip.com/
|
|
* Analog Devices ADT75
|
|
Prefix: 'adt75'
|
|
Addresses scanned: none
|
|
Datasheet: Publicly available at the Analog Devices website
|
|
http://www.analog.com/adt75
|
|
* ST Microelectronics STDS75
|
|
Prefix: 'stds75'
|
|
Addresses scanned: none
|
|
Datasheet: Publicly available at the ST website
|
|
http://www.st.com/internet/analog/product/121769.jsp
|
|
* ST Microelectronics STLM75
|
|
Prefix: 'stlm75'
|
|
Addresses scanned: none
|
|
Datasheet: Publicly available at the ST website
|
|
https://www.st.com/resource/en/datasheet/stlm75.pdf
|
|
* Texas Instruments TMP100, TMP101, TMP105, TMP112, TMP75, TMP75C, TMP175, TMP275
|
|
Prefixes: 'tmp100', 'tmp101', 'tmp105', 'tmp112', 'tmp175', 'tmp75', 'tmp75c', 'tmp275'
|
|
Addresses scanned: none
|
|
Datasheet: Publicly available at the Texas Instruments website
|
|
http://www.ti.com/product/tmp100
|
|
http://www.ti.com/product/tmp101
|
|
http://www.ti.com/product/tmp105
|
|
http://www.ti.com/product/tmp112
|
|
http://www.ti.com/product/tmp75
|
|
http://www.ti.com/product/tmp75c
|
|
http://www.ti.com/product/tmp175
|
|
http://www.ti.com/product/tmp275
|
|
* NXP LM75B
|
|
Prefix: 'lm75b'
|
|
Addresses scanned: none
|
|
Datasheet: Publicly available at the NXP website
|
|
http://www.nxp.com/documents/data_sheet/LM75B.pdf
|
|
|
|
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 driver caches the values for a period varying between 1 second for the
|
|
slowest chips and 125 ms for the fastest chips; reading it more often
|
|
will do no harm, but will return 'old' values.
|
|
|
|
The original LM75 was typically used in combination with LM78-like chips
|
|
on PC motherboards, to measure the temperature of the processor(s). Clones
|
|
are now used in various embedded designs.
|
|
|
|
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 clones are not detected by the driver, unless
|
|
they reproduce the exact register tricks of the original LM75, and must
|
|
therefore be instantiated explicitly. Higher resolution up to 16-bit
|
|
is supported by this driver, other specific enhancements are not.
|
|
|
|
The LM77 is not supported, contrary to what we pretended for a long time.
|
|
Both chips are simply not compatible, value encoding differs.
|