From patchwork Fri Jun 3 08:23:01 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Boris Brezillon X-Patchwork-Id: 629701 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3rLckD1knMz9t88 for ; Fri, 3 Jun 2016 18:31:00 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932136AbcFCI3I (ORCPT ); Fri, 3 Jun 2016 04:29:08 -0400 Received: from down.free-electrons.com ([37.187.137.238]:45818 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752379AbcFCIXW (ORCPT ); Fri, 3 Jun 2016 04:23:22 -0400 Received: by mail.free-electrons.com (Postfix, from userid 110) id 97CE93D6; Fri, 3 Jun 2016 10:23:20 +0200 (CEST) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on mail.free-electrons.com X-Spam-Level: X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED,SHORTCIRCUIT, URIBL_BLOCKED shortcircuit=ham autolearn=disabled version=3.4.0 Received: from bbrezillon.home (LStLambert-657-1-97-87.w90-63.abo.wanadoo.fr [90.63.216.87]) by mail.free-electrons.com (Postfix) with ESMTPSA id F14842E0; Fri, 3 Jun 2016 10:23:19 +0200 (CEST) From: Boris Brezillon To: Thierry Reding , linux-pwm@vger.kernel.org, Mark Brown , Liam Girdwood Cc: Heiko Stuebner , linux-rockchip@lists.infradead.org, Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Milo Kim , Doug Anderson , Caesar Wang , Stephen Barber , Brian Norris , Ajit Pal Singh , Srinivas Kandagatla , Maxime Coquelin , Patrice Chotard , kernel@stlinux.com, Boris Brezillon Subject: [PATCH 03/14] pwm: rockchip: Fix period and duty_cycle approximation Date: Fri, 3 Jun 2016 10:23:01 +0200 Message-Id: <1464942192-25967-4-git-send-email-boris.brezillon@free-electrons.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1464942192-25967-1-git-send-email-boris.brezillon@free-electrons.com> References: <1464942192-25967-1-git-send-email-boris.brezillon@free-electrons.com> Sender: linux-pwm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pwm@vger.kernel.org The current implementation always round down the duty and period values, while it would be better to round them to the closest integer. Signed-off-by: Boris Brezillon Reviewed-by: Brian Norris Tested-by: Brian Norris --- drivers/pwm/pwm-rockchip.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c index 7d9cc90..68d72ce 100644 --- a/drivers/pwm/pwm-rockchip.c +++ b/drivers/pwm/pwm-rockchip.c @@ -114,12 +114,11 @@ static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, * default prescaler value for all practical clock rate values. */ div = clk_rate * period_ns; - do_div(div, pc->data->prescaler * NSEC_PER_SEC); - period = div; + period = DIV_ROUND_CLOSEST_ULL(div, + pc->data->prescaler * NSEC_PER_SEC); div = clk_rate * duty_ns; - do_div(div, pc->data->prescaler * NSEC_PER_SEC); - duty = div; + duty = DIV_ROUND_CLOSEST_ULL(div, pc->data->prescaler * NSEC_PER_SEC); ret = clk_enable(pc->clk); if (ret)