From 8156c7dd47b92fc4a70c9ea58e7a9e88c8bc32be Mon Sep 17 00:00:00 2001 From: Oleksij Rempel Date: Thu, 26 Oct 2023 16:48:21 +0200 Subject: regulator: Introduce handling for system-critical under-voltage events Handle under-voltage events for crucial regulators to maintain system stability and avoid issues during power drops. Signed-off-by: Oleksij Rempel Link: https://lore.kernel.org/r/20231026144824.4065145-3-o.rempel@pengutronix.de Signed-off-by: Mark Brown --- drivers/regulator/core.c | 38 ++++++++++++++++++++++++++++++++++++++ drivers/regulator/of_regulator.c | 2 ++ 2 files changed, 40 insertions(+) (limited to 'drivers/regulator') diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 3137e40fcd3e..a072f721f288 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include @@ -5061,6 +5062,41 @@ void regulator_bulk_free(int num_consumers, } EXPORT_SYMBOL_GPL(regulator_bulk_free); +/** + * regulator_handle_critical - Handle events for system-critical regulators. + * @rdev: The regulator device. + * @event: The event being handled. + * + * This function handles critical events such as under-voltage, over-current, + * and unknown errors for regulators deemed system-critical. On detecting such + * events, it triggers a hardware protection shutdown with a defined timeout. + */ +static void regulator_handle_critical(struct regulator_dev *rdev, + unsigned long event) +{ + const char *reason = NULL; + + if (!rdev->constraints->system_critical) + return; + + switch (event) { + case REGULATOR_EVENT_UNDER_VOLTAGE: + reason = "System critical regulator: voltage drop detected"; + break; + case REGULATOR_EVENT_OVER_CURRENT: + reason = "System critical regulator: over-current detected"; + break; + case REGULATOR_EVENT_FAIL: + reason = "System critical regulator: unknown error"; + } + + if (!reason) + return; + + hw_protection_shutdown(reason, + REGULATOR_DEF_UV_LESS_CRITICAL_WINDOW_MS); +} + /** * regulator_notifier_call_chain - call regulator event notifier * @rdev: regulator source @@ -5073,6 +5109,8 @@ EXPORT_SYMBOL_GPL(regulator_bulk_free); int regulator_notifier_call_chain(struct regulator_dev *rdev, unsigned long event, void *data) { + regulator_handle_critical(rdev, event); + _notifier_call_chain(rdev, event, data); return NOTIFY_DONE; diff --git a/drivers/regulator/of_regulator.c b/drivers/regulator/of_regulator.c index 1b65e5e4e40f..3bdd6f1919a4 100644 --- a/drivers/regulator/of_regulator.c +++ b/drivers/regulator/of_regulator.c @@ -131,6 +131,8 @@ static int of_get_regulation_constraints(struct device *dev, constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS; constraints->pull_down = of_property_read_bool(np, "regulator-pull-down"); + constraints->system_critical = of_property_read_bool(np, + "system-critical-regulator"); if (of_property_read_bool(np, "regulator-allow-bypass")) constraints->valid_ops_mask |= REGULATOR_CHANGE_BYPASS; -- cgit v1.2.3 From 1e22152aa59d793743fc53051dd7a042f362aecb Mon Sep 17 00:00:00 2001 From: Oleksij Rempel Date: Thu, 26 Oct 2023 16:48:24 +0200 Subject: regulator: Implement uv_survival_time for handling under-voltage events 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 Link: https://lore.kernel.org/r/20231026144824.4065145-6-o.rempel@pengutronix.de Signed-off-by: Mark Brown --- drivers/regulator/core.c | 2 +- drivers/regulator/of_regulator.c | 7 +++++++ include/linux/regulator/machine.h | 8 ++++++++ 3 files changed, 16 insertions(+), 1 deletion(-) (limited to 'drivers/regulator') diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index a072f721f288..a6cb84af989e 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -5094,7 +5094,7 @@ static void regulator_handle_critical(struct regulator_dev *rdev, return; hw_protection_shutdown(reason, - REGULATOR_DEF_UV_LESS_CRITICAL_WINDOW_MS); + rdev->constraints->uv_less_critical_window_ms); } /** diff --git a/drivers/regulator/of_regulator.c b/drivers/regulator/of_regulator.c index 3bdd6f1919a4..03afc160fc72 100644 --- a/drivers/regulator/of_regulator.c +++ b/drivers/regulator/of_regulator.c @@ -175,6 +175,13 @@ 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_less_critical_window_ms = pval; + else + constraints->uv_less_critical_window_ms = + REGULATOR_DEF_UV_LESS_CRITICAL_WINDOW_MS; + constraints->soft_start = of_property_read_bool(np, "regulator-soft-start"); ret = of_property_read_u32(np, "regulator-active-discharge", &pval); diff --git a/include/linux/regulator/machine.h b/include/linux/regulator/machine.h index e0ddfb5593c9..0cd76d264727 100644 --- a/include/linux/regulator/machine.h +++ b/include/linux/regulator/machine.h @@ -162,6 +162,13 @@ struct notification_limit { * regulator_active_discharge values are used for * initialisation. * @enable_time: Turn-on time of the rails (unit: microseconds) + * @uv_less_critical_window_ms: Specifies the time window (in milliseconds) + * following a critical under-voltage (UV) event + * during which less critical actions can be + * safely carried out by the system (for example + * logging). After this time window more critical + * actions should be done (for example prevent + * HW damage). */ struct regulation_constraints { @@ -213,6 +220,7 @@ struct regulation_constraints { unsigned int settling_time_up; unsigned int settling_time_down; unsigned int enable_time; + unsigned int uv_less_critical_window_ms; unsigned int active_discharge; -- cgit v1.2.3