drivers/gpio/tc35892-gpio.c - kernel/msm-4.9 - Gitiles

 /*
  * Copyright (C) ST-Ericsson SA 2010
  *
  * License Terms: GNU General Public License, version 2
  * Author: Hanumath Prasad <hanumath.prasad@stericsson.com> for ST-Ericsson
  * Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
  */

 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/gpio.h>
 #include <linux/irq.h>
 #include <linux/interrupt.h>
 #include <linux/mfd/tc35892.h>

 /*
  * These registers are modified under the irq bus lock and cached to avoid
  * unnecessary writes in bus_sync_unlock.
  */
 enum { REG_IBE, REG_IEV, REG_IS, REG_IE };

 #define CACHE_NR_REGS	4
 #define CACHE_NR_BANKS	3

 struct tc35892_gpio {
 	struct gpio_chip chip;
 	struct tc35892 *tc35892;
 	struct device *dev;
 	struct mutex irq_lock;

 	int irq_base;

 	/* Caches of interrupt control registers for bus_lock */
 	u8 regs[CACHE_NR_REGS][CACHE_NR_BANKS];
 	u8 oldregs[CACHE_NR_REGS][CACHE_NR_BANKS];
 };

 static inline struct tc35892_gpio *to_tc35892_gpio(struct gpio_chip *chip)
 {
 	return container_of(chip, struct tc35892_gpio, chip);
 }

 static int tc35892_gpio_get(struct gpio_chip *chip, unsigned offset)
 {
 	struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);
 	struct tc35892 *tc35892 = tc35892_gpio->tc35892;
 	u8 reg = TC35892_GPIODATA0 + (offset / 8) * 2;
 	u8 mask = 1 << (offset % 8);
 	int ret;

 	ret = tc35892_reg_read(tc35892, reg);
 	if (ret < 0)
 		return ret;

 	return ret & mask;
 }

 static void tc35892_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
 {
 	struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);
 	struct tc35892 *tc35892 = tc35892_gpio->tc35892;
 	u8 reg = TC35892_GPIODATA0 + (offset / 8) * 2;
 	unsigned pos = offset % 8;
 	u8 data[] = {!!val << pos, 1 << pos};

 	tc35892_block_write(tc35892, reg, ARRAY_SIZE(data), data);
 }

 static int tc35892_gpio_direction_output(struct gpio_chip *chip,
 					 unsigned offset, int val)
 {
 	struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);
 	struct tc35892 *tc35892 = tc35892_gpio->tc35892;
 	u8 reg = TC35892_GPIODIR0 + offset / 8;
 	unsigned pos = offset % 8;

 	tc35892_gpio_set(chip, offset, val);

 	return tc35892_set_bits(tc35892, reg, 1 << pos, 1 << pos);
 }

 static int tc35892_gpio_direction_input(struct gpio_chip *chip,
 					unsigned offset)
 {
 	struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);
 	struct tc35892 *tc35892 = tc35892_gpio->tc35892;
 	u8 reg = TC35892_GPIODIR0 + offset / 8;
 	unsigned pos = offset % 8;

 	return tc35892_set_bits(tc35892, reg, 1 << pos, 0);
 }

 static int tc35892_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 {
 	struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);

 	return tc35892_gpio->irq_base + offset;
 }

 static struct gpio_chip template_chip = {
 	.label			= "tc35892",
 	.owner			= THIS_MODULE,
 	.direction_input	= tc35892_gpio_direction_input,
 	.get			= tc35892_gpio_get,
 	.direction_output	= tc35892_gpio_direction_output,
 	.set			= tc35892_gpio_set,
 	.to_irq			= tc35892_gpio_to_irq,
 	.can_sleep		= 1,
 };

 static int tc35892_gpio_irq_set_type(unsigned int irq, unsigned int type)
 {
 	struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);
 	int offset = irq - tc35892_gpio->irq_base;
 	int regoffset = offset / 8;
 	int mask = 1 << (offset % 8);

 	if (type == IRQ_TYPE_EDGE_BOTH) {
 		tc35892_gpio->regs[REG_IBE][regoffset] |= mask;
 		return 0;
 	}

 	tc35892_gpio->regs[REG_IBE][regoffset] &= ~mask;

 	if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_LEVEL_HIGH)
 		tc35892_gpio->regs[REG_IS][regoffset] |= mask;
 	else
 		tc35892_gpio->regs[REG_IS][regoffset] &= ~mask;

 	if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH)
 		tc35892_gpio->regs[REG_IEV][regoffset] |= mask;
 	else
 		tc35892_gpio->regs[REG_IEV][regoffset] &= ~mask;

 	return 0;
 }

 static void tc35892_gpio_irq_lock(unsigned int irq)
 {
 	struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);

 	mutex_lock(&tc35892_gpio->irq_lock);
 }

 static void tc35892_gpio_irq_sync_unlock(unsigned int irq)
 {
 	struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);
 	struct tc35892 *tc35892 = tc35892_gpio->tc35892;
 	static const u8 regmap[] = {
 		[REG_IBE]	= TC35892_GPIOIBE0,
 		[REG_IEV]	= TC35892_GPIOIEV0,
 		[REG_IS]	= TC35892_GPIOIS0,
 		[REG_IE]	= TC35892_GPIOIE0,
 	};
 	int i, j;

 	for (i = 0; i < CACHE_NR_REGS; i++) {
 		for (j = 0; j < CACHE_NR_BANKS; j++) {
 			u8 old = tc35892_gpio->oldregs[i][j];
 			u8 new = tc35892_gpio->regs[i][j];

 			if (new == old)
 				continue;

 			tc35892_gpio->oldregs[i][j] = new;
 			tc35892_reg_write(tc35892, regmap[i] + j * 8, new);
 		}
 	}

 	mutex_unlock(&tc35892_gpio->irq_lock);
 }

 static void tc35892_gpio_irq_mask(unsigned int irq)
 {
 	struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);
 	int offset = irq - tc35892_gpio->irq_base;
 	int regoffset = offset / 8;
 	int mask = 1 << (offset % 8);

 	tc35892_gpio->regs[REG_IE][regoffset] &= ~mask;
 }

 static void tc35892_gpio_irq_unmask(unsigned int irq)
 {
 	struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);
 	int offset = irq - tc35892_gpio->irq_base;
 	int regoffset = offset / 8;
 	int mask = 1 << (offset % 8);

 	tc35892_gpio->regs[REG_IE][regoffset] |= mask;
 }

 static struct irq_chip tc35892_gpio_irq_chip = {
 	.name			= "tc35892-gpio",
 	.bus_lock		= tc35892_gpio_irq_lock,
 	.bus_sync_unlock	= tc35892_gpio_irq_sync_unlock,
 	.mask			= tc35892_gpio_irq_mask,
 	.unmask			= tc35892_gpio_irq_unmask,
 	.set_type		= tc35892_gpio_irq_set_type,
 };

 static irqreturn_t tc35892_gpio_irq(int irq, void *dev)
 {
 	struct tc35892_gpio *tc35892_gpio = dev;
 	struct tc35892 *tc35892 = tc35892_gpio->tc35892;
 	u8 status[CACHE_NR_BANKS];
 	int ret;
 	int i;

 	ret = tc35892_block_read(tc35892, TC35892_GPIOMIS0,
 				 ARRAY_SIZE(status), status);
 	if (ret < 0)
 		return IRQ_NONE;

 	for (i = 0; i < ARRAY_SIZE(status); i++) {
 		unsigned int stat = status[i];
 		if (!stat)
 			continue;

 		while (stat) {
 			int bit = __ffs(stat);
 			int line = i * 8 + bit;

 			handle_nested_irq(tc35892_gpio->irq_base + line);
 			stat &= ~(1 << bit);
 		}

 		tc35892_reg_write(tc35892, TC35892_GPIOIC0 + i, status[i]);
 	}

 	return IRQ_HANDLED;
 }

 static int tc35892_gpio_irq_init(struct tc35892_gpio *tc35892_gpio)
 {
 	int base = tc35892_gpio->irq_base;
 	int irq;

 	for (irq = base; irq < base + tc35892_gpio->chip.ngpio; irq++) {
 		set_irq_chip_data(irq, tc35892_gpio);
 		set_irq_chip_and_handler(irq, &tc35892_gpio_irq_chip,
 					 handle_simple_irq);
 		set_irq_nested_thread(irq, 1);
 #ifdef CONFIG_ARM
 		set_irq_flags(irq, IRQF_VALID);
 #else
 		set_irq_noprobe(irq);
 #endif
 	}

 	return 0;
 }

 static void tc35892_gpio_irq_remove(struct tc35892_gpio *tc35892_gpio)
 {
 	int base = tc35892_gpio->irq_base;
 	int irq;

 	for (irq = base; irq < base + tc35892_gpio->chip.ngpio; irq++) {
 #ifdef CONFIG_ARM
 		set_irq_flags(irq, 0);
 #endif
 		set_irq_chip_and_handler(irq, NULL, NULL);
 		set_irq_chip_data(irq, NULL);
 	}
 }

 static int __devinit tc35892_gpio_probe(struct platform_device *pdev)
 {
 	struct tc35892 *tc35892 = dev_get_drvdata(pdev->dev.parent);
 	struct tc35892_gpio_platform_data *pdata;
 	struct tc35892_gpio *tc35892_gpio;
 	int ret;
 	int irq;

 	pdata = tc35892->pdata->gpio;
 	if (!pdata)
 		return -ENODEV;

 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0)
 		return irq;

 	tc35892_gpio = kzalloc(sizeof(struct tc35892_gpio), GFP_KERNEL);
 	if (!tc35892_gpio)
 		return -ENOMEM;

 	mutex_init(&tc35892_gpio->irq_lock);

 	tc35892_gpio->dev = &pdev->dev;
 	tc35892_gpio->tc35892 = tc35892;

 	tc35892_gpio->chip = template_chip;
 	tc35892_gpio->chip.ngpio = tc35892->num_gpio;
 	tc35892_gpio->chip.dev = &pdev->dev;
 	tc35892_gpio->chip.base = pdata->gpio_base;

 	tc35892_gpio->irq_base = tc35892->irq_base + TC35892_INT_GPIO(0);

 	/* Bring the GPIO module out of reset */
 	ret = tc35892_set_bits(tc35892, TC35892_RSTCTRL,
 			       TC35892_RSTCTRL_GPIRST, 0);
 	if (ret < 0)
 		goto out_free;

 	ret = tc35892_gpio_irq_init(tc35892_gpio);
 	if (ret)
 		goto out_free;

 	ret = request_threaded_irq(irq, NULL, tc35892_gpio_irq, IRQF_ONESHOT,
 				   "tc35892-gpio", tc35892_gpio);
 	if (ret) {
 		dev_err(&pdev->dev, "unable to get irq: %d\n", ret);
 		goto out_removeirq;
 	}

 	ret = gpiochip_add(&tc35892_gpio->chip);
 	if (ret) {
 		dev_err(&pdev->dev, "unable to add gpiochip: %d\n", ret);
 		goto out_freeirq;
 	}

 	platform_set_drvdata(pdev, tc35892_gpio);

 	return 0;

 out_freeirq:
 	free_irq(irq, tc35892_gpio);
 out_removeirq:
 	tc35892_gpio_irq_remove(tc35892_gpio);
 out_free:
 	kfree(tc35892_gpio);
 	return ret;
 }

 static int __devexit tc35892_gpio_remove(struct platform_device *pdev)
 {
 	struct tc35892_gpio *tc35892_gpio = platform_get_drvdata(pdev);
 	int irq = platform_get_irq(pdev, 0);
 	int ret;

 	ret = gpiochip_remove(&tc35892_gpio->chip);
 	if (ret < 0) {
 		dev_err(tc35892_gpio->dev,
 			"unable to remove gpiochip: %d\n", ret);
 		return ret;
 	}

 	free_irq(irq, tc35892_gpio);
 	tc35892_gpio_irq_remove(tc35892_gpio);

 	platform_set_drvdata(pdev, NULL);
 	kfree(tc35892_gpio);

 	return 0;
 }

 static struct platform_driver tc35892_gpio_driver = {
 	.driver.name	= "tc35892-gpio",
 	.driver.owner	= THIS_MODULE,
 	.probe		= tc35892_gpio_probe,
 	.remove		= __devexit_p(tc35892_gpio_remove),
 };

 static int __init tc35892_gpio_init(void)
 {
 	return platform_driver_register(&tc35892_gpio_driver);
 }
 subsys_initcall(tc35892_gpio_init);

 static void __exit tc35892_gpio_exit(void)
 {
 	platform_driver_unregister(&tc35892_gpio_driver);
 }
 module_exit(tc35892_gpio_exit);

 MODULE_LICENSE("GPL v2");
 MODULE_DESCRIPTION("TC35892 GPIO driver");
 MODULE_AUTHOR("Hanumath Prasad, Rabin Vincent");
	/*
	* Copyright (C) ST-Ericsson SA 2010
	*
	* License Terms: GNU General Public License, version 2
	* Author: Hanumath Prasad <hanumath.prasad@stericsson.com> for ST-Ericsson
	* Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
	*/

	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>
	#include <linux/gpio.h>
	#include <linux/irq.h>
	#include <linux/interrupt.h>
	#include <linux/mfd/tc35892.h>

	/*
	* These registers are modified under the irq bus lock and cached to avoid
	* unnecessary writes in bus_sync_unlock.
	*/
	enum { REG_IBE, REG_IEV, REG_IS, REG_IE };

	#define CACHE_NR_REGS 4
	#define CACHE_NR_BANKS 3

	struct tc35892_gpio {
	struct gpio_chip chip;
	struct tc35892 *tc35892;
	struct device *dev;
	struct mutex irq_lock;

	int irq_base;

	/* Caches of interrupt control registers for bus_lock */
	u8 regs[CACHE_NR_REGS][CACHE_NR_BANKS];
	u8 oldregs[CACHE_NR_REGS][CACHE_NR_BANKS];
	};

	static inline struct tc35892_gpio to_tc35892_gpio(struct gpio_chip chip)
	{
	return container_of(chip, struct tc35892_gpio, chip);
	}

	static int tc35892_gpio_get(struct gpio_chip *chip, unsigned offset)
	{
	struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);
	struct tc35892 *tc35892 = tc35892_gpio->tc35892;
	u8 reg = TC35892_GPIODATA0 + (offset / 8) * 2;
	u8 mask = 1 << (offset % 8);
	int ret;

	ret = tc35892_reg_read(tc35892, reg);
	if (ret < 0)
	return ret;

	return ret & mask;
	}

	static void tc35892_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
	{
	struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);
	struct tc35892 *tc35892 = tc35892_gpio->tc35892;
	u8 reg = TC35892_GPIODATA0 + (offset / 8) * 2;
	unsigned pos = offset % 8;
	u8 data[] = {!!val << pos, 1 << pos};

	tc35892_block_write(tc35892, reg, ARRAY_SIZE(data), data);
	}

	static int tc35892_gpio_direction_output(struct gpio_chip *chip,
	unsigned offset, int val)
	{
	struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);
	struct tc35892 *tc35892 = tc35892_gpio->tc35892;
	u8 reg = TC35892_GPIODIR0 + offset / 8;
	unsigned pos = offset % 8;

	tc35892_gpio_set(chip, offset, val);

	return tc35892_set_bits(tc35892, reg, 1 << pos, 1 << pos);
	}

	static int tc35892_gpio_direction_input(struct gpio_chip *chip,
	unsigned offset)
	{
	struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);
	struct tc35892 *tc35892 = tc35892_gpio->tc35892;
	u8 reg = TC35892_GPIODIR0 + offset / 8;
	unsigned pos = offset % 8;

	return tc35892_set_bits(tc35892, reg, 1 << pos, 0);
	}

	static int tc35892_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
	{
	struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);

	return tc35892_gpio->irq_base + offset;
	}

	static struct gpio_chip template_chip = {
	.label = "tc35892",
	.owner = THIS_MODULE,
	.direction_input = tc35892_gpio_direction_input,
	.get = tc35892_gpio_get,
	.direction_output = tc35892_gpio_direction_output,
	.set = tc35892_gpio_set,
	.to_irq = tc35892_gpio_to_irq,
	.can_sleep = 1,
	};

	static int tc35892_gpio_irq_set_type(unsigned int irq, unsigned int type)
	{
	struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);
	int offset = irq - tc35892_gpio->irq_base;
	int regoffset = offset / 8;
	int mask = 1 << (offset % 8);

	if (type == IRQ_TYPE_EDGE_BOTH) {
	tc35892_gpio->regs[REG_IBE][regoffset] \|= mask;
	return 0;
	}

	tc35892_gpio->regs[REG_IBE][regoffset] &= ~mask;

	if (type == IRQ_TYPE_LEVEL_LOW \|\| type == IRQ_TYPE_LEVEL_HIGH)
	tc35892_gpio->regs[REG_IS][regoffset] \|= mask;
	else
	tc35892_gpio->regs[REG_IS][regoffset] &= ~mask;

	if (type == IRQ_TYPE_EDGE_RISING \|\| type == IRQ_TYPE_LEVEL_HIGH)
	tc35892_gpio->regs[REG_IEV][regoffset] \|= mask;
	else
	tc35892_gpio->regs[REG_IEV][regoffset] &= ~mask;

	return 0;
	}

	static void tc35892_gpio_irq_lock(unsigned int irq)
	{
	struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);

	mutex_lock(&tc35892_gpio->irq_lock);
	}

	static void tc35892_gpio_irq_sync_unlock(unsigned int irq)
	{
	struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);
	struct tc35892 *tc35892 = tc35892_gpio->tc35892;
	static const u8 regmap[] = {
	[REG_IBE] = TC35892_GPIOIBE0,
	[REG_IEV] = TC35892_GPIOIEV0,
	[REG_IS] = TC35892_GPIOIS0,
	[REG_IE] = TC35892_GPIOIE0,
	};
	int i, j;

	for (i = 0; i < CACHE_NR_REGS; i++) {
	for (j = 0; j < CACHE_NR_BANKS; j++) {
	u8 old = tc35892_gpio->oldregs[i][j];
	u8 new = tc35892_gpio->regs[i][j];

	if (new == old)
	continue;

	tc35892_gpio->oldregs[i][j] = new;
	tc35892_reg_write(tc35892, regmap[i] + j * 8, new);
	}
	}

	mutex_unlock(&tc35892_gpio->irq_lock);
	}

	static void tc35892_gpio_irq_mask(unsigned int irq)
	{
	struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);
	int offset = irq - tc35892_gpio->irq_base;
	int regoffset = offset / 8;
	int mask = 1 << (offset % 8);

	tc35892_gpio->regs[REG_IE][regoffset] &= ~mask;
	}

	static void tc35892_gpio_irq_unmask(unsigned int irq)
	{
	struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);
	int offset = irq - tc35892_gpio->irq_base;
	int regoffset = offset / 8;
	int mask = 1 << (offset % 8);

	tc35892_gpio->regs[REG_IE][regoffset] \|= mask;
	}

	static struct irq_chip tc35892_gpio_irq_chip = {
	.name = "tc35892-gpio",
	.bus_lock = tc35892_gpio_irq_lock,
	.bus_sync_unlock = tc35892_gpio_irq_sync_unlock,
	.mask = tc35892_gpio_irq_mask,
	.unmask = tc35892_gpio_irq_unmask,
	.set_type = tc35892_gpio_irq_set_type,
	};

	static irqreturn_t tc35892_gpio_irq(int irq, void *dev)
	{
	struct tc35892_gpio *tc35892_gpio = dev;
	struct tc35892 *tc35892 = tc35892_gpio->tc35892;
	u8 status[CACHE_NR_BANKS];
	int ret;
	int i;

	ret = tc35892_block_read(tc35892, TC35892_GPIOMIS0,
	ARRAY_SIZE(status), status);
	if (ret < 0)
	return IRQ_NONE;

	for (i = 0; i < ARRAY_SIZE(status); i++) {
	unsigned int stat = status[i];
	if (!stat)
	continue;

	while (stat) {
	int bit = __ffs(stat);
	int line = i * 8 + bit;

	handle_nested_irq(tc35892_gpio->irq_base + line);
	stat &= ~(1 << bit);
	}

	tc35892_reg_write(tc35892, TC35892_GPIOIC0 + i, status[i]);
	}

	return IRQ_HANDLED;
	}

	static int tc35892_gpio_irq_init(struct tc35892_gpio *tc35892_gpio)
	{
	int base = tc35892_gpio->irq_base;
	int irq;

	for (irq = base; irq < base + tc35892_gpio->chip.ngpio; irq++) {
	set_irq_chip_data(irq, tc35892_gpio);
	set_irq_chip_and_handler(irq, &tc35892_gpio_irq_chip,
	handle_simple_irq);
	set_irq_nested_thread(irq, 1);
	#ifdef CONFIG_ARM
	set_irq_flags(irq, IRQF_VALID);
	#else
	set_irq_noprobe(irq);
	#endif
	}

	return 0;
	}

	static void tc35892_gpio_irq_remove(struct tc35892_gpio *tc35892_gpio)
	{
	int base = tc35892_gpio->irq_base;
	int irq;

	for (irq = base; irq < base + tc35892_gpio->chip.ngpio; irq++) {
	#ifdef CONFIG_ARM
	set_irq_flags(irq, 0);
	#endif
	set_irq_chip_and_handler(irq, NULL, NULL);
	set_irq_chip_data(irq, NULL);
	}
	}

	static int __devinit tc35892_gpio_probe(struct platform_device *pdev)
	{
	struct tc35892 *tc35892 = dev_get_drvdata(pdev->dev.parent);
	struct tc35892_gpio_platform_data *pdata;
	struct tc35892_gpio *tc35892_gpio;
	int ret;
	int irq;

	pdata = tc35892->pdata->gpio;
	if (!pdata)
	return -ENODEV;

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
	return irq;

	tc35892_gpio = kzalloc(sizeof(struct tc35892_gpio), GFP_KERNEL);
	if (!tc35892_gpio)
	return -ENOMEM;

	mutex_init(&tc35892_gpio->irq_lock);

	tc35892_gpio->dev = &pdev->dev;
	tc35892_gpio->tc35892 = tc35892;

	tc35892_gpio->chip = template_chip;
	tc35892_gpio->chip.ngpio = tc35892->num_gpio;
	tc35892_gpio->chip.dev = &pdev->dev;
	tc35892_gpio->chip.base = pdata->gpio_base;

	tc35892_gpio->irq_base = tc35892->irq_base + TC35892_INT_GPIO(0);

	/* Bring the GPIO module out of reset */
	ret = tc35892_set_bits(tc35892, TC35892_RSTCTRL,
	TC35892_RSTCTRL_GPIRST, 0);
	if (ret < 0)
	goto out_free;

	ret = tc35892_gpio_irq_init(tc35892_gpio);
	if (ret)
	goto out_free;

	ret = request_threaded_irq(irq, NULL, tc35892_gpio_irq, IRQF_ONESHOT,
	"tc35892-gpio", tc35892_gpio);
	if (ret) {
	dev_err(&pdev->dev, "unable to get irq: %d\n", ret);
	goto out_removeirq;
	}

	ret = gpiochip_add(&tc35892_gpio->chip);
	if (ret) {
	dev_err(&pdev->dev, "unable to add gpiochip: %d\n", ret);
	goto out_freeirq;
	}

	platform_set_drvdata(pdev, tc35892_gpio);

	return 0;

	out_freeirq:
	free_irq(irq, tc35892_gpio);
	out_removeirq:
	tc35892_gpio_irq_remove(tc35892_gpio);
	out_free:
	kfree(tc35892_gpio);
	return ret;
	}

	static int __devexit tc35892_gpio_remove(struct platform_device *pdev)
	{
	struct tc35892_gpio *tc35892_gpio = platform_get_drvdata(pdev);
	int irq = platform_get_irq(pdev, 0);
	int ret;

	ret = gpiochip_remove(&tc35892_gpio->chip);
	if (ret < 0) {
	dev_err(tc35892_gpio->dev,
	"unable to remove gpiochip: %d\n", ret);
	return ret;
	}

	free_irq(irq, tc35892_gpio);
	tc35892_gpio_irq_remove(tc35892_gpio);

	platform_set_drvdata(pdev, NULL);
	kfree(tc35892_gpio);

	return 0;
	}

	static struct platform_driver tc35892_gpio_driver = {
	.driver.name = "tc35892-gpio",
	.driver.owner = THIS_MODULE,
	.probe = tc35892_gpio_probe,
	.remove = __devexit_p(tc35892_gpio_remove),
	};

	static int __init tc35892_gpio_init(void)
	{
	return platform_driver_register(&tc35892_gpio_driver);
	}
	subsys_initcall(tc35892_gpio_init);

	static void __exit tc35892_gpio_exit(void)
	{
	platform_driver_unregister(&tc35892_gpio_driver);
	}
	module_exit(tc35892_gpio_exit);

	MODULE_LICENSE("GPL v2");
	MODULE_DESCRIPTION("TC35892 GPIO driver");
	MODULE_AUTHOR("Hanumath Prasad, Rabin Vincent");