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SubjectRe: [PATCH v2 2/2] spi: add SPI controller driver for UniPhier SoC
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On Thu, 2018-07-26 at 11:46 +0300, Andy Shevchenko wrote:
> > +
> > + /*
> > + * the supported rates are even numbers from 4 to 254. (4,6,8...254)
> > + * round up as we look for equal or less speed
> > + */
> > + ckrat = DIV_ROUND_UP(clk_get_rate(priv->clk), speed);
> > + ckrat = roundup(ckrat, 2);
>
> ckrat += ckrat & 1;

Either way, the compiler produces the same code:

add r0, r0, #1
bic r0, r0, #1

I.e., ckrat = (ckrat + 1) & ~1, one "add" and one "and".

Might as well use the macro so it's clear. There is also round_up(x,y),
which I believe is intended to be used only with power of 2 values of
y.
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