From: Andy Shevchenko <andriy.shevchenko-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
To: Jarkko Nikula
<jarkko.nikula-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>,
Mark Brown <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "Puustinen,
Ismo" <ismo.puustinen-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: Andy Shevchenko
<andriy.shevchenko-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Subject: [PATCH v2 1/1] spi-pxa2xx: choose closest lower speed
Date: Tue, 13 Oct 2015 17:09:14 +0300 [thread overview]
Message-ID: <1444745354-85940-1-git-send-email-andriy.shevchenko@linux.intel.com> (raw)
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-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---
drivers/spi/spi-pxa2xx.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index dee5b38..82493c2 100644
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -734,7 +734,7 @@ 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) {
@@ -759,7 +759,7 @@ 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);
/*
@@ -778,13 +778,13 @@ 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 */
--
2.5.3
--
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reply other threads:[~2015-10-13 14:09 UTC|newest]
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