watchdog: dw_wdt: Fix default timeout

The Synopsys Watchdog driver sets the default timeout to 30 seconds,
but on some devices this is not a valid timeout. E.g. on RK3588 the
actual timeout being used is 44 seconds instead.

Once the watchdog is started the value is updated accordingly, but
it would be better to expose a sensible timeout to userspace without
the need to first start the watchdog.

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20250717-dw-wdt-fix-initial-timeout-v1-1-86dc864d48dd@kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

drivers/watchdog/dw_wdt.c

@@ -644,6 +644,8 @@ static int dw_wdt_drv_probe(struct platform_device *pdev)
 	} else {
 		wdd->timeout = DW_WDT_DEFAULT_SECONDS;
 		watchdog_init_timeout(wdd, 0, dev);
+		/* Limit timeout value to hardware constraints. */
+		dw_wdt_set_timeout(wdd, wdd->timeout);
 	}
 
 	platform_set_drvdata(pdev, dw_wdt);