Yenta socket and mmc/sd slot

[Russell King]

On Wed, Aug 31, 2005 at 11:52:44AM +0200, Stephan Wienczny wrote:
> Am Mittwoch, 31. August 2005 09:34 schrieb Russell King:
> > On Tue, Aug 30, 2005 at 11:44:11PM +0200, Stephan Wienczny wrote:
> > > I'm trying to write a driver for the Ricoh RL5c476 for the mmc/sd
> > > layer. This device is integrated into the RL5c476 chip. Does anybody
> > > have a tip how to do that? Who is familiar with that device?
> >
> > There is no public inforamtion on the SD/MMC interfaces for these
> > devices.
> 
> I know that there is no public information about this device. The device I'm 
> talking about is a partly supported. The pcmcia part is supported.  I thought 
> you might have some informal information about how this device works.

The data sheet for the device only documents the PCMCIA functions.

Devices which have MMC/SD support appear to have an additional
"firmware" interface, which isn't documented except for the standard
PCI registers.

My guess is that the SD card interface is internal to the device,
which means that only the firmware can directly access the SD slot.
This means that without the firmware or the programming information
for this interface, it's going to be very very difficult to get it
working.

However, I have no direct access to this hardware, so I'm unable to
play with it to confirm this - eg, the firmware might be already
loaded by the BIOS and present an obvious interface.

(Even if I did have such hardware, I do not have enough spare time
to indulge myself in such an investigation at present.)

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:  2.6 Serial core