Documentation/hwmon/lm83.rst

Source file repositories/reference/linux-study-clean/Documentation/hwmon/lm83.rst

File Facts

System
Linux kernel
Corpus path
Documentation/hwmon/lm83.rst
Extension
.rst
Size
3808 bytes
Lines
98
Domain
Support Tooling And Documentation
Bucket
Documentation
Inferred role
Support Tooling And Documentation: documentation
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

Kernel driver lm83
==================

Supported chips:

  * National Semiconductor LM83

    Prefix: 'lm83'

    Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e

    Datasheet: Publicly available at the National Semiconductor website

	       http://www.national.com/pf/LM/LM83.html

  * National Semiconductor LM82

    Addresses scanned: I2C 0x18 - 0x1a, 0x29 - 0x2b, 0x4c - 0x4e

    Datasheet: Publicly available at the National Semiconductor website

	       http://www.national.com/pf/LM/LM82.html

Author: Jean Delvare <jdelvare@suse.de>

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

The LM83 is a digital temperature sensor. It senses its own temperature as
well as the temperature of up to three external diodes. The LM82 is
a stripped down version of the LM83 that only supports one external diode.
Both are compatible with many other devices such as the LM84 and all
other ADM1021 clones. The main difference between the LM83 and the LM84
in that the later can only sense the temperature of one external diode.

Using the adm1021 driver for a LM83 should work, but only two temperatures
will be reported instead of four.

The LM83 is only found on a handful of motherboards. Both a confirmed
list and an unconfirmed list follow. If you can confirm or infirm the
fact that any of these motherboards do actually have an LM83, please
contact us. Note that the LM90 can easily be misdetected as a LM83.

Confirmed motherboards:
    ===		=====
    SBS         P014
    SBS         PSL09
    ===		=====

Unconfirmed motherboards:
    =========== ==========
    Gigabyte    GA-8IK1100
    Iwill       MPX2
    Soltek      SL-75DRV5
    =========== ==========

The LM82 is confirmed to have been found on most AMD Geode reference
designs and test platforms.

The driver has been successfully tested by Magnus Forsström, who I'd
like to thank here. More testers will be of course welcome.

The fact that the LM83 is only scarcely used can be easily explained.
Most motherboards come with more than just temperature sensors for
health monitoring. They also have voltage and fan rotation speed
sensors. This means that temperature-only chips are usually used as
secondary chips coupled with another chip such as an IT8705F or similar
chip, which provides more features. Since systems usually need three
temperature sensors (motherboard, processor, power supply) and primary
chips provide some temperature sensors, the secondary chip, if needed,

Annotation

Implementation Notes