Warn when the device is registered if the hardware watchdog is currently
running and report the remaining time left.

Signed-off-by: Simon Arlott <si...@fire.lp0.eu>
---
 drivers/watchdog/bcm63xx_wdt.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/watchdog/bcm63xx_wdt.c b/drivers/watchdog/bcm63xx_wdt.c
index ab4a794..2312dc2 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 <linux/clk.h>
+#include <linux/delay.h>
 #include <linux/errno.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
@@ -159,6 +160,8 @@ 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);
@@ -199,7 +202,6 @@ static int bcm63xx_wdt_probe(struct platform_device *pdev)
        }
 
        raw_spin_lock_init(&hw->lock);
-       hw->running = false;
 
        wdd->parent = &pdev->dev;
        wdd->ops = &bcm63xx_wdt_ops;
@@ -213,6 +215,23 @@ 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 = watchdog_register_device(wdd);
        if (ret < 0) {
                dev_err(&pdev->dev, "failed to register watchdog device\n");
@@ -230,6 +249,8 @@ 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_watchdog:
-- 
2.1.4


-- 
Simon Arlott
--
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