From patchwork Wed Feb 10 13:02:21 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lee Jones X-Patchwork-Id: 581407 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 47BB21402C9 for ; Thu, 11 Feb 2016 00:07:29 +1100 (AEDT) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=linaro.org header.i=@linaro.org header.b=cQvrjy2K; dkim-atps=neutral Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751276AbcBJNHD (ORCPT ); Wed, 10 Feb 2016 08:07:03 -0500 Received: from mail-wm0-f41.google.com ([74.125.82.41]:37676 "EHLO mail-wm0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751353AbcBJNEk (ORCPT ); Wed, 10 Feb 2016 08:04:40 -0500 Received: by mail-wm0-f41.google.com with SMTP id g62so25824180wme.0 for ; Wed, 10 Feb 2016 05:04:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=SZtDauQNC1SMdtfO9bNskbO4DzcclMvG7h9Oda36xFc=; b=cQvrjy2KAyP1mblPR2Z7N1sCZb5WL/+WzcUG68QDStmtSBx2wljU52lQhv4Ysapujw gA48wSTqO5FnjHaArH4ocPzLXxzJ8xrRIkvCEnWsjntwmSJ9PfHQSdZXqgfjtrKpcH67 GTAcVFT3/xmkIpgoXBrnIr0XJ6Kj2nvQYkJtA= 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=SZtDauQNC1SMdtfO9bNskbO4DzcclMvG7h9Oda36xFc=; b=LrmqnjJWQiwloEAF9bu/k0INCYqbFpgwdZ2bnh1N6IDmKC8JBfJ/PRCrC+P5I7bPIx scUc7EE4KORYseSxItJQeZ5fYZWfFo6LhhmBP59tqqAgZnsi9yDpsQgG3Gi7f1FyBalN aG9qvpB+ZjqH+JjUUs6HLkSMzhKojyUumQqDtFoN88whOJNP5qbiMPz45apdfG+IpLxA cYiWHJ/xih1cE4R8qiQJuI3yVbLRF3QjhItHlu/wWZLg/WFQu8uIAMyTxSvVb5/8zf82 fD2BmO2n04CmjG+MdKuKGxRjewgtSptVJSU9mMDXKtJdkZaGE0mXRAX+PBGqPuzWEUa/ 7KCA== X-Gm-Message-State: AG10YOToCmSU/sWXQ+UdiAGDJBQbpmrPy1WQLxntXXzxfxBbBmInCsdEZlgXkC+n3uXJ2wZJ X-Received: by 10.194.240.66 with SMTP id vy2mr39986158wjc.28.1455109479204; Wed, 10 Feb 2016 05:04:39 -0800 (PST) Received: from localhost.localdomain (host81-129-170-149.range81-129.btcentralplus.com. [81.129.170.149]) by smtp.gmail.com with ESMTPSA id q75sm22429319wmd.6.2016.02.10.05.04.38 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 10 Feb 2016 05:04:38 -0800 (PST) From: Lee Jones To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, thierry.reding@gmail.com, linux-pwm@vger.kernel.org, ajitpal.singh@st.com Cc: kernel@stlinux.com, maxime.coquelin@st.com, Lee Jones Subject: [PATCH 04/11] pwm: sti: Only request clock rate when you need to Date: Wed, 10 Feb 2016 13:02:21 +0000 Message-Id: <1455109348-32767-5-git-send-email-lee.jones@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1455109348-32767-1-git-send-email-lee.jones@linaro.org> References: <1455109348-32767-1-git-send-email-lee.jones@linaro.org> Sender: linux-pwm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pwm@vger.kernel.org In the original code the clock rate was only obtained during initialisation; however, the rate may change between then and its use. This patch ensures the correct rate is acquired just before use. Signed-off-by: Lee Jones --- drivers/pwm/pwm-sti.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/drivers/pwm/pwm-sti.c b/drivers/pwm/pwm-sti.c index 4e06c4d..aa217e2 100644 --- a/drivers/pwm/pwm-sti.c +++ b/drivers/pwm/pwm-sti.c @@ -51,7 +51,6 @@ struct sti_pwm_compat_data { struct sti_pwm_chip { struct device *dev; - unsigned long clk_rate; struct clk *pwm_clk; struct regmap *regmap; struct sti_pwm_compat_data *cdata; @@ -86,13 +85,20 @@ static int sti_pwm_get_prescale(struct sti_pwm_chip *pc, unsigned long period, unsigned int *prescale) { struct sti_pwm_compat_data *cdata = pc->cdata; + unsigned long clk_rate; unsigned long val; unsigned int ps; + clk_rate = clk_get_rate(pc->pwm_clk); + if (!clk_rate) { + dev_err(pc->dev, "failed to get clock rate\n"); + return -EINVAL; + } + /* * prescale = ((period_ns * clk_rate) / (10^9 * (max_pwm_count + 1)) - 1 */ - val = NSEC_PER_SEC / pc->clk_rate; + val = NSEC_PER_SEC / clk_rate; val *= cdata->max_pwm_cnt + 1; if (period % val) { @@ -353,12 +359,6 @@ static int sti_pwm_probe(struct platform_device *pdev) return PTR_ERR(pc->pwm_clk); } - pc->clk_rate = clk_get_rate(pc->pwm_clk); - if (!pc->clk_rate) { - dev_err(dev, "failed to get clock rate\n"); - return -EINVAL; - } - ret = clk_prepare(pc->pwm_clk); if (ret) { dev_err(dev, "failed to prepare clock\n");