Re: [PATCH] [9/50] mmc: Added quirks for Ricoh 1180:e823 lower base clock

Chris Ball
2011-07-29T02:49:31Z

Hi,

On Thu, Jul 28 2011, matsumur@nts.ricoh.co.jp wrote:
> As you know, SD ver.1.1 and 2.0(SDHC) cards can be applied 50MHz SD-CLK..
> SD 3.0 (UHS-I) cards also can be applied 50Mhz. However UHS-I cards are
> available 200 or 100Mhz SD-CLK.
> I would like to know if the current SD Host driver has the function of
> setting SD-CLK to 200Mhz for SD ver3.0 compliant Host Controller.

Yes, we normally would set the higher clock rates for SDv3 controllers.
We are only restricting to 50MHz on this Ricoh 0xe823 controller.

We added support for the SDR104 UHS-1 speeds in Linux 3.0, thanks to
a patchset from Arindam Nath.

Thanks,

- Chris.
--
Chris Ball <cjb@laptop.org> <http://printf.net/>
One Laptop Per Child