diff mbox series

[v2,5/6] gpio: max77759: add Maxim MAX77759 gpio driver

Message ID 20250226-max77759-mfd-v2-5-a65ebe2bc0a9@linaro.org
State New
Headers show
Series Maxim Integrated MAX77759 PMIC MFD-based drivers | expand

Commit Message

André Draszik Feb. 26, 2025, 5:51 p.m. UTC
The Maxim MAX77759 is a companion PMIC for USB Type-C applications and
includes Battery Charger, Fuel Gauge, temperature sensors, USB Type-C
Port Controller (TCPC), NVMEM, and a GPIO expander.

This driver supports the GPIO functions using the platform device
registered by the core MFD driver.

Signed-off-by: André Draszik <andre.draszik@linaro.org>

---
v2:
* fix max77759_gpio_direction_from_control()
* add missing error handling of devm_mutex_init() (Christophe)
* align sentinel in max77759_gpio_of_id[] with other max77759 drivers
  (Christophe)
---
 MAINTAINERS                  |   1 +
 drivers/gpio/Kconfig         |  13 ++
 drivers/gpio/Makefile        |   1 +
 drivers/gpio/gpio-max77759.c | 528 +++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 543 insertions(+)

Comments

André Draszik Feb. 28, 2025, 10:58 a.m. UTC | #1
Hi Linus,

Thanks for you review!

On Fri, 2025-02-28 at 08:10 +0100, Linus Walleij wrote:
> Hi André,
> 
> thanks for your patch!
> 
> mostly looks fine, given the MFD design is accepted.
> Nitpicks below:
> 
> On Wed, Feb 26, 2025 at 6:51 PM André Draszik <andre.draszik@linaro.org> wrote:
> 
> > +static irqreturn_t max77759_gpio_irqhandler(int irq, void *data)
> > +{
> > +       int handled = 0;
> 
> bool handled = false;
> 
> (...)
> > +               for_each_set_bit(offset, &pending, MAX77759_N_GPIOS) {
> > +                       unsigned int virq;
> 
> I usually just call this "irq", as it's not any more virtual than any other
> Linux magic number, and it can confuse people working with
> actual virtualization when we call things virtual like this.

Calling it 'irq' would shadow the first argument of this irq
handler function, which is also and usually called irq and which
I'd like to avoid shadowing.

Are you OK with 'subirq'? Or any other preference?

Cheers,
Andre'
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index 38844ea24e464d0b58f8852b79e2b94f18d48998..ef3aadcf86ce35d8807733c94f790cde0f7255af 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14352,6 +14352,7 @@  M:	André Draszik <andre.draszik@linaro.org>
 L:	linux-kernel@vger.kernel.org
 S:	Maintained
 F:	Documentation/devicetree/bindings/*/maxim,max77759*.yaml
+F:	drivers/gpio/gpio-max77759.c
 F:	drivers/mfd/max77759.c
 F:	include/linux/mfd/max77759.h
 
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 3e9b174fee84142a8b50cdca5b967671eeda6dd3..216e80580fa443160c20da3e0916979fd08df99a 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1463,6 +1463,19 @@  config GPIO_MAX77650
 	  GPIO driver for MAX77650/77651 PMIC from Maxim Semiconductor.
 	  These chips have a single pin that can be configured as GPIO.
 
+config GPIO_MAX77759
+	tristate "Maxim Integrated MAX77759 GPIO support"
+	depends on MFD_MAX77759
+	default MFD_MAX77759
+	select GPIOLIB_IRQCHIP
+	help
+	  GPIO driver for MAX77759 PMIC from Maxim Integrated.
+	  There are two GPIOs available on these chips in total, both of
+	  which can also generate interrupts.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called gpio-max77759.
+
 config GPIO_PALMAS
 	bool "TI PALMAS series PMICs GPIO"
 	depends on MFD_PALMAS
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index af130882ffeeef8b1d518867bfe1493ec4f21b5f..3b9a55f9f79eda33c135cfedb230ef7775b51bee 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -105,6 +105,7 @@  obj-$(CONFIG_GPIO_MAX730X)		+= gpio-max730x.o
 obj-$(CONFIG_GPIO_MAX732X)		+= gpio-max732x.o
 obj-$(CONFIG_GPIO_MAX77620)		+= gpio-max77620.o
 obj-$(CONFIG_GPIO_MAX77650)		+= gpio-max77650.o
+obj-$(CONFIG_GPIO_MAX77759)		+= gpio-max77759.o
 obj-$(CONFIG_GPIO_MB86S7X)		+= gpio-mb86s7x.o
 obj-$(CONFIG_GPIO_MC33880)		+= gpio-mc33880.o
 obj-$(CONFIG_GPIO_MENZ127)		+= gpio-menz127.o
diff --git a/drivers/gpio/gpio-max77759.c b/drivers/gpio/gpio-max77759.c
new file mode 100644
index 0000000000000000000000000000000000000000..b304c533dc9d6bf792d179c6c36b467c2c134e56
--- /dev/null
+++ b/drivers/gpio/gpio-max77759.c
@@ -0,0 +1,528 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+//
+// Copyright 2020 Google Inc
+// Copyright 2025 Linaro Ltd.
+//
+// GPIO driver for Maxim MAX77759
+
+#include <linux/dev_printk.h>
+#include <linux/device.h>
+#include <linux/device/driver.h>
+#include <linux/gpio/driver.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqreturn.h>
+#include <linux/lockdep.h>
+#include <linux/mfd/max77759.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/overflow.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/seq_file.h>
+
+#define MAX77759_N_GPIOS   ARRAY_SIZE(max77759_gpio_line_names)
+static const char * const max77759_gpio_line_names[] = { "GPIO5", "GPIO6" };
+
+struct max77759_gpio_chip {
+	struct regmap *map;
+	struct max77759_mfd *max77759_mfd;
+	struct gpio_chip gc;
+	struct mutex maxq_lock; /* protect MaxQ r/m/w operations */
+
+	struct mutex irq_lock; /* protect irq bus */
+	int irq_mask;
+	int irq_mask_changed;
+	int irq_trig;
+	int irq_trig_changed;
+};
+
+#define MAX77759_GPIOx_TRIGGER(offs, val) (((val) & 1) << (offs))
+#define MAX77759_GPIOx_TRIGGER_MASK(offs) MAX77759_GPIOx_TRIGGER(offs, ~0)
+enum max77759_trigger_gpio_type {
+	MAX77759_GPIO_TRIGGER_RISING = 0,
+	MAX77759_GPIO_TRIGGER_FALLING = 1
+};
+
+#define MAX77759_GPIOx_DIR(offs, dir) (((dir) & 1) << (2 + (3 * (offs))))
+#define MAX77759_GPIOx_DIR_MASK(offs) MAX77759_GPIOx_DIR(offs, ~0)
+enum max77759_control_gpio_dir {
+	MAX77759_GPIO_DIR_IN = 0,
+	MAX77759_GPIO_DIR_OUT = 1
+};
+
+#define MAX77759_GPIOx_OUTVAL(offs, val) (((val) & 1) << (3 + (3 * (offs))))
+#define MAX77759_GPIOx_OUTVAL_MASK(offs) MAX77759_GPIOx_OUTVAL(offs, ~0)
+
+#define MAX77759_GPIOx_INVAL_MASK(offs) (BIT(4) << (3 * (offs)))
+
+static int max77759_gpio_maxq_gpio_trigger_read(struct max77759_gpio_chip *chip)
+{
+	DEFINE_FLEX(struct max77759_maxq_command, cmd, cmd, length, 1);
+	DEFINE_FLEX(struct max77759_maxq_response, rsp, rsp, length, 2);
+	int ret;
+
+	cmd->cmd[0] = MAX77759_MAXQ_OPCODE_GPIO_TRIGGER_READ;
+
+	ret = max77759_maxq_command(chip->max77759_mfd, cmd, rsp);
+	if (ret < 0)
+		return ret;
+
+	return rsp->rsp[1];
+}
+
+static int max77759_gpio_maxq_gpio_trigger_write(struct max77759_gpio_chip *chip,
+						 u8 trigger)
+{
+	DEFINE_FLEX(struct max77759_maxq_command, cmd, cmd, length, 2);
+
+	cmd->cmd[0] = MAX77759_MAXQ_OPCODE_GPIO_TRIGGER_WRITE;
+	cmd->cmd[1] = trigger;
+
+	return max77759_maxq_command(chip->max77759_mfd, cmd, NULL);
+}
+
+static int max77759_gpio_maxq_gpio_control_read(struct max77759_gpio_chip *chip)
+{
+	DEFINE_FLEX(struct max77759_maxq_command, cmd, cmd, length, 1);
+	DEFINE_FLEX(struct max77759_maxq_response, rsp, rsp, length, 2);
+	int ret;
+
+	cmd->cmd[0] = MAX77759_MAXQ_OPCODE_GPIO_CONTROL_READ;
+
+	ret = max77759_maxq_command(chip->max77759_mfd, cmd, rsp);
+	if (ret < 0)
+		return ret;
+
+	return rsp->rsp[1];
+}
+
+static int max77759_gpio_maxq_gpio_control_write(struct max77759_gpio_chip *chip,
+						 u8 ctrl)
+{
+	DEFINE_FLEX(struct max77759_maxq_command, cmd, cmd, length, 2);
+
+	cmd->cmd[0] = MAX77759_MAXQ_OPCODE_GPIO_CONTROL_WRITE;
+	cmd->cmd[1] = ctrl;
+
+	return max77759_maxq_command(chip->max77759_mfd, cmd, NULL);
+}
+
+static int
+max77759_gpio_direction_from_control(int ctrl, unsigned int offset)
+{
+	enum max77759_control_gpio_dir dir;
+
+	dir = !!(ctrl & MAX77759_GPIOx_DIR_MASK(offset));
+	return ((dir == MAX77759_GPIO_DIR_OUT)
+		? GPIO_LINE_DIRECTION_OUT
+		: GPIO_LINE_DIRECTION_IN);
+}
+
+static int max77759_gpio_get_direction(struct gpio_chip *gc,
+				       unsigned int offset)
+{
+	struct max77759_gpio_chip *chip = gpiochip_get_data(gc);
+	int ctrl;
+
+	ctrl = max77759_gpio_maxq_gpio_control_read(chip);
+	if (ctrl < 0)
+		return ctrl;
+
+	return max77759_gpio_direction_from_control(ctrl, offset);
+}
+
+static int max77759_gpio_direction_helper(struct gpio_chip *gc,
+					  unsigned int offset,
+					  enum max77759_control_gpio_dir dir,
+					  int value)
+{
+	struct max77759_gpio_chip *chip = gpiochip_get_data(gc);
+	int ctrl, new_ctrl;
+
+	guard(mutex)(&chip->maxq_lock);
+
+	ctrl = max77759_gpio_maxq_gpio_control_read(chip);
+	if (ctrl < 0)
+		return ctrl;
+
+	new_ctrl = ctrl & ~MAX77759_GPIOx_DIR_MASK(offset);
+	new_ctrl |= MAX77759_GPIOx_DIR(offset, dir);
+
+	if (dir == MAX77759_GPIO_DIR_OUT) {
+		new_ctrl &= ~MAX77759_GPIOx_OUTVAL_MASK(offset);
+		new_ctrl |= MAX77759_GPIOx_OUTVAL(offset, value);
+	}
+
+	if (new_ctrl == ctrl)
+		return 0;
+
+	return max77759_gpio_maxq_gpio_control_write(chip, new_ctrl);
+}
+
+static int max77759_gpio_direction_input(struct gpio_chip *gc,
+					 unsigned int offset)
+{
+	return max77759_gpio_direction_helper(gc, offset,
+					      MAX77759_GPIO_DIR_IN, -1);
+}
+
+static int max77759_gpio_direction_output(struct gpio_chip *gc,
+					  unsigned int offset, int value)
+{
+	return max77759_gpio_direction_helper(gc, offset,
+					      MAX77759_GPIO_DIR_OUT, value);
+}
+
+static int max77759_gpio_get_value(struct gpio_chip *gc, unsigned int offset)
+{
+	struct max77759_gpio_chip *chip = gpiochip_get_data(gc);
+	int ctrl, mask;
+
+	ctrl = max77759_gpio_maxq_gpio_control_read(chip);
+	if (ctrl < 0)
+		return ctrl;
+
+	/*
+	 * The input status bit doesn't reflect the pin state when the GPIO is
+	 * configured as an output. Check the direction, and inspect the input
+	 * or output bit accordingly.
+	 */
+	mask = ((max77759_gpio_direction_from_control(ctrl, offset)
+		 == GPIO_LINE_DIRECTION_IN)
+		? MAX77759_GPIOx_INVAL_MASK(offset)
+		: MAX77759_GPIOx_OUTVAL_MASK(offset));
+
+	return !!(ctrl & mask);
+}
+
+static void max77759_gpio_set_value(struct gpio_chip *gc,
+				    unsigned int offset, int value)
+{
+	struct max77759_gpio_chip *chip = gpiochip_get_data(gc);
+	int ctrl, new_ctrl;
+
+	guard(mutex)(&chip->maxq_lock);
+
+	ctrl = max77759_gpio_maxq_gpio_control_read(chip);
+	if (ctrl < 0)
+		return;
+
+	new_ctrl = ctrl & ~MAX77759_GPIOx_OUTVAL_MASK(offset);
+	new_ctrl |= MAX77759_GPIOx_OUTVAL(offset, value);
+
+	if (new_ctrl == ctrl)
+		return;
+
+	max77759_gpio_maxq_gpio_control_write(chip, new_ctrl);
+}
+
+static void max77759_gpio_irq_mask(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct max77759_gpio_chip *chip = gpiochip_get_data(gc);
+	irq_hw_number_t hwirq = irqd_to_hwirq(d);
+
+	chip->irq_mask &= ~MAX77759_MAXQ_REG_UIC_INT1_GPIOxI_MASK(hwirq);
+	chip->irq_mask |= MAX77759_MAXQ_REG_UIC_INT1_GPIOxI(hwirq, 1);
+	chip->irq_mask_changed |= MAX77759_MAXQ_REG_UIC_INT1_GPIOxI(hwirq, 1);
+
+	gpiochip_disable_irq(gc, hwirq);
+}
+
+static void max77759_gpio_irq_unmask(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct max77759_gpio_chip *chip = gpiochip_get_data(gc);
+	irq_hw_number_t hwirq = irqd_to_hwirq(d);
+
+	gpiochip_enable_irq(gc, hwirq);
+
+	chip->irq_mask &= ~MAX77759_MAXQ_REG_UIC_INT1_GPIOxI_MASK(hwirq);
+	chip->irq_mask |= MAX77759_MAXQ_REG_UIC_INT1_GPIOxI(hwirq, 0);
+	chip->irq_mask_changed |= MAX77759_MAXQ_REG_UIC_INT1_GPIOxI(hwirq, 1);
+}
+
+static int max77759_gpio_set_irq_type(struct irq_data *d, unsigned int type)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct max77759_gpio_chip *chip = gpiochip_get_data(gc);
+	irq_hw_number_t hwirq = irqd_to_hwirq(d);
+
+	chip->irq_trig &= ~MAX77759_GPIOx_TRIGGER_MASK(hwirq);
+	switch (type) {
+	case IRQ_TYPE_EDGE_RISING:
+		chip->irq_trig |= MAX77759_GPIOx_TRIGGER(hwirq,
+						MAX77759_GPIO_TRIGGER_RISING);
+		break;
+
+	case IRQ_TYPE_EDGE_FALLING:
+		chip->irq_trig |= MAX77759_GPIOx_TRIGGER(hwirq,
+						MAX77759_GPIO_TRIGGER_FALLING);
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	chip->irq_trig_changed |= MAX77759_GPIOx_TRIGGER(hwirq, 1);
+
+	return 0;
+}
+
+static void max77759_gpio_bus_lock(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct max77759_gpio_chip *chip = gpiochip_get_data(gc);
+
+	mutex_lock(&chip->irq_lock);
+}
+
+static int max77759_gpio_bus_sync_unlock_helper(struct gpio_chip *gc,
+						struct max77759_gpio_chip *chip)
+					       __must_hold(&chip->maxq_lock)
+{
+	int ctrl, trigger, new_trigger, new_ctrl;
+	unsigned long irq_trig_changed;
+	int offset;
+	int ret;
+
+	lockdep_assert_held(&chip->maxq_lock);
+
+	ctrl = max77759_gpio_maxq_gpio_control_read(chip);
+	trigger = max77759_gpio_maxq_gpio_trigger_read(chip);
+	if (ctrl < 0 || trigger < 0) {
+		dev_err(gc->parent, "failed to read current state: %d / %d\n",
+			ctrl, trigger);
+		return (ctrl < 0) ? ctrl : trigger;
+	}
+
+	new_trigger = trigger & ~chip->irq_trig_changed;
+	new_trigger |= (chip->irq_trig & chip->irq_trig_changed);
+
+	/* change GPIO direction if required */
+	new_ctrl = ctrl;
+	irq_trig_changed = chip->irq_trig_changed;
+	for_each_set_bit(offset, &irq_trig_changed, MAX77759_N_GPIOS) {
+		new_ctrl &= ~MAX77759_GPIOx_DIR_MASK(offset);
+		new_ctrl |= MAX77759_GPIOx_DIR(offset, MAX77759_GPIO_DIR_IN);
+	}
+
+	if (new_trigger != trigger) {
+		ret = max77759_gpio_maxq_gpio_trigger_write(chip, new_trigger);
+		if (ret) {
+			dev_err(gc->parent,
+				"failed to write new trigger: %d\n", ret);
+			return ret;
+		}
+	}
+
+	if (new_ctrl != ctrl) {
+		ret = max77759_gpio_maxq_gpio_control_write(chip, new_ctrl);
+		if (ret) {
+			dev_err(gc->parent,
+				"failed to write new control: %d\n", ret);
+			return ret;
+		}
+	}
+
+	chip->irq_trig_changed = 0;
+
+	return 0;
+}
+
+static void max77759_gpio_bus_sync_unlock(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct max77759_gpio_chip *chip = gpiochip_get_data(gc);
+	int ret;
+
+	scoped_guard(mutex, &chip->maxq_lock) {
+		ret = max77759_gpio_bus_sync_unlock_helper(gc, chip);
+		if (ret)
+			goto out_unlock;
+	}
+
+	ret = regmap_update_bits(chip->map,
+				 MAX77759_MAXQ_REG_UIC_INT1_M,
+				 chip->irq_mask_changed, chip->irq_mask);
+	if (ret) {
+		dev_err(gc->parent,
+			"failed to update UIC_INT1 irq mask: %d\n", ret);
+		goto out_unlock;
+	}
+
+	chip->irq_mask_changed = 0;
+
+out_unlock:
+	mutex_unlock(&chip->irq_lock);
+}
+
+static void max77759_gpio_irq_print_chip(struct irq_data *d, struct seq_file *p)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+
+	seq_puts(p, dev_name(gc->parent));
+}
+
+static const struct irq_chip max77759_gpio_irq_chip = {
+	.irq_mask		= max77759_gpio_irq_mask,
+	.irq_unmask		= max77759_gpio_irq_unmask,
+	.irq_set_type		= max77759_gpio_set_irq_type,
+	.irq_bus_lock		= max77759_gpio_bus_lock,
+	.irq_bus_sync_unlock	= max77759_gpio_bus_sync_unlock,
+	.irq_print_chip		= max77759_gpio_irq_print_chip,
+	.flags			= IRQCHIP_IMMUTABLE,
+	GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
+
+static irqreturn_t max77759_gpio_irqhandler(int irq, void *data)
+{
+	struct max77759_gpio_chip *chip = data;
+	struct gpio_chip *gc = &chip->gc;
+	int handled = 0;
+
+	/* iterate until no interrupt is pending */
+	handled = 0;
+	while (true) {
+		unsigned int uic_int1;
+		int ret;
+		unsigned long pending;
+		int offset;
+
+		ret = regmap_read(chip->map, MAX77759_MAXQ_REG_UIC_INT1,
+				  &uic_int1);
+		if (ret < 0) {
+			dev_err_ratelimited(gc->parent,
+					    "failed to read IRQ status: %d\n",
+					    ret);
+			/*
+			 * If handled == 0, we have looped not even once, which
+			 * means we should return IRQ_NONE in that case (and
+			 * of course IRQ_HANDLED otherwise).
+			 */
+			return IRQ_RETVAL(handled);
+		}
+
+		pending = uic_int1;
+		pending &= (MAX77759_MAXQ_REG_UIC_INT1_GPIO6I
+			    | MAX77759_MAXQ_REG_UIC_INT1_GPIO5I);
+		if (!pending)
+			break;
+
+		for_each_set_bit(offset, &pending, MAX77759_N_GPIOS) {
+			unsigned int virq;
+
+			/*
+			 * ACK interrupt by writing 1 to bit 'offset', all
+			 * others need to be written as 0. This needs to be
+			 * done unconditionally hence regmap_set_bits() is
+			 * inappropriate here.
+			 */
+			regmap_write(chip->map, MAX77759_MAXQ_REG_UIC_INT1,
+				     BIT(offset));
+
+			virq = irq_find_mapping(gc->irq.domain, offset);
+			handle_nested_irq(virq);
+
+			handled = 1;
+		}
+	}
+
+	return IRQ_RETVAL(handled);
+}
+
+static int max77759_gpio_probe(struct platform_device *pdev)
+{
+	struct max77759_gpio_chip *chip;
+	int irq;
+	struct gpio_irq_chip *girq;
+	int ret;
+	unsigned long irq_flags;
+	struct irq_data *irqd;
+
+	chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->map = dev_get_regmap(pdev->dev.parent, "maxq");
+	if (!chip->map)
+		return dev_err_probe(&pdev->dev, -ENODEV, "Missing regmap\n");
+
+	irq = platform_get_irq_byname(pdev, "GPI");
+	if (irq < 0)
+		return dev_err_probe(&pdev->dev, irq, "Failed to get IRQ\n");
+
+	chip->max77759_mfd = dev_get_drvdata(pdev->dev.parent);
+	ret = devm_mutex_init(&pdev->dev, &chip->maxq_lock);
+	if (ret)
+		return ret;
+	ret = devm_mutex_init(&pdev->dev, &chip->irq_lock);
+	if (ret)
+		return ret;
+
+	chip->gc.base = -1;
+	chip->gc.label = dev_name(&pdev->dev);
+	chip->gc.parent = &pdev->dev;
+	chip->gc.owner = THIS_MODULE;
+	chip->gc.can_sleep = true;
+
+	chip->gc.names = max77759_gpio_line_names;
+	chip->gc.ngpio = MAX77759_N_GPIOS;
+	chip->gc.get_direction = max77759_gpio_get_direction;
+	chip->gc.direction_input = max77759_gpio_direction_input;
+	chip->gc.direction_output = max77759_gpio_direction_output;
+	chip->gc.get = max77759_gpio_get_value;
+	chip->gc.set = max77759_gpio_set_value;
+
+	girq = &chip->gc.irq;
+	gpio_irq_chip_set_chip(girq, &max77759_gpio_irq_chip);
+	/* This will let us handle the parent IRQ in the driver */
+	girq->parent_handler = NULL;
+	girq->num_parents = 0;
+	girq->parents = NULL;
+	girq->default_type = IRQ_TYPE_NONE;
+	girq->handler = handle_simple_irq;
+	girq->threaded = true;
+
+	ret = devm_gpiochip_add_data(&pdev->dev, &chip->gc, chip);
+	if (ret < 0)
+		return dev_err_probe(&pdev->dev, ret,
+				     "Failed to add GPIO chip\n");
+
+	irq_flags = IRQF_ONESHOT | IRQF_SHARED;
+	irqd = irq_get_irq_data(irq);
+	if (irqd)
+		irq_flags |= irqd_get_trigger_type(irqd);
+
+	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+					max77759_gpio_irqhandler, irq_flags,
+					dev_name(&pdev->dev), chip);
+	if (ret < 0)
+		return dev_err_probe(&pdev->dev, ret,
+				     "Failed to request IRQ\n");
+
+	return ret;
+}
+
+static const struct of_device_id max77759_gpio_of_id[] = {
+	{ .compatible = "maxim,max77759-gpio", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, max77759_gpio_of_id);
+
+static struct platform_driver max77759_gpio_driver = {
+	.driver = {
+		.name = "max77759-gpio",
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+		.of_match_table = max77759_gpio_of_id,
+	},
+	.probe = max77759_gpio_probe,
+};
+
+module_platform_driver(max77759_gpio_driver);
+
+MODULE_AUTHOR("André Draszik <andre.draszik@linaro.org>");
+MODULE_DESCRIPTION("GPIO driver for Maxim MAX77759");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:max77759-gpio");