Add interrupt support for under-voltage notification. This functionality
can be used on systems capable to detect under-voltage state and having
enough capacity to let the SoC do some emergency preparation.
This change enforce default policy to shutdown system as soon as
interrupt is triggered.
Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
---
drivers/regulator/fixed.c | 47 +++++++++++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)
diff --git a/drivers/regulator/fixed.c b/drivers/regulator/fixed.c
index 55130efae9b8..c60ea7ac7762 100644
--- a/drivers/regulator/fixed.c
+++ b/drivers/regulator/fixed.c
@@ -20,6 +20,7 @@
#include <linux/platform_device.h>
#include <linux/pm_domain.h>
#include <linux/pm_opp.h>
+#include <linux/reboot.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/fixed.h>
#include <linux/gpio/consumer.h>
@@ -29,6 +30,8 @@
#include <linux/regulator/machine.h>
#include <linux/clk.h>
+/* Default time in millisecond to wait for emergency shutdown */
+#define FV_DEF_EMERG_SHUTDWN_TMO 10
struct fixed_voltage_data {
struct regulator_desc desc;
@@ -105,6 +108,46 @@ static int reg_is_enabled(struct regulator_dev *rdev)
return priv->enable_counter > 0;
}
+static irqreturn_t reg_fixed_under_voltage_irq_handler(int irq, void *data)
+{
+ hw_protection_shutdown("Critical voltage drop reached",
+ FV_DEF_EMERG_SHUTDWN_TMO);
+
+ return IRQ_HANDLED;
+}
+
+/**
+ * reg_fixed_get_irqs - Get and register the optional IRQ for fixed voltage
+ * regulator.
+ * @dev: Pointer to the device structure.
+ * @priv: Pointer to fixed_voltage_data structure containing private data.
+ *
+ * This function tries to get the IRQ from the device firmware node.
+ * If it's an optional IRQ and not found, it returns 0.
+ * Otherwise, it attempts to request the threaded IRQ.
+ *
+ * Return: 0 on success, or error code on failure.
+ */
+static int reg_fixed_get_irqs(struct device *dev,
+ struct fixed_voltage_data *priv)
+{
+ int ret;
+
+ ret = fwnode_irq_get(dev_fwnode(dev), 0);
+ /* This is optional IRQ. If not found we will get -EINVAL */
+ if (ret == -EINVAL)
+ return 0;
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Failed to get IRQ\n");
+
+ ret = devm_request_threaded_irq(dev, ret, NULL,
+ reg_fixed_under_voltage_irq_handler,
+ IRQF_ONESHOT, "under-voltage", priv);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to request IRQ\n");
+
+ return 0;
+}
/**
* of_get_fixed_voltage_config - extract fixed_voltage_config structure info
@@ -294,6 +337,10 @@ static int reg_fixed_voltage_probe(struct platform_device *pdev)
dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
drvdata->desc.fixed_uV);
+ ret = reg_fixed_get_irqs(dev, drvdata);
+ if (ret)
+ return ret;
+
return 0;
}
--
2.39.2
