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regulator: fixed: add support for under-voltage IRQ

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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@pengutronix.de>
Link: https://lore.kernel.org/r/20231025084614.3092295-6-o.rempel@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Oleksij Rempel 2023-10-25 10:46:12 +02:00 committed by Mark Brown
parent 0ab1dc9c65
commit ecb6f1f456
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1 changed files with 50 additions and 0 deletions
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50
drivers/regulator/fixed.c
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@ -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 +108,49 @@ 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)
{
struct fixed_voltage_data *priv = data;
struct regulator_dev *rdev = priv->dev;
regulator_notifier_call_chain(rdev, REGULATOR_EVENT_UNDER_VOLTAGE,
NULL);
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 +340,10 @@ 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;
}