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From: Axel Lin <axel.lin@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: Sangbeom Kim <sbkim73@samsung.com>, Liam Girdwood <lrg@ti.com>,
	Mark Brown <broonie@opensource.wolfsonmicro.com>
Subject: [PATCH] regulator: s5m8767: Use DIV_ROUND_UP to calculate selector
Date: Fri, 13 Apr 2012 09:30:05 +0800	[thread overview]
Message-ID: <1334280605.6755.1.camel@phoenix> (raw)

Integer division may truncate the result.
Use DIV_ROUND_UP to ensure new voltage setting falls within specified range.

Also properly handle the case min_vol < desc->min to ensure we don't return
negative value for selector.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
---
 drivers/regulator/s5m8767.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/drivers/regulator/s5m8767.c b/drivers/regulator/s5m8767.c
index cb53187..ebe72d0 100644
--- a/drivers/regulator/s5m8767.c
+++ b/drivers/regulator/s5m8767.c
@@ -347,7 +347,10 @@ static int s5m8767_convert_voltage_to_sel(
 	if (max_vol < desc->min || min_vol > desc->max)
 		return -EINVAL;
 
-	selector = (min_vol - desc->min) / desc->step;
+	if (min_vol < desc->min)
+		min_vol = desc->min;
+
+	selector = DIV_ROUND_UP(min_vol - desc->min, desc->step);
 
 	if (desc->min + desc->step * selector > max_vol)
 		return -EINVAL;
-- 
1.7.5.4




             reply	other threads:[~2012-04-13  1:30 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-04-13  1:30 Axel Lin [this message]
2012-04-23 12:18 ` [PATCH] regulator: s5m8767: Use DIV_ROUND_UP to calculate selector Mark Brown

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