Re: MMC: Make the configuration memory resource optional

Guennadi Liakhovetski
2009-08-05T19:44:51Z

On Wed, 5 Aug 2009, Ian Molton wrote:

> Hi all,
>
> Could all non-MFD users of tmio-mmc please ensure that the following is
> actually true on your hardware?
>
> mmc->f_max = pdata->hclk;
> mmc->f_min = mmc->f_max / 512;

That's what I currently have in the driver, yes.

> According to all the data I have, the smallest divider setting of 0x100 is /2
> and only MFD controllers with the CNF area can select no-divider mode.
>
> this would mean that non-MFD chips should be doing:
>
> mmc->f_max = pdata->hclk / 2;
> mmc->f_min = pdata->hclk / 512;

How do we verify this? Do I need some "very fast" card, so that sd would
try to drive the clock beyond pdata->hclk / 2, which should then fail?
Currently I'm using 24MHz (copied from the original driver), and the only
thing I know about the controller is its "Maximum operating frequency: 25
MHz."

Thanks
Guennadi
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Guennadi Liakhovetski