[maemo-developers] How to port SDIO stack to N800/ N810 OSs ?

[From: Marcel Holtmann]

Hi Darius,

> Kind request to developers from Nokia.
> 
> Is there any chance to port SDIO stack to N800/N810 OSs in near
> future ?
> I am dreaming using internal SDIO gps card in N800 one day.
> CF gps card works fine in some PDAs.
> 
> from
> http://sourceforge.net/projects/sdio-linux/
>  
> The SDIO-Linux project provides an open source SDIO-stack. The stack
> comes complete with drivers for the Host and Bus controllers, SD/MMC
> memory cards, SDIO-bluetooth and Atheros’ WLAN driver.

this project is never gonna make it into the Linux kernel. While it
might work, it is a really bad example of doing a SDIO stack. However
starting with 2.6.24-rc1 the Linux kernel has its own SDIO stack which
is working perfectly fine. It also comes with host and bus controllers
and drivers for GPS, Bluetooth and Marvell WLAN drivers. A driver for
the AR6k cards from Atheros are work in progress.

However the real problem is to get a working host driver. While on most
laptop based system the host will follow the SDHCI standard, in the
embedded world it is a special host controller. And while most
controllers are supported, this doesn't automatically mean the will work
with SDIO. In theory they should, but the reality with this embedded
host controllers is different.

So if the MMC/SD controller inside the N800 supports SDIO (this is not a
must and didn't look at the hardware specs for it), then you might get
lucky and it works or you have to port the host controller to support
SDIO. After that you actually have to check if your specific GPS card
follows the specification or if it needs a vendor driver.

Regards

Marcel