[PATCH v2 2/3] watchdog: da9063: Make use of pre-configured timeout during probe

From: Stefan Riedmueller
Date: Fri Apr 03 2020 - 09:07:34 EST


The watchdog might already be running during boot with a timeout set by
e.g. the bootloader. Make use of this pre-configured timeout instead of
falling back to the default timeout if no device tree value is given.

Signed-off-by: Stefan Riedmueller <s.riedmueller@xxxxxxxxx>
---
Changes in v2:
- Reworked patch to use the pre-configured timeout onyl as a fallback
instead of the default value.
- Removed info message.
---
drivers/watchdog/da9063_wdt.c | 20 ++++++++++++++------
1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/watchdog/da9063_wdt.c b/drivers/watchdog/da9063_wdt.c
index 3d65e92a4e3f..423584252606 100644
--- a/drivers/watchdog/da9063_wdt.c
+++ b/drivers/watchdog/da9063_wdt.c
@@ -46,15 +46,16 @@ static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs)
}

/*
- * Return 0 if watchdog is disabled, else non zero.
+ * Read the currently active timeout.
+ * Zero means the watchdog is disabled.
*/
-static unsigned int da9063_wdt_is_running(struct da9063 *da9063)
+static unsigned int da9063_wdt_read_timeout(struct da9063 *da9063)
{
unsigned int val;

regmap_read(da9063->regmap, DA9063_REG_CONTROL_D, &val);

- return val & DA9063_TWDSCALE_MASK;
+ return wdt_timeout[val & DA9063_TWDSCALE_MASK];
}

static int da9063_wdt_disable_timer(struct da9063 *da9063)
@@ -191,6 +192,7 @@ static int da9063_wdt_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev;
struct da9063 *da9063;
struct watchdog_device *wdd;
+ unsigned int timeout;

if (!dev->parent)
return -EINVAL;
@@ -214,13 +216,19 @@ static int da9063_wdt_probe(struct platform_device *pdev)
watchdog_set_restart_priority(wdd, 128);
watchdog_set_drvdata(wdd, da9063);

- /* Set default timeout, maybe override it with DT value, scale it */
wdd->timeout = DA9063_WDG_TIMEOUT;
+
+ /* Use pre-configured timeout if watchdog is already running. */
+ timeout = da9063_wdt_read_timeout(da9063);
+ if (timeout)
+ wdd->timeout = timeout;
+
+ /* Set timeout, maybe override it with DT value, scale it */
watchdog_init_timeout(wdd, 0, dev);
da9063_wdt_set_timeout(wdd, wdd->timeout);

- /* Change the timeout to the default value if the watchdog is running */
- if (da9063_wdt_is_running(da9063)) {
+ /* Update timeout if the watchdog is already running. */
+ if (timeout) {
da9063_wdt_update_timeout(da9063, wdd->timeout);
set_bit(WDOG_HW_RUNNING, &wdd->status);
}
--
2.23.0