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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: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
hifive-unleashed-5.1
Andy Shevchenko 2015-10-13 17:09:14 +03:00 committed by Mark Brown
parent 289de5541c
commit 3ad4806223
1 changed files with 4 additions and 4 deletions
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8
drivers/spi/spi-pxa2xx.c
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@ -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 */