[PATCH 0/2] watchdog: gpio-wdt: add support for more dt-bindings

[PATCH 0/2] watchdog: gpio-wdt: add support for more dt-bindings

[Steffen Trumtrar]

Update the gpio-wdt with support for more upstream devicetree bindings:

    - always-running
    - reset-from-wdt-gpios

always-running is already upstream, reset-from-gpios will be in v7.4.

Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
---
Steffen Trumtrar (2):
      watchdog: gpio: support always-running
      watchdog: gpio: support reset-from-wdt gpio

 drivers/watchdog/gpio_wdt.c | 28 +++++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)
---
base-commit: 5c46c205c8d1a7c57b9dbaa5e516758a6c0a4d80
change-id: 20261030-v2026-10-0-topic-gpio-wdt-70bda699af5e

Best regards,
--  
Steffen Trumtrar <s.trumtrar@pengutronix.de>

[PATCH 1/2] watchdog: gpio: support always-running

[Steffen Trumtrar]

The devicetree binding describes an always-running property for gpio
watchdogs that cannot be disabled. Add support for this property to the
driver.

Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
---
 drivers/watchdog/gpio_wdt.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/watchdog/gpio_wdt.c b/drivers/watchdog/gpio_wdt.c
index 5fa98f87c6b..3270c15ed16 100644
--- a/drivers/watchdog/gpio_wdt.c
+++ b/drivers/watchdog/gpio_wdt.c
@@ -19,6 +19,7 @@ enum {
 struct gpio_wdt_priv {
 	struct gpio_desc *gpiod;
 	bool		state;
+	bool		always_running;
 	bool		started;
 	unsigned int	hw_algo;
 	struct watchdog	wdd;
@@ -63,13 +64,17 @@ static void gpio_wdt_start(struct gpio_wdt_priv *priv)
 	priv->state = false;
 	gpiod_direction_output(priv->gpiod, priv->state);
 	priv->started = true;
+
+	priv->wdd.running = WDOG_HW_RUNNING;
 }
 
 static int gpio_wdt_set_timeout(struct watchdog *wdd, unsigned int new_timeout)
 {
 	struct gpio_wdt_priv *priv = to_gpio_wdt_priv(wdd);
 
-	if (!new_timeout) {
+	if (!new_timeout && priv->always_running) {
+		return -ENOSYS;
+	} else if (!new_timeout) {
 		gpio_wdt_disable(priv);
 		return 0;
 	}
@@ -117,11 +122,16 @@ static int gpio_wdt_probe(struct device *dev)
 	if (IS_ERR(priv->gpiod))
 		return PTR_ERR(priv->gpiod);
 
+	priv->always_running = of_property_read_bool(dev->of_node, "always-running");
+
 	priv->wdd.hwdev		= dev;
 	priv->wdd.timeout_max	= hw_margin / 1000;
 	priv->wdd.priority	= 129;
 	priv->wdd.set_timeout	= gpio_wdt_set_timeout;
 
+	if (priv->always_running)
+		gpio_wdt_start(priv);
+
 	return watchdog_register(&priv->wdd);
 }
 

-- 
2.52.0

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

[Steffen Trumtrar]

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