mirror of
https://github.com/lm-sensors/lm-sensors.git
synced 2026-10-18 11:09:32 +00:00
Jean Delvare
2f070b1860
porting the chips documentation to Linux 2.6. git-svn-id: http://lm-sensors.org/svn/lm-sensors/trunk@3007 7894878c-1315-0410-8ee3-d5d059ff63e0
58 lines
1.6 KiB
Plaintext
58 lines
1.6 KiB
Plaintext
Kernel driver `mic74.o'
|
|
=========================
|
|
|
|
Status: Beta
|
|
|
|
Supported chips:
|
|
* Micrel MIC74
|
|
Prefix: 'mic74'
|
|
Addresses scanned: I2C 0x20 - 0x27
|
|
Datasheet: Publicly available at the Micrel website
|
|
http://www.micrel.com/
|
|
|
|
Authors: zebo25
|
|
mds (cleanups and this doc)
|
|
|
|
Module Parameters
|
|
-----------------
|
|
|
|
|
|
Description
|
|
-----------
|
|
The MIC74 is an 8-bit I/O expander for the I2C bus.
|
|
Semiconductors. It is designed to provide a byte I2C interface to up to 8
|
|
separate devices.
|
|
|
|
This device consists of a quasi-bidirectionnal port. Each of the eight I/Os
|
|
can be independently used as an input or output.
|
|
|
|
The driver does not initialize the ports, they will be at their
|
|
power-up defaults, or however the BIOS programmed them.
|
|
|
|
For more information see the datasheet.
|
|
|
|
|
|
Accessing MIC74 via /proc interface
|
|
-------------------------------------
|
|
|
|
! Be careful !
|
|
The chip is plainly impossible to detect ! Stupid chip.
|
|
So every chip with adress in the interval [20..27] could be
|
|
detected as an MIC74 or a PCF8574. Don't load both drivers.
|
|
If you have other chips in this address
|
|
range, the workaround is to load this module after the one
|
|
for your others chips.
|
|
|
|
On detection, directories are created for each detected chip:
|
|
|
|
/proc/sys/dev/sensors/mic74-<0>-<1>/
|
|
where <0> is the bus the chip was detected on (e. g. i2c-0)
|
|
and <1> the chip address [20..27]:
|
|
./mic74-i2c-0-27/
|
|
|
|
Inside these directories, there are seven files each,
|
|
one for each of the seven registers in the device.
|
|
|
|
At this point you really need the datasheet.
|
|
It should be self-explanatory which file is for which register.
|