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Commit 3ad48062 authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Mark Brown
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spi: pxa2xx: choose closest lower speed 

As per discussion [1] the best choice is to set closest speed which is not
going over the asked one.

Do the same approach for Intel Quark boards.

[1] http://www.spinics.net/lists/linux-spi/msg03389.html



Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 289de554

drivers/spi/spi-pxa2xx.c

+4 −4
Original line number Diff line number Diff line
@@ -730,7 +730,7 @@ static unsigned int quark_x1000_get_clk_div(int rate, u32 *dds) 
	mul = (1 << 24) >> 1;



	/* Calculate initial quot */

	q1 = DIV_ROUND_CLOSEST(fref1, rate);

	q1 = DIV_ROUND_UP(fref1, rate);



	/* Scale q1 if it's too big */

	if (q1 > 256) {
@@ -755,7 +755,7 @@ static unsigned int quark_x1000_get_clk_div(int rate, u32 *dds) 


	/* Case 2 */



	q2 = DIV_ROUND_CLOSEST(fref2, rate);

	q2 = DIV_ROUND_UP(fref2, rate);

	r2 = abs(fref2 / q2 - rate);



	/*
@@ -774,13 +774,13 @@ static unsigned int quark_x1000_get_clk_div(int rate, u32 *dds) 
		mul = (1 << 24) * 2 / 5;

	}



	/* Check case 3 only If the divisor is big enough */

	/* Check case 3 only if the divisor is big enough */

	if (fref / rate >= 80) {

		u64 fssp;

		u32 m;



		/* Calculate initial quot */

		q1 = DIV_ROUND_CLOSEST(fref, rate);

		q1 = DIV_ROUND_UP(fref, rate);

		m = (1 << 24) / q1;



		/* Get the remainder */