This series add under-voltage and emergency shutdown for system critical
regulators
changes v4:
- rebase against latest regulator/for-next
- drop mainlined patches
- rename regulator-uv-survival-time-ms to regulator-uv-less-critical-window-ms
to fit it to actual use case
- avoid some of words in commit messages
- us switch case to parse critical events
changes v3:
- add system-critical-regulator property
- add regulator-uv-survival-time-ms property
- implement default policy for system critical uv events
changes v2:
- drop event forwarding support
- use emergency shutdown directly instead of generating under-voltage
error event.
- fix devicetree patch
- drop interrupt-names support
Oleksij Rempel (5):
regulator: dt-bindings: Add system-critical-regulator property
regulator: Introduce handling for system-critical under-voltage events
regulator: dt-bindings: Allow system-critical marking for
fixed-regulator
regulator: dt-bindings: Add 'regulator-uv-less-critical-window-ms'
property
regulator: Implement uv_survival_time for handling under-voltage
events
.../bindings/regulator/fixed-regulator.yaml | 2 +
.../bindings/regulator/regulator.yaml | 13 +++++++
drivers/regulator/core.c | 38 +++++++++++++++++++
drivers/regulator/of_regulator.c | 9 +++++
include/linux/regulator/machine.h | 18 +++++++++
5 files changed, 80 insertions(+)
--
2.39.2
Handle under-voltage events for crucial regulators to maintain system
stability and avoid issues during power drops.
Signed-off-by: Oleksij Rempel <[email protected]>
---
drivers/regulator/core.c | 38 +++++++++++++++++++++++++++++++
drivers/regulator/of_regulator.c | 2 ++
include/linux/regulator/machine.h | 10 ++++++++
3 files changed, 50 insertions(+)
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 <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/of.h>
+#include <linux/reboot.h>
#include <linux/regmap.h>
#include <linux/regulator/of_regulator.h>
#include <linux/regulator/consumer.h>
@@ -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;
diff --git a/include/linux/regulator/machine.h b/include/linux/regulator/machine.h
index 621b7f4a3639..e0ddfb5593c9 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.
@@ -214,6 +223,7 @@ 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 */
--
2.39.2
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 <[email protected]>
---
drivers/regulator/core.c | 2 +-
drivers/regulator/of_regulator.c | 7 +++++++
include/linux/regulator/machine.h | 8 ++++++++
3 files changed, 16 insertions(+), 1 deletion(-)
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;
--
2.39.2