From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752183Ab2GRDa3 (ORCPT ); Tue, 17 Jul 2012 23:30:29 -0400 Received: from mail-yx0-f174.google.com ([209.85.213.174]:51537 "EHLO mail-yx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751484Ab2GRDaW (ORCPT ); Tue, 17 Jul 2012 23:30:22 -0400 Message-ID: <1342582211.12515.2.camel@phoenix> Subject: [PATCH] regulator: palmas: Fix calculating selector in palmas_map_voltage_ldo From: Axel Lin To: Mark Brown Cc: linux-kernel@vger.kernel.org, Graeme Gregory , Liam Girdwood Date: Wed, 18 Jul 2012 11:30:11 +0800 Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 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 This patch fixes below issues when choosing selector: 1. Current code returns negative selector if min_uV < 900000 which is wrong. For example, it is possible to satisfy the request with selector = 1 if the requested min_uV is 850000. 2. Current code may select a voltage lower than requested min_uV. For example, if the requested min_uV is 945000, current code chooses selector = 1 which is lower than requested min_uV. DIV_ROUND_UP to avoid this case. Signed-off-by: Axel Lin --- drivers/regulator/palmas-regulator.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/regulator/palmas-regulator.c b/drivers/regulator/palmas-regulator.c index 17d19fb..0fcf355 100644 --- a/drivers/regulator/palmas-regulator.c +++ b/drivers/regulator/palmas-regulator.c @@ -486,9 +486,12 @@ static int palmas_map_voltage_ldo(struct regulator_dev *rdev, { int ret, voltage; - ret = ((min_uV - 900000) / 50000) + 1; - if (ret < 0) - return ret; + if (min_uV == 0) + return 0; + + if (min_uV < 900000) + min_uV = 900000; + ret = DIV_ROUND_UP(min_uV - 900000, 50000) + 1; /* Map back into a voltage to verify we're still in bounds */ voltage = palmas_list_voltage_ldo(rdev, ret); -- 1.7.9.5