diff options
Diffstat (limited to 'kernel/Documentation/hwmon/lm75')
| -rw-r--r-- | kernel/Documentation/hwmon/lm75 | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/kernel/Documentation/hwmon/lm75 b/kernel/Documentation/hwmon/lm75 new file mode 100644 index 000000000..67691a0aa --- /dev/null +++ b/kernel/Documentation/hwmon/lm75 @@ -0,0 +1,92 @@ +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 + Prefixes: 'max6625', 'max6626' + 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 + * Texas Instruments TMP100, TMP101, TMP105, TMP112, TMP75, TMP175, TMP275 + Prefixes: 'tmp100', 'tmp101', 'tmp105', 'tmp112', 'tmp175', 'tmp75', '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/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 12-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. |