> Yes, that works as well. Note that it will actually print something like
> "watchdog: <device>: ..." due to the pr_fmt() at the top of watchdog_core.c.
> I guess that should be ok.

I have the following diff applied on top of patch 2. Works with and
without a parent device. I am not super happy casting 'identity' but
since its u8-type is exported to userspace, I think we can't avoid it.
Guenter, is this cast safe? Here is the diff:

diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c
index cd3ca6b366ef..62be9e52a4de 100644
--- a/drivers/watchdog/watchdog_core.c
+++ b/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;
 
@@ -126,8 +128,8 @@ int watchdog_init_timeout(struct watchdog_device *wdd,
 			wdd->timeout = timeout_parm;
 			return 0;
 		}
-		dev_err(dev, "driver supplied timeout (%u) out of range\n",
-			timeout_parm);
+		pr_err("%s: driver supplied timeout (%u) out of range\n",
+			dev_str, timeout_parm);
 		ret = -EINVAL;
 	}
 
@@ -138,12 +140,13 @@ int watchdog_init_timeout(struct watchdog_device *wdd,
 			wdd->timeout = t;
 			return 0;
 		}
-		dev_err(dev, "DT supplied timeout (%u) out of range\n", t);
+		pr_err("%s: DT supplied timeout (%u) out of range\n", dev_str, t);
 		ret = -EINVAL;
 	}
 
 	if (ret < 0 && wdd->timeout)
-		dev_warn(dev, "falling back to default timeout (%u)\n", wdd->timeout);
+		pr_warn("%s: falling back to default timeout (%u)\n", dev_str,
+			wdd->timeout);
 
 	return ret;
 }