[PATCH] dw_mmc: Add Synopsys DesignWare mmc host driver.

[Will Newton]

On Sat, Dec 11, 2010 at 7:23 PM, Chris Ball <cjb at laptop.org> wrote:
> Hi Will,
>
> On Thu, Dec 09, 2010 at 05:24:26PM +0000, Will Newton wrote:
>> This adds the mmc host driver for the Synopsys DesignWare mmc
>> host controller, found in a number of embedded SoC designs.
>>
>> Signed-off-by: Will Newton <will.newton at imgtec.com>
>> Reviewed-by: Matt Fleming <matt at console-pimps.org>
>
> Running a test build on ARM fails:
>
> drivers/mmc/host/dw_mmc.c: In function ‘dw_mci_push_data64’:
> drivers/mmc/host/dw_mmc.c:985: error: implicit declaration of function ‘__raw_writeq’
> drivers/mmc/host/dw_mmc.c: In function ‘dw_mci_pull_data64’:
> drivers/mmc/host/dw_mmc.c:998: error: implicit declaration of function ‘__raw_readq’
>
> because arch/arm doesn't implement raw versions of these 64-bit accesses.
> I'm surprised that this driver hasn't been compiled on ARM before!  What

That particular bit of code has been added since it was last built for
arm. Our architecture can do 64bit accesses so we implement readq.
Unfortunately there doesn't seem to be a sane way to conditionalize
code for architectures that have or don't have readq, so I suspect
I'll have to just remove that branch of the if statement for now.

> kind of arch are you testing on?  Do you have any ARM hardware (lpc313x?)
> to verify the driver on?

Our architecture is not merged into mainline yet (although I am
working on that). I don't have an lpc313x board but I would be happy
to work on this code with anyone who does.