From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1423793AbcFHJ10 (ORCPT ); Wed, 8 Jun 2016 05:27:26 -0400 Received: from mail-wm0-f51.google.com ([74.125.82.51]:33940 "EHLO mail-wm0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161958AbcFHJVi (ORCPT ); Wed, 8 Jun 2016 05:21:38 -0400 From: Lee Jones To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: kernel@stlinux.com, maxime.coquelin@st.com, patrice.chotard@st.com, thierry.reding@gmail.com, robh+dt@kernel.org, linux-pwm@vger.kernel.org, devicetree@vger.kernel.org, Lee Jones Subject: [PATCH v3 12/20] pwm: sti: Only request clock rate when you need to Date: Wed, 8 Jun 2016 10:21:27 +0100 Message-Id: <20160608092135.21184-13-lee.jones@linaro.org> X-Mailer: git-send-email 2.8.3 In-Reply-To: <20160608092135.21184-1-lee.jones@linaro.org> References: <20160608092135.21184-1-lee.jones@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@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 5fbee61..c4a34af 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"); -- 2.8.3