Re: [RFC] Secure Digital Host Controller PCI class

Greg KH
2005-11-22T06:40:41Z

On Tue, Nov 22, 2005 at 07:07:18AM +0100, Pierre Ossman wrote:
> Greg KH wrote:
>
> >On Mon, Nov 21, 2005 at 12:45:40PM +0100, Pierre Ossman wrote:
> >
> >
> >>I'm working on a driver for the Secure Digital Host Controller
> >>interface. This is a generic interface, so it uses a PCI class for
> >>identification instead of vendor/device ids.
> >>
> >>The class ID used is 0805 and the programming interface (correct term?)
> >>indicates DMA capabilities. Greg, since you're the PCI maintainer,
> >>perhaps you have the possibility of checking this ID?
> >>
> >>
> >
> >What do you mean "checking this ID"? Checking it with what?
> >
> >
> >
>
> I figured you might have access to the official allocations from the PCI
> SIG.

I do have access to the PCI specs from the SIG website by virtue of my
current employer, not by any recognition by the PCI-SIG that Linux is
important at all...

If you let me know what document you think this might be in, I'll dig
around to see if I can find it.

> >>The standard also dictates a register at offset 0x40 in PCI space. This
> >>is a one byte register detailing the number of slots on the controller
> >>and the first BAR to use.
> >>
> >>
> >
> >Do you have a pointer to the standard?
> >
> >
> >
>
> The SDHC standard itself is a well guarded secret. We're basing this
> work on the little information that is out there and reverse engineering
> the Windows driver. The PCI registers are described in a spec. by Texas
> Instruments though:
>
> http://www-s.ti.com/sc/ds/pci6411.pdf
>
> They only use three bits for each field (since their controller only has
> three slots), but the Windows driver reads four so that is what I've put
> in the patch.

Nice, thanks for the link.

But how about I wait to add your patch, until you submit your driver
that needs that change? At that time I'll be glad to add it.

thanks,

greg k-h