Commit 270cc3c5 authored by Wolfram Sang's avatar Wolfram Sang
Browse files

i2c: support gpio-binding for SMBAlerts 



Most I2C controllers do not have a dedicated pin for SMBus Alerts. Allow
them to define a GPIO as a side-channel.

Signed-off-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: default avatarAndi Shyti <andi.shyti@kernel.org>
parent 6b238b3c

drivers/i2c/i2c-core-smbus.c

+6 −3
Original line number Diff line number Diff line
@@ -712,12 +712,15 @@ int i2c_setup_smbus_alert(struct i2c_adapter *adapter) 
	if (!parent)

		return 0;



	/* Report serious errors */

	irq = device_property_match_string(parent, "interrupt-names", "smbus_alert");

	if (irq == -EINVAL || irq == -ENODATA)

		return 0;

	else if (irq < 0)

	if (irq < 0 && irq != -EINVAL && irq != -ENODATA)

		return irq;



	/* Skip setup when no irq was found */

	if (irq < 0 && !device_property_present(parent, "smbalert-gpios"))

		return 0;



	return PTR_ERR_OR_ZERO(i2c_new_smbus_alert_device(adapter, NULL));

}

#endif

drivers/i2c/i2c-smbus.c

+16 −6
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 


#include <linux/device.h>

#include <linux/dmi.h>

#include <linux/gpio/consumer.h>

#include <linux/i2c.h>

#include <linux/i2c-smbus.h>

#include <linux/interrupt.h>
@@ -167,6 +168,8 @@ static int smbalert_probe(struct i2c_client *ara) 
	struct i2c_smbus_alert_setup *setup = dev_get_platdata(&ara->dev);

	struct i2c_smbus_alert *alert;

	struct i2c_adapter *adapter = ara->adapter;

	unsigned long irqflags = IRQF_SHARED | IRQF_ONESHOT;

	struct gpio_desc *gpiod;

	int res, irq;



	alert = devm_kzalloc(&ara->dev, sizeof(struct i2c_smbus_alert),
@@ -179,18 +182,25 @@ static int smbalert_probe(struct i2c_client *ara) 
	} else {

		irq = fwnode_irq_get_byname(dev_fwnode(adapter->dev.parent),

					    "smbus_alert");

		if (irq <= 0) {

			gpiod = devm_gpiod_get(adapter->dev.parent, "smbalert", GPIOD_IN);

			if (IS_ERR(gpiod))

				return PTR_ERR(gpiod);



			irq = gpiod_to_irq(gpiod);

			if (irq <= 0)

				return irq;



			irqflags |= IRQF_TRIGGER_FALLING;

		}

	}



	INIT_WORK(&alert->alert, smbalert_work);

	alert->ara = ara;



	if (irq > 0) {

		res = devm_request_threaded_irq(&ara->dev, irq,

						NULL, smbus_alert,

						IRQF_SHARED | IRQF_ONESHOT,

						"smbus_alert", alert);

		res = devm_request_threaded_irq(&ara->dev, irq, NULL, smbus_alert,

						irqflags, "smbus_alert", alert);

		if (res)

			return res;

	}