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 X-Spam-Level: X-Spam-Status: No, score=-6.5 required=3.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED,DKIM_VALID,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C3CFDC35254 for ; Mon, 10 Feb 2020 17:46:19 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9B12720842 for ; Mon, 10 Feb 2020 17:46:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="YdzjBNeJ"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bVqj8QgM" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9B12720842 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=pZNocAqpBM8j6v+uq2lTMEdczSIRLH2Ln+qR1ejvgV4=; b=YdzjBNeJVQlm4E bMF1xH/7LmzqEdqJFp82RQSfP/3ustsWxtWuaFQPk04fi8ArN302pq9pKuxnlwjTQ8HwPrXqQjTDI Fy0SJFay5iRXFbdQyS32vnb9ZaNj0GHEKnt1L3RpfcFFAVSdNzQWflDRvUds0hOGhNQiII+ZKtHL2 EzK4KNTf+/GKcm5R98xVSyELy86BK/jFqLQKCCESMvUpaPytd9PLbj20aklLaFXnzFf7ZWQBAgEi+ O8f0oi9oCx7aaR+DL+ftyTGMPzMm8edVsKu8jzC54dR6Arycuz32d1L1v3EfQ3hZsMLD1JgTXj3H0 1oTttvG9SvMN9iwupJWg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1j1D8N-0002gT-Jz; Mon, 10 Feb 2020 17:46:11 +0000 Received: from mail-yw1-xc41.google.com ([2607:f8b0:4864:20::c41]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1j1D8J-0002ez-VJ for linux-arm-kernel@lists.infradead.org; Mon, 10 Feb 2020 17:46:09 +0000 Received: by mail-yw1-xc41.google.com with SMTP id 10so3806683ywv.5 for ; Mon, 10 Feb 2020 09:46:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=c1zhLfQHfrUfvkp0MTuGkuwB8y82vgQU4IfRGdXFd5k=; b=bVqj8QgM5OlikSgs9Kf4RXNCDtoJmQ8E9efAXgds9jlaEE8+UbeRTMgRb5fstC1Mhx k/uub/bsuUK6xPR8j7coolX+ew3ilVxeZCq31NwF6TXcA2Hb+LoyfERWncfohs0bkU8V WzGgCq76QV9mI4MUzvzifjm9XDvYFWfdfASEavK/AQmrfXaLldxGckLWZfEVqzJb11wM ujgBmMnXoXLnfrsQx+fmI9MSue6BDkhA7xo4fdq/IwQomihaNVIb7irhAhenqAd3NMz3 SW28jXWBvrBDX+ft5xVZrOB4r+LSEAuyLMsSsdwdOaWorFAzJR9abp4BwrzfMFfhAWt6 u5cw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=c1zhLfQHfrUfvkp0MTuGkuwB8y82vgQU4IfRGdXFd5k=; b=Gr/60zlYt06+yhfh/I1mgO0QRAt0P81gl4hMAzlhrcRRyWnaTCxoRa/L2wqeYGedFK wmSCbkixO7IB0UUz4Ql39zSvbna/c/WCjCUwa5yn3bQ3OHMoW9uq3hbs1D0K/4uLQ4Tn 4CXqjfAHNAzE0Zc5hx7ac/J2w0haoZgdAiJ2pY7+EZKusdhxpzL74Nh8CcKMgoftaMVE 4lLQn79/J82gwZaMZW5FBL7vO2VoO0MQw3Q6S+ggvfJxHwhxNDcP5RZ8OwWOkIbI9iVh wJQdOTETr5iZqrJFQVx/bFoEY1O1GsAPc48mIuvWGDar3TbdwroYZA5zSKussd3PR0Ls sndA== X-Gm-Message-State: APjAAAXm4PXhZIh97KU33vFUlohMB4JOUYiRm4CFt1ymjIM5Sou4yyrS 05ZtweRUD6YK49c24Sjee20= X-Google-Smtp-Source: APXvYqylUh8O1JaCDocqRa9z5ZfVTr6cLqiL1RjJNIIGfFN2TwYqpRxHFKwWH3DBkxpkZ9FGw44sOg== X-Received: by 2002:a0d:cb54:: with SMTP id n81mr1817971ywd.375.1581356766107; Mon, 10 Feb 2020 09:46:06 -0800 (PST) Received: from icarus (072-189-064-225.res.spectrum.com. [72.189.64.225]) by smtp.gmail.com with ESMTPSA id m62sm530815ywb.107.2020.02.10.09.46.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 10 Feb 2020 09:46:05 -0800 (PST) Date: Mon, 10 Feb 2020 12:45:50 -0500 From: William Breathitt Gray To: Fabrice Gasnier Subject: Re: [PATCH v2] counter: stm32-timer-cnt: add power management support Message-ID: <20200210174550.GA4626@icarus> References: <1581355198-30428-1-git-send-email-fabrice.gasnier@st.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1581355198-30428-1-git-send-email-fabrice.gasnier@st.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200210_094608_010442_2296AE30 X-CRM114-Status: GOOD ( 19.75 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: alexandre.torgue@st.com, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, mcoquelin.stm32@gmail.com, linux-stm32@st-md-mailman.stormreply.com, jic23@kernel.org, benjamin.gaignard@st.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Feb 10, 2020 at 06:19:58PM +0100, Fabrice Gasnier wrote: > Add suspend/resume PM sleep ops. When going to low power, enforce the > counter isn't active. Gracefully restore its state upon resume in case > it's been left enabled prior to suspend. > > Acked-by: William Breathitt Gray > Signed-off-by: Fabrice Gasnier > --- > Changes in v2: > - Don't refuse to suspend in case the counter has been left enabled. > Gracefully disable it and restore its state upon resume. > --- > drivers/counter/stm32-timer-cnt.c | 63 +++++++++++++++++++++++++++++++++++++++ > 1 file changed, 63 insertions(+) > > diff --git a/drivers/counter/stm32-timer-cnt.c b/drivers/counter/stm32-timer-cnt.c > index 3eafcce..50496f4 100644 > --- a/drivers/counter/stm32-timer-cnt.c > +++ b/drivers/counter/stm32-timer-cnt.c > @@ -12,6 +12,7 @@ > #include Unrelated to your patch but it caught my eye: are iio headers necessary for this file? I suspect they are not needed since this driver does not make use of the IIO interface. William Breathitt Gray > #include > #include > +#include > #include > > #define TIM_CCMR_CCXS (BIT(8) | BIT(0)) > @@ -20,11 +21,20 @@ > #define TIM_CCER_MASK (TIM_CCER_CC1P | TIM_CCER_CC1NP | \ > TIM_CCER_CC2P | TIM_CCER_CC2NP) > > +struct stm32_timer_regs { > + u32 cr1; > + u32 cnt; > + u32 smcr; > + u32 arr; > +}; > + > struct stm32_timer_cnt { > struct counter_device counter; > struct regmap *regmap; > struct clk *clk; > u32 ceiling; > + bool enabled; > + struct stm32_timer_regs bak; > }; > > /** > @@ -224,6 +234,9 @@ static ssize_t stm32_count_enable_write(struct counter_device *counter, > clk_disable(priv->clk); > } > > + /* Keep enabled state to properly handle low power states */ > + priv->enabled = enable; > + > return len; > } > > @@ -358,10 +371,59 @@ static int stm32_timer_cnt_probe(struct platform_device *pdev) > priv->counter.num_signals = ARRAY_SIZE(stm32_signals); > priv->counter.priv = priv; > > + platform_set_drvdata(pdev, priv); > + > /* Register Counter device */ > return devm_counter_register(dev, &priv->counter); > } > > +static int __maybe_unused stm32_timer_cnt_suspend(struct device *dev) > +{ > + struct stm32_timer_cnt *priv = dev_get_drvdata(dev); > + > + /* Only take care of enabled counter: don't disturb other MFD child */ > + if (priv->enabled) { > + /* Backup registers that may get lost in low power mode */ > + regmap_read(priv->regmap, TIM_SMCR, &priv->bak.smcr); > + regmap_read(priv->regmap, TIM_ARR, &priv->bak.arr); > + regmap_read(priv->regmap, TIM_CNT, &priv->bak.cnt); > + regmap_read(priv->regmap, TIM_CR1, &priv->bak.cr1); > + > + /* Disable the counter */ > + regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0); > + clk_disable(priv->clk); > + } > + > + return pinctrl_pm_select_sleep_state(dev); > +} > + > +static int __maybe_unused stm32_timer_cnt_resume(struct device *dev) > +{ > + struct stm32_timer_cnt *priv = dev_get_drvdata(dev); > + int ret; > + > + ret = pinctrl_pm_select_default_state(dev); > + if (ret) > + return ret; > + > + if (priv->enabled) { > + clk_enable(priv->clk); > + > + /* Restore registers that may have been lost */ > + regmap_write(priv->regmap, TIM_SMCR, priv->bak.smcr); > + regmap_write(priv->regmap, TIM_ARR, priv->bak.arr); > + regmap_write(priv->regmap, TIM_CNT, priv->bak.cnt); > + > + /* Also re-enables the counter */ > + regmap_write(priv->regmap, TIM_CR1, priv->bak.cr1); > + } > + > + return 0; > +} > + > +static SIMPLE_DEV_PM_OPS(stm32_timer_cnt_pm_ops, stm32_timer_cnt_suspend, > + stm32_timer_cnt_resume); > + > static const struct of_device_id stm32_timer_cnt_of_match[] = { > { .compatible = "st,stm32-timer-counter", }, > {}, > @@ -373,6 +435,7 @@ static struct platform_driver stm32_timer_cnt_driver = { > .driver = { > .name = "stm32-timer-counter", > .of_match_table = stm32_timer_cnt_of_match, > + .pm = &stm32_timer_cnt_pm_ops, > }, > }; > module_platform_driver(stm32_timer_cnt_driver); > -- > 2.7.4 > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel