[PATCH] mmci: corrected calculation of clock div for ux500

[Russell King - ARM Linux]

On Thu, Dec 02, 2010 at 05:51:18PM +0100, Linus Walleij wrote:
> From: Ulf Hansson <ulf.hansson at stericsson.com>
> 
> The Ux500 variant of this block has a different divider.
> The value used right now is too big and which means a loss
> in performance. This fix corrects it.

Err.

> +		} else if (variant->st_clkdiv) {
> +			clk = ((host->mclk + desired - 1) / desired) - 2;
> +			if (clk >= 256)
> +				clk = 255;
> +			host->cclk = host->mclk / (clk + 2);

This causes the divider to be selected for the 'nearest' frequency.
You are not allowed to _exceed_ the desired frequency - you must
always round down.

IOW, if 10MHz is requested and you can't do 10MHz, 10.5MHz will not
do - you must select a frequency below 10MHz.