[PATCH v5 3/5] watchdog: da9062: reset board on watchdog timeout

Andrej Picej
2021-12-06T06:47:48Z

Implement a method to change watchdog timeout configuration based on DT
binding ("dlg,wdt-sd"). There is a possibility to change the behaviour
of watchdog reset. Setting WATCHDOG_SD bit enables SHUTDOWN mode, and
clearing it enables POWERDOWN mode on watchdog timeout.

If no DT binding is specified the WATCHDOG_SD bit stays in default
configuration, not breaking behaviour of devices which might depend on
default fuse configuration.

Note: This patch requires that the config register CONFIG_I is
configured as writable in the da9061/2 multi function device.

Signed-off-by: Andrej Picej <andrej.picej@norik.com>
---
Changes in v5:
- fix spelling mistake in commit message

Changes in v4:
- move the code to probe function

Changes in v3:
- no changes

Changes in v2:
- don't force the "reset" for all da9062-watchdog users, instead add DT
binding where the behavior can be selected
---
drivers/watchdog/da9062_wdt.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)

diff --git a/drivers/watchdog/da9062_wdt.c b/drivers/watchdog/da9062_wdt.c
index f02cbd530538..bd85f84b0fd4 100644
--- a/drivers/watchdog/da9062_wdt.c
+++ b/drivers/watchdog/da9062_wdt.c
@@ -195,8 +195,11 @@ static int da9062_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
unsigned int timeout;
+ unsigned int mask;
struct da9062 *chip;
struct da9062_watchdog *wdt;
+ int ret;
+ u32 val;

chip = dev_get_drvdata(dev->parent);
if (!chip)
@@ -236,6 +239,30 @@ static int da9062_wdt_probe(struct platform_device *pdev)
set_bit(WDOG_HW_RUNNING, &wdt->wdtdev.status);
}

+ /*
+ * Configure what happens on watchdog timeout. Can be specified with
+ * "dlg,wdt-sd" dt-binding (0 -> POWERDOWN, 1 -> SHUTDOWN).
+ * If "dlg,wdt-sd" dt-binding is NOT set use the default.
+ */
+ ret = device_property_read_u32(dev, "dlg,wdt-sd", &val);
+ if (!ret) {
+ if (val)
+ /* Use da9062's SHUTDOWN mode */
+ mask = DA9062AA_WATCHDOG_SD_MASK;
+ else
+ /* Use da9062's POWERDOWN mode. */
+ mask = 0x0;
+
+ ret = regmap_update_bits(wdt->hw->regmap,
+ DA9062AA_CONFIG_I,
+ DA9062AA_WATCHDOG_SD_MASK,
+ mask);
+
+ if (ret)
+ dev_err(dev, "failed to set wdt reset mode: %d\n",
+ ret);
+ }
+
return devm_watchdog_register_device(dev, &wdt->wdtdev);
}

--
2.25.1