From patchwork Thu May 11 00:19:48 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marek Vasut X-Patchwork-Id: 13237388 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 14011C7EE23 for ; Thu, 11 May 2023 00:20:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236812AbjEKAUO (ORCPT ); Wed, 10 May 2023 20:20:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58740 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231924AbjEKAUN (ORCPT ); Wed, 10 May 2023 20:20:13 -0400 Received: from phobos.denx.de (phobos.denx.de [IPv6:2a01:238:438b:c500:173d:9f52:ddab:ee01]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3E8CE5256; Wed, 10 May 2023 17:20:11 -0700 (PDT) Received: from tr.lan (ip-86-49-120-218.bb.vodafone.cz [86.49.120.218]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: marex@denx.de) by phobos.denx.de (Postfix) with ESMTPSA id 27457860B3; Thu, 11 May 2023 02:20:09 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1683764409; bh=JAdKkP1r6AtKqNAK9hod+5izP15YI2QZmix547xQpUU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yVa8Y06IL9yU/rP5YxanY5iA0tYjd9YvBUbwLt9j+zfJmI0vwgmd7gpHtLkarYcgQ 3KkWj/robHwn4FUZe0zys4SDJi5AXR/EcOqkQHxGINhcuCqCCbNKQGU8Y2O+0WyNiD NAJ3lvnOfO+1Tpk0lrtimGTI+2dlWFQbDYEEhaXlfLTerTGt7NzLzr6L+MPTkfbkBR 5MQIYHv87l+DHOObk2UDKECjgLNP5WrZlFvA1DQqWoKnC9Ke2bg0xTCLvGADMsCkm2 vJNxB5qvDXHfbTkaJ0vTkZlRJXzMb9a27vjm/zB27Hwqs9+BbNK8TaXpYN1r9kRAa5 NfQqG/vMXwekg== From: Marek Vasut To: linux-arm-kernel@lists.infradead.org Cc: Marek Vasut , Alexandre Torgue , Guenter Roeck , Krzysztof Kozlowski , Marc Zyngier , Maxime Coquelin , Richard Cochran , Rob Herring , Thomas Gleixner , Wim Van Sebroeck , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-watchdog@vger.kernel.org Subject: [PATCH 2/3] watchdog: stm32_iwdg: Add pretimeout support Date: Thu, 11 May 2023 02:19:48 +0200 Message-Id: <20230511001949.179521-2-marex@denx.de> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230511001949.179521-1-marex@denx.de> References: <20230511001949.179521-1-marex@denx.de> MIME-Version: 1.0 X-Virus-Scanned: clamav-milter 0.103.8 at phobos.denx.de X-Virus-Status: Clean Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org The STM32MP15xx IWDG adds registers which permit this IP to generate pretimeout interrupt. This interrupt can also be used to wake the CPU from suspend. Implement support for generating this interrupt and let userspace configure the pretimeout. In case the pretimeout is not configured by user, set pretimeout to half of the WDT timeout cycle. Signed-off-by: Marek Vasut Reviewed-by: Antonio Borneo --- Cc: Alexandre Torgue Cc: Guenter Roeck Cc: Krzysztof Kozlowski Cc: Marc Zyngier Cc: Maxime Coquelin Cc: Richard Cochran Cc: Rob Herring Cc: Thomas Gleixner Cc: Wim Van Sebroeck Cc: devicetree@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: linux-stm32@st-md-mailman.stormreply.com Cc: linux-watchdog@vger.kernel.org --- drivers/watchdog/stm32_iwdg.c | 93 ++++++++++++++++++++++++++++++++++- 1 file changed, 92 insertions(+), 1 deletion(-) diff --git a/drivers/watchdog/stm32_iwdg.c b/drivers/watchdog/stm32_iwdg.c index 570a71509d2a9..098ce83a3eb88 100644 --- a/drivers/watchdog/stm32_iwdg.c +++ b/drivers/watchdog/stm32_iwdg.c @@ -19,6 +19,7 @@ #include #include #include +#include #include /* IWDG registers */ @@ -27,6 +28,7 @@ #define IWDG_RLR 0x08 /* ReLoad Register */ #define IWDG_SR 0x0C /* Status Register */ #define IWDG_WINR 0x10 /* Windows Register */ +#define IWDG_EWCR 0x14 /* Early Wake-up Register */ /* IWDG_KR register bit mask */ #define KR_KEY_RELOAD 0xAAAA /* reload counter enable */ @@ -46,22 +48,29 @@ #define SR_PVU BIT(0) /* Watchdog prescaler value update */ #define SR_RVU BIT(1) /* Watchdog counter reload value update */ +#define EWCR_EWIT GENMASK(11, 0) /* Watchdog counter window value */ +#define EWCR_EWIC BIT(14) /* Watchdog early interrupt acknowledge */ +#define EWCR_EWIE BIT(15) /* Watchdog early interrupt enable */ + /* set timeout to 100000 us */ #define TIMEOUT_US 100000 #define SLEEP_US 1000 struct stm32_iwdg_data { bool has_pclk; + bool has_early_wakeup; u32 max_prescaler; }; static const struct stm32_iwdg_data stm32_iwdg_data = { .has_pclk = false, + .has_early_wakeup = false, .max_prescaler = 256, }; static const struct stm32_iwdg_data stm32mp1_iwdg_data = { .has_pclk = true, + .has_early_wakeup = true, .max_prescaler = 1024, }; @@ -87,13 +96,17 @@ static inline void reg_write(void __iomem *base, u32 reg, u32 val) static int stm32_iwdg_start(struct watchdog_device *wdd) { struct stm32_iwdg *wdt = watchdog_get_drvdata(wdd); - u32 tout, presc, iwdg_rlr, iwdg_pr, iwdg_sr; + u32 tout, ptot, presc, iwdg_rlr, iwdg_ewcr, iwdg_pr, iwdg_sr; int ret; dev_dbg(wdd->parent, "%s\n", __func__); + if (!wdd->pretimeout) + wdd->pretimeout = wdd->timeout / 2; + tout = clamp_t(unsigned int, wdd->timeout, wdd->min_timeout, wdd->max_hw_heartbeat_ms / 1000); + ptot = clamp_t(unsigned int, wdd->pretimeout, wdd->min_timeout, tout); presc = DIV_ROUND_UP(tout * wdt->rate, RLR_MAX + 1); @@ -101,6 +114,7 @@ static int stm32_iwdg_start(struct watchdog_device *wdd) presc = roundup_pow_of_two(presc); iwdg_pr = presc <= 1 << PR_SHIFT ? 0 : ilog2(presc) - PR_SHIFT; iwdg_rlr = ((tout * wdt->rate) / presc) - 1; + iwdg_ewcr = ((ptot * wdt->rate) / presc) - 1; /* enable write access */ reg_write(wdt->regs, IWDG_KR, KR_KEY_EWA); @@ -108,6 +122,8 @@ static int stm32_iwdg_start(struct watchdog_device *wdd) /* set prescaler & reload registers */ reg_write(wdt->regs, IWDG_PR, iwdg_pr); reg_write(wdt->regs, IWDG_RLR, iwdg_rlr); + if (wdt->data->has_early_wakeup) + reg_write(wdt->regs, IWDG_EWCR, iwdg_ewcr | EWCR_EWIE); reg_write(wdt->regs, IWDG_KR, KR_KEY_ENABLE); /* wait for the registers to be updated (max 100ms) */ @@ -150,6 +166,34 @@ static int stm32_iwdg_set_timeout(struct watchdog_device *wdd, return 0; } +static int stm32_iwdg_set_pretimeout(struct watchdog_device *wdd, + unsigned int pretimeout) +{ + dev_dbg(wdd->parent, "%s pretimeout: %d sec\n", __func__, pretimeout); + + wdd->pretimeout = pretimeout; + + if (watchdog_active(wdd)) + return stm32_iwdg_start(wdd); + + return 0; +} + +static irqreturn_t stm32_iwdg_isr(int irq, void *wdog_arg) +{ + struct watchdog_device *wdd = wdog_arg; + struct stm32_iwdg *wdt = watchdog_get_drvdata(wdd); + u32 reg; + + reg = reg_read(wdt->regs, IWDG_EWCR); + reg |= EWCR_EWIC; + reg_write(wdt->regs, IWDG_EWCR, reg); + + watchdog_notify_pretimeout(wdd); + + return IRQ_HANDLED; +} + static void stm32_clk_disable_unprepare(void *data) { clk_disable_unprepare(data); @@ -206,11 +250,20 @@ static const struct watchdog_info stm32_iwdg_info = { .identity = "STM32 Independent Watchdog", }; +static const struct watchdog_info stm32_iwdg_preinfo = { + .options = WDIOF_SETTIMEOUT | + WDIOF_MAGICCLOSE | + WDIOF_KEEPALIVEPING | + WDIOF_PRETIMEOUT, + .identity = "STM32 Independent Watchdog", +}; + static const struct watchdog_ops stm32_iwdg_ops = { .owner = THIS_MODULE, .start = stm32_iwdg_start, .ping = stm32_iwdg_ping, .set_timeout = stm32_iwdg_set_timeout, + .set_pretimeout = stm32_iwdg_set_pretimeout, }; static const struct of_device_id stm32_iwdg_of_match[] = { @@ -220,6 +273,39 @@ static const struct of_device_id stm32_iwdg_of_match[] = { }; MODULE_DEVICE_TABLE(of, stm32_iwdg_of_match); +static int stm32_iwdg_irq_init(struct platform_device *pdev, + struct stm32_iwdg *wdt) +{ + struct device_node *np = pdev->dev.of_node; + struct watchdog_device *wdd = &wdt->wdd; + struct device *dev = &pdev->dev; + int irq, ret; + + if (!wdt->data->has_early_wakeup) + return 0; + + irq = platform_get_irq(pdev, 0); + if (irq <= 0) + return 0; + + if (of_property_read_bool(np, "wakeup-source")) { + ret = device_init_wakeup(&pdev->dev, true); + if (ret) + return ret; + + ret = dev_pm_set_wake_irq(&pdev->dev, irq); + if (ret) + return ret; + } + + ret = devm_request_irq(dev, irq, stm32_iwdg_isr, 0, + dev_name(dev), wdd); + if (!ret) + wdd->info = &stm32_iwdg_preinfo; + + return ret; +} + static int stm32_iwdg_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -253,6 +339,11 @@ static int stm32_iwdg_probe(struct platform_device *pdev) wdd->max_hw_heartbeat_ms = ((RLR_MAX + 1) * wdt->data->max_prescaler * 1000) / wdt->rate; + /* Initialize IRQ, this might override wdd->info, hence it is here. */ + ret = stm32_iwdg_irq_init(pdev, wdt); + if (ret) + return ret; + watchdog_set_drvdata(wdd, wdt); watchdog_set_nowayout(wdd, WATCHDOG_NOWAYOUT); watchdog_init_timeout(wdd, 0, dev);