Unverified Commit ecb6f1f4 authored by Oleksij Rempel's avatar Oleksij Rempel Committed by Mark Brown
Browse files

regulator: fixed: add support for under-voltage IRQ 



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: default avatarOleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20231025084614.3092295-6-o.rempel@pengutronix.de


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 0ab1dc9c

drivers/regulator/fixed.c

+50 −0
Original line number Diff line number Diff line
@@ -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;

}