[PATCH 2/2] watchdog: gpio_wdt: add "start-at-boot" feature

From: Francesco Zanella
Date: Wed Apr 21 2021 - 12:27:40 EST


If "start-at-boot" property is present in the device tree, start pinging
hw watchdog at probe, in order to take advantage of kernel configs:
- WATCHDOG_HANDLE_BOOT_ENABLED: Avoid possible reboot if hw watchdog was
been enabled before the kernel (by uboot for example) and userspace
doesn't take control of /dev/watchdog in time;
- WATCHDOG_OPEN_TIMEOUT: Reboot if userspace doesn't take control of
/dev/watchdog within the timeout.

Signed-off-by: Francesco Zanella <francesco.zanella@xxxxxxxxx>
---
drivers/watchdog/gpio_wdt.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/watchdog/gpio_wdt.c b/drivers/watchdog/gpio_wdt.c
index 0923201ce874..1e6f0322ab7a 100644
--- a/drivers/watchdog/gpio_wdt.c
+++ b/drivers/watchdog/gpio_wdt.c
@@ -31,6 +31,7 @@ struct gpio_wdt_priv {
struct gpio_desc *gpiod;
bool state;
bool always_running;
+ bool start_at_boot;
unsigned int hw_algo;
struct watchdog_device wdd;
};
@@ -147,6 +148,9 @@ static int gpio_wdt_probe(struct platform_device *pdev)
priv->always_running = of_property_read_bool(np,
"always-running");

+ priv->start_at_boot = of_property_read_bool(np,
+ "start-at-boot");
+
watchdog_set_drvdata(&priv->wdd, priv);

priv->wdd.info = &gpio_wdt_ident;
@@ -161,7 +165,7 @@ static int gpio_wdt_probe(struct platform_device *pdev)

watchdog_stop_on_reboot(&priv->wdd);

- if (priv->always_running)
+ if (priv->always_running || priv->start_at_boot)
gpio_wdt_start(&priv->wdd);

return devm_watchdog_register_device(dev, &priv->wdd);
--
2.17.1