diff --git a/Documentation/devicetree/bindings/regulator/fixed-regulator.yaml b/Documentation/devicetree/bindings/regulator/fixed-regulator.yaml index ce7751b9129c..9ff9abf2691a 100644 --- a/Documentation/devicetree/bindings/regulator/fixed-regulator.yaml +++ b/Documentation/devicetree/bindings/regulator/fixed-regulator.yaml @@ -105,6 +105,8 @@ properties: description: Interrupt signaling a critical under-voltage event. + system-critical-regulator: true + required: - compatible - regulator-name diff --git a/Documentation/devicetree/bindings/regulator/regulator.yaml b/Documentation/devicetree/bindings/regulator/regulator.yaml index 9daf0fc2465f..1ef380d1515e 100644 --- a/Documentation/devicetree/bindings/regulator/regulator.yaml +++ b/Documentation/devicetree/bindings/regulator/regulator.yaml @@ -114,6 +114,11 @@ properties: description: Enable pull down resistor when the regulator is disabled. type: boolean + system-critical-regulator: + description: Set if the regulator is critical to system stability or + functionality. + type: boolean + regulator-over-current-protection: description: Enable over current protection. type: boolean @@ -181,6 +186,14 @@ properties: be enabled but limit setting can be omitted. Limit is given as microvolt offset from voltage set to regulator. + regulator-uv-less-critical-window-ms: + description: Specifies the time window (in milliseconds) following a + critical under-voltage event during which the system can continue to + operate safely while performing less critical operations. This property + provides a defined duration before a more severe reaction to the + under-voltage event is needed, allowing for certain non-urgent actions to + be carried out in preparation for potential power loss. + regulator-temp-protection-kelvin: description: Set over temperature protection limit. This is a limit where hardware performs emergency shutdown. Zero can be passed to disable diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 00221ff369c2..4aa9ec8c22f3 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include @@ -5065,6 +5066,41 @@ 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, + rdev->constraints->uv_less_critical_window_ms); +} + /** * regulator_notifier_call_chain - call regulator event notifier * @rdev: regulator source @@ -5077,6 +5113,8 @@ 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..03afc160fc72 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; @@ -173,6 +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 621b7f4a3639..0cd76d264727 100644 --- a/include/linux/regulator/machine.h +++ b/include/linux/regulator/machine.h @@ -49,6 +49,13 @@ struct regulator; #define DISABLE_IN_SUSPEND 1 #define ENABLE_IN_SUSPEND 2 +/* + * Default time window (in milliseconds) following a critical under-voltage + * event during which less critical actions can be safely carried out by the + * system. + */ +#define REGULATOR_DEF_UV_LESS_CRITICAL_WINDOW_MS 10 + /* Regulator active discharge flags */ enum regulator_active_discharge { REGULATOR_ACTIVE_DISCHARGE_DEFAULT, @@ -127,6 +134,8 @@ struct notification_limit { * @ramp_disable: Disable ramp delay when initialising or when setting voltage. * @soft_start: Enable soft start so that voltage ramps slowly. * @pull_down: Enable pull down when regulator is disabled. + * @system_critical: Set if the regulator is critical to system stability or + * functionality. * @over_current_protection: Auto disable on over current event. * * @over_current_detection: Configure over current limits. @@ -153,6 +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 { @@ -204,6 +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; @@ -214,6 +231,7 @@ struct regulation_constraints { unsigned ramp_disable:1; /* disable ramp delay */ unsigned soft_start:1; /* ramp voltage slowly */ unsigned pull_down:1; /* pull down resistor when regulator off */ + unsigned system_critical:1; /* critical to system stability */ unsigned over_current_protection:1; /* auto disable on over current */ unsigned over_current_detection:1; /* notify on over current */ unsigned over_voltage_detection:1; /* notify on over voltage */