watchdog: sama5d4: readout initial state

Readout the AT91_WDT_MR bit at probe so that it becomes possible to get the
pre-userspace handler working.

Signed-off-by: Mathieu Othacehe <othacehe@gnu.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230819084726.11037-1-othacehe@gnu.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

Author: Mathieu Othacehe

drivers/watchdog/sama5d4_wdt.c

@@ -254,6 +254,7 @@ static int sama5d4_wdt_probe(struct platform_device *pdev)
 	struct sama5d4_wdt *wdt;
 	void __iomem *regs;
 	u32 irq = 0;
+	u32 reg;
 	int ret;
 
 	wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
@@ -304,6 +305,12 @@ static int sama5d4_wdt_probe(struct platform_device *pdev)
 
 	watchdog_init_timeout(wdd, wdt_timeout, dev);
 
+	reg = wdt_read(wdt, AT91_WDT_MR);
+	if (!(reg & AT91_WDT_WDDIS)) {
+		wdt->mr &= ~AT91_WDT_WDDIS;
+		set_bit(WDOG_HW_RUNNING, &wdd->status);
+	}
+
 	ret = sama5d4_wdt_init(wdt);
 	if (ret)
 		return ret;