[PATCH 5.10 04/20] rtc: pcf2127: only use watchdog when explicitly available

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

commit 71ac13457d9d1007effde65b54818106b2c2b525 upstream.

Most boards using the pcf2127 chip (in my bubble) don't make use of the
watchdog functionality and the respective output is not connected. The
effect on such a board is that there is a watchdog device provided that
doesn't work.

So only register the watchdog if the device tree has a "reset-source"
property.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
[RV: s/has-watchdog/reset-source/]
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201218101054.25416-3-rasmus.villemoes@prevas.dk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/rtc/rtc-pcf2127.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/rtc/rtc-pcf2127.c
+++ b/drivers/rtc/rtc-pcf2127.c
@@ -336,7 +336,8 @@ static int pcf2127_watchdog_init(struct
 	u32 wdd_timeout;
 	int ret;
 
-	if (!IS_ENABLED(CONFIG_WATCHDOG))
+	if (!IS_ENABLED(CONFIG_WATCHDOG) ||
+	    !device_property_read_bool(dev, "reset-source"))
 		return 0;
 
 	pcf2127->wdd.parent = dev;