IXP4xx support

[Sascha Hauer]

On Sun, Feb 07, 2010 at 11:50:22AM +0100, Marc Kleine-Budde wrote:
> Krzysztof Halasa wrote:
> > I'm thinking about adding Barebox support for a certain platform using
> > IXP425 (ARM, usually big-endian) CPU. This means the startup code
> > (trivial, already got it working in little-endian mode), drivers for
> > hardware Queue Manager, Network Processing Engines and built-in Ethernet
> > interfaces (all of them easy to port from Linux).
> > 
> > This also means supporting the NOR flash: the CPU has 16-bit, always
> > big-endian, "value-preserving" EXP bus for connecting such devices. In
> > LE mode the address has to be XORed with 2, and if it's byte-oriented
> > data (i.e. not a command/response), it has to be byte-swapped. Only
> > 16-bit writes can be made.
> > 
> > Doing the above in the flash driver would complicate things a lot. The
> > drivers currently use plain pointers to access the flash. I'm thinking
> > about moving the low-level access (R/W) routines to arch code (with a
> > generic defaults), and calling them via the NOR flash platform struct
> > (which doesn't do anything useful ATM).
> 
> have a look at the current uboot cfi flash driver. They have read/write
> functions to access the flash. By default they are macros to IIRC
> __raw_read,write.
> 
> From the first look, the driver looks much cleaner than the "old" one
> used in barebox (modulo my bugfix from last week).

It seems it still has the same driver under the hood.

I suggest to remove the "old" driver in favor for the cfi_flash_new
driver so that this ongoing confusion ends and Krzysztof has some base
to work on. I think the flash accesses can be ported from U-Boot if
necessary.

Sascha

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |