SDIO WiFi Driver Development Questions

Werner Almesberger werner at
Thu Mar 5 15:11:20 CET 2009

dongas wrote:
> Do you mean that the ar6000 driver in 2.6.29 is also compatible with
> the card with firmware 1.1?

As far as I know, it isn't. The issue is that Atheros apparently
change the interface between the kernel and the firmware for each
major revision.

> If yes , i'm not need have to get a card with firmware 1.3 or 2.0 for
> the testing.

I think the news are worse for you: if your firmware is 1.1 and if
1.1 is buggier than 1.3, you'll find it unusable as a general WLAN
solution. If you're in a controlled environment, i.e., if you can
select what access points and what protocols are used, then 1.1
may work for you.

Also, if 1.1 is actually less buggy than 1.3 or 2.0, then it may
work well as a general WLAN solution.

> I remember in OpenMoko 2.6.24, s3cmci driver and s3c24xx_hcd driver is
> two individual moduels for different using, sd card and sdio wifi,
> respectively. right?

s3cmci is the driver for the Linux SDIO stack and s3c24xx_hcd was
for the Atheros stack.

> So, is there still a atheros like sdio hcd driver in kernel 2.6.29?

No, the whole stack has been removed. This means that also
s3c24xx_hcd is gone.

> Can you suggest some code for me to refer to for the implementaion of
> the hcd driver based on linux sdio stack?

Hmm, you mean drivers/mmc/host/* ? :-)

> I know from the Openmoko Wiki that the freerunner is based on s3c2442.
> However i read the s3c2442 datasheet and found that there's only one
> SDIO slot on chip.
> How do you deal with this situation when both the sd card and sdio
> wifi are on using?

We have another MMC (not SDIO) controller in the Glamo. So we use
that one for the uSD slot and we use the controller in the S3C2442
to talk to the AR6001.

- Werner

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