| 1 | Kernel driver lm75 |
| 2 | ================== |
| 3 | |
| 4 | Supported chips: |
| 5 | * National Semiconductor LM75 |
| 6 | Prefix: 'lm75' |
| 7 | Addresses scanned: I2C 0x48 - 0x4f |
| 8 | Datasheet: Publicly available at the National Semiconductor website |
| 9 | http://www.national.com/ |
| 10 | * National Semiconductor LM75A |
| 11 | Prefix: 'lm75a' |
| 12 | Addresses scanned: I2C 0x48 - 0x4f |
| 13 | Datasheet: Publicly available at the National Semiconductor website |
| 14 | http://www.national.com/ |
| 15 | * Dallas Semiconductor (now Maxim) DS75, DS1775, DS7505 |
| 16 | Prefixes: 'ds75', 'ds1775', 'ds7505' |
| 17 | Addresses scanned: none |
| 18 | Datasheet: Publicly available at the Maxim website |
| 19 | http://www.maximintegrated.com/ |
| 20 | * Maxim MAX6625, MAX6626 |
| 21 | Prefixes: 'max6625', 'max6626' |
| 22 | Addresses scanned: none |
| 23 | Datasheet: Publicly available at the Maxim website |
| 24 | http://www.maxim-ic.com/ |
| 25 | * Microchip (TelCom) TCN75 |
| 26 | Prefix: 'tcn75' |
| 27 | Addresses scanned: none |
| 28 | Datasheet: Publicly available at the Microchip website |
| 29 | http://www.microchip.com/ |
| 30 | * Microchip MCP9800, MCP9801, MCP9802, MCP9803 |
| 31 | Prefix: 'mcp980x' |
| 32 | Addresses scanned: none |
| 33 | Datasheet: Publicly available at the Microchip website |
| 34 | http://www.microchip.com/ |
| 35 | * Analog Devices ADT75 |
| 36 | Prefix: 'adt75' |
| 37 | Addresses scanned: none |
| 38 | Datasheet: Publicly available at the Analog Devices website |
| 39 | http://www.analog.com/adt75 |
| 40 | * ST Microelectronics STDS75 |
| 41 | Prefix: 'stds75' |
| 42 | Addresses scanned: none |
| 43 | Datasheet: Publicly available at the ST website |
| 44 | http://www.st.com/internet/analog/product/121769.jsp |
| 45 | * Texas Instruments TMP100, TMP101, TMP105, TMP75, TMP175, TMP275 |
| 46 | Prefixes: 'tmp100', 'tmp101', 'tmp105', 'tmp175', 'tmp75', 'tmp275' |
| 47 | Addresses scanned: none |
| 48 | Datasheet: Publicly available at the Texas Instruments website |
| 49 | http://www.ti.com/product/tmp100 |
| 50 | http://www.ti.com/product/tmp101 |
| 51 | http://www.ti.com/product/tmp105 |
| 52 | http://www.ti.com/product/tmp75 |
| 53 | http://www.ti.com/product/tmp175 |
| 54 | http://www.ti.com/product/tmp275 |
| 55 | |
| 56 | Author: Frodo Looijaard <frodol@dds.nl> |
| 57 | |
| 58 | Description |
| 59 | ----------- |
| 60 | |
| 61 | The LM75 implements one temperature sensor. Limits can be set through the |
| 62 | Overtemperature Shutdown register and Hysteresis register. Each value can be |
| 63 | set and read to half-degree accuracy. |
| 64 | An alarm is issued (usually to a connected LM78) when the temperature |
| 65 | gets higher then the Overtemperature Shutdown value; it stays on until |
| 66 | the temperature falls below the Hysteresis value. |
| 67 | All temperatures are in degrees Celsius, and are guaranteed within a |
| 68 | range of -55 to +125 degrees. |
| 69 | |
| 70 | The driver caches the values for a period varying between 1 second for the |
| 71 | slowest chips and 125 ms for the fastest chips; reading it more often |
| 72 | will do no harm, but will return 'old' values. |
| 73 | |
| 74 | The original LM75 was typically used in combination with LM78-like chips |
| 75 | on PC motherboards, to measure the temperature of the processor(s). Clones |
| 76 | are now used in various embedded designs. |
| 77 | |
| 78 | The LM75 is essentially an industry standard; there may be other |
| 79 | LM75 clones not listed here, with or without various enhancements, |
| 80 | that are supported. The clones are not detected by the driver, unless |
| 81 | they reproduce the exact register tricks of the original LM75, and must |
| 82 | therefore be instantiated explicitly. Higher resolution up to 12-bit |
| 83 | is supported by this driver, other specific enhancements are not. |
| 84 | |
| 85 | The LM77 is not supported, contrary to what we pretended for a long time. |
| 86 | Both chips are simply not compatible, value encoding differs. |