From nobody Mon Sep 29 20:19:11 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AFB33C00140 for ; Mon, 15 Aug 2022 23:14:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240899AbiHOXOD (ORCPT ); Mon, 15 Aug 2022 19:14:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41480 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352800AbiHOXMv (ORCPT ); Mon, 15 Aug 2022 19:12:51 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5D8C274CEB; Mon, 15 Aug 2022 13:00:47 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 68355B80EB1; Mon, 15 Aug 2022 20:00:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AFBB6C433C1; Mon, 15 Aug 2022 20:00:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660593645; bh=y3f1Ezg+rUCk+EdK3CnTflc75Nt5LJa0SLevHviZC8M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hw67W5LkDVomEipsOU1J2M+u26KsWzYhx7HMEUrcm/exrvPcPa2jlv4udyF4Y7DC3 JQitL5aN6a97BTqvgEtYPM2oFd9Ujyo149pJjtP2XF1L1ji6/FHHjLhud72lEe9Yzx zz2iDTQQ8gSN0pbTmLCpNIK9XW5Z+bWUknL0gwqY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , Emil Renner Berthing , Thierry Reding , Sasha Levin Subject: [PATCH 5.19 0301/1157] pwm: sifive: Ensure the clk is enabled exactly once per running PWM Date: Mon, 15 Aug 2022 19:54:17 +0200 Message-Id: <20220815180451.693166637@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180439.416659447@linuxfoundation.org> References: <20220815180439.416659447@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Uwe Kleine-K=C3=B6nig [ Upstream commit ace41d7564e655c39f709a78c035188a460c7cbd ] .apply() assumes the clk to be for a given PWM iff the PWM is enabled. So make sure this is the case when .probe() completes. And in .remove() disable the according number of times. This fixes a clk enable/disable imbalance, if some PWMs are already running at probe time. Fixes: 9e37a53eb051 (pwm: sifive: Add a driver for SiFive SoC PWM) Signed-off-by: Uwe Kleine-K=C3=B6nig Tested-by: Emil Renner Berthing Signed-off-by: Thierry Reding Signed-off-by: Sasha Levin --- drivers/pwm/pwm-sifive.c | 46 ++++++++++++++++++++++++++++++++-------- 1 file changed, 37 insertions(+), 9 deletions(-) diff --git a/drivers/pwm/pwm-sifive.c b/drivers/pwm/pwm-sifive.c index b7fc33b08d82..3fbc1d96fcb6 100644 --- a/drivers/pwm/pwm-sifive.c +++ b/drivers/pwm/pwm-sifive.c @@ -228,6 +228,8 @@ static int pwm_sifive_probe(struct platform_device *pde= v) struct pwm_sifive_ddata *ddata; struct pwm_chip *chip; int ret; + u32 val; + unsigned int enabled_pwms =3D 0, enabled_clks =3D 1; =20 ddata =3D devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL); if (!ddata) @@ -254,6 +256,33 @@ static int pwm_sifive_probe(struct platform_device *pd= ev) return ret; } =20 + val =3D readl(ddata->regs + PWM_SIFIVE_PWMCFG); + if (val & PWM_SIFIVE_PWMCFG_EN_ALWAYS) { + unsigned int i; + + for (i =3D 0; i < chip->npwm; ++i) { + val =3D readl(ddata->regs + PWM_SIFIVE_PWMCMP(i)); + if (val > 0) + ++enabled_pwms; + } + } + + /* The clk should be on once for each running PWM. */ + if (enabled_pwms) { + while (enabled_clks < enabled_pwms) { + /* This is not expected to fail as the clk is already on */ + ret =3D clk_enable(ddata->clk); + if (unlikely(ret)) { + dev_err_probe(dev, ret, "Failed to enable clk\n"); + goto disable_clk; + } + ++enabled_clks; + } + } else { + clk_disable(ddata->clk); + enabled_clks =3D 0; + } + /* Watch for changes to underlying clock frequency */ ddata->notifier.notifier_call =3D pwm_sifive_clock_notifier; ret =3D clk_notifier_register(ddata->clk, &ddata->notifier); @@ -276,7 +305,11 @@ static int pwm_sifive_probe(struct platform_device *pd= ev) unregister_clk: clk_notifier_unregister(ddata->clk, &ddata->notifier); disable_clk: - clk_disable_unprepare(ddata->clk); + while (enabled_clks) { + clk_disable(ddata->clk); + --enabled_clks; + } + clk_unprepare(ddata->clk); =20 return ret; } @@ -284,21 +317,16 @@ static int pwm_sifive_probe(struct platform_device *p= dev) static int pwm_sifive_remove(struct platform_device *dev) { struct pwm_sifive_ddata *ddata =3D platform_get_drvdata(dev); - bool is_enabled =3D false; struct pwm_device *pwm; int ch; =20 for (ch =3D 0; ch < ddata->chip.npwm; ch++) { pwm =3D &ddata->chip.pwms[ch]; - if (pwm->state.enabled) { - is_enabled =3D true; - break; - } + if (pwm->state.enabled) + clk_disable(ddata->clk); } - if (is_enabled) - clk_disable(ddata->clk); =20 - clk_disable_unprepare(ddata->clk); + clk_unprepare(ddata->clk); pwmchip_remove(&ddata->chip); clk_notifier_unregister(ddata->clk, &ddata->notifier); =20 --=20 2.35.1