From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935008Ab2DMBaS (ORCPT ); Thu, 12 Apr 2012 21:30:18 -0400 Received: from mail-iy0-f174.google.com ([209.85.210.174]:62967 "EHLO mail-iy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754028Ab2DMBaQ (ORCPT ); Thu, 12 Apr 2012 21:30:16 -0400 Message-ID: <1334280605.6755.1.camel@phoenix> Subject: [PATCH] regulator: s5m8767: Use DIV_ROUND_UP to calculate selector From: Axel Lin To: linux-kernel@vger.kernel.org Cc: Sangbeom Kim , Liam Girdwood , Mark Brown Date: Fri, 13 Apr 2012 09:30:05 +0800 Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.2- Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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