watchdog: add error messages when initializing timeout fails

This not only removes boilerplate code from watchdog drivers, it can
also be more specific which of the supplied value actually fails. Also,
the loglevel becomes now consistent across drivers.
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

drivers/watchdog/watchdog_core.c

@@ -115,6 +115,8 @@ static void watchdog_check_min_max_timeout(struct watchdog_device *wdd)
 int watchdog_init_timeout(struct watchdog_device *wdd,
 				unsigned int timeout_parm, struct device *dev)
 {
+	const char *dev_str = wdd->parent ? dev_name(wdd->parent) :
+			      (const char *)wdd->info->identity;
 	unsigned int t = 0;
 	int ret = 0;
 
@@ -126,6 +128,8 @@ int watchdog_init_timeout(struct watchdog_device *wdd,
 			wdd->timeout = timeout_parm;
 			return 0;
 		}
+		pr_err("%s: driver supplied timeout (%u) out of range\n",
+			dev_str, timeout_parm);
 		ret = -EINVAL;
 	}
 
@@ -136,9 +140,14 @@ int watchdog_init_timeout(struct watchdog_device *wdd,
 			wdd->timeout = t;
 			return 0;
 		}
+		pr_err("%s: DT supplied timeout (%u) out of range\n", dev_str, t);
 		ret = -EINVAL;
 	}
 
+	if (ret < 0 && wdd->timeout)
+		pr_warn("%s: falling back to default timeout (%u)\n", dev_str,
+			wdd->timeout);
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(watchdog_init_timeout);