diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
new file mode 100644
index 0000000..023a32c
--- /dev/null
+++ b/drivers/gpio/gpio-pca953x.c
@@ -0,0 +1,1017 @@
+/*
+ *  PCA953x 4/8/16/24/40 bit I/O ports
+ *
+ *  Copyright (C) 2005 Ben Gardner <bgardner@wabtec.com>
+ *  Copyright (C) 2007 Marvell International Ltd.
+ *
+ *  Derived from drivers/i2c/chips/pca9539.c
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; version 2 of the License.
+ */
+
+#include <linux/acpi.h>
+#include <linux/gpio/driver.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/platform_data/pca953x.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+
+#include <asm/unaligned.h>
+
+#define PCA953X_INPUT		0x00
+#define PCA953X_OUTPUT		0x01
+#define PCA953X_INVERT		0x02
+#define PCA953X_DIRECTION	0x03
+
+#define REG_ADDR_AI		0x80
+
+#define PCA957X_IN		0x00
+#define PCA957X_INVRT		0x01
+#define PCA957X_BKEN		0x02
+#define PCA957X_PUPD		0x03
+#define PCA957X_CFG		0x04
+#define PCA957X_OUT		0x05
+#define PCA957X_MSK		0x06
+#define PCA957X_INTS		0x07
+
+#define PCAL953X_OUT_STRENGTH	0x20
+#define PCAL953X_IN_LATCH	0x22
+#define PCAL953X_PULL_EN	0x23
+#define PCAL953X_PULL_SEL	0x24
+#define PCAL953X_INT_MASK	0x25
+#define PCAL953X_INT_STAT	0x26
+#define PCAL953X_OUT_CONF	0x27
+
+#define PCAL6524_INT_EDGE	0x28
+#define PCAL6524_INT_CLR	0x2a
+#define PCAL6524_IN_STATUS	0x2b
+#define PCAL6524_OUT_INDCONF	0x2c
+#define PCAL6524_DEBOUNCE	0x2d
+
+#define PCA_GPIO_MASK		0x00FF
+
+#define PCAL_GPIO_MASK		0x1f
+#define PCAL_PINCTRL_MASK	0xe0
+
+#define PCA_INT			0x0100
+#define PCA_PCAL		0x0200
+#define PCA_LATCH_INT (PCA_PCAL | PCA_INT)
+#define PCA953X_TYPE		0x1000
+#define PCA957X_TYPE		0x2000
+#define PCA_TYPE_MASK		0xF000
+
+#define PCA_CHIP_TYPE(x)	((x) & PCA_TYPE_MASK)
+
+static const struct i2c_device_id pca953x_id[] = {
+	{ "pca9505", 40 | PCA953X_TYPE | PCA_INT, },
+	{ "pca9534", 8  | PCA953X_TYPE | PCA_INT, },
+	{ "pca9535", 16 | PCA953X_TYPE | PCA_INT, },
+	{ "pca9536", 4  | PCA953X_TYPE, },
+	{ "pca9537", 4  | PCA953X_TYPE | PCA_INT, },
+	{ "pca9538", 8  | PCA953X_TYPE | PCA_INT, },
+	{ "pca9539", 16 | PCA953X_TYPE | PCA_INT, },
+	{ "pca9554", 8  | PCA953X_TYPE | PCA_INT, },
+	{ "pca9555", 16 | PCA953X_TYPE | PCA_INT, },
+	{ "pca9556", 8  | PCA953X_TYPE, },
+	{ "pca9557", 8  | PCA953X_TYPE, },
+	{ "pca9574", 8  | PCA957X_TYPE | PCA_INT, },
+	{ "pca9575", 16 | PCA957X_TYPE | PCA_INT, },
+	{ "pca9698", 40 | PCA953X_TYPE, },
+
+	{ "pcal6524", 24 | PCA953X_TYPE | PCA_INT | PCA_PCAL, },
+	{ "pcal9555a", 16 | PCA953X_TYPE | PCA_INT | PCA_PCAL, },
+
+	{ "max7310", 8  | PCA953X_TYPE, },
+	{ "max7312", 16 | PCA953X_TYPE | PCA_INT, },
+	{ "max7313", 16 | PCA953X_TYPE | PCA_INT, },
+	{ "max7315", 8  | PCA953X_TYPE | PCA_INT, },
+	{ "max7318", 16 | PCA953X_TYPE | PCA_INT, },
+	{ "pca6107", 8  | PCA953X_TYPE | PCA_INT, },
+	{ "tca6408", 8  | PCA953X_TYPE | PCA_INT, },
+	{ "tca6416", 16 | PCA953X_TYPE | PCA_INT, },
+	{ "tca6424", 24 | PCA953X_TYPE | PCA_INT, },
+	{ "tca9539", 16 | PCA953X_TYPE | PCA_INT, },
+	{ "tca9554", 8  | PCA953X_TYPE | PCA_INT, },
+	{ "xra1202", 8  | PCA953X_TYPE },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, pca953x_id);
+
+static const struct acpi_device_id pca953x_acpi_ids[] = {
+	{ "INT3491", 16 | PCA953X_TYPE | PCA_INT | PCA_PCAL, },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, pca953x_acpi_ids);
+
+#define MAX_BANK 5
+#define BANK_SZ 8
+
+#define NBANK(chip) DIV_ROUND_UP(chip->gpio_chip.ngpio, BANK_SZ)
+
+struct pca953x_reg_config {
+	int direction;
+	int output;
+	int input;
+};
+
+static const struct pca953x_reg_config pca953x_regs = {
+	.direction = PCA953X_DIRECTION,
+	.output = PCA953X_OUTPUT,
+	.input = PCA953X_INPUT,
+};
+
+static const struct pca953x_reg_config pca957x_regs = {
+	.direction = PCA957X_CFG,
+	.output = PCA957X_OUT,
+	.input = PCA957X_IN,
+};
+
+struct pca953x_chip {
+	unsigned gpio_start;
+	u8 reg_output[MAX_BANK];
+	u8 reg_direction[MAX_BANK];
+	struct mutex i2c_lock;
+
+#ifdef CONFIG_GPIO_PCA953X_IRQ
+	struct mutex irq_lock;
+	u8 irq_mask[MAX_BANK];
+	u8 irq_stat[MAX_BANK];
+	u8 irq_trig_raise[MAX_BANK];
+	u8 irq_trig_fall[MAX_BANK];
+#endif
+
+	struct i2c_client *client;
+	struct gpio_chip gpio_chip;
+	const char *const *names;
+	unsigned long driver_data;
+	struct regulator *regulator;
+
+	const struct pca953x_reg_config *regs;
+
+	int (*write_regs)(struct pca953x_chip *, int, u8 *);
+	int (*read_regs)(struct pca953x_chip *, int, u8 *);
+};
+
+static int pca953x_read_single(struct pca953x_chip *chip, int reg, u32 *val,
+				int off)
+{
+	int ret;
+	int bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ);
+	int offset = off / BANK_SZ;
+
+	ret = i2c_smbus_read_byte_data(chip->client,
+				(reg << bank_shift) + offset);
+	*val = ret;
+
+	if (ret < 0) {
+		dev_err(&chip->client->dev, "failed reading register\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int pca953x_write_single(struct pca953x_chip *chip, int reg, u32 val,
+				int off)
+{
+	int ret;
+	int bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ);
+	int offset = off / BANK_SZ;
+
+	ret = i2c_smbus_write_byte_data(chip->client,
+					(reg << bank_shift) + offset, val);
+
+	if (ret < 0) {
+		dev_err(&chip->client->dev, "failed writing register\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int pca953x_write_regs_8(struct pca953x_chip *chip, int reg, u8 *val)
+{
+	return i2c_smbus_write_byte_data(chip->client, reg, *val);
+}
+
+static int pca953x_write_regs_16(struct pca953x_chip *chip, int reg, u8 *val)
+{
+	u16 word = get_unaligned((u16 *)val);
+
+	return i2c_smbus_write_word_data(chip->client, reg << 1, word);
+}
+
+static int pca957x_write_regs_16(struct pca953x_chip *chip, int reg, u8 *val)
+{
+	int ret;
+
+	ret = i2c_smbus_write_byte_data(chip->client, reg << 1, val[0]);
+	if (ret < 0)
+		return ret;
+
+	return i2c_smbus_write_byte_data(chip->client, (reg << 1) + 1, val[1]);
+}
+
+static int pca953x_write_regs_24(struct pca953x_chip *chip, int reg, u8 *val)
+{
+	int bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ);
+	int addr = (reg & PCAL_GPIO_MASK) << bank_shift;
+	int pinctrl = (reg & PCAL_PINCTRL_MASK) << 1;
+
+	return i2c_smbus_write_i2c_block_data(chip->client,
+					      pinctrl | addr | REG_ADDR_AI,
+					      NBANK(chip), val);
+}
+
+static int pca953x_write_regs(struct pca953x_chip *chip, int reg, u8 *val)
+{
+	int ret = 0;
+
+	ret = chip->write_regs(chip, reg, val);
+	if (ret < 0) {
+		dev_err(&chip->client->dev, "failed writing register\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int pca953x_read_regs_8(struct pca953x_chip *chip, int reg, u8 *val)
+{
+	int ret;
+
+	ret = i2c_smbus_read_byte_data(chip->client, reg);
+	*val = ret;
+
+	return ret;
+}
+
+static int pca953x_read_regs_16(struct pca953x_chip *chip, int reg, u8 *val)
+{
+	int ret;
+
+	ret = i2c_smbus_read_word_data(chip->client, reg << 1);
+	put_unaligned(ret, (u16 *)val);
+
+	return ret;
+}
+
+static int pca953x_read_regs_24(struct pca953x_chip *chip, int reg, u8 *val)
+{
+	int bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ);
+	int addr = (reg & PCAL_GPIO_MASK) << bank_shift;
+	int pinctrl = (reg & PCAL_PINCTRL_MASK) << 1;
+
+	return i2c_smbus_read_i2c_block_data(chip->client,
+					     pinctrl | addr | REG_ADDR_AI,
+					     NBANK(chip), val);
+}
+
+static int pca953x_read_regs(struct pca953x_chip *chip, int reg, u8 *val)
+{
+	int ret;
+
+	ret = chip->read_regs(chip, reg, val);
+	if (ret < 0) {
+		dev_err(&chip->client->dev, "failed reading register\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int pca953x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
+{
+	struct pca953x_chip *chip = gpiochip_get_data(gc);
+	u8 reg_val;
+	int ret;
+
+	mutex_lock(&chip->i2c_lock);
+	reg_val = chip->reg_direction[off / BANK_SZ] | (1u << (off % BANK_SZ));
+
+	ret = pca953x_write_single(chip, chip->regs->direction, reg_val, off);
+	if (ret)
+		goto exit;
+
+	chip->reg_direction[off / BANK_SZ] = reg_val;
+exit:
+	mutex_unlock(&chip->i2c_lock);
+	return ret;
+}
+
+static int pca953x_gpio_direction_output(struct gpio_chip *gc,
+		unsigned off, int val)
+{
+	struct pca953x_chip *chip = gpiochip_get_data(gc);
+	u8 reg_val;
+	int ret;
+
+	mutex_lock(&chip->i2c_lock);
+	/* set output level */
+	if (val)
+		reg_val = chip->reg_output[off / BANK_SZ]
+			| (1u << (off % BANK_SZ));
+	else
+		reg_val = chip->reg_output[off / BANK_SZ]
+			& ~(1u << (off % BANK_SZ));
+
+	ret = pca953x_write_single(chip, chip->regs->output, reg_val, off);
+	if (ret)
+		goto exit;
+
+	chip->reg_output[off / BANK_SZ] = reg_val;
+
+	/* then direction */
+	reg_val = chip->reg_direction[off / BANK_SZ] & ~(1u << (off % BANK_SZ));
+	ret = pca953x_write_single(chip, chip->regs->direction, reg_val, off);
+	if (ret)
+		goto exit;
+
+	chip->reg_direction[off / BANK_SZ] = reg_val;
+exit:
+	mutex_unlock(&chip->i2c_lock);
+	return ret;
+}
+
+static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off)
+{
+	struct pca953x_chip *chip = gpiochip_get_data(gc);
+	u32 reg_val;
+	int ret;
+
+	mutex_lock(&chip->i2c_lock);
+	ret = pca953x_read_single(chip, chip->regs->input, &reg_val, off);
+	mutex_unlock(&chip->i2c_lock);
+	if (ret < 0) {
+		/* NOTE:  diagnostic already emitted; that's all we should
+		 * do unless gpio_*_value_cansleep() calls become different
+		 * from their nonsleeping siblings (and report faults).
+		 */
+		return 0;
+	}
+
+	return (reg_val & (1u << (off % BANK_SZ))) ? 1 : 0;
+}
+
+static void pca953x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
+{
+	struct pca953x_chip *chip = gpiochip_get_data(gc);
+	u8 reg_val;
+	int ret;
+
+	mutex_lock(&chip->i2c_lock);
+	if (val)
+		reg_val = chip->reg_output[off / BANK_SZ]
+			| (1u << (off % BANK_SZ));
+	else
+		reg_val = chip->reg_output[off / BANK_SZ]
+			& ~(1u << (off % BANK_SZ));
+
+	ret = pca953x_write_single(chip, chip->regs->output, reg_val, off);
+	if (ret)
+		goto exit;
+
+	chip->reg_output[off / BANK_SZ] = reg_val;
+exit:
+	mutex_unlock(&chip->i2c_lock);
+}
+
+static int pca953x_gpio_get_direction(struct gpio_chip *gc, unsigned off)
+{
+	struct pca953x_chip *chip = gpiochip_get_data(gc);
+	u32 reg_val;
+	int ret;
+
+	mutex_lock(&chip->i2c_lock);
+	ret = pca953x_read_single(chip, chip->regs->direction, &reg_val, off);
+	mutex_unlock(&chip->i2c_lock);
+	if (ret < 0)
+		return ret;
+
+	return !!(reg_val & (1u << (off % BANK_SZ)));
+}
+
+static void pca953x_gpio_set_multiple(struct gpio_chip *gc,
+				      unsigned long *mask, unsigned long *bits)
+{
+	struct pca953x_chip *chip = gpiochip_get_data(gc);
+	unsigned int bank_mask, bank_val;
+	int bank_shift, bank;
+	u8 reg_val[MAX_BANK];
+	int ret;
+
+	bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ);
+
+	mutex_lock(&chip->i2c_lock);
+	memcpy(reg_val, chip->reg_output, NBANK(chip));
+	for (bank = 0; bank < NBANK(chip); bank++) {
+		bank_mask = mask[bank / sizeof(*mask)] >>
+			   ((bank % sizeof(*mask)) * 8);
+		if (bank_mask) {
+			bank_val = bits[bank / sizeof(*bits)] >>
+				  ((bank % sizeof(*bits)) * 8);
+			bank_val &= bank_mask;
+			reg_val[bank] = (reg_val[bank] & ~bank_mask) | bank_val;
+		}
+	}
+
+	ret = i2c_smbus_write_i2c_block_data(chip->client,
+					     chip->regs->output << bank_shift,
+					     NBANK(chip), reg_val);
+	if (ret)
+		goto exit;
+
+	memcpy(chip->reg_output, reg_val, NBANK(chip));
+exit:
+	mutex_unlock(&chip->i2c_lock);
+}
+
+static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios)
+{
+	struct gpio_chip *gc;
+
+	gc = &chip->gpio_chip;
+
+	gc->direction_input  = pca953x_gpio_direction_input;
+	gc->direction_output = pca953x_gpio_direction_output;
+	gc->get = pca953x_gpio_get_value;
+	gc->set = pca953x_gpio_set_value;
+	gc->get_direction = pca953x_gpio_get_direction;
+	gc->set_multiple = pca953x_gpio_set_multiple;
+	gc->can_sleep = true;
+
+	gc->base = chip->gpio_start;
+	gc->ngpio = gpios;
+	gc->label = chip->client->name;
+	gc->parent = &chip->client->dev;
+	gc->owner = THIS_MODULE;
+	gc->names = chip->names;
+}
+
+#ifdef CONFIG_GPIO_PCA953X_IRQ
+static void pca953x_irq_mask(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct pca953x_chip *chip = gpiochip_get_data(gc);
+
+	chip->irq_mask[d->hwirq / BANK_SZ] &= ~(1 << (d->hwirq % BANK_SZ));
+}
+
+static void pca953x_irq_unmask(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct pca953x_chip *chip = gpiochip_get_data(gc);
+
+	chip->irq_mask[d->hwirq / BANK_SZ] |= 1 << (d->hwirq % BANK_SZ);
+}
+
+static void pca953x_irq_bus_lock(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct pca953x_chip *chip = gpiochip_get_data(gc);
+
+	mutex_lock(&chip->irq_lock);
+}
+
+static void pca953x_irq_bus_sync_unlock(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct pca953x_chip *chip = gpiochip_get_data(gc);
+	u8 new_irqs;
+	int level, i;
+	u8 invert_irq_mask[MAX_BANK];
+
+	if (chip->driver_data & PCA_PCAL) {
+		/* Enable latch on interrupt-enabled inputs */
+		pca953x_write_regs(chip, PCAL953X_IN_LATCH, chip->irq_mask);
+
+		for (i = 0; i < NBANK(chip); i++)
+			invert_irq_mask[i] = ~chip->irq_mask[i];
+
+		/* Unmask enabled interrupts */
+		pca953x_write_regs(chip, PCAL953X_INT_MASK, invert_irq_mask);
+	}
+
+	/* Look for any newly setup interrupt */
+	for (i = 0; i < NBANK(chip); i++) {
+		new_irqs = chip->irq_trig_fall[i] | chip->irq_trig_raise[i];
+		new_irqs &= ~chip->reg_direction[i];
+
+		while (new_irqs) {
+			level = __ffs(new_irqs);
+			pca953x_gpio_direction_input(&chip->gpio_chip,
+							level + (BANK_SZ * i));
+			new_irqs &= ~(1 << level);
+		}
+	}
+
+	mutex_unlock(&chip->irq_lock);
+}
+
+static int pca953x_irq_set_type(struct irq_data *d, unsigned int type)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct pca953x_chip *chip = gpiochip_get_data(gc);
+	int bank_nb = d->hwirq / BANK_SZ;
+	u8 mask = 1 << (d->hwirq % BANK_SZ);
+
+	if (!(type & IRQ_TYPE_EDGE_BOTH)) {
+		dev_err(&chip->client->dev, "irq %d: unsupported type %d\n",
+			d->irq, type);
+		return -EINVAL;
+	}
+
+	if (type & IRQ_TYPE_EDGE_FALLING)
+		chip->irq_trig_fall[bank_nb] |= mask;
+	else
+		chip->irq_trig_fall[bank_nb] &= ~mask;
+
+	if (type & IRQ_TYPE_EDGE_RISING)
+		chip->irq_trig_raise[bank_nb] |= mask;
+	else
+		chip->irq_trig_raise[bank_nb] &= ~mask;
+
+	return 0;
+}
+
+static void pca953x_irq_shutdown(struct irq_data *d)
+{
+	struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);
+	u8 mask = 1 << (d->hwirq % BANK_SZ);
+
+	chip->irq_trig_raise[d->hwirq / BANK_SZ] &= ~mask;
+	chip->irq_trig_fall[d->hwirq / BANK_SZ] &= ~mask;
+}
+
+static struct irq_chip pca953x_irq_chip = {
+	.name			= "pca953x",
+	.irq_mask		= pca953x_irq_mask,
+	.irq_unmask		= pca953x_irq_unmask,
+	.irq_bus_lock		= pca953x_irq_bus_lock,
+	.irq_bus_sync_unlock	= pca953x_irq_bus_sync_unlock,
+	.irq_set_type		= pca953x_irq_set_type,
+	.irq_shutdown		= pca953x_irq_shutdown,
+};
+
+static bool pca953x_irq_pending(struct pca953x_chip *chip, u8 *pending)
+{
+	u8 cur_stat[MAX_BANK];
+	u8 old_stat[MAX_BANK];
+	bool pending_seen = false;
+	bool trigger_seen = false;
+	u8 trigger[MAX_BANK];
+	int ret, i;
+
+	if (chip->driver_data & PCA_PCAL) {
+		/* Read the current interrupt status from the device */
+		ret = pca953x_read_regs(chip, PCAL953X_INT_STAT, trigger);
+		if (ret)
+			return false;
+
+		/* Check latched inputs and clear interrupt status */
+		ret = pca953x_read_regs(chip, PCA953X_INPUT, cur_stat);
+		if (ret)
+			return false;
+
+		for (i = 0; i < NBANK(chip); i++) {
+			/* Apply filter for rising/falling edge selection */
+			pending[i] = (~cur_stat[i] & chip->irq_trig_fall[i]) |
+				(cur_stat[i] & chip->irq_trig_raise[i]);
+			pending[i] &= trigger[i];
+			if (pending[i])
+				pending_seen = true;
+		}
+
+		return pending_seen;
+	}
+
+	ret = pca953x_read_regs(chip, chip->regs->input, cur_stat);
+	if (ret)
+		return false;
+
+	/* Remove output pins from the equation */
+	for (i = 0; i < NBANK(chip); i++)
+		cur_stat[i] &= chip->reg_direction[i];
+
+	memcpy(old_stat, chip->irq_stat, NBANK(chip));
+
+	for (i = 0; i < NBANK(chip); i++) {
+		trigger[i] = (cur_stat[i] ^ old_stat[i]) & chip->irq_mask[i];
+		if (trigger[i])
+			trigger_seen = true;
+	}
+
+	if (!trigger_seen)
+		return false;
+
+	memcpy(chip->irq_stat, cur_stat, NBANK(chip));
+
+	for (i = 0; i < NBANK(chip); i++) {
+		pending[i] = (old_stat[i] & chip->irq_trig_fall[i]) |
+			(cur_stat[i] & chip->irq_trig_raise[i]);
+		pending[i] &= trigger[i];
+		if (pending[i])
+			pending_seen = true;
+	}
+
+	return pending_seen;
+}
+
+static irqreturn_t pca953x_irq_handler(int irq, void *devid)
+{
+	struct pca953x_chip *chip = devid;
+	u8 pending[MAX_BANK];
+	u8 level;
+	unsigned nhandled = 0;
+	int i;
+
+	if (!pca953x_irq_pending(chip, pending))
+		return IRQ_NONE;
+
+	for (i = 0; i < NBANK(chip); i++) {
+		while (pending[i]) {
+			level = __ffs(pending[i]);
+			handle_nested_irq(irq_find_mapping(chip->gpio_chip.irq.domain,
+							level + (BANK_SZ * i)));
+			pending[i] &= ~(1 << level);
+			nhandled++;
+		}
+	}
+
+	return (nhandled > 0) ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static int pca953x_irq_setup(struct pca953x_chip *chip,
+			     int irq_base)
+{
+	struct i2c_client *client = chip->client;
+	int ret, i;
+
+	if (client->irq && irq_base != -1
+			&& (chip->driver_data & PCA_INT)) {
+		ret = pca953x_read_regs(chip,
+					chip->regs->input, chip->irq_stat);
+		if (ret)
+			return ret;
+
+		/*
+		 * There is no way to know which GPIO line generated the
+		 * interrupt.  We have to rely on the previous read for
+		 * this purpose.
+		 */
+		for (i = 0; i < NBANK(chip); i++)
+			chip->irq_stat[i] &= chip->reg_direction[i];
+		mutex_init(&chip->irq_lock);
+
+		ret = devm_request_threaded_irq(&client->dev,
+					client->irq,
+					   NULL,
+					   pca953x_irq_handler,
+					   IRQF_TRIGGER_LOW | IRQF_ONESHOT |
+						   IRQF_SHARED,
+					   dev_name(&client->dev), chip);
+		if (ret) {
+			dev_err(&client->dev, "failed to request irq %d\n",
+				client->irq);
+			return ret;
+		}
+
+		ret =  gpiochip_irqchip_add_nested(&chip->gpio_chip,
+						   &pca953x_irq_chip,
+						   irq_base,
+						   handle_simple_irq,
+						   IRQ_TYPE_NONE);
+		if (ret) {
+			dev_err(&client->dev,
+				"could not connect irqchip to gpiochip\n");
+			return ret;
+		}
+
+		gpiochip_set_nested_irqchip(&chip->gpio_chip,
+					    &pca953x_irq_chip,
+					    client->irq);
+	}
+
+	return 0;
+}
+
+#else /* CONFIG_GPIO_PCA953X_IRQ */
+static int pca953x_irq_setup(struct pca953x_chip *chip,
+			     int irq_base)
+{
+	struct i2c_client *client = chip->client;
+
+	if (client->irq && irq_base != -1 && (chip->driver_data & PCA_INT))
+		dev_warn(&client->dev, "interrupt support not compiled in\n");
+
+	return 0;
+}
+#endif
+
+static int device_pca953x_init(struct pca953x_chip *chip, u32 invert)
+{
+	int ret;
+	u8 val[MAX_BANK];
+
+	chip->regs = &pca953x_regs;
+
+	ret = pca953x_read_regs(chip, chip->regs->output, chip->reg_output);
+	if (ret)
+		goto out;
+
+	ret = pca953x_read_regs(chip, chip->regs->direction,
+				chip->reg_direction);
+	if (ret)
+		goto out;
+
+	/* set platform specific polarity inversion */
+	if (invert)
+		memset(val, 0xFF, NBANK(chip));
+	else
+		memset(val, 0, NBANK(chip));
+
+	ret = pca953x_write_regs(chip, PCA953X_INVERT, val);
+out:
+	return ret;
+}
+
+static int device_pca957x_init(struct pca953x_chip *chip, u32 invert)
+{
+	int ret;
+	u8 val[MAX_BANK];
+
+	chip->regs = &pca957x_regs;
+
+	ret = pca953x_read_regs(chip, chip->regs->output, chip->reg_output);
+	if (ret)
+		goto out;
+	ret = pca953x_read_regs(chip, chip->regs->direction,
+				chip->reg_direction);
+	if (ret)
+		goto out;
+
+	/* set platform specific polarity inversion */
+	if (invert)
+		memset(val, 0xFF, NBANK(chip));
+	else
+		memset(val, 0, NBANK(chip));
+	ret = pca953x_write_regs(chip, PCA957X_INVRT, val);
+	if (ret)
+		goto out;
+
+	/* To enable register 6, 7 to control pull up and pull down */
+	memset(val, 0x02, NBANK(chip));
+	ret = pca953x_write_regs(chip, PCA957X_BKEN, val);
+	if (ret)
+		goto out;
+
+	return 0;
+out:
+	return ret;
+}
+
+static const struct of_device_id pca953x_dt_ids[];
+
+static int pca953x_probe(struct i2c_client *client,
+				   const struct i2c_device_id *i2c_id)
+{
+	struct pca953x_platform_data *pdata;
+	struct pca953x_chip *chip;
+	int irq_base = 0;
+	int ret;
+	u32 invert = 0;
+	struct regulator *reg;
+
+	chip = devm_kzalloc(&client->dev,
+			sizeof(struct pca953x_chip), GFP_KERNEL);
+	if (chip == NULL)
+		return -ENOMEM;
+
+	pdata = dev_get_platdata(&client->dev);
+	if (pdata) {
+		irq_base = pdata->irq_base;
+		chip->gpio_start = pdata->gpio_base;
+		invert = pdata->invert;
+		chip->names = pdata->names;
+	} else {
+		struct gpio_desc *reset_gpio;
+
+		chip->gpio_start = -1;
+		irq_base = 0;
+
+		/*
+		 * See if we need to de-assert a reset pin.
+		 *
+		 * There is no known ACPI-enabled platforms that are
+		 * using "reset" GPIO. Otherwise any of those platform
+		 * must use _DSD method with corresponding property.
+		 */
+		reset_gpio = devm_gpiod_get_optional(&client->dev, "reset",
+						     GPIOD_OUT_LOW);
+		if (IS_ERR(reset_gpio))
+			return PTR_ERR(reset_gpio);
+	}
+
+	chip->client = client;
+
+	reg = devm_regulator_get(&client->dev, "vcc");
+	if (IS_ERR(reg)) {
+		ret = PTR_ERR(reg);
+		if (ret != -EPROBE_DEFER)
+			dev_err(&client->dev, "reg get err: %d\n", ret);
+		return ret;
+	}
+	ret = regulator_enable(reg);
+	if (ret) {
+		dev_err(&client->dev, "reg en err: %d\n", ret);
+		return ret;
+	}
+	chip->regulator = reg;
+
+	if (i2c_id) {
+		chip->driver_data = i2c_id->driver_data;
+	} else {
+		const struct acpi_device_id *acpi_id;
+		struct device *dev = &client->dev;
+
+		chip->driver_data = (uintptr_t)of_device_get_match_data(dev);
+		if (!chip->driver_data) {
+			acpi_id = acpi_match_device(pca953x_acpi_ids, dev);
+			if (!acpi_id) {
+				ret = -ENODEV;
+				goto err_exit;
+			}
+
+			chip->driver_data = acpi_id->driver_data;
+		}
+	}
+
+	mutex_init(&chip->i2c_lock);
+	/*
+	 * In case we have an i2c-mux controlled by a GPIO provided by an
+	 * expander using the same driver higher on the device tree, read the
+	 * i2c adapter nesting depth and use the retrieved value as lockdep
+	 * subclass for chip->i2c_lock.
+	 *
+	 * REVISIT: This solution is not complete. It protects us from lockdep
+	 * false positives when the expander controlling the i2c-mux is on
+	 * a different level on the device tree, but not when it's on the same
+	 * level on a different branch (in which case the subclass number
+	 * would be the same).
+	 *
+	 * TODO: Once a correct solution is developed, a similar fix should be
+	 * applied to all other i2c-controlled GPIO expanders (and potentially
+	 * regmap-i2c).
+	 */
+	lockdep_set_subclass(&chip->i2c_lock,
+			     i2c_adapter_depth(client->adapter));
+
+	/* initialize cached registers from their original values.
+	 * we can't share this chip with another i2c master.
+	 */
+	pca953x_setup_gpio(chip, chip->driver_data & PCA_GPIO_MASK);
+
+	if (chip->gpio_chip.ngpio <= 8) {
+		chip->write_regs = pca953x_write_regs_8;
+		chip->read_regs = pca953x_read_regs_8;
+	} else if (chip->gpio_chip.ngpio >= 24) {
+		chip->write_regs = pca953x_write_regs_24;
+		chip->read_regs = pca953x_read_regs_24;
+	} else {
+		if (PCA_CHIP_TYPE(chip->driver_data) == PCA953X_TYPE)
+			chip->write_regs = pca953x_write_regs_16;
+		else
+			chip->write_regs = pca957x_write_regs_16;
+		chip->read_regs = pca953x_read_regs_16;
+	}
+
+	if (PCA_CHIP_TYPE(chip->driver_data) == PCA953X_TYPE)
+		ret = device_pca953x_init(chip, invert);
+	else
+		ret = device_pca957x_init(chip, invert);
+	if (ret)
+		goto err_exit;
+
+	ret = devm_gpiochip_add_data(&client->dev, &chip->gpio_chip, chip);
+	if (ret)
+		goto err_exit;
+
+	ret = pca953x_irq_setup(chip, irq_base);
+	if (ret)
+		goto err_exit;
+
+	if (pdata && pdata->setup) {
+		ret = pdata->setup(client, chip->gpio_chip.base,
+				chip->gpio_chip.ngpio, pdata->context);
+		if (ret < 0)
+			dev_warn(&client->dev, "setup failed, %d\n", ret);
+	}
+
+	i2c_set_clientdata(client, chip);
+	return 0;
+
+err_exit:
+	regulator_disable(chip->regulator);
+	return ret;
+}
+
+static int pca953x_remove(struct i2c_client *client)
+{
+	struct pca953x_platform_data *pdata = dev_get_platdata(&client->dev);
+	struct pca953x_chip *chip = i2c_get_clientdata(client);
+	int ret;
+
+	if (pdata && pdata->teardown) {
+		ret = pdata->teardown(client, chip->gpio_chip.base,
+				chip->gpio_chip.ngpio, pdata->context);
+		if (ret < 0)
+			dev_err(&client->dev, "%s failed, %d\n",
+					"teardown", ret);
+	} else {
+		ret = 0;
+	}
+
+	regulator_disable(chip->regulator);
+
+	return ret;
+}
+
+/* convenience to stop overlong match-table lines */
+#define OF_953X(__nrgpio, __int) (void *)(__nrgpio | PCA953X_TYPE | __int)
+#define OF_957X(__nrgpio, __int) (void *)(__nrgpio | PCA957X_TYPE | __int)
+
+static const struct of_device_id pca953x_dt_ids[] = {
+	{ .compatible = "nxp,pca9505", .data = OF_953X(40, PCA_INT), },
+	{ .compatible = "nxp,pca9534", .data = OF_953X( 8, PCA_INT), },
+	{ .compatible = "nxp,pca9535", .data = OF_953X(16, PCA_INT), },
+	{ .compatible = "nxp,pca9536", .data = OF_953X( 4, 0), },
+	{ .compatible = "nxp,pca9537", .data = OF_953X( 4, PCA_INT), },
+	{ .compatible = "nxp,pca9538", .data = OF_953X( 8, PCA_INT), },
+	{ .compatible = "nxp,pca9539", .data = OF_953X(16, PCA_INT), },
+	{ .compatible = "nxp,pca9554", .data = OF_953X( 8, PCA_INT), },
+	{ .compatible = "nxp,pca9555", .data = OF_953X(16, PCA_INT), },
+	{ .compatible = "nxp,pca9556", .data = OF_953X( 8, 0), },
+	{ .compatible = "nxp,pca9557", .data = OF_953X( 8, 0), },
+	{ .compatible = "nxp,pca9574", .data = OF_957X( 8, PCA_INT), },
+	{ .compatible = "nxp,pca9575", .data = OF_957X(16, PCA_INT), },
+	{ .compatible = "nxp,pca9698", .data = OF_953X(40, 0), },
+
+	{ .compatible = "nxp,pcal6524", .data = OF_953X(24, PCA_LATCH_INT), },
+	{ .compatible = "nxp,pcal9555a", .data = OF_953X(16, PCA_LATCH_INT), },
+
+	{ .compatible = "maxim,max7310", .data = OF_953X( 8, 0), },
+	{ .compatible = "maxim,max7312", .data = OF_953X(16, PCA_INT), },
+	{ .compatible = "maxim,max7313", .data = OF_953X(16, PCA_INT), },
+	{ .compatible = "maxim,max7315", .data = OF_953X( 8, PCA_INT), },
+	{ .compatible = "maxim,max7318", .data = OF_953X(16, PCA_INT), },
+
+	{ .compatible = "ti,pca6107", .data = OF_953X( 8, PCA_INT), },
+	{ .compatible = "ti,pca9536", .data = OF_953X( 4, 0), },
+	{ .compatible = "ti,tca6408", .data = OF_953X( 8, PCA_INT), },
+	{ .compatible = "ti,tca6416", .data = OF_953X(16, PCA_INT), },
+	{ .compatible = "ti,tca6424", .data = OF_953X(24, PCA_INT), },
+
+	{ .compatible = "onnn,pca9654", .data = OF_953X( 8, PCA_INT), },
+
+	{ .compatible = "exar,xra1202", .data = OF_953X( 8, 0), },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(of, pca953x_dt_ids);
+
+static struct i2c_driver pca953x_driver = {
+	.driver = {
+		.name	= "pca953x",
+		.of_match_table = pca953x_dt_ids,
+		.acpi_match_table = ACPI_PTR(pca953x_acpi_ids),
+	},
+	.probe		= pca953x_probe,
+	.remove		= pca953x_remove,
+	.id_table	= pca953x_id,
+};
+
+static int __init pca953x_init(void)
+{
+	return i2c_add_driver(&pca953x_driver);
+}
+/* register after i2c postcore initcall and before
+ * subsys initcalls that may rely on these GPIOs
+ */
+subsys_initcall(pca953x_init);
+
+static void __exit pca953x_exit(void)
+{
+	i2c_del_driver(&pca953x_driver);
+}
+module_exit(pca953x_exit);
+
+MODULE_AUTHOR("eric miao <eric.miao@marvell.com>");
+MODULE_DESCRIPTION("GPIO expander driver for PCA953x");
+MODULE_LICENSE("GPL");