The DA9063 watchdog always resets the system when it changes the timeout
value after the bootloader (e.g. Barebox) has it already set.
To update the timeout value we have to disable the watchdog, clear the
watchdog counter value and write the new timeout value to the watchdog.
Clearing the counter value is a feature to be on the safe side, because the
data sheet doesn't describe the behaviour of the watchdog counter value
after a watchdog disabling-enable-sequence.
The patch is based on Philipp Zabel's <p.zabel@xxxxxxxxxxxxxx> previous
patch but doesn't wait 150us because the DA9063 doesn't need this delay.
Fixes: 5e9c16e37608 ("watchdog: Add DA9063 PMIC watchdog driver.")
Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx>
---
drivers/watchdog/da9063_wdt.c | 33 +++++++++++++++++++++++++++++++--
1 file changed, 31 insertions(+), 2 deletions(-)
diff --git a/drivers/watchdog/da9063_wdt.c b/drivers/watchdog/da9063_wdt.c
index b17ac1bb1f28..bca247d44737 100644
--- a/drivers/watchdog/da9063_wdt.c
+++ b/drivers/watchdog/da9063_wdt.c
@@ -45,8 +45,38 @@ static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs)
return DA9063_TWDSCALE_MAX;
}
+/*
+ * Writing a '1' to the self-clearing WATCHDOG bit resets the watchdog counter
+ * value.
+ */
+static int _da9063_wdt_reset_timer(struct da9063 *da9063)
+{
+ return regmap_write(da9063->regmap, DA9063_REG_CONTROL_F,
+ DA9063_WATCHDOG);
+}
+
static int _da9063_wdt_set_timeout(struct da9063 *da9063, unsigned int regval)
{
+ int ret;
+
+ /*
+ * The watchdog trigger a reboot if a timeout value is already
+ * programmed. Because the timeout value combines two functions in
+ * one: indicating the counter limit and starting the watchdog. To be
+ * able to set the watchdog a second time (first time was done by the
+ * bootloader) disable the watchdog clear the counter value manually and
+ * set the new timeout value.
+ */
+ ret = regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
+ DA9063_TWDSCALE_MASK, DA9063_TWDSCALE_DISABLE);
+ if (ret)
+ dev_warn(da9063->dev,
+ "Failed to disable watchdog before setting new timeout\n");
+
+ ret = _da9063_wdt_reset_timer(da9063);
+ if (ret)
+ dev_warn(da9063->dev, "Failed to reset watchdog counter\n");
+
return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
DA9063_TWDSCALE_MASK, regval);
}
@@ -85,8 +115,7 @@ static int da9063_wdt_ping(struct watchdog_device *wdd)
struct da9063 *da9063 = watchdog_get_drvdata(wdd);
int ret;
- ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F,
- DA9063_WATCHDOG);
+ ret = _da9063_wdt_reset_timer(da9063);
if (ret)
dev_alert(da9063->dev, "Failed to ping the watchdog (err = %d)\n",
ret);
--
2.17.0
--
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