Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755327AbbKXWQG (ORCPT ); Tue, 24 Nov 2015 17:16:06 -0500 Received: from proxima.lp0.eu ([81.2.80.65]:54473 "EHLO proxima.lp0.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754006AbbKXWQD (ORCPT ); Tue, 24 Nov 2015 17:16:03 -0500 Message-ID: In-Reply-To: <5651CC90.7090402@simon.arlott.org.uk> References: <5650BFD6.5030700@simon.arlott.org.uk> <5650C08C.6090300@simon.arlott.org.uk> <5650E2FA.6090408@roeck-us.net> <5650E5BB.6020404@simon.arlott.org.uk> <56512937.6030903@roeck-us.net> <5651CB13.4090704@simon.arlott.org.uk> <5651CC90.7090402@simon.arlott.org.uk> Date: Tue, 24 Nov 2015 22:15:59 -0000 Subject: [PATCH (v2) 7/10] watchdog: bcm63xx_wdt: Add get_timeleft function From: "Simon Arlott" To: linux-watchdog@vger.kernel.org Cc: "Guenter Roeck" , "devicetree@vger.kernel.org" , "Ralf Baechle" , "Thomas Gleixner" , "Jason Cooper" , "Marc Zyngier" , "Kevin Cernekee" , "Florian Fainelli" , "Wim Van Sebroeck" , "Maxime Bizon" , "Linux Kernel Mailing List" , linux-mips@linux-mips.org, "Rob Herring" , "Pawel Moll" , "Mark Rutland" , "Ian Campbell" , "Kumar Gala" , "Jonas Gorski" User-Agent: SquirrelMail/1.4.22 MIME-Version: 1.0 Content-Type: text/plain;charset=utf-8 Content-Transfer-Encoding: 8bit X-Priority: 3 (Normal) Importance: Normal Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3617 Lines: 114 Return the remaining time from the hardware control register. Warn when the device is registered if the hardware watchdog is currently running and report the remaining time left. Signed-off-by: Simon Arlott --- Changed "if (timeleft > 0)" to "if (hw->running)" when checking if a warning should be printed, in case the time left is truncated down to 0 seconds. drivers/watchdog/bcm63xx_wdt.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/drivers/watchdog/bcm63xx_wdt.c b/drivers/watchdog/bcm63xx_wdt.c index 3c7667a..9d099e0 100644 --- a/drivers/watchdog/bcm63xx_wdt.c +++ b/drivers/watchdog/bcm63xx_wdt.c @@ -14,6 +14,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include +#include #include #include #include @@ -75,6 +76,19 @@ static int bcm63xx_wdt_stop(struct watchdog_device *wdd) return 0; } +static unsigned int bcm63xx_wdt_get_timeleft(struct watchdog_device *wdd) +{ + struct bcm63xx_wdt_hw *hw = watchdog_get_drvdata(wdd); + unsigned long flags; + u32 val; + + raw_spin_lock_irqsave(&hw->lock, flags); + val = __raw_readl(hw->regs + WDT_CTL_REG); + val /= hw->clock_hz; + raw_spin_unlock_irqrestore(&hw->lock, flags); + return val; +} + static int bcm63xx_wdt_set_timeout(struct watchdog_device *wdd, unsigned int timeout) { @@ -130,6 +144,7 @@ static struct watchdog_ops bcm63xx_wdt_ops = { .owner = THIS_MODULE, .start = bcm63xx_wdt_start, .stop = bcm63xx_wdt_stop, + .get_timeleft = bcm63xx_wdt_get_timeleft, .set_timeout = bcm63xx_wdt_set_timeout, }; @@ -144,6 +159,8 @@ static int bcm63xx_wdt_probe(struct platform_device *pdev) struct bcm63xx_wdt_hw *hw; struct watchdog_device *wdd; struct resource *r; + u32 timeleft1, timeleft2; + unsigned int timeleft; int ret; hw = devm_kzalloc(&pdev->dev, sizeof(*hw), GFP_KERNEL); @@ -197,6 +214,23 @@ static int bcm63xx_wdt_probe(struct platform_device *pdev) watchdog_init_timeout(wdd, 0, &pdev->dev); watchdog_set_nowayout(wdd, nowayout); + /* Compare two reads of the time left value, 2 clock ticks apart */ + rmb(); + timeleft1 = __raw_readl(hw->regs + WDT_CTL_REG); + udelay(DIV_ROUND_UP(1000000, hw->clock_hz / 2)); + /* Ensure the register is read twice */ + rmb(); + timeleft2 = __raw_readl(hw->regs + WDT_CTL_REG); + + /* If the time left is changing, the watchdog is running */ + if (timeleft1 != timeleft2) { + hw->running = true; + timeleft = bcm63xx_wdt_get_timeleft(wdd); + } else { + hw->running = false; + timeleft = 0; + } + ret = bcm63xx_timer_register(TIMER_WDT_ID, bcm63xx_wdt_isr, wdd); if (ret < 0) { dev_err(&pdev->dev, "failed to register wdt timer isr\n"); @@ -214,6 +248,8 @@ static int bcm63xx_wdt_probe(struct platform_device *pdev) dev_name(wdd->dev), hw->regs, wdd->timeout, wdd->max_timeout); + if (hw->running) + dev_alert(wdd->dev, "running, reboot in %us\n", timeleft); return 0; unregister_timer: @@ -255,6 +291,7 @@ module_platform_driver(bcm63xx_wdt_driver); MODULE_AUTHOR("Miguel Gaio "); MODULE_AUTHOR("Florian Fainelli "); +MODULE_AUTHOR("Simon Arlott"); MODULE_DESCRIPTION("Driver for the Broadcom BCM63xx SoC watchdog"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:bcm63xx-wdt"); -- 2.1.4 -- Simon Arlott -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/