| 1 | Kernel driver `lm75.o' |
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| 2 | ===================== |
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| 3 | |
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| 4 | Status: Complete and well-tested |
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| 5 | |
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| 6 | Supported chips: |
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| 7 | * National Semiconductor LM75 |
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| 8 | Prefix: 'lm75' |
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| 9 | Addresses scanned: I2C 0x48 - 0x4f |
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| 10 | Datasheet: Publicly available at the National Semiconductor website |
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| 11 | http://www.national.com/ |
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| 12 | * Dallas Semiconductor DS75 |
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| 13 | Prefix: 'lm75' |
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| 14 | Addresses scanned: I2C 0x48 - 0x4f |
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| 15 | Datasheet: Publicly available at the Maxim website |
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| 16 | http://www.maxim-ic.com/ |
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| 17 | * Dallas Semiconductor DS1775 |
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| 18 | Prefix: 'lm75' |
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| 19 | Addresses scanned: I2C 0x48 - 0x4f |
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| 20 | Datasheet: Publicly available at the Maxim website |
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| 21 | http://www.maxim-ic.com/ |
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| 22 | * Maxim MAX6625, MAX6626 |
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| 23 | Prefix: 'lm75' |
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| 24 | Addresses scanned: I2C 0x48 - 0x4b |
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| 25 | Datasheet: Publicly available at the Maxim website |
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| 26 | http://www.maxim-ic.com/ |
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| 27 | * Microchip (TelCom) TCN75 |
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| 28 | Prefix: 'lm75' |
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| 29 | Addresses scanned: I2C 0x48 - 0x4f |
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| 30 | Datasheet: Publicly available at the Microchip website |
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| 31 | http://www.microchip.com/ |
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| 32 | * Texas Instruments TMP100, TMP101 |
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| 33 | Prefix: 'lm75' |
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| 34 | Addresses scanned: I2C 0x48 - 0x4f |
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| 35 | Datasheet: Publicly available at the TI website |
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| 36 | http://www.ti.com/ |
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| 37 | |
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| 38 | Author: Frodo Looijaard <frodol@dds.nl> |
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| 39 | |
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| 40 | |
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| 41 | Module Parameters |
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| 42 | ----------------- |
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| 43 | |
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| 44 | * force: short array (min = 1, max = 48) |
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| 45 | List of adapter,address pairs to boldly assume to be present |
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| 46 | * force_lm75: short array (min = 1, max = 48) |
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| 47 | List of adapter,address pairs which are unquestionably assumed to contain |
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| 48 | a `lm75' chip |
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| 49 | * ignore: short array (min = 1, max = 48) |
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| 50 | List of adapter,address pairs not to scan |
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| 51 | * ignore_range: short array (min = 1, max = 48) |
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| 52 | List of adapter,start-addr,end-addr triples not to scan |
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| 53 | * probe: short array (min = 1, max = 48) |
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| 54 | List of adapter,address pairs to scan additionally |
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| 55 | * probe_range: short array (min = 1, max = 48) |
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| 56 | List of adapter,start-addr,end-addr triples to scan additionally |
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| 57 | |
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| 58 | |
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| 59 | Description |
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| 60 | ----------- |
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| 61 | |
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| 62 | The LM75 implements one temperature sensor. Limits can be set through the |
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| 63 | Overtemperature Shutdown register and Hysteresis register. Each value can be |
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| 64 | set and read to half-degree accuracy. |
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| 65 | An alarm is issued (usually to a connected LM78) when the temperature |
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| 66 | gets higher then the Overtemperature Shutdown value; it stays on until |
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| 67 | the temperature falls below the Hysteresis value. |
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| 68 | All temperatures are in degrees Celsius, and are guaranteed within a |
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| 69 | range of -55 to +125 degrees. |
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| 70 | |
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| 71 | The LM75 only updates its values each 1.5 seconds; reading it more often |
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| 72 | will do no harm, but will return 'old' values. |
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| 73 | |
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| 74 | The LM75 is usually used in combination with LM78-like chips, to measure |
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| 75 | the temperature of the processor(s). |
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| 76 | |
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| 77 | The DS75, DS1775, MAX6625, MAX6626, and others are supported as well. |
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| 78 | They are not distinguished from an LM75. While most of these chips |
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| 79 | have three additional bits of accuracy (12 vs. 9 for the LM75), |
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| 80 | the additional bits are not supported. Not only that, but these chips will |
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| 81 | not be detected if not in 9-bit precision mode (use the force parameter if |
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| 82 | needed). |
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| 83 | The prefix in the /proc directory is still 'lm75'. |
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| 84 | |
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| 85 | The LM75 is essentially an industry standard; there may be other |
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| 86 | LM75 clones not listed here, with or without various enhancements, |
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| 87 | that are supported. |
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| 88 | |
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| 89 | The LM77 is not supported, contrary to what we pretended for a long time. |
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| 90 | Both chips are simply not compatible, value encoding differs. |
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| 91 | |
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| 92 | |
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| 93 | Chip Features |
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| 94 | ------------- |
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| 95 | |
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| 96 | Chip `lm75' |
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| 97 | LABEL LABEL CLASS COMPUTE CLASS ACCESS MAGNITUDE |
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| 98 | temp NONE NONE R 1 |
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| 99 | temp_hyst temp temp RW 1 |
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| 100 | temp_over temp temp RW 1 |
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| 101 | |
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| 102 | LABEL FEATURE SYMBOL SYSCTL FILE:OFFSET |
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| 103 | temp SENSORS_LM75_TEMP temp:3 |
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| 104 | temp_hyst SENSORS_LM75_TEMP_HYST temp:2 |
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| 105 | temp_over SENSORS_LM75_TEMP_OVER temp:1 |
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| 106 | |
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| 107 | |
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