From patchwork Sat Jul 18 04:46:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Scott Branden X-Patchwork-Id: 1331487 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-pwm-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=broadcom.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=broadcom.com header.i=@broadcom.com header.a=rsa-sha256 header.s=google header.b=bY/0au6W; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4B7wRy03sZz9sRk for ; Sat, 18 Jul 2020 14:46:21 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726262AbgGREqV (ORCPT ); Sat, 18 Jul 2020 00:46:21 -0400 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) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; h=from:to:cc:subject:date:message-id; bh=6XtgaMcVkuKZN6Vqx9za29ZMiqRwMaKdWv8eAb+N9vg=; b=bY/0au6WAL+u8vh4fua/qFVLuU47TL1PTMEtiMXHJM49ItyD0NffJ8wZiiwrOGWaTD eBswM0qBkTmIt+JunE0pptyKPWhBHOu+L7miR1ny6lkFWsjiMicvX/VTfHfxfO7Afb7r b4wYNVuoxS+gyaOXlmDxE90qT2T3znv3d3m14= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=6XtgaMcVkuKZN6Vqx9za29ZMiqRwMaKdWv8eAb+N9vg=; b=QxgY0ZDmbWetLbLmh4CYGgFLjHE1k9QvtmAxZ1lqXi7tOXszxJIXL4WIVkwhfbVETO LVjqYowaeQevoUlxBRyneyNh8iFecpPWeE3eAhPRMqOsFB35ZTCroSBa/Y/9vMRwa/P6 n3m7GtFYghSx4It2DYD/fp1uJXyrH8Vgi7+bMt4l8HyFwLZMNNrFvul8zZwtPic9URVa BsCI+r7hakQYL4SluzeaseAppibCb1wC95ROMkDaWxAikHsD/xdU9yKZ0R/YMecZxEeo vtXdVYzAEvuomXBoz2XsqOIKpxtgz8eDcvffx4FoA62P42w5zl3b5yZFx5eUJUdt5Bq1 gA9g== X-Gm-Message-State: AOAM532bqJGtI8ksSISycpr6jr5hJyCkn1IX49Um92Fx9yKckrrggODI CAL2lDLuGXmOUvPOlEt65iZKOw== X-Google-Smtp-Source: ABdhPJy1oAFtDdH08tlydsMUGH/N2FrHzxaMP3ualaq1GVbB+RmhdCMIkpJOIZUQjDN/KFBT7tG6vw== X-Received: by 2002:a17:906:3945:: with SMTP id g5mr12271263eje.549.1595047579113; Fri, 17 Jul 2020 21:46:19 -0700 (PDT) Received: from lbrmn-lnxub113.broadcom.net ([192.19.228.250]) by smtp.gmail.com with ESMTPSA id u13sm9680553ejx.3.2020.07.17.21.46.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 17 Jul 2020 21:46:18 -0700 (PDT) From: Scott Branden To: Thierry Reding , Lee Jones Cc: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= , BCM Kernel Feedback , linux-pwm@vger.kernel.org, linux-kernel@vger.kernel.org, Rayagonda Kokatanur , 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> X-Mailer: git-send-email 2.17.1 Sender: linux-pwm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pwm@vger.kernel.org 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 Reviewed-by: Uwe Kleine-König --- 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;