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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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