Kernel driver `lm90.o'
======================

Status: Complete and well tested

Supported chips: 
  * National Semiconductor LM90
    Prefix: `lm90'
    Addresses scanned: I2C 0x4c
    Datasheet: Publicly available at the National Semiconductor website
               http://www.national.com/pf/LM/LM90.html
  * National Semiconductor LM89
    Prefix: `lm99'
    Addresses scanned: I2C 0x4c and 0x4d
    Datasheet: Publicly available at the National Semiconductor website
               http://www.national.com/pf/LM/LM89.html
  * National Semiconductor LM99
    Prefix: `lm99'
    Addresses scanned: I2C 0x4c and 0x4d
    Datasheet: Publicly available at the National Semiconductor website
               http://www.national.com/pf/LM/LM99.html
  * Analog Devices ADM1032
    Prefix: `adm1032'
    Addresses scanned: I2C 0x4c
    Datasheet: Publicly available at the Analog Devices website
               http://products.analog.com/products/info.asp?product=ADM1032


Author: Jean Delvare <khali@linux-fr.org>

License: GPL


Module Parameters
-----------------

* force: short array (min = 1, max = 48)
  List of adapter,address pairs to boldly assume to be present
* force_lm90: short array (min = 1, max = 48)
  List of adapter,address pairs which are unquestionably assumed to contain
  a `lm90' chip
* force_adm1032: short array (min = 1, max = 48)
  List of adapter,address pairs which are unquestionably assumed to contain
  a `adm1032' chip
* force_lm99: short array (min = 1, max = 48)
  List of adapter,address pairs which are unquestionably assumed to contain
  a `lm99' chip
* probe: short array (min = 1, max = 48)
  List of adapter,address pairs to scan additionally
* probe_range: short array (min = 1, max = 48)
  List of adapter,start-addr,end-addr triples to scan additionally
* ignore: short array (min = 1, max = 48)
  List of adapter,address pairs not to scan
* ignore_range: short array (min = 1, max = 48)
  List of adapter,start-addr,end-addr triples not to scan


Description
-----------

The LM90 is a digital temperature sensor. It senses its own temperature as
well as the temperature of up to one external diode. It is compatible
with many other devices such as the LM86, the LM89, the LM99, the ADM1032,
the MAX6657 and the MAX6658. Of these, only the ADM1032, LM89 and LM99 are
supported for now, but the others can be forced (and later added).

The specificity of this family of chipsets over the ADM1021/LM84
family is that it features critical limits with hysteresis, and an
increased resolution of the remote temperature measurement.

The different chipsets of the family are not strictly identical, although
very similar. This driver doesn't handle any specific feature for now,
but could if there ever was a need for it. For reference, here comes a
non-exhaustive list of specific features:

LM90:
  * Filter and alert configuration register at 0xBF.
  * ALERT is triggered by temperatures over critical limits.

LM89:
  * Same as LM90
  * Better external channel accuracy
  
LM99:
  * Same as LM89
  * External temperature shifted by 16 degrees down

ADM1032:
  * Consecutive alert register at 0x22.
  * Conversion averaging.
  * Up to 64 conversions/s.
  * ALERT is triggered by open remote sensor.

All temperature values are given in degrees Celcius. Resolution
is 1.0 degree for the local temperature, 0.125 degree for the remote
temperature.

Each sensor has its own high and low limits, plus a critical limit.
Additionally, there is a relative hysteresis value common to both critical
values. To make life easier to user-space applications, two absolute values
are exported, one for each channel, but these values are of course linked.
Only the local hysteresis can be set from user-space, and the same delta
applies to the remote hysteresis.

The lm90 driver will not update its values more frequently than every
other second; reading them more often will do no harm, but will return
'old' values.


Chip Features
-------------

Chips 'lm90', adm1032' and 'lm99'

LABEL                 LABEL CLASS           COMPUTE CLASS          MODE  MAGN
temp1                 -                     -                       R-     0
temp1_high            temp1                 temp1                   RW     0
temp1_low             temp1                 temp1                   RW     0
temp2                 -                     -                       R-     1
temp2_high            temp2                 temp2                   RW     1
temp2_low             temp2                 temp2                   RW     1
tcrit1                temp1                 temp1                   RW     0
tcrit2                temp2                 temp2                   RW     0
hyst1                 temp1                 temp1                   RW     0
hyst2                 temp2                 temp2                   R-     0
alarms                -                     -                       R-     0

LABEL                 FEATURE SYMBOL                              SYSCTL FILE:N
temp1                 SENSORS_LM90_LOCAL_TEMP                           temp1:3
temp1_high            SENSORS_LM90_LOCAL_HIGH                           temp1:1
temp1_low             SENSORS_LM90_LOCAL_LOW                            temp1:2
temp2                 SENSORS_LM90_REMOTE_TEMP                          temp2:3
temp2_high            SENSORS_LM90_REMOTE_HIGH                          temp2:1
temp2_low             SENSORS_LM90_REMOTE_LOW                           temp2:2
tcrit1                SENSORS_LM90_LOCAL_TCRIT                         tcrit1:1
tcrit2                SENSORS_LM90_REMOTE_TCRIT                        tcrit2:1
hyst1                 SENSORS_LM90_LOCAL_TCRIT_HYST                     hyst1:1
hyst2                 SENSORS_LM90_REMOTE_TCRIT_HYST                    hyst2:1
alarms                SENSORS_LM90_ALARMS                              alarms:1
