From patchwork Thu Jul 30 02:03:10 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anson Huang X-Patchwork-Id: 11692197 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 964D1138A for ; Thu, 30 Jul 2020 02:09:10 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 6FB3C2075D for ; Thu, 30 Jul 2020 02:09:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="cUSnzgr+" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6FB3C2075D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=nxp.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:MIME-Version:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:In-Reply-To:References:List-Owner; bh=xAoqvxKnO2YROLgFwg7L25/RO9F6GF8y+5S3iDT38xE=; b=cUSnzgr+WWmPGbnGZCyxxwTvhn G6Ka3NW6qzwaTLL7vAS5ORDg2f8Ws6fZg5XXr5VNYi2WW15Ujdc7gDa5PRS8qJQrApRowSiuifP2N 3gtgewTPYzhsic07euZAzHpaFs70XAvbPN86UPA46PHTNwZkI6g8RlqzB5omFUdLvRWhh55bfujQk lbSx9N/ByHVX4ZHPdK/LTyB2FcwqFMJw19hdhRs3VL68bGH78p7Znd8PjbrVpuw3BG+zbNxvWgRWq oXF097b9BVlTs+55Q+qDNAKfpj3M/KcyMNCSNcxiufxjUTagVfT9zqssEjsmoFhBSY8CfBkP9/XGQ 1FSdORPw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k0xyn-0008KL-US; Thu, 30 Jul 2020 02:07:33 +0000 Received: from inva021.nxp.com ([92.121.34.21]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1k0xyl-0008Jh-Vu for linux-arm-kernel@lists.infradead.org; Thu, 30 Jul 2020 02:07:33 +0000 Received: from inva021.nxp.com (localhost [127.0.0.1]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id 1AB8320114A; Thu, 30 Jul 2020 04:07:31 +0200 (CEST) Received: from invc005.ap-rdc01.nxp.com (invc005.ap-rdc01.nxp.com [165.114.16.14]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id CEFA6201144; Thu, 30 Jul 2020 04:07:26 +0200 (CEST) Received: from localhost.localdomain (shlinux2.ap.freescale.net [10.192.224.44]) by invc005.ap-rdc01.nxp.com (Postfix) with ESMTP id 78DA040302; Thu, 30 Jul 2020 04:07:21 +0200 (CEST) From: Anson Huang To: wim@linux-watchdog.org, linux@roeck-us.net, shawnguo@kernel.org, s.hauer@pengutronix.de, kernel@pengutronix.de, festevam@gmail.com, linux-watchdog@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH V3 1/2] watchdog: imx7ulp: Strictly follow the sequence for wdog operations Date: Thu, 30 Jul 2020 10:03:10 +0800 Message-Id: <1596074591-4207-1-git-send-email-Anson.Huang@nxp.com> X-Mailer: git-send-email 2.7.4 X-Virus-Scanned: ClamAV using ClamSMTP X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200729_220732_240424_A1B61CC6 X-CRM114-Status: GOOD ( 19.39 ) X-Spam-Score: -2.3 (--) X-Spam-Report: SpamAssassin version 3.4.4 on merlin.infradead.org summary: Content analysis details: (-2.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [92.121.34.21 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record 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: Linux-imx@nxp.com MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org According to reference manual, the i.MX7ULP WDOG's operations except refresh should follow below sequence: 1. disable global interrupts; 2. unlock the wdog and wait unlock bit set; 3. reconfigure the wdog and wait for reconfiguration bit set; 4. enabel global interrupts. Strictly follow the recommended sequence can make it more robust. Signed-off-by: Anson Huang --- changes since V2: - change the wait timeout to 20us according to experiment; - drop WARN_ON when timeout, and check its return value in each caller for unlock wait, no need to handle the return value for reconfiguration. --- drivers/watchdog/imx7ulp_wdt.c | 74 ++++++++++++++++++++++++++++++++++-------- 1 file changed, 61 insertions(+), 13 deletions(-) diff --git a/drivers/watchdog/imx7ulp_wdt.c b/drivers/watchdog/imx7ulp_wdt.c index 7993c8c..010ddd1 100644 --- a/drivers/watchdog/imx7ulp_wdt.c +++ b/drivers/watchdog/imx7ulp_wdt.c @@ -5,6 +5,7 @@ #include #include +#include #include #include #include @@ -36,6 +37,7 @@ #define DEFAULT_TIMEOUT 60 #define MAX_TIMEOUT 128 #define WDOG_CLOCK_RATE 1000 +#define WDOG_WAIT_TIMEOUT 20 static bool nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, bool, 0000); @@ -48,17 +50,40 @@ struct imx7ulp_wdt_device { struct clk *clk; }; -static void imx7ulp_wdt_enable(struct watchdog_device *wdog, bool enable) +static int imx7ulp_wdt_wait(void __iomem *base, u32 mask) +{ + u32 val = readl(base + WDOG_CS); + + if (!(val & mask) && readl_poll_timeout_atomic(base + WDOG_CS, val, + val & mask, 0, + WDOG_WAIT_TIMEOUT)) + return -ETIMEDOUT; + + return 0; +} + +static int imx7ulp_wdt_enable(struct watchdog_device *wdog, bool enable) { struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog); u32 val = readl(wdt->base + WDOG_CS); + int ret; + local_irq_disable(); writel(UNLOCK, wdt->base + WDOG_CNT); + ret = imx7ulp_wdt_wait(wdt->base, WDOG_CS_ULK); + if (ret) + goto enable_out; if (enable) writel(val | WDOG_CS_EN, wdt->base + WDOG_CS); else writel(val & ~WDOG_CS_EN, wdt->base + WDOG_CS); + imx7ulp_wdt_wait(wdt->base, WDOG_CS_RCS); + +enable_out: + local_irq_enable(); + + return ret; } static bool imx7ulp_wdt_is_enabled(void __iomem *base) @@ -79,17 +104,12 @@ static int imx7ulp_wdt_ping(struct watchdog_device *wdog) static int imx7ulp_wdt_start(struct watchdog_device *wdog) { - - imx7ulp_wdt_enable(wdog, true); - - return 0; + return imx7ulp_wdt_enable(wdog, true); } static int imx7ulp_wdt_stop(struct watchdog_device *wdog) { - imx7ulp_wdt_enable(wdog, false); - - return 0; + return imx7ulp_wdt_enable(wdog, false); } static int imx7ulp_wdt_set_timeout(struct watchdog_device *wdog, @@ -97,22 +117,37 @@ static int imx7ulp_wdt_set_timeout(struct watchdog_device *wdog, { struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog); u32 val = WDOG_CLOCK_RATE * timeout; + int ret; + local_irq_disable(); writel(UNLOCK, wdt->base + WDOG_CNT); + ret = imx7ulp_wdt_wait(wdt->base, WDOG_CS_ULK); + if (ret) + goto timeout_out; writel(val, wdt->base + WDOG_TOVAL); + imx7ulp_wdt_wait(wdt->base, WDOG_CS_RCS); + +timeout_out: + local_irq_enable(); wdog->timeout = timeout; - return 0; + return ret; } static int imx7ulp_wdt_restart(struct watchdog_device *wdog, unsigned long action, void *data) { struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog); + int ret; + + ret = imx7ulp_wdt_enable(wdog, true); + if (ret) + return ret; - imx7ulp_wdt_enable(wdog, true); - imx7ulp_wdt_set_timeout(&wdt->wdd, 1); + ret = imx7ulp_wdt_set_timeout(&wdt->wdd, 1); + if (ret) + return ret; /* wait for wdog to fire */ while (true) @@ -136,19 +171,30 @@ static const struct watchdog_info imx7ulp_wdt_info = { WDIOF_MAGICCLOSE, }; -static void imx7ulp_wdt_init(void __iomem *base, unsigned int timeout) +static int imx7ulp_wdt_init(void __iomem *base, unsigned int timeout) { u32 val; + int ret; + local_irq_disable(); /* unlock the wdog for reconfiguration */ writel_relaxed(UNLOCK_SEQ0, base + WDOG_CNT); writel_relaxed(UNLOCK_SEQ1, base + WDOG_CNT); + ret = imx7ulp_wdt_wait(base, WDOG_CS_ULK); + if (ret) + goto init_out; /* set an initial timeout value in TOVAL */ writel(timeout, base + WDOG_TOVAL); /* enable 32bit command sequence and reconfigure */ val = WDOG_CS_CMD32EN | WDOG_CS_CLK | WDOG_CS_UPDATE; writel(val, base + WDOG_CS); + imx7ulp_wdt_wait(base, WDOG_CS_RCS); + +init_out: + local_irq_enable(); + + return ret; } static void imx7ulp_wdt_action(void *data) @@ -199,7 +245,9 @@ static int imx7ulp_wdt_probe(struct platform_device *pdev) watchdog_stop_on_reboot(wdog); watchdog_stop_on_unregister(wdog); watchdog_set_drvdata(wdog, imx7ulp_wdt); - imx7ulp_wdt_init(imx7ulp_wdt->base, wdog->timeout * WDOG_CLOCK_RATE); + ret = imx7ulp_wdt_init(imx7ulp_wdt->base, wdog->timeout * WDOG_CLOCK_RATE); + if (ret) + return ret; return devm_watchdog_register_device(dev, wdog); } From patchwork Thu Jul 30 02:03:11 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anson Huang X-Patchwork-Id: 11692195 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BD9D6138A for ; Thu, 30 Jul 2020 02:09:07 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 974002075D for ; Thu, 30 Jul 2020 02:09:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="DmqATlrf" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 974002075D Authentication-Results: mail.kernel.org; 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Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k0xyv-0008LI-DS; Thu, 30 Jul 2020 02:07:41 +0000 Received: from inva021.nxp.com ([92.121.34.21]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1k0xym-0008Jl-OP for linux-arm-kernel@lists.infradead.org; Thu, 30 Jul 2020 02:07:33 +0000 Received: from inva021.nxp.com (localhost [127.0.0.1]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id F018E201144; Thu, 30 Jul 2020 04:07:31 +0200 (CEST) Received: from invc005.ap-rdc01.nxp.com (invc005.ap-rdc01.nxp.com [165.114.16.14]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id DADA8201145; Thu, 30 Jul 2020 04:07:27 +0200 (CEST) Received: from localhost.localdomain (shlinux2.ap.freescale.net [10.192.224.44]) by invc005.ap-rdc01.nxp.com (Postfix) with ESMTP id 7BECB40310; Thu, 30 Jul 2020 04:07:22 +0200 (CEST) From: Anson Huang To: wim@linux-watchdog.org, linux@roeck-us.net, shawnguo@kernel.org, s.hauer@pengutronix.de, kernel@pengutronix.de, festevam@gmail.com, linux-watchdog@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH V3 2/2] watchdog: imx7ulp: Watchdog should continue running for wait/stop mode Date: Thu, 30 Jul 2020 10:03:11 +0800 Message-Id: <1596074591-4207-2-git-send-email-Anson.Huang@nxp.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1596074591-4207-1-git-send-email-Anson.Huang@nxp.com> References: <1596074591-4207-1-git-send-email-Anson.Huang@nxp.com> X-Virus-Scanned: ClamAV using ClamSMTP X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200729_220732_904920_90B0C71F X-CRM114-Status: GOOD ( 11.54 ) X-Spam-Score: -2.3 (--) X-Spam-Report: SpamAssassin version 3.4.4 on merlin.infradead.org summary: Content analysis details: (-2.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [92.121.34.21 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record 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: Linux-imx@nxp.com MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org When kernel idle, system will enter wait/stop mode, wdog should continue running in this scenario, and the refresh thread can wake up system from wait/stop mode. Signed-off-by: Anson Huang Reviewed-by: Guenter Roeck --- no change. --- drivers/watchdog/imx7ulp_wdt.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/watchdog/imx7ulp_wdt.c b/drivers/watchdog/imx7ulp_wdt.c index 010ddd1..77773b0 100644 --- a/drivers/watchdog/imx7ulp_wdt.c +++ b/drivers/watchdog/imx7ulp_wdt.c @@ -22,6 +22,8 @@ #define WDOG_CS_CLK (LPO_CLK << LPO_CLK_SHIFT) #define WDOG_CS_EN BIT(7) #define WDOG_CS_UPDATE BIT(5) +#define WDOG_CS_WAIT BIT(1) +#define WDOG_CS_STOP BIT(0) #define WDOG_CNT 0x4 #define WDOG_TOVAL 0x8 @@ -187,7 +189,8 @@ static int imx7ulp_wdt_init(void __iomem *base, unsigned int timeout) /* set an initial timeout value in TOVAL */ writel(timeout, base + WDOG_TOVAL); /* enable 32bit command sequence and reconfigure */ - val = WDOG_CS_CMD32EN | WDOG_CS_CLK | WDOG_CS_UPDATE; + val = WDOG_CS_CMD32EN | WDOG_CS_CLK | WDOG_CS_UPDATE | + WDOG_CS_WAIT | WDOG_CS_STOP; writel(val, base + WDOG_CS); imx7ulp_wdt_wait(base, WDOG_CS_RCS);