drivers/gpio/gpio-adp5588.c - linux - Git at Google

 /*
  * GPIO Chip driver for Analog Devices
  * ADP5588/ADP5587 I/O Expander and QWERTY Keypad Controller
  *
  * Copyright 2009-2010 Analog Devices Inc.
  *
  * Licensed under the GPL-2 or later.
  */

 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/i2c.h>
 #include <linux/gpio.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>

 #include <linux/i2c/adp5588.h>

 #define DRV_NAME	"adp5588-gpio"

 /*
  * Early pre 4.0 Silicon required to delay readout by at least 25ms,
  * since the Event Counter Register updated 25ms after the interrupt
  * asserted.
  */
 #define WA_DELAYED_READOUT_REVID(rev)	((rev) < 4)

 struct adp5588_gpio {
 	struct i2c_client *client;
 	struct gpio_chip gpio_chip;
 	struct mutex lock;	/* protect cached dir, dat_out */
 	/* protect serialized access to the interrupt controller bus */
 	struct mutex irq_lock;
 	unsigned gpio_start;
 	unsigned irq_base;
 	uint8_t dat_out[3];
 	uint8_t dir[3];
 	uint8_t int_lvl[3];
 	uint8_t int_en[3];
 	uint8_t irq_mask[3];
 	uint8_t irq_stat[3];
 };

 static int adp5588_gpio_read(struct i2c_client *client, u8 reg)
 {
 	int ret = i2c_smbus_read_byte_data(client, reg);

 	if (ret < 0)
 		dev_err(&client->dev, "Read Error\n");

 	return ret;
 }

 static int adp5588_gpio_write(struct i2c_client *client, u8 reg, u8 val)
 {
 	int ret = i2c_smbus_write_byte_data(client, reg, val);

 	if (ret < 0)
 		dev_err(&client->dev, "Write Error\n");

 	return ret;
 }

 static int adp5588_gpio_get_value(struct gpio_chip *chip, unsigned off)
 {
 	struct adp5588_gpio *dev = gpiochip_get_data(chip);
 	unsigned bank = ADP5588_BANK(off);
 	unsigned bit = ADP5588_BIT(off);
 	int val;

 	mutex_lock(&dev->lock);

 	if (dev->dir[bank] & bit)
 		val = dev->dat_out[bank];
 	else
 		val = adp5588_gpio_read(dev->client, GPIO_DAT_STAT1 + bank);

 	mutex_unlock(&dev->lock);

 	return !!(val & bit);
 }

 static void adp5588_gpio_set_value(struct gpio_chip *chip,
 				   unsigned off, int val)
 {
 	unsigned bank, bit;
 	struct adp5588_gpio *dev = gpiochip_get_data(chip);

 	bank = ADP5588_BANK(off);
 	bit = ADP5588_BIT(off);

 	mutex_lock(&dev->lock);
 	if (val)
 		dev->dat_out[bank] |= bit;
 	else
 		dev->dat_out[bank] &= ~bit;

 	adp5588_gpio_write(dev->client, GPIO_DAT_OUT1 + bank,
 			   dev->dat_out[bank]);
 	mutex_unlock(&dev->lock);
 }

 static int adp5588_gpio_direction_input(struct gpio_chip *chip, unsigned off)
 {
 	int ret;
 	unsigned bank;
 	struct adp5588_gpio *dev = gpiochip_get_data(chip);

 	bank = ADP5588_BANK(off);

 	mutex_lock(&dev->lock);
 	dev->dir[bank] &= ~ADP5588_BIT(off);
 	ret = adp5588_gpio_write(dev->client, GPIO_DIR1 + bank, dev->dir[bank]);
 	mutex_unlock(&dev->lock);

 	return ret;
 }

 static int adp5588_gpio_direction_output(struct gpio_chip *chip,
 					 unsigned off, int val)
 {
 	int ret;
 	unsigned bank, bit;
 	struct adp5588_gpio *dev = gpiochip_get_data(chip);

 	bank = ADP5588_BANK(off);
 	bit = ADP5588_BIT(off);

 	mutex_lock(&dev->lock);
 	dev->dir[bank] |= bit;

 	if (val)
 		dev->dat_out[bank] |= bit;
 	else
 		dev->dat_out[bank] &= ~bit;

 	ret = adp5588_gpio_write(dev->client, GPIO_DAT_OUT1 + bank,
 				 dev->dat_out[bank]);
 	ret |= adp5588_gpio_write(dev->client, GPIO_DIR1 + bank,
 				 dev->dir[bank]);
 	mutex_unlock(&dev->lock);

 	return ret;
 }

 #ifdef CONFIG_GPIO_ADP5588_IRQ
 static int adp5588_gpio_to_irq(struct gpio_chip *chip, unsigned off)
 {
 	struct adp5588_gpio *dev = gpiochip_get_data(chip);

 	return dev->irq_base + off;
 }

 static void adp5588_irq_bus_lock(struct irq_data *d)
 {
 	struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);

 	mutex_lock(&dev->irq_lock);
 }

  /*
   * genirq core code can issue chip->mask/unmask from atomic context.
   * This doesn't work for slow busses where an access needs to sleep.
   * bus_sync_unlock() is therefore called outside the atomic context,
   * syncs the current irq mask state with the slow external controller
   * and unlocks the bus.
   */

 static void adp5588_irq_bus_sync_unlock(struct irq_data *d)
 {
 	struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
 	int i;

 	for (i = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++)
 		if (dev->int_en[i] ^ dev->irq_mask[i]) {
 			dev->int_en[i] = dev->irq_mask[i];
 			adp5588_gpio_write(dev->client, GPIO_INT_EN1 + i,
 					   dev->int_en[i]);
 		}

 	mutex_unlock(&dev->irq_lock);
 }

 static void adp5588_irq_mask(struct irq_data *d)
 {
 	struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
 	unsigned gpio = d->irq - dev->irq_base;

 	dev->irq_mask[ADP5588_BANK(gpio)] &= ~ADP5588_BIT(gpio);
 }

 static void adp5588_irq_unmask(struct irq_data *d)
 {
 	struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
 	unsigned gpio = d->irq - dev->irq_base;

 	dev->irq_mask[ADP5588_BANK(gpio)] |= ADP5588_BIT(gpio);
 }

 static int adp5588_irq_set_type(struct irq_data *d, unsigned int type)
 {
 	struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
 	uint16_t gpio = d->irq - dev->irq_base;
 	unsigned bank, bit;

 	if ((type & IRQ_TYPE_EDGE_BOTH)) {
 		dev_err(&dev->client->dev, "irq %d: unsupported type %d\n",
 			d->irq, type);
 		return -EINVAL;
 	}

 	bank = ADP5588_BANK(gpio);
 	bit = ADP5588_BIT(gpio);

 	if (type & IRQ_TYPE_LEVEL_HIGH)
 		dev->int_lvl[bank] |= bit;
 	else if (type & IRQ_TYPE_LEVEL_LOW)
 		dev->int_lvl[bank] &= ~bit;
 	else
 		return -EINVAL;

 	adp5588_gpio_direction_input(&dev->gpio_chip, gpio);
 	adp5588_gpio_write(dev->client, GPIO_INT_LVL1 + bank,
 			   dev->int_lvl[bank]);

 	return 0;
 }

 static struct irq_chip adp5588_irq_chip = {
 	.name			= "adp5588",
 	.irq_mask		= adp5588_irq_mask,
 	.irq_unmask		= adp5588_irq_unmask,
 	.irq_bus_lock		= adp5588_irq_bus_lock,
 	.irq_bus_sync_unlock	= adp5588_irq_bus_sync_unlock,
 	.irq_set_type		= adp5588_irq_set_type,
 };

 static int adp5588_gpio_read_intstat(struct i2c_client *client, u8 *buf)
 {
 	int ret = i2c_smbus_read_i2c_block_data(client, GPIO_INT_STAT1, 3, buf);

 	if (ret < 0)
 		dev_err(&client->dev, "Read INT_STAT Error\n");

 	return ret;
 }

 static irqreturn_t adp5588_irq_handler(int irq, void *devid)
 {
 	struct adp5588_gpio *dev = devid;
 	unsigned status, bank, bit, pending;
 	int ret;
 	status = adp5588_gpio_read(dev->client, INT_STAT);

 	if (status & ADP5588_GPI_INT) {
 		ret = adp5588_gpio_read_intstat(dev->client, dev->irq_stat);
 		if (ret < 0)
 			memset(dev->irq_stat, 0, ARRAY_SIZE(dev->irq_stat));

 		for (bank = 0, bit = 0; bank <= ADP5588_BANK(ADP5588_MAXGPIO);
 			bank++, bit = 0) {
 			pending = dev->irq_stat[bank] & dev->irq_mask[bank];

 			while (pending) {
 				if (pending & (1 << bit)) {
 					handle_nested_irq(dev->irq_base +
 							  (bank << 3) + bit);
 					pending &= ~(1 << bit);

 				}
 				bit++;
 			}
 		}
 	}

 	adp5588_gpio_write(dev->client, INT_STAT, status); /* Status is W1C */

 	return IRQ_HANDLED;
 }

 static int adp5588_irq_setup(struct adp5588_gpio *dev)
 {
 	struct i2c_client *client = dev->client;
 	struct adp5588_gpio_platform_data *pdata =
 			dev_get_platdata(&client->dev);
 	unsigned gpio;
 	int ret;

 	adp5588_gpio_write(client, CFG, ADP5588_AUTO_INC);
 	adp5588_gpio_write(client, INT_STAT, -1); /* status is W1C */
 	adp5588_gpio_read_intstat(client, dev->irq_stat); /* read to clear */

 	dev->irq_base = pdata->irq_base;
 	mutex_init(&dev->irq_lock);

 	for (gpio = 0; gpio < dev->gpio_chip.ngpio; gpio++) {
 		int irq = gpio + dev->irq_base;
 		irq_set_chip_data(irq, dev);
 		irq_set_chip_and_handler(irq, &adp5588_irq_chip,
 					 handle_level_irq);
 		irq_set_nested_thread(irq, 1);
 		irq_modify_status(irq, IRQ_NOREQUEST, IRQ_NOPROBE);
 	}

 	ret = request_threaded_irq(client->irq,
 				   NULL,
 				   adp5588_irq_handler,
 				   IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 				   dev_name(&client->dev), dev);
 	if (ret) {
 		dev_err(&client->dev, "failed to request irq %d\n",
 			client->irq);
 		goto out;
 	}

 	dev->gpio_chip.to_irq = adp5588_gpio_to_irq;
 	adp5588_gpio_write(client, CFG,
 		ADP5588_AUTO_INC | ADP5588_INT_CFG | ADP5588_GPI_INT);

 	return 0;

 out:
 	dev->irq_base = 0;
 	return ret;
 }

 static void adp5588_irq_teardown(struct adp5588_gpio *dev)
 {
 	if (dev->irq_base)
 		free_irq(dev->client->irq, dev);
 }

 #else
 static int adp5588_irq_setup(struct adp5588_gpio *dev)
 {
 	struct i2c_client *client = dev->client;
 	dev_warn(&client->dev, "interrupt support not compiled in\n");

 	return 0;
 }

 static void adp5588_irq_teardown(struct adp5588_gpio *dev)
 {
 }
 #endif /* CONFIG_GPIO_ADP5588_IRQ */

 static int adp5588_gpio_probe(struct i2c_client *client,
 					const struct i2c_device_id *id)
 {
 	struct adp5588_gpio_platform_data *pdata =
 			dev_get_platdata(&client->dev);
 	struct adp5588_gpio *dev;
 	struct gpio_chip *gc;
 	int ret, i, revid;

 	if (!pdata) {
 		dev_err(&client->dev, "missing platform data\n");
 		return -ENODEV;
 	}

 	if (!i2c_check_functionality(client->adapter,
 					I2C_FUNC_SMBUS_BYTE_DATA)) {
 		dev_err(&client->dev, "SMBUS Byte Data not Supported\n");
 		return -EIO;
 	}

 	dev = devm_kzalloc(&client->dev, sizeof(*dev), GFP_KERNEL);
 	if (!dev)
 		return -ENOMEM;

 	dev->client = client;

 	gc = &dev->gpio_chip;
 	gc->direction_input = adp5588_gpio_direction_input;
 	gc->direction_output = adp5588_gpio_direction_output;
 	gc->get = adp5588_gpio_get_value;
 	gc->set = adp5588_gpio_set_value;
 	gc->can_sleep = true;

 	gc->base = pdata->gpio_start;
 	gc->ngpio = ADP5588_MAXGPIO;
 	gc->label = client->name;
 	gc->owner = THIS_MODULE;
 	gc->names = pdata->names;

 	mutex_init(&dev->lock);

 	ret = adp5588_gpio_read(dev->client, DEV_ID);
 	if (ret < 0)
 		goto err;

 	revid = ret & ADP5588_DEVICE_ID_MASK;

 	for (i = 0, ret = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++) {
 		dev->dat_out[i] = adp5588_gpio_read(client, GPIO_DAT_OUT1 + i);
 		dev->dir[i] = adp5588_gpio_read(client, GPIO_DIR1 + i);
 		ret |= adp5588_gpio_write(client, KP_GPIO1 + i, 0);
 		ret |= adp5588_gpio_write(client, GPIO_PULL1 + i,
 				(pdata->pullup_dis_mask >> (8 * i)) & 0xFF);
 		ret |= adp5588_gpio_write(client, GPIO_INT_EN1 + i, 0);
 		if (ret)
 			goto err;
 	}

 	if (pdata->irq_base) {
 		if (WA_DELAYED_READOUT_REVID(revid)) {
 			dev_warn(&client->dev, "GPIO int not supported\n");
 		} else {
 			ret = adp5588_irq_setup(dev);
 			if (ret)
 				goto err;
 		}
 	}

 	ret = gpiochip_add_data(&dev->gpio_chip, dev);
 	if (ret)
 		goto err_irq;

 	dev_info(&client->dev, "IRQ Base: %d Rev.: %d\n",
 			pdata->irq_base, revid);

 	if (pdata->setup) {
 		ret = pdata->setup(client, gc->base, gc->ngpio, pdata->context);
 		if (ret < 0)
 			dev_warn(&client->dev, "setup failed, %d\n", ret);
 	}

 	i2c_set_clientdata(client, dev);

 	return 0;

 err_irq:
 	adp5588_irq_teardown(dev);
 err:
 	return ret;
 }

 static int adp5588_gpio_remove(struct i2c_client *client)
 {
 	struct adp5588_gpio_platform_data *pdata =
 			dev_get_platdata(&client->dev);
 	struct adp5588_gpio *dev = i2c_get_clientdata(client);
 	int ret;

 	if (pdata->teardown) {
 		ret = pdata->teardown(client,
 				      dev->gpio_chip.base, dev->gpio_chip.ngpio,
 				      pdata->context);
 		if (ret < 0) {
 			dev_err(&client->dev, "teardown failed %d\n", ret);
 			return ret;
 		}
 	}

 	if (dev->irq_base)
 		free_irq(dev->client->irq, dev);

 	gpiochip_remove(&dev->gpio_chip);

 	return 0;
 }

 static const struct i2c_device_id adp5588_gpio_id[] = {
 	{DRV_NAME, 0},
 	{}
 };

 MODULE_DEVICE_TABLE(i2c, adp5588_gpio_id);

 static struct i2c_driver adp5588_gpio_driver = {
 	.driver = {
 		   .name = DRV_NAME,
 		   },
 	.probe = adp5588_gpio_probe,
 	.remove = adp5588_gpio_remove,
 	.id_table = adp5588_gpio_id,
 };

 module_i2c_driver(adp5588_gpio_driver);

 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 MODULE_DESCRIPTION("GPIO ADP5588 Driver");
 MODULE_LICENSE("GPL");
	/*
	* GPIO Chip driver for Analog Devices
	* ADP5588/ADP5587 I/O Expander and QWERTY Keypad Controller
	*
	* Copyright 2009-2010 Analog Devices Inc.
	*
	* Licensed under the GPL-2 or later.
	*/

	#include <linux/module.h>
	#include <linux/kernel.h>
	#include <linux/slab.h>
	#include <linux/init.h>
	#include <linux/i2c.h>
	#include <linux/gpio.h>
	#include <linux/interrupt.h>
	#include <linux/irq.h>

	#include <linux/i2c/adp5588.h>

	#define DRV_NAME "adp5588-gpio"

	/*
	* Early pre 4.0 Silicon required to delay readout by at least 25ms,
	* since the Event Counter Register updated 25ms after the interrupt
	* asserted.
	*/
	#define WA_DELAYED_READOUT_REVID(rev) ((rev) < 4)

	struct adp5588_gpio {
	struct i2c_client *client;
	struct gpio_chip gpio_chip;
	struct mutex lock; /* protect cached dir, dat_out */
	/* protect serialized access to the interrupt controller bus */
	struct mutex irq_lock;
	unsigned gpio_start;
	unsigned irq_base;
	uint8_t dat_out[3];
	uint8_t dir[3];
	uint8_t int_lvl[3];
	uint8_t int_en[3];
	uint8_t irq_mask[3];
	uint8_t irq_stat[3];
	};

	static int adp5588_gpio_read(struct i2c_client *client, u8 reg)
	{
	int ret = i2c_smbus_read_byte_data(client, reg);

	if (ret < 0)
	dev_err(&client->dev, "Read Error\n");

	return ret;
	}

	static int adp5588_gpio_write(struct i2c_client *client, u8 reg, u8 val)
	{
	int ret = i2c_smbus_write_byte_data(client, reg, val);

	if (ret < 0)
	dev_err(&client->dev, "Write Error\n");

	return ret;
	}

	static int adp5588_gpio_get_value(struct gpio_chip *chip, unsigned off)
	{
	struct adp5588_gpio *dev = gpiochip_get_data(chip);
	unsigned bank = ADP5588_BANK(off);
	unsigned bit = ADP5588_BIT(off);
	int val;

	mutex_lock(&dev->lock);

	if (dev->dir[bank] & bit)
	val = dev->dat_out[bank];
	else
	val = adp5588_gpio_read(dev->client, GPIO_DAT_STAT1 + bank);

	mutex_unlock(&dev->lock);

	return !!(val & bit);
	}

	static void adp5588_gpio_set_value(struct gpio_chip *chip,
	unsigned off, int val)
	{
	unsigned bank, bit;
	struct adp5588_gpio *dev = gpiochip_get_data(chip);

	bank = ADP5588_BANK(off);
	bit = ADP5588_BIT(off);

	mutex_lock(&dev->lock);
	if (val)
	dev->dat_out[bank] \|= bit;
	else
	dev->dat_out[bank] &= ~bit;

	adp5588_gpio_write(dev->client, GPIO_DAT_OUT1 + bank,
	dev->dat_out[bank]);
	mutex_unlock(&dev->lock);
	}

	static int adp5588_gpio_direction_input(struct gpio_chip *chip, unsigned off)
	{
	int ret;
	unsigned bank;
	struct adp5588_gpio *dev = gpiochip_get_data(chip);

	bank = ADP5588_BANK(off);

	mutex_lock(&dev->lock);
	dev->dir[bank] &= ~ADP5588_BIT(off);
	ret = adp5588_gpio_write(dev->client, GPIO_DIR1 + bank, dev->dir[bank]);
	mutex_unlock(&dev->lock);

	return ret;
	}

	static int adp5588_gpio_direction_output(struct gpio_chip *chip,
	unsigned off, int val)
	{
	int ret;
	unsigned bank, bit;
	struct adp5588_gpio *dev = gpiochip_get_data(chip);

	bank = ADP5588_BANK(off);
	bit = ADP5588_BIT(off);

	mutex_lock(&dev->lock);
	dev->dir[bank] \|= bit;

	if (val)
	dev->dat_out[bank] \|= bit;
	else
	dev->dat_out[bank] &= ~bit;

	ret = adp5588_gpio_write(dev->client, GPIO_DAT_OUT1 + bank,
	dev->dat_out[bank]);
	ret \|= adp5588_gpio_write(dev->client, GPIO_DIR1 + bank,
	dev->dir[bank]);
	mutex_unlock(&dev->lock);

	return ret;
	}

	#ifdef CONFIG_GPIO_ADP5588_IRQ
	static int adp5588_gpio_to_irq(struct gpio_chip *chip, unsigned off)
	{
	struct adp5588_gpio *dev = gpiochip_get_data(chip);

	return dev->irq_base + off;
	}

	static void adp5588_irq_bus_lock(struct irq_data *d)
	{
	struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);

	mutex_lock(&dev->irq_lock);
	}

	/*
	* genirq core code can issue chip->mask/unmask from atomic context.
	* This doesn't work for slow busses where an access needs to sleep.
	* bus_sync_unlock() is therefore called outside the atomic context,
	* syncs the current irq mask state with the slow external controller
	* and unlocks the bus.
	*/

	static void adp5588_irq_bus_sync_unlock(struct irq_data *d)
	{
	struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
	int i;

	for (i = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++)
	if (dev->int_en[i] ^ dev->irq_mask[i]) {
	dev->int_en[i] = dev->irq_mask[i];
	adp5588_gpio_write(dev->client, GPIO_INT_EN1 + i,
	dev->int_en[i]);
	}

	mutex_unlock(&dev->irq_lock);
	}

	static void adp5588_irq_mask(struct irq_data *d)
	{
	struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
	unsigned gpio = d->irq - dev->irq_base;

	dev->irq_mask[ADP5588_BANK(gpio)] &= ~ADP5588_BIT(gpio);
	}

	static void adp5588_irq_unmask(struct irq_data *d)
	{
	struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
	unsigned gpio = d->irq - dev->irq_base;

	dev->irq_mask[ADP5588_BANK(gpio)] \|= ADP5588_BIT(gpio);
	}

	static int adp5588_irq_set_type(struct irq_data *d, unsigned int type)
	{
	struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
	uint16_t gpio = d->irq - dev->irq_base;
	unsigned bank, bit;

	if ((type & IRQ_TYPE_EDGE_BOTH)) {
	dev_err(&dev->client->dev, "irq %d: unsupported type %d\n",
	d->irq, type);
	return -EINVAL;
	}

	bank = ADP5588_BANK(gpio);
	bit = ADP5588_BIT(gpio);

	if (type & IRQ_TYPE_LEVEL_HIGH)
	dev->int_lvl[bank] \|= bit;
	else if (type & IRQ_TYPE_LEVEL_LOW)
	dev->int_lvl[bank] &= ~bit;
	else
	return -EINVAL;

	adp5588_gpio_direction_input(&dev->gpio_chip, gpio);
	adp5588_gpio_write(dev->client, GPIO_INT_LVL1 + bank,
	dev->int_lvl[bank]);

	return 0;
	}

	static struct irq_chip adp5588_irq_chip = {
	.name = "adp5588",
	.irq_mask = adp5588_irq_mask,
	.irq_unmask = adp5588_irq_unmask,
	.irq_bus_lock = adp5588_irq_bus_lock,
	.irq_bus_sync_unlock = adp5588_irq_bus_sync_unlock,
	.irq_set_type = adp5588_irq_set_type,
	};

	static int adp5588_gpio_read_intstat(struct i2c_client client, u8 buf)
	{
	int ret = i2c_smbus_read_i2c_block_data(client, GPIO_INT_STAT1, 3, buf);

	if (ret < 0)
	dev_err(&client->dev, "Read INT_STAT Error\n");

	return ret;
	}

	static irqreturn_t adp5588_irq_handler(int irq, void *devid)
	{
	struct adp5588_gpio *dev = devid;
	unsigned status, bank, bit, pending;
	int ret;
	status = adp5588_gpio_read(dev->client, INT_STAT);

	if (status & ADP5588_GPI_INT) {
	ret = adp5588_gpio_read_intstat(dev->client, dev->irq_stat);
	if (ret < 0)
	memset(dev->irq_stat, 0, ARRAY_SIZE(dev->irq_stat));

	for (bank = 0, bit = 0; bank <= ADP5588_BANK(ADP5588_MAXGPIO);
	bank++, bit = 0) {
	pending = dev->irq_stat[bank] & dev->irq_mask[bank];

	while (pending) {
	if (pending & (1 << bit)) {
	handle_nested_irq(dev->irq_base +
	(bank << 3) + bit);
	pending &= ~(1 << bit);

	}
	bit++;
	}
	}
	}

	adp5588_gpio_write(dev->client, INT_STAT, status); /* Status is W1C */

	return IRQ_HANDLED;
	}

	static int adp5588_irq_setup(struct adp5588_gpio *dev)
	{
	struct i2c_client *client = dev->client;
	struct adp5588_gpio_platform_data *pdata =
	dev_get_platdata(&client->dev);
	unsigned gpio;
	int ret;

	adp5588_gpio_write(client, CFG, ADP5588_AUTO_INC);
	adp5588_gpio_write(client, INT_STAT, -1); /* status is W1C */
	adp5588_gpio_read_intstat(client, dev->irq_stat); /* read to clear */

	dev->irq_base = pdata->irq_base;
	mutex_init(&dev->irq_lock);

	for (gpio = 0; gpio < dev->gpio_chip.ngpio; gpio++) {
	int irq = gpio + dev->irq_base;
	irq_set_chip_data(irq, dev);
	irq_set_chip_and_handler(irq, &adp5588_irq_chip,
	handle_level_irq);
	irq_set_nested_thread(irq, 1);
	irq_modify_status(irq, IRQ_NOREQUEST, IRQ_NOPROBE);
	}

	ret = request_threaded_irq(client->irq,
	NULL,
	adp5588_irq_handler,
	IRQF_TRIGGER_FALLING \| IRQF_ONESHOT,
	dev_name(&client->dev), dev);
	if (ret) {
	dev_err(&client->dev, "failed to request irq %d\n",
	client->irq);
	goto out;
	}

	dev->gpio_chip.to_irq = adp5588_gpio_to_irq;
	adp5588_gpio_write(client, CFG,
	ADP5588_AUTO_INC \| ADP5588_INT_CFG \| ADP5588_GPI_INT);

	return 0;

	out:
	dev->irq_base = 0;
	return ret;
	}

	static void adp5588_irq_teardown(struct adp5588_gpio *dev)
	{
	if (dev->irq_base)
	free_irq(dev->client->irq, dev);
	}

	#else
	static int adp5588_irq_setup(struct adp5588_gpio *dev)
	{
	struct i2c_client *client = dev->client;
	dev_warn(&client->dev, "interrupt support not compiled in\n");

	return 0;
	}

	static void adp5588_irq_teardown(struct adp5588_gpio *dev)
	{
	}
	#endif /* CONFIG_GPIO_ADP5588_IRQ */

	static int adp5588_gpio_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct adp5588_gpio_platform_data *pdata =
	dev_get_platdata(&client->dev);
	struct adp5588_gpio *dev;
	struct gpio_chip *gc;
	int ret, i, revid;

	if (!pdata) {
	dev_err(&client->dev, "missing platform data\n");
	return -ENODEV;
	}

	if (!i2c_check_functionality(client->adapter,
	I2C_FUNC_SMBUS_BYTE_DATA)) {
	dev_err(&client->dev, "SMBUS Byte Data not Supported\n");
	return -EIO;
	}

	dev = devm_kzalloc(&client->dev, sizeof(*dev), GFP_KERNEL);
	if (!dev)
	return -ENOMEM;

	dev->client = client;

	gc = &dev->gpio_chip;
	gc->direction_input = adp5588_gpio_direction_input;
	gc->direction_output = adp5588_gpio_direction_output;
	gc->get = adp5588_gpio_get_value;
	gc->set = adp5588_gpio_set_value;
	gc->can_sleep = true;

	gc->base = pdata->gpio_start;
	gc->ngpio = ADP5588_MAXGPIO;
	gc->label = client->name;
	gc->owner = THIS_MODULE;
	gc->names = pdata->names;

	mutex_init(&dev->lock);

	ret = adp5588_gpio_read(dev->client, DEV_ID);
	if (ret < 0)
	goto err;

	revid = ret & ADP5588_DEVICE_ID_MASK;

	for (i = 0, ret = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++) {
	dev->dat_out[i] = adp5588_gpio_read(client, GPIO_DAT_OUT1 + i);
	dev->dir[i] = adp5588_gpio_read(client, GPIO_DIR1 + i);
	ret \|= adp5588_gpio_write(client, KP_GPIO1 + i, 0);
	ret \|= adp5588_gpio_write(client, GPIO_PULL1 + i,
	(pdata->pullup_dis_mask >> (8 * i)) & 0xFF);
	ret \|= adp5588_gpio_write(client, GPIO_INT_EN1 + i, 0);
	if (ret)
	goto err;
	}

	if (pdata->irq_base) {
	if (WA_DELAYED_READOUT_REVID(revid)) {
	dev_warn(&client->dev, "GPIO int not supported\n");
	} else {
	ret = adp5588_irq_setup(dev);
	if (ret)
	goto err;
	}
	}

	ret = gpiochip_add_data(&dev->gpio_chip, dev);
	if (ret)
	goto err_irq;

	dev_info(&client->dev, "IRQ Base: %d Rev.: %d\n",
	pdata->irq_base, revid);

	if (pdata->setup) {
	ret = pdata->setup(client, gc->base, gc->ngpio, pdata->context);
	if (ret < 0)
	dev_warn(&client->dev, "setup failed, %d\n", ret);
	}

	i2c_set_clientdata(client, dev);

	return 0;

	err_irq:
	adp5588_irq_teardown(dev);
	err:
	return ret;
	}

	static int adp5588_gpio_remove(struct i2c_client *client)
	{
	struct adp5588_gpio_platform_data *pdata =
	dev_get_platdata(&client->dev);
	struct adp5588_gpio *dev = i2c_get_clientdata(client);
	int ret;

	if (pdata->teardown) {
	ret = pdata->teardown(client,
	dev->gpio_chip.base, dev->gpio_chip.ngpio,
	pdata->context);
	if (ret < 0) {
	dev_err(&client->dev, "teardown failed %d\n", ret);
	return ret;
	}
	}

	if (dev->irq_base)
	free_irq(dev->client->irq, dev);

	gpiochip_remove(&dev->gpio_chip);

	return 0;
	}

	static const struct i2c_device_id adp5588_gpio_id[] = {
	{DRV_NAME, 0},
	{}
	};

	MODULE_DEVICE_TABLE(i2c, adp5588_gpio_id);

	static struct i2c_driver adp5588_gpio_driver = {
	.driver = {
	.name = DRV_NAME,
	},
	.probe = adp5588_gpio_probe,
	.remove = adp5588_gpio_remove,
	.id_table = adp5588_gpio_id,
	};

	module_i2c_driver(adp5588_gpio_driver);

	MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
	MODULE_DESCRIPTION("GPIO ADP5588 Driver");
	MODULE_LICENSE("GPL");