From mboxrd@z Thu Jan 1 00:00:00 1970 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 4E568C00140 for ; Mon, 15 Aug 2022 18:48:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243958AbiHOSsI (ORCPT ); Mon, 15 Aug 2022 14:48:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38004 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242674AbiHOSm4 (ORCPT ); Mon, 15 Aug 2022 14:42:56 -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 9FBAA2AE13; Mon, 15 Aug 2022 11:26:32 -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 5DDB4B8107A; Mon, 15 Aug 2022 18:26:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A6F85C433D7; Mon, 15 Aug 2022 18:26:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660587990; bh=aeRuvv4n+RQx3rdfldF9GjNSj+5s1DQan1L3wad8ZI0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CdciEexMDv/p15jJBSIbcD2e8WyVHBEARv4NuMwlJCtQgkkuChN/b1zk/i0cBYAOI UNA6SFCYZ/6A9LMuXwmZxVUo0o4Bf+vbbQ2bbz7cKFJ4tKjVQ638WPcomklc61x91M +PjoccPDhFsrahQuNBJ7B0fLDOsZxgl1yuoqletU= 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 5.15 229/779] pwm: sifive: Ensure the clk is enabled exactly once per running PWM Date: Mon, 15 Aug 2022 19:57:53 +0200 Message-Id: <20220815180347.084421171@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180337.130757997@linuxfoundation.org> References: <20220815180337.130757997@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Uwe Kleine-König [ 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-König 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 a55f7345dc87..3936fda53366 100644 --- a/drivers/pwm/pwm-sifive.c +++ b/drivers/pwm/pwm-sifive.c @@ -229,6 +229,8 @@ static int pwm_sifive_probe(struct platform_device *pdev) struct pwm_sifive_ddata *ddata; struct pwm_chip *chip; int ret; + u32 val; + unsigned int enabled_pwms = 0, enabled_clks = 1; ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL); if (!ddata) @@ -255,6 +257,33 @@ static int pwm_sifive_probe(struct platform_device *pdev) return ret; } + val = readl(ddata->regs + PWM_SIFIVE_PWMCFG); + if (val & PWM_SIFIVE_PWMCFG_EN_ALWAYS) { + unsigned int i; + + for (i = 0; i < chip->npwm; ++i) { + val = 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 = 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 = 0; + } + /* Watch for changes to underlying clock frequency */ ddata->notifier.notifier_call = pwm_sifive_clock_notifier; ret = clk_notifier_register(ddata->clk, &ddata->notifier); @@ -277,7 +306,11 @@ static int pwm_sifive_probe(struct platform_device *pdev) 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); return ret; } @@ -285,21 +318,16 @@ static int pwm_sifive_probe(struct platform_device *pdev) static int pwm_sifive_remove(struct platform_device *dev) { struct pwm_sifive_ddata *ddata = platform_get_drvdata(dev); - bool is_enabled = false; struct pwm_device *pwm; int ch; for (ch = 0; ch < ddata->chip.npwm; ch++) { pwm = &ddata->chip.pwms[ch]; - if (pwm->state.enabled) { - is_enabled = true; - break; - } + if (pwm->state.enabled) + clk_disable(ddata->clk); } - if (is_enabled) - clk_disable(ddata->clk); - clk_disable_unprepare(ddata->clk); + clk_unprepare(ddata->clk); pwmchip_remove(&ddata->chip); clk_notifier_unregister(ddata->clk, &ddata->notifier); -- 2.35.1