From patchwork Sat Jan 30 04:26:53 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "David Rivshin (Allworx)" X-Patchwork-Id: 8169521 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 81EF79F818 for ; Sat, 30 Jan 2016 04:32:32 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id B147220398 for ; Sat, 30 Jan 2016 04:32:31 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D36B220396 for ; Sat, 30 Jan 2016 04:32:30 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1aPNBd-0007po-Bd; Sat, 30 Jan 2016 04:31:01 +0000 Received: from mail-qg0-x242.google.com ([2607:f8b0:400d:c04::242]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1aPNBT-0007kA-5O for linux-arm-kernel@lists.infradead.org; Sat, 30 Jan 2016 04:30:52 +0000 Received: by mail-qg0-x242.google.com with SMTP id 94so6632647qgt.1 for ; Fri, 29 Jan 2016 20:30:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=F+N9yqBVFIdiu/uUIfBX65mkN8qWSO5bxOBEzrwfh0I=; b=yXvd/MOYIQAeuS5reDont8YRXkkIC+O3a01boOa0f2Qv+inmIFNG0cd85F70X0gOs6 eBOvCtVcw4lZrD08ogvPVwnI5M/2rcyneP0nWA02eOo+2KtJIVeC4r1nAcxD4d1g2cb9 NrPSb2sobuy+jCymVqaLMkKMj1liflbj2/+QoZU+4H23eC0gDAgSHKH0Zm/AmFvbeZRa I+MtxfDQwL1CcK0zXXwcHaZVQevfq8us/uq2+tvgHvs3b0TiLkn1WMGmgqQAqgmG5rAA L1Fs9fxgZe1GpFKTe4MU2Er15n6PRgoeOEiFuM1dwBdavlkGKo9BLkeqM7D32MSPfS8w NPPQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=F+N9yqBVFIdiu/uUIfBX65mkN8qWSO5bxOBEzrwfh0I=; b=S3MExUZ536gQlQxqvE/eZzIqrRcEAszUPxGls8XjWQ7CxM6/FZQ4ibjMF+LIYFjzwY UWS9PR38QgkzbY3xnh5kfiCZi+ss79O+PcYDZSRtAenHRkWCk/jfdhP8r6vbCdU/Gjtd 0zi9pH18q41acPzlJR/rZpszmbg5O/24svvUFVfOKLJ4Y1GUGsCC+8J6QCmIlL+N4j8x TC8Bk7Ca4W4yq2FNyRWa/GFXk2IjaWykO7gWhRvhqYpGDGtI5CCsv3XVhDqxL5J90YaY qzf8MJA1qwpopjC8FMc9iV2dSxm6AcwHRof+zkXbpOBnlJCfoDd53e1ZnnET4HEhFk4t 3p9Q== X-Gm-Message-State: AG10YOTG1XcY2a+P0q7KJDTaSWn8dzQzb9Ou4vPe92RGw7CYfocFG40hvJJ6jTtbUloZUg== X-Received: by 10.140.134.74 with SMTP id 71mr15954580qhg.75.1454128235231; Fri, 29 Jan 2016 20:30:35 -0800 (PST) Received: from drivshin-linux.crosskeys.inscitek.com ([24.213.148.66]) by smtp.gmail.com with ESMTPSA id y104sm8404563qgd.33.2016.01.29.20.30.34 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 29 Jan 2016 20:30:34 -0800 (PST) From: "David Rivshin (Allworx)" To: linux-pwm@vger.kernel.org, Thierry Reding , Neil Armstrong Subject: [PATCH 3/4] pwm: omap-dmtimer: round load and match values rather than truncate Date: Fri, 29 Jan 2016 23:26:53 -0500 Message-Id: <1454128014-22866-4-git-send-email-drivshin.allworx@gmail.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1454128014-22866-1-git-send-email-drivshin.allworx@gmail.com> References: <1454128014-22866-1-git-send-email-drivshin.allworx@gmail.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160129_203051_407245_517F8C47 X-CRM114-Status: GOOD ( 10.45 ) X-Spam-Score: -2.7 (--) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Tony Lindgren , Joachim Eastwood , NeilBrown , Grant Erickson , linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.1 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, T_DKIM_INVALID, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: David Rivshin When converting period and duty_cycle from nanoseconds to fclk cycles, the error introduced by the integer division can be appreciable, especially in the case of slow fclk or short period. Use DIV_ROUND_CLOSEST_ULL() so that the error is kept to +/- 0.5 clock cycles. Fixes: 6604c6556db9 ("pwm: Add PWM driver for OMAP using dual-mode timers") Signed-off-by: David Rivshin Acked-by: Neil Armstrong --- drivers/pwm/pwm-omap-dmtimer.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/drivers/pwm/pwm-omap-dmtimer.c b/drivers/pwm/pwm-omap-dmtimer.c index 103d729..8c9953c 100644 --- a/drivers/pwm/pwm-omap-dmtimer.c +++ b/drivers/pwm/pwm-omap-dmtimer.c @@ -49,11 +49,7 @@ to_pwm_omap_dmtimer_chip(struct pwm_chip *chip) static u32 pwm_omap_dmtimer_get_clock_cycles(unsigned long clk_rate, int ns) { - u64 c = (u64)clk_rate * ns; - - do_div(c, NSEC_PER_SEC); - - return c; + return DIV_ROUND_CLOSEST_ULL((u64)clk_rate * ns, NSEC_PER_SEC); } static void pwm_omap_dmtimer_start(struct pwm_omap_dmtimer_chip *omap)