pcf

I2C总线LINUX驱动程序

<simon>
This file written by Hans Berglund, who developed the pcf driver included
in this directory.
</simon>
BACKGROUND
==========

This is an update to Simons i2c driver, based on his 19990214 version.

I do care about the PCF8584 part only, that means the following files:

	algo_pcf.c	- PCF8584 algorithm, no HW access here.
	algo_pcf.h	- Header file for the PCF algorithm.
	pcf_isa.c	- The Elektor ISA I2C board interface. The
			  I/O address, interrupt etc. is defined here.
	pcf_isa.h	- Header file for HW definitions
	pcf8584.h	- PCF8584 registers and bits.

I have always got plenty of warnings when compiling the i2c driver. The
warnings come from the C preprocessor complaining about '-' in variable
names. My suggestion is to avoid '-' and use '_' instead.


VERSIONS
========

20000109 (Frodo Looijaard, [e-mail])
-----------------------------------------

- Hopefully fixed the horribly broken pcf_xfer function
- Added I2C_M_NOSTART and I2C_M_REV_DIR_ADDR support

19990218
--------
- Changed default clock setting to 0x1c
- Changes in pcf_isa.c to make interrupt work
- Added changes from Simons 19990214 version

19990202 (Changes from Simons 19990118)
---------------------------------------
- Added algo_pcf.c
- Added algo_pcf.h
- Added pcf_isa.c
- Added pcf_isa.h
- Moved pcf8584.h from "old-code", and did minor changes.
- Changed detect/detect.c to give nicer output.
- Use i2c_debug in i2c-dev.c


LOCATIONS
=========

This driver: http://home.telia.no/hansb/I2C_page.htm
     Additions to Simons driver to make it work with PCF8584.
     Interrupthandling added. Some testing performed, but still
     experimental version.

Simons driver: http://www.tk.uni-linz.ac.at/~simon/private/i2c/v4l/
     The baseline for further development.

Pybes driver: http://www.iae.nl/users/pybe/linux/index.htm
     More advanced PCF8584 additions. Supports message passing on 
     module level