From patchwork Mon Dec 17 15:10:06 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Marek_Beh=C3=BAn?= X-Patchwork-Id: 1014575 X-Patchwork-Delegate: sr@denx.de Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=lists.denx.de (client-ip=81.169.180.215; helo=lists.denx.de; envelope-from=u-boot-bounces@lists.denx.de; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=nic.cz Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; secure) header.d=nic.cz header.i=@nic.cz header.b="cejfuYDR"; dkim-atps=neutral Received: from lists.denx.de (dione.denx.de [81.169.180.215]) by ozlabs.org (Postfix) with ESMTP id 43JPqf0bTsz9sBh for ; Tue, 18 Dec 2018 02:15:57 +1100 (AEDT) Received: by lists.denx.de (Postfix, from userid 105) id 586B1C2217A; Mon, 17 Dec 2018 15:12:33 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on lists.denx.de X-Spam-Level: X-Spam-Status: No, score=0.0 required=5.0 tests=T_DKIM_INVALID autolearn=unavailable autolearn_force=no version=3.4.0 Received: from lists.denx.de (localhost [IPv6:::1]) by lists.denx.de (Postfix) with ESMTP id A965DC2218C; Mon, 17 Dec 2018 15:10:24 +0000 (UTC) Received: by lists.denx.de (Postfix, from userid 105) id 602BFC2206E; Mon, 17 Dec 2018 15:10:16 +0000 (UTC) Received: from mail.nic.cz (mail.nic.cz [217.31.204.67]) by lists.denx.de (Postfix) with ESMTPS id 27AA4C2206E for ; Mon, 17 Dec 2018 15:10:16 +0000 (UTC) Received: from dellmb.labs.office.nic.cz (unknown [IPv6:2001:1488:fffe:6:cac7:3539:7f1f:463]) by mail.nic.cz (Postfix) with ESMTP id C197D63149; Mon, 17 Dec 2018 16:10:15 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=nic.cz; s=default; t=1545059415; bh=2WOdgLjApnk7k/SJ56Tmi62WEUEu/dFKHUcJiAe9rdk=; h=From:To:Date; b=cejfuYDRXHytqKzWZGz+SHWZzAf+AjqpaqzpFekGCHKQNuXWQLiMSOueUrVsoOjy/ Iz3CpTtq36bmHAcEUDOoRtXCo5NG6b+RhuYh69b4dBRf6iZfRQx/WRHPLtq/87wmM4 oEr0dSWn45IOZtlRZPJHzqyruQjSrNzCuGBCwPK4= From: =?utf-8?q?Marek_Beh=C3=BAn?= To: u-boot@lists.denx.de Date: Mon, 17 Dec 2018 16:10:06 +0100 Message-Id: <20181217151010.24024-7-marek.behun@nic.cz> X-Mailer: git-send-email 2.18.1 In-Reply-To: <20181217151010.24024-1-marek.behun@nic.cz> References: <20181217151010.24024-1-marek.behun@nic.cz> MIME-Version: 1.0 X-Virus-Scanned: clamav-milter 0.99.2 at mail X-Virus-Status: Clean Cc: Stefan Roese Subject: [U-Boot] [PATCH v4 06/10] watchdog: armada_37xx: Fix compliance with kernel's driver X-BeenThere: u-boot@lists.denx.de X-Mailman-Version: 2.1.18 Precedence: list List-Id: U-Boot discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: u-boot-bounces@lists.denx.de Sender: "U-Boot" The Armada 37xx watchdog driver was recently accepted for mainline kernel by watchdog subsystem maintainer, but the driver works a little different than the one in U-Boot. This patch fixes this. In the previous implementation there was a tiny period of time when the watchdog was disabled and the system was vulnerables - this was during pinging, which was done by disabling, setting, and enabling the counter. Now pinging is done without disabling the watchdog. We use 2 counters: Counter 1 is the watchdog counter - on expiry, the system is reset. Counter 0 is used to reset Counter 1 to start counting from the set timeout again. So Counter 1 is set to be reset on Counter 0 expiry event event and pinging is done by forcing an immediate expiry event on Counter 0. Signed-off-by: Marek Behún --- drivers/watchdog/armada-37xx-wdt.c | 109 ++++++++++++++++++----------- 1 file changed, 67 insertions(+), 42 deletions(-) diff --git a/drivers/watchdog/armada-37xx-wdt.c b/drivers/watchdog/armada-37xx-wdt.c index 0fa4fda4fc..91cd8a6e6a 100644 --- a/drivers/watchdog/armada-37xx-wdt.c +++ b/drivers/watchdog/armada-37xx-wdt.c @@ -22,42 +22,63 @@ struct a37xx_wdt { }; /* - * We use Counter 1 for watchdog timer, because so does Marvell's Linux by - * default. + * We use Counter 1 as watchdog timer, and Counter 0 for re-triggering Counter 1 */ -#define CNTR_CTRL 0x10 +#define CNTR_CTRL(id) ((id) * 0x10) #define CNTR_CTRL_ENABLE 0x0001 #define CNTR_CTRL_ACTIVE 0x0002 #define CNTR_CTRL_MODE_MASK 0x000c #define CNTR_CTRL_MODE_ONESHOT 0x0000 +#define CNTR_CTRL_MODE_HWSIG 0x000c +#define CNTR_CTRL_TRIG_SRC_MASK 0x00f0 +#define CNTR_CTRL_TRIG_SRC_PREV_CNTR 0x0050 #define CNTR_CTRL_PRESCALE_MASK 0xff00 #define CNTR_CTRL_PRESCALE_MIN 2 #define CNTR_CTRL_PRESCALE_SHIFT 8 -#define CNTR_COUNT_LOW 0x14 -#define CNTR_COUNT_HIGH 0x18 +#define CNTR_COUNT_LOW(id) (CNTR_CTRL(id) + 0x4) +#define CNTR_COUNT_HIGH(id) (CNTR_CTRL(id) + 0x8) -static void set_counter_value(struct a37xx_wdt *priv) +static void set_counter_value(struct a37xx_wdt *priv, int id, u64 val) { - writel(priv->timeout & 0xffffffff, priv->reg + CNTR_COUNT_LOW); - writel(priv->timeout >> 32, priv->reg + CNTR_COUNT_HIGH); + writel(val & 0xffffffff, priv->reg + CNTR_COUNT_LOW(id)); + writel(val >> 32, priv->reg + CNTR_COUNT_HIGH(id)); } -static void a37xx_wdt_enable(struct a37xx_wdt *priv) +static void counter_enable(struct a37xx_wdt *priv, int id) { - u32 reg = readl(priv->reg + CNTR_CTRL); + setbits_le32(priv->reg + CNTR_CTRL(id), CNTR_CTRL_ENABLE); +} - reg |= CNTR_CTRL_ENABLE; - writel(reg, priv->reg + CNTR_CTRL); +static void counter_disable(struct a37xx_wdt *priv, int id) +{ + clrbits_le32(priv->reg + CNTR_CTRL(id), CNTR_CTRL_ENABLE); } -static void a37xx_wdt_disable(struct a37xx_wdt *priv) +static int init_counter(struct a37xx_wdt *priv, int id, u32 mode, u32 trig_src) { - u32 reg = readl(priv->reg + CNTR_CTRL); + u32 reg; + + reg = readl(priv->reg + CNTR_CTRL(id)); + if (reg & CNTR_CTRL_ACTIVE) + return -EBUSY; + + reg &= ~(CNTR_CTRL_MODE_MASK | CNTR_CTRL_PRESCALE_MASK | + CNTR_CTRL_TRIG_SRC_MASK); + + /* set mode */ + reg |= mode; + + /* set prescaler to the min value */ + reg |= CNTR_CTRL_PRESCALE_MIN << CNTR_CTRL_PRESCALE_SHIFT; + + /* set trigger source */ + reg |= trig_src; - reg &= ~CNTR_CTRL_ENABLE; - writel(reg, priv->reg + CNTR_CTRL); + writel(reg, priv->reg + CNTR_CTRL(id)); + + return 0; } static int a37xx_wdt_reset(struct udevice *dev) @@ -67,9 +88,9 @@ static int a37xx_wdt_reset(struct udevice *dev) if (!priv->timeout) return -EINVAL; - a37xx_wdt_disable(priv); - set_counter_value(priv); - a37xx_wdt_enable(priv); + /* counter 1 is retriggered by forcing end count on counter 0 */ + counter_disable(priv, 0); + counter_enable(priv, 0); return 0; } @@ -78,10 +99,14 @@ static int a37xx_wdt_expire_now(struct udevice *dev, ulong flags) { struct a37xx_wdt *priv = dev_get_priv(dev); - a37xx_wdt_disable(priv); - priv->timeout = 0; - set_counter_value(priv); - a37xx_wdt_enable(priv); + /* first we set timeout to 0 */ + counter_disable(priv, 1); + set_counter_value(priv, 1, 0); + counter_enable(priv, 1); + + /* and then we start counter 1 by forcing end count on counter 0 */ + counter_disable(priv, 0); + counter_enable(priv, 0); return 0; } @@ -89,26 +114,25 @@ static int a37xx_wdt_expire_now(struct udevice *dev, ulong flags) static int a37xx_wdt_start(struct udevice *dev, u64 ms, ulong flags) { struct a37xx_wdt *priv = dev_get_priv(dev); - u32 reg; - - reg = readl(priv->reg + CNTR_CTRL); - - if (reg & CNTR_CTRL_ACTIVE) - return -EBUSY; + int err; - /* set mode */ - reg = (reg & ~CNTR_CTRL_MODE_MASK) | CNTR_CTRL_MODE_ONESHOT; + err = init_counter(priv, 0, CNTR_CTRL_MODE_ONESHOT, 0); + if (err < 0) + return err; - /* set prescaler to the min value */ - reg &= ~CNTR_CTRL_PRESCALE_MASK; - reg |= CNTR_CTRL_PRESCALE_MIN << CNTR_CTRL_PRESCALE_SHIFT; + err = init_counter(priv, 1, CNTR_CTRL_MODE_HWSIG, + CNTR_CTRL_TRIG_SRC_PREV_CNTR); + if (err < 0) + return err; priv->timeout = ms * priv->clk_rate / 1000 / CNTR_CTRL_PRESCALE_MIN; - writel(reg, priv->reg + CNTR_CTRL); + set_counter_value(priv, 0, 0); + set_counter_value(priv, 1, priv->timeout); + counter_enable(priv, 1); - set_counter_value(priv); - a37xx_wdt_enable(priv); + /* we have to force end count on counter 0 to start counter 1 */ + counter_enable(priv, 0); return 0; } @@ -117,7 +141,9 @@ static int a37xx_wdt_stop(struct udevice *dev) { struct a37xx_wdt *priv = dev_get_priv(dev); - a37xx_wdt_disable(priv); + counter_disable(priv, 1); + counter_disable(priv, 0); + writel(0, priv->sel_reg); return 0; } @@ -139,11 +165,10 @@ static int a37xx_wdt_probe(struct udevice *dev) priv->clk_rate = (ulong)get_ref_clk() * 1000000; - a37xx_wdt_disable(priv); - /* - * We use timer 1 as watchdog timer (because Marvell's Linux uses that - * timer as default), therefore we only set bit TIMER1_IS_WCHDOG_TIMER. + * We use counter 1 as watchdog timer, therefore we only set bit + * TIMER1_IS_WCHDOG_TIMER. Counter 0 is only used to force re-trigger on + * counter 1. */ writel(1 << 1, priv->sel_reg);