SDIO WiFi Driver Development Questions

Werner Almesberger werner at
Wed Mar 4 11:50:54 CET 2009

dongas wrote:
> I was told by the card verdor that the card i used is based on
> firmware version 1.1.

Hmm, if 1.1 is buggier than 1.3, then your troubles will only start
when you have the driver working. E.g., 1.3 made SSH fail (not sure
if only some or all of the time.)

> I guess sdio function driver should has no dependence on hcd driver in
> standard sdio stack, right?

That's correct. As long as you have an SDIO driver, the stack above
it will be happy.

> Do you know that whether the ar6000 driver in your 2.6.29 kernel can
> also work in 2.6.25 kernel?

That should be fine, yes. I wrote most of the Linux SDIO HIF and did
SD-SPI work on 2.6.24. Of course, you'd have to backport any fixes
we put into 2.6.29 ...

> Can you share me some experience on how to do that or any other useful
> documents as well?

You just use hif2.c instead of hif.c and it will use the Linux SDIO
stack. If you have a driver for that one, you're done.

> Is there any big diference on developping hcd driver between standard
> sdio stack and Atheros customed sdio stack?

Of course :-) The good thing about the Linux stack is that you have
plenty of reference code (that follows Linux coding style :) and
that it'll be around for a while.

- Werner

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