[v3,7/7] regulator: Implement uv_survival_time for handling under-voltage events
Commit Message
Add 'uv_survival_time' field to regulation_constraints for specifying
survival time post critical under-voltage event. Update the regulator
notifier call chain and Device Tree property parsing to use this new
field, allowing a configurable timeout before emergency shutdown.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
drivers/regulator/core.c | 2 +-
drivers/regulator/of_regulator.c | 6 ++++++
include/linux/regulator/machine.h | 6 ++++++
3 files changed, 13 insertions(+), 1 deletion(-)
@@ -5077,7 +5077,7 @@ int regulator_notifier_call_chain(struct regulator_dev *rdev,
if (rdev->constraints->system_critical &&
event == REGULATOR_EVENT_UNDER_VOLTAGE)
hw_protection_shutdown("System critical voltage drop detected",
- REGULATOR_DEF_EMERG_SHUTDWN_TMO);
+ rdev->constraints->uv_survival_time);
_notifier_call_chain(rdev, event, data);
return NOTIFY_DONE;
@@ -175,6 +175,12 @@ static int of_get_regulation_constraints(struct device *dev,
if (!ret)
constraints->enable_time = pval;
+ ret = of_property_read_u32(np, "regulator-uv-survival-time-ms", &pval);
+ if (!ret)
+ constraints->uv_survival_time = pval;
+ else
+ constraints->uv_survival_time = REGULATOR_DEF_EMERG_SHUTDWN_TMO;
+
constraints->soft_start = of_property_read_bool(np,
"regulator-soft-start");
ret = of_property_read_u32(np, "regulator-active-discharge", &pval);
@@ -158,6 +158,11 @@ struct notification_limit {
* regulator_active_discharge values are used for
* initialisation.
* @enable_time: Turn-on time of the rails (unit: microseconds)
+ * @uv_survival_time: Survival time post a critical under-voltage event. Time
+ * the system can operate before the on-board capacitors
+ * fail, providing a window for necessary actions or
+ * preparations to be taken before power loss.
+ * (unit: microseconds)
*/
struct regulation_constraints {
@@ -209,6 +214,7 @@ struct regulation_constraints {
unsigned int settling_time_up;
unsigned int settling_time_down;
unsigned int enable_time;
+ unsigned int uv_survival_time;
unsigned int active_discharge;