Add the "min_hw_margin_ms" parameter to gpio_wdt devices, allowing a
minimum interval to be specified, stopping watchdog devices from being
fed too quickly if they require a certain interval between feeds.
Signed-off-by: Isaac True <isaac.true@xxxxxxxxxxxxx>
---
drivers/watchdog/gpio_wdt.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/watchdog/gpio_wdt.c b/drivers/watchdog/gpio_wdt.c
index 0923201ce874..309f66536a14 100644
--- a/drivers/watchdog/gpio_wdt.c
+++ b/drivers/watchdog/gpio_wdt.c
@@ -110,6 +110,7 @@ static int gpio_wdt_probe(struct platform_device *pdev)
struct gpio_wdt_priv *priv;
enum gpiod_flags gflags;
unsigned int hw_margin;
+ unsigned int min_hw_margin;
const char *algo;
int ret;
@@ -144,6 +145,16 @@ static int gpio_wdt_probe(struct platform_device *pdev)
if (hw_margin < 2 || hw_margin > 65535)
return -EINVAL;
+ ret = of_property_read_u32(np, "min_hw_margin_ms", &min_hw_margin);
+ if (ret)
+ min_hw_margin = 0;
+
+ if (min_hw_margin > hw_margin) {
+ dev_err(dev,
+ "Minimum interval cannot be greater than the watchdog interval");
+ return -EINVAL;
+ }
+
priv->always_running = of_property_read_bool(np,
"always-running");
@@ -152,6 +163,7 @@ static int gpio_wdt_probe(struct platform_device *pdev)
priv->wdd.info = &gpio_wdt_ident;
priv->wdd.ops = &gpio_wdt_ops;
priv->wdd.min_timeout = SOFT_TIMEOUT_MIN;
+ priv->wdd.min_hw_heartbeat_ms = min_hw_margin;
priv->wdd.max_hw_heartbeat_ms = hw_margin;
priv->wdd.parent = dev;
priv->wdd.timeout = SOFT_TIMEOUT_DEF;
--
2.34.1
