[PATCH 2/2] watchdog: gpio: support reset-from-wdt gpio

[Steffen Trumtrar <s.trumtrar@pengutronix.de>]

Support the new reset-from-wdt-gpios device tree binding.

This gpio connection signals, that the last reset was issued by this
watchdog.

Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
---
 drivers/watchdog/gpio_wdt.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/watchdog/gpio_wdt.c b/drivers/watchdog/gpio_wdt.c
index 3270c15ed1..6a0df75326 100644
--- a/drivers/watchdog/gpio_wdt.c
+++ b/drivers/watchdog/gpio_wdt.c
@@ -8,6 +8,7 @@
 #include <common.h>
 #include <driver.h>
 #include <watchdog.h>
+#include <reset_source.h>
 #include <superio.h>
 #include <linux/gpio/consumer.h>
 
@@ -18,6 +19,7 @@ enum {
 
 struct gpio_wdt_priv {
 	struct gpio_desc *gpiod;
+	struct gpio_desc *wdt_reset;
 	bool		state;
 	bool		always_running;
 	bool		started;
@@ -122,6 +124,20 @@ static int gpio_wdt_probe(struct device *dev)
 	if (IS_ERR(priv->gpiod))
 		return PTR_ERR(priv->gpiod);
 
+	priv->wdt_reset = gpiod_get_optional(dev, "reset-from-wdt", GPIOD_IN);
+	if (IS_ERR(priv->wdt_reset))
+		return dev_errp_probe(dev, priv->wdt_reset, "no reset-from-wdt found");
+
+	if (priv->wdt_reset) {
+		int val = gpiod_get_value(priv->wdt_reset);
+
+		if (val < 0)
+			return val;
+
+		if (val)
+			reset_source_set_device(dev, RESET_WDG, 200);
+	}
+
 	priv->always_running = of_property_read_bool(dev->of_node, "always-running");
 
 	priv->wdd.hwdev		= dev;

-- 
2.52.0