From mboxrd@z Thu Jan 1 00:00:00 1970 From: Scott Branden Subject: [PATCH v4] pwm: bcm-iproc: handle clk_get_rate() return Date: Fri, 17 Jul 2020 21:46:06 -0700 Message-ID: <20200718044606.18739-1-scott.branden@broadcom.com> Return-path: Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34668 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725809AbgGREqU (ORCPT ); Sat, 18 Jul 2020 00:46:20 -0400 Received: from mail-ej1-x643.google.com (mail-ej1-x643.google.com [IPv6:2a00:1450:4864:20::643]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 840AFC0619D2 for ; Fri, 17 Jul 2020 21:46:20 -0700 (PDT) Received: by mail-ej1-x643.google.com with SMTP id dp18so12961047ejc.8 for ; Fri, 17 Jul 2020 21:46:20 -0700 (PDT) Sender: linux-pwm-owner@vger.kernel.org List-Id: linux-pwm@vger.kernel.org To: Thierry Reding , Lee Jones Cc: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , BCM Kernel Feedback , linux-pwm@vger.kernel.org, linux-kernel@vger.kernel.org, Rayagonda Kokatanur , Scott Branden From: Rayagonda Kokatanur Handle clk_get_rate() returning 0 to avoid possible division by zero. Fixes: daa5abc41c80 ("pwm: Add support for Broadcom iProc PWM controller") Signed-off-by: Rayagonda Kokatanur Signed-off-by: Scott Branden Reviewed-by: Ray Jui --- Changes from v3: fixed typo in commit message: Reviewed-off-by. Hopefully everything clean now. Changes from v2: update commit message to remove <= condition as clk_get_rate only returns value >= 0 --- drivers/pwm/pwm-bcm-iproc.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/pwm/pwm-bcm-iproc.c b/drivers/pwm/pwm-bcm-iproc.c index 1f829edd8ee7..d392a828fc49 100644 --- a/drivers/pwm/pwm-bcm-iproc.c +++ b/drivers/pwm/pwm-bcm-iproc.c @@ -85,8 +85,6 @@ static void iproc_pwmc_get_state(struct pwm_chip *chip, struct pwm_device *pwm, u64 tmp, multi, rate; u32 value, prescale; - rate = clk_get_rate(ip->clk); - value = readl(ip->base + IPROC_PWM_CTRL_OFFSET); if (value & BIT(IPROC_PWM_CTRL_EN_SHIFT(pwm->hwpwm))) @@ -99,6 +97,13 @@ static void iproc_pwmc_get_state(struct pwm_chip *chip, struct pwm_device *pwm, else state->polarity = PWM_POLARITY_INVERSED; + rate = clk_get_rate(ip->clk); + if (rate == 0) { + state->period = 0; + state->duty_cycle = 0; + return; + } + value = readl(ip->base + IPROC_PWM_PRESCALE_OFFSET); prescale = value >> IPROC_PWM_PRESCALE_SHIFT(pwm->hwpwm); prescale &= IPROC_PWM_PRESCALE_MAX; -- 2.17.1