linux/Documentation/hwmon/adm1021
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   1Kernel driver adm1021
   2=====================
   3
   4Supported chips:
   5  * Analog Devices ADM1021
   6    Prefix: 'adm1021'
   7    Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
   8    Datasheet: Publicly available at the Analog Devices website
   9  * Analog Devices ADM1021A/ADM1023
  10    Prefix: 'adm1023'
  11    Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
  12    Datasheet: Publicly available at the Analog Devices website
  13  * Genesys Logic GL523SM
  14    Prefix: 'gl523sm'
  15    Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
  16    Datasheet:
  17  * Intel Xeon Processor
  18    Prefix: - any other - may require 'force_adm1021' parameter
  19    Addresses scanned: none
  20    Datasheet: Publicly available at Intel website
  21  * Maxim MAX1617
  22    Prefix: 'max1617'
  23    Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
  24    Datasheet: Publicly available at the Maxim website
  25  * Maxim MAX1617A
  26    Prefix: 'max1617a'
  27    Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
  28    Datasheet: Publicly available at the Maxim website
  29  * National Semiconductor LM84
  30    Prefix: 'lm84'
  31    Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
  32    Datasheet: Publicly available at the National Semiconductor website
  33  * Philips NE1617
  34    Prefix: 'max1617' (probably detected as a max1617)
  35    Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
  36    Datasheet: Publicly available at the Philips website
  37  * Philips NE1617A
  38    Prefix: 'max1617' (probably detected as a max1617)
  39    Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
  40    Datasheet: Publicly available at the Philips website
  41  * TI THMC10
  42    Prefix: 'thmc10'
  43    Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
  44    Datasheet: Publicly available at the TI website
  45  * Onsemi MC1066
  46    Prefix: 'mc1066'
  47    Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e
  48    Datasheet: Publicly available at the Onsemi website
  49
  50
  51Authors:
  52        Frodo Looijaard <frodol@dds.nl>,
  53        Philip Edelbrock <phil@netroedge.com>
  54
  55Module Parameters
  56-----------------
  57
  58* read_only: int
  59  Don't set any values, read only mode
  60
  61
  62Description
  63-----------
  64
  65The chips supported by this driver are very similar. The Maxim MAX1617 is
  66the oldest; it has the problem that it is not very well detectable. The
  67MAX1617A solves that. The ADM1021 is a straight clone of the MAX1617A.
  68Ditto for the THMC10. From here on, we will refer to all these chips as
  69ADM1021-clones.
  70
  71The ADM1021 and MAX1617A reports a die code, which is a sort of revision
  72code. This can help us pinpoint problems; it is not very useful
  73otherwise.
  74
  75ADM1021-clones implement two temperature sensors. One of them is internal,
  76and measures the temperature of the chip itself; the other is external and
  77is realised in the form of a transistor-like device. A special alarm
  78indicates whether the remote sensor is connected.
  79
  80Each sensor has its own low and high limits. When they are crossed, the
  81corresponding alarm is set and remains on as long as the temperature stays
  82out of range. Temperatures are measured in degrees Celsius. Measurements
  83are possible between -65 and +127 degrees, with a resolution of one degree.
  84
  85If an alarm triggers, it will remain triggered until the hardware register
  86is read at least once. This means that the cause for the alarm may already
  87have disappeared!
  88
  89This driver only updates its values each 1.5 seconds; reading it more often
  90will do no harm, but will return 'old' values. It is possible to make
  91ADM1021-clones do faster measurements, but there is really no good reason
  92for that.
  93
  94Xeon support
  95------------
  96
  97Some Xeon processors have real max1617, adm1021, or compatible chips
  98within them, with two temperature sensors.
  99
 100Other Xeons have chips with only one sensor.
 101
 102If you have a Xeon, and the adm1021 module loads, and both temperatures
 103appear valid, then things are good.
 104
 105If the adm1021 module doesn't load, you should try this:
 106        modprobe adm1021 force_adm1021=BUS,ADDRESS
 107        ADDRESS can only be 0x18, 0x1a, 0x29, 0x2b, 0x4c, or 0x4e.
 108
 109If you have dual Xeons you may have appear to have two separate
 110adm1021-compatible chips, or two single-temperature sensors, at distinct
 111addresses.
 112