Documentation/hwmon/lm75

   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 DS75, DS1775
  16     Prefixes: 'ds75', 'ds1775'
  17     Addresses scanned: none
  18     Datasheet: Publicly available at the Dallas Semiconductor website
  19                http://www.maxim-ic.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: 'lm75'
  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 LM75 only updates its values each 1.5 seconds; reading it more often
  71 will do no harm, but will return 'old' values.
  72
  73 The original LM75 was typically used in combination with LM78-like chips
  74 on PC motherboards, to measure the temperature of the processor(s). Clones
  75 are now used in various embedded designs.
  76
  77 The LM75 is essentially an industry standard; there may be other
  78 LM75 clones not listed here, with or without various enhancements,
  79 that are supported. The clones are not detected by the driver, unless
  80 they reproduce the exact register tricks of the original LM75, and must
  81 therefore be instantiated explicitly. The specific enhancements (such as
  82 higher resolution) are not currently supported by the driver.
  83
  84 The LM77 is not supported, contrary to what we pretended for a long time.
  85 Both chips are simply not compatible, value encoding differs.