drivers/gpio/gpio-pl061.c - arm/linux-arm-legacy - Git at Google

 /*
  * Copyright (C) 2008, 2009 Provigent Ltd.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
  * Driver for the ARM PrimeCell(tm) General Purpose Input/Output (PL061)
  *
  * Data sheet: ARM DDI 0190B, September 2000
  */
 #include <linux/spinlock.h>
 #include <linux/errno.h>
 #include <linux/module.h>
 #include <linux/io.h>
 #include <linux/ioport.h>
 #include <linux/irq.h>
 #include <linux/irqdomain.h>
 #include <linux/irqchip/chained_irq.h>
 #include <linux/bitops.h>
 #include <linux/workqueue.h>
 #include <linux/gpio.h>
 #include <linux/device.h>
 #include <linux/amba/bus.h>
 #include <linux/amba/pl061.h>
 #include <linux/slab.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/pm.h>

 #define GPIODIR 0x400
 #define GPIOIS  0x404
 #define GPIOIBE 0x408
 #define GPIOIEV 0x40C
 #define GPIOIE  0x410
 #define GPIORIS 0x414
 #define GPIOMIS 0x418
 #define GPIOIC  0x41C

 #define PL061_GPIO_NR	8

 #ifdef CONFIG_PM
 struct pl061_context_save_regs {
 	u8 gpio_data;
 	u8 gpio_dir;
 	u8 gpio_is;
 	u8 gpio_ibe;
 	u8 gpio_iev;
 	u8 gpio_ie;
 };
 #endif

 struct pl061_gpio {
 	spinlock_t		lock;

 	void __iomem		*base;
 	struct irq_domain	*domain;
 	struct gpio_chip	gc;

 #ifdef CONFIG_PM
 	struct pl061_context_save_regs csave_regs;
 #endif
 };

 static int pl061_gpio_request(struct gpio_chip *chip, unsigned offset)
 {
 	/*
 	 * Map back to global GPIO space and request muxing, the direction
 	 * parameter does not matter for this controller.
 	 */
 	int gpio = chip->base + offset;

 	return pinctrl_request_gpio(gpio);
 }

 static void pl061_gpio_free(struct gpio_chip *chip, unsigned offset)
 {
 	int gpio = chip->base + offset;

 	pinctrl_free_gpio(gpio);
 }

 static int pl061_direction_input(struct gpio_chip *gc, unsigned offset)
 {
 	struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
 	unsigned long flags;
 	unsigned char gpiodir;

 	if (offset >= gc->ngpio)
 		return -EINVAL;

 	spin_lock_irqsave(&chip->lock, flags);
 	gpiodir = readb(chip->base + GPIODIR);
 	gpiodir &= ~(1 << offset);
 	writeb(gpiodir, chip->base + GPIODIR);
 	spin_unlock_irqrestore(&chip->lock, flags);

 	return 0;
 }

 static int pl061_direction_output(struct gpio_chip *gc, unsigned offset,
 		int value)
 {
 	struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
 	unsigned long flags;
 	unsigned char gpiodir;

 	if (offset >= gc->ngpio)
 		return -EINVAL;

 	spin_lock_irqsave(&chip->lock, flags);
 	writeb(!!value << offset, chip->base + (1 << (offset + 2)));
 	gpiodir = readb(chip->base + GPIODIR);
 	gpiodir |= 1 << offset;
 	writeb(gpiodir, chip->base + GPIODIR);

 	/*
 	 * gpio value is set again, because pl061 doesn't allow to set value of
 	 * a gpio pin before configuring it in OUT mode.
 	 */
 	writeb(!!value << offset, chip->base + (1 << (offset + 2)));
 	spin_unlock_irqrestore(&chip->lock, flags);

 	return 0;
 }

 static int pl061_get_value(struct gpio_chip *gc, unsigned offset)
 {
 	struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);

 	return !!readb(chip->base + (1 << (offset + 2)));
 }

 static void pl061_set_value(struct gpio_chip *gc, unsigned offset, int value)
 {
 	struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);

 	writeb(!!value << offset, chip->base + (1 << (offset + 2)));
 }

 static int pl061_to_irq(struct gpio_chip *gc, unsigned offset)
 {
 	struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);

 	return irq_create_mapping(chip->domain, offset);
 }

 static int pl061_irq_type(struct irq_data *d, unsigned trigger)
 {
 	struct pl061_gpio *chip = irq_data_get_irq_chip_data(d);
 	int offset = irqd_to_hwirq(d);
 	unsigned long flags;
 	u8 gpiois, gpioibe, gpioiev;

 	if (offset < 0 || offset >= PL061_GPIO_NR)
 		return -EINVAL;

 	spin_lock_irqsave(&chip->lock, flags);

 	gpioiev = readb(chip->base + GPIOIEV);

 	gpiois = readb(chip->base + GPIOIS);
 	if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
 		gpiois |= 1 << offset;
 		if (trigger & IRQ_TYPE_LEVEL_HIGH)
 			gpioiev |= 1 << offset;
 		else
 			gpioiev &= ~(1 << offset);
 	} else
 		gpiois &= ~(1 << offset);
 	writeb(gpiois, chip->base + GPIOIS);

 	gpioibe = readb(chip->base + GPIOIBE);
 	if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH)
 		gpioibe |= 1 << offset;
 	else {
 		gpioibe &= ~(1 << offset);
 		if (trigger & IRQ_TYPE_EDGE_RISING)
 			gpioiev |= 1 << offset;
 		else if (trigger & IRQ_TYPE_EDGE_FALLING)
 			gpioiev &= ~(1 << offset);
 	}
 	writeb(gpioibe, chip->base + GPIOIBE);

 	writeb(gpioiev, chip->base + GPIOIEV);

 	spin_unlock_irqrestore(&chip->lock, flags);

 	return 0;
 }

 static void pl061_irq_handler(unsigned irq, struct irq_desc *desc)
 {
 	unsigned long pending;
 	int offset;
 	struct pl061_gpio *chip = irq_desc_get_handler_data(desc);
 	struct irq_chip *irqchip = irq_desc_get_chip(desc);

 	chained_irq_enter(irqchip, desc);

 	pending = readb(chip->base + GPIOMIS);
 	writeb(pending, chip->base + GPIOIC);
 	if (pending) {
 		for_each_set_bit(offset, &pending, PL061_GPIO_NR)
 			generic_handle_irq(pl061_to_irq(&chip->gc, offset));
 	}

 	chained_irq_exit(irqchip, desc);
 }

 static void pl061_irq_mask(struct irq_data *d)
 {
 	struct pl061_gpio *chip = irq_data_get_irq_chip_data(d);
 	u8 mask = 1 << (irqd_to_hwirq(d) % PL061_GPIO_NR);
 	u8 gpioie;

 	spin_lock(&chip->lock);
 	gpioie = readb(chip->base + GPIOIE) & ~mask;
 	writeb(gpioie, chip->base + GPIOIE);
 	spin_unlock(&chip->lock);
 }

 static void pl061_irq_unmask(struct irq_data *d)
 {
 	struct pl061_gpio *chip = irq_data_get_irq_chip_data(d);
 	u8 mask = 1 << (irqd_to_hwirq(d) % PL061_GPIO_NR);
 	u8 gpioie;

 	spin_lock(&chip->lock);
 	gpioie = readb(chip->base + GPIOIE) | mask;
 	writeb(gpioie, chip->base + GPIOIE);
 	spin_unlock(&chip->lock);
 }

 static struct irq_chip pl061_irqchip = {
 	.name		= "pl061 gpio",
 	.irq_mask	= pl061_irq_mask,
 	.irq_unmask	= pl061_irq_unmask,
 	.irq_set_type	= pl061_irq_type,
 };

 static int pl061_irq_map(struct irq_domain *d, unsigned int irq,
 			 irq_hw_number_t hwirq)
 {
 	struct pl061_gpio *chip = d->host_data;

 	irq_set_chip_and_handler_name(irq, &pl061_irqchip, handle_simple_irq,
 				      "pl061");
 	irq_set_chip_data(irq, chip);
 	irq_set_irq_type(irq, IRQ_TYPE_NONE);

 	return 0;
 }

 static const struct irq_domain_ops pl061_domain_ops = {
 	.map	= pl061_irq_map,
 	.xlate	= irq_domain_xlate_twocell,
 };

 /* Parse gpio base from DT */
 static int pl061_parse_gpio_base(struct device *dev)
 {
 	struct device_node *np = dev->of_node;
 	int ret;

 	if (of_property_read_u32(np, "linux,gpio-base", &ret))
 		return -ENOENT;
 	if (ret >= 0)
 		return ret;
 	return -EINVAL;
 }

 static int pl061_probe(struct amba_device *adev, const struct amba_id *id)
 {
 	struct device *dev = &adev->dev;
 	struct pl061_platform_data *pdata = dev_get_platdata(dev);
 	struct pl061_gpio *chip;
 	int ret, irq, i, irq_base;

 	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
 	if (chip == NULL)
 		return -ENOMEM;

 	if (pdata) {
 		chip->gc.base = pdata->gpio_base;
 		irq_base = pdata->irq_base;
 		if (irq_base <= 0)
 			return -ENODEV;
 	} else {
 		chip->gc.base = pl061_parse_gpio_base(dev);
 		irq_base = 0;
 	}

 	if (!devm_request_mem_region(dev, adev->res.start,
 				     resource_size(&adev->res), "pl061"))
 		return -EBUSY;

 	chip->base = devm_ioremap(dev, adev->res.start,
 				  resource_size(&adev->res));
 	if (!chip->base)
 		return -ENOMEM;

 	spin_lock_init(&chip->lock);

 	/* Hook the request()/free() for pinctrl operation */
 	if (of_get_property(dev->of_node, "gpio-ranges", NULL)) {
 		chip->gc.request = pl061_gpio_request;
 		chip->gc.free = pl061_gpio_free;
 	}
 	chip->gc.direction_input = pl061_direction_input;
 	chip->gc.direction_output = pl061_direction_output;
 	chip->gc.get = pl061_get_value;
 	chip->gc.set = pl061_set_value;
 	chip->gc.to_irq = pl061_to_irq;
 	chip->gc.ngpio = PL061_GPIO_NR;
 	chip->gc.label = dev_name(dev);
 	chip->gc.dev = dev;
 	chip->gc.owner = THIS_MODULE;

 	ret = gpiochip_add(&chip->gc);
 	if (ret)
 		return ret;

 	/*
 	 * irq_chip support
 	 */
 	writeb(0, chip->base + GPIOIE); /* disable irqs */
 	irq = adev->irq[0];
 	if (irq < 0)
 		return -ENODEV;

 	irq_set_chained_handler(irq, pl061_irq_handler);
 	irq_set_handler_data(irq, chip);

 	chip->domain = irq_domain_add_simple(adev->dev.of_node, PL061_GPIO_NR,
 					     irq_base, &pl061_domain_ops, chip);
 	if (!chip->domain)
 		return -ENODEV;

 	for (i = 0; i < PL061_GPIO_NR; i++) {
 		if (pdata) {
 			if (pdata->directions & (1 << i))
 				pl061_direction_output(&chip->gc, i,
 						pdata->values & (1 << i));
 			else
 				pl061_direction_input(&chip->gc, i);
 		}
 	}

 	amba_set_drvdata(adev, chip);

 	return 0;
 }

 #ifdef CONFIG_PM
 static int pl061_suspend(struct device *dev)
 {
 	struct pl061_gpio *chip = dev_get_drvdata(dev);
 	int offset;

 	chip->csave_regs.gpio_data = 0;
 	chip->csave_regs.gpio_dir = readb(chip->base + GPIODIR);
 	chip->csave_regs.gpio_is = readb(chip->base + GPIOIS);
 	chip->csave_regs.gpio_ibe = readb(chip->base + GPIOIBE);
 	chip->csave_regs.gpio_iev = readb(chip->base + GPIOIEV);
 	chip->csave_regs.gpio_ie = readb(chip->base + GPIOIE);

 	for (offset = 0; offset < PL061_GPIO_NR; offset++) {
 		if (chip->csave_regs.gpio_dir & (1 << offset))
 			chip->csave_regs.gpio_data |=
 				pl061_get_value(&chip->gc, offset) << offset;
 	}

 	return 0;
 }

 static int pl061_resume(struct device *dev)
 {
 	struct pl061_gpio *chip = dev_get_drvdata(dev);
 	int offset;

 	for (offset = 0; offset < PL061_GPIO_NR; offset++) {
 		if (chip->csave_regs.gpio_dir & (1 << offset))
 			pl061_direction_output(&chip->gc, offset,
 					chip->csave_regs.gpio_data &
 					(1 << offset));
 		else
 			pl061_direction_input(&chip->gc, offset);
 	}

 	writeb(chip->csave_regs.gpio_is, chip->base + GPIOIS);
 	writeb(chip->csave_regs.gpio_ibe, chip->base + GPIOIBE);
 	writeb(chip->csave_regs.gpio_iev, chip->base + GPIOIEV);
 	writeb(chip->csave_regs.gpio_ie, chip->base + GPIOIE);

 	return 0;
 }

 static const struct dev_pm_ops pl061_dev_pm_ops = {
 	.suspend = pl061_suspend,
 	.resume = pl061_resume,
 	.freeze = pl061_suspend,
 	.restore = pl061_resume,
 };
 #endif

 static struct amba_id pl061_ids[] = {
 	{
 		.id	= 0x00041061,
 		.mask	= 0x000fffff,
 	},
 	{ 0, 0 },
 };

 MODULE_DEVICE_TABLE(amba, pl061_ids);

 static struct amba_driver pl061_gpio_driver = {
 	.drv = {
 		.name	= "pl061_gpio",
 #ifdef CONFIG_PM
 		.pm	= &pl061_dev_pm_ops,
 #endif
 	},
 	.id_table	= pl061_ids,
 	.probe		= pl061_probe,
 };

 static int __init pl061_gpio_init(void)
 {
 	return amba_driver_register(&pl061_gpio_driver);
 }
 module_init(pl061_gpio_init);

 MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
 MODULE_DESCRIPTION("PL061 GPIO driver");
 MODULE_LICENSE("GPL");
	/*
	* Copyright (C) 2008, 2009 Provigent Ltd.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	* Driver for the ARM PrimeCell(tm) General Purpose Input/Output (PL061)
	*
	* Data sheet: ARM DDI 0190B, September 2000
	*/
	#include <linux/spinlock.h>
	#include <linux/errno.h>
	#include <linux/module.h>
	#include <linux/io.h>
	#include <linux/ioport.h>
	#include <linux/irq.h>
	#include <linux/irqdomain.h>
	#include <linux/irqchip/chained_irq.h>
	#include <linux/bitops.h>
	#include <linux/workqueue.h>
	#include <linux/gpio.h>
	#include <linux/device.h>
	#include <linux/amba/bus.h>
	#include <linux/amba/pl061.h>
	#include <linux/slab.h>
	#include <linux/pinctrl/consumer.h>
	#include <linux/pm.h>

	#define GPIODIR 0x400
	#define GPIOIS 0x404
	#define GPIOIBE 0x408
	#define GPIOIEV 0x40C
	#define GPIOIE 0x410
	#define GPIORIS 0x414
	#define GPIOMIS 0x418
	#define GPIOIC 0x41C

	#define PL061_GPIO_NR 8

	#ifdef CONFIG_PM
	struct pl061_context_save_regs {
	u8 gpio_data;
	u8 gpio_dir;
	u8 gpio_is;
	u8 gpio_ibe;
	u8 gpio_iev;
	u8 gpio_ie;
	};
	#endif

	struct pl061_gpio {
	spinlock_t lock;

	void __iomem *base;
	struct irq_domain *domain;
	struct gpio_chip gc;

	#ifdef CONFIG_PM
	struct pl061_context_save_regs csave_regs;
	#endif
	};

	static int pl061_gpio_request(struct gpio_chip *chip, unsigned offset)
	{
	/*
	* Map back to global GPIO space and request muxing, the direction
	* parameter does not matter for this controller.
	*/
	int gpio = chip->base + offset;

	return pinctrl_request_gpio(gpio);
	}

	static void pl061_gpio_free(struct gpio_chip *chip, unsigned offset)
	{
	int gpio = chip->base + offset;

	pinctrl_free_gpio(gpio);
	}

	static int pl061_direction_input(struct gpio_chip *gc, unsigned offset)
	{
	struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
	unsigned long flags;
	unsigned char gpiodir;

	if (offset >= gc->ngpio)
	return -EINVAL;

	spin_lock_irqsave(&chip->lock, flags);
	gpiodir = readb(chip->base + GPIODIR);
	gpiodir &= ~(1 << offset);
	writeb(gpiodir, chip->base + GPIODIR);
	spin_unlock_irqrestore(&chip->lock, flags);

	return 0;
	}

	static int pl061_direction_output(struct gpio_chip *gc, unsigned offset,
	int value)
	{
	struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
	unsigned long flags;
	unsigned char gpiodir;

	if (offset >= gc->ngpio)
	return -EINVAL;

	spin_lock_irqsave(&chip->lock, flags);
	writeb(!!value << offset, chip->base + (1 << (offset + 2)));
	gpiodir = readb(chip->base + GPIODIR);
	gpiodir \|= 1 << offset;
	writeb(gpiodir, chip->base + GPIODIR);

	/*
	* gpio value is set again, because pl061 doesn't allow to set value of
	* a gpio pin before configuring it in OUT mode.
	*/
	writeb(!!value << offset, chip->base + (1 << (offset + 2)));
	spin_unlock_irqrestore(&chip->lock, flags);

	return 0;
	}

	static int pl061_get_value(struct gpio_chip *gc, unsigned offset)
	{
	struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);

	return !!readb(chip->base + (1 << (offset + 2)));
	}

	static void pl061_set_value(struct gpio_chip *gc, unsigned offset, int value)
	{
	struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);

	writeb(!!value << offset, chip->base + (1 << (offset + 2)));
	}

	static int pl061_to_irq(struct gpio_chip *gc, unsigned offset)
	{
	struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);

	return irq_create_mapping(chip->domain, offset);
	}

	static int pl061_irq_type(struct irq_data *d, unsigned trigger)
	{
	struct pl061_gpio *chip = irq_data_get_irq_chip_data(d);
	int offset = irqd_to_hwirq(d);
	unsigned long flags;
	u8 gpiois, gpioibe, gpioiev;

	if (offset < 0 \|\| offset >= PL061_GPIO_NR)
	return -EINVAL;

	spin_lock_irqsave(&chip->lock, flags);

	gpioiev = readb(chip->base + GPIOIEV);

	gpiois = readb(chip->base + GPIOIS);
	if (trigger & (IRQ_TYPE_LEVEL_HIGH \| IRQ_TYPE_LEVEL_LOW)) {
	gpiois \|= 1 << offset;
	if (trigger & IRQ_TYPE_LEVEL_HIGH)
	gpioiev \|= 1 << offset;
	else
	gpioiev &= ~(1 << offset);
	} else
	gpiois &= ~(1 << offset);
	writeb(gpiois, chip->base + GPIOIS);

	gpioibe = readb(chip->base + GPIOIBE);
	if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH)
	gpioibe \|= 1 << offset;
	else {
	gpioibe &= ~(1 << offset);
	if (trigger & IRQ_TYPE_EDGE_RISING)
	gpioiev \|= 1 << offset;
	else if (trigger & IRQ_TYPE_EDGE_FALLING)
	gpioiev &= ~(1 << offset);
	}
	writeb(gpioibe, chip->base + GPIOIBE);

	writeb(gpioiev, chip->base + GPIOIEV);

	spin_unlock_irqrestore(&chip->lock, flags);

	return 0;
	}

	static void pl061_irq_handler(unsigned irq, struct irq_desc *desc)
	{
	unsigned long pending;
	int offset;
	struct pl061_gpio *chip = irq_desc_get_handler_data(desc);
	struct irq_chip *irqchip = irq_desc_get_chip(desc);

	chained_irq_enter(irqchip, desc);

	pending = readb(chip->base + GPIOMIS);
	writeb(pending, chip->base + GPIOIC);
	if (pending) {
	for_each_set_bit(offset, &pending, PL061_GPIO_NR)
	generic_handle_irq(pl061_to_irq(&chip->gc, offset));
	}

	chained_irq_exit(irqchip, desc);
	}

	static void pl061_irq_mask(struct irq_data *d)
	{
	struct pl061_gpio *chip = irq_data_get_irq_chip_data(d);
	u8 mask = 1 << (irqd_to_hwirq(d) % PL061_GPIO_NR);
	u8 gpioie;

	spin_lock(&chip->lock);
	gpioie = readb(chip->base + GPIOIE) & ~mask;
	writeb(gpioie, chip->base + GPIOIE);
	spin_unlock(&chip->lock);
	}

	static void pl061_irq_unmask(struct irq_data *d)
	{
	struct pl061_gpio *chip = irq_data_get_irq_chip_data(d);
	u8 mask = 1 << (irqd_to_hwirq(d) % PL061_GPIO_NR);
	u8 gpioie;

	spin_lock(&chip->lock);
	gpioie = readb(chip->base + GPIOIE) \| mask;
	writeb(gpioie, chip->base + GPIOIE);
	spin_unlock(&chip->lock);
	}

	static struct irq_chip pl061_irqchip = {
	.name = "pl061 gpio",
	.irq_mask = pl061_irq_mask,
	.irq_unmask = pl061_irq_unmask,
	.irq_set_type = pl061_irq_type,
	};

	static int pl061_irq_map(struct irq_domain *d, unsigned int irq,
	irq_hw_number_t hwirq)
	{
	struct pl061_gpio *chip = d->host_data;

	irq_set_chip_and_handler_name(irq, &pl061_irqchip, handle_simple_irq,
	"pl061");
	irq_set_chip_data(irq, chip);
	irq_set_irq_type(irq, IRQ_TYPE_NONE);

	return 0;
	}

	static const struct irq_domain_ops pl061_domain_ops = {
	.map = pl061_irq_map,
	.xlate = irq_domain_xlate_twocell,
	};

	/* Parse gpio base from DT */
	static int pl061_parse_gpio_base(struct device *dev)
	{
	struct device_node *np = dev->of_node;
	int ret;

	if (of_property_read_u32(np, "linux,gpio-base", &ret))
	return -ENOENT;
	if (ret >= 0)
	return ret;
	return -EINVAL;
	}

	static int pl061_probe(struct amba_device adev, const struct amba_id id)
	{
	struct device *dev = &adev->dev;
	struct pl061_platform_data *pdata = dev_get_platdata(dev);
	struct pl061_gpio *chip;
	int ret, irq, i, irq_base;

	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
	if (chip == NULL)
	return -ENOMEM;

	if (pdata) {
	chip->gc.base = pdata->gpio_base;
	irq_base = pdata->irq_base;
	if (irq_base <= 0)
	return -ENODEV;
	} else {
	chip->gc.base = pl061_parse_gpio_base(dev);
	irq_base = 0;
	}

	if (!devm_request_mem_region(dev, adev->res.start,
	resource_size(&adev->res), "pl061"))
	return -EBUSY;

	chip->base = devm_ioremap(dev, adev->res.start,
	resource_size(&adev->res));
	if (!chip->base)
	return -ENOMEM;

	spin_lock_init(&chip->lock);

	/* Hook the request()/free() for pinctrl operation */
	if (of_get_property(dev->of_node, "gpio-ranges", NULL)) {
	chip->gc.request = pl061_gpio_request;
	chip->gc.free = pl061_gpio_free;
	}
	chip->gc.direction_input = pl061_direction_input;
	chip->gc.direction_output = pl061_direction_output;
	chip->gc.get = pl061_get_value;
	chip->gc.set = pl061_set_value;
	chip->gc.to_irq = pl061_to_irq;
	chip->gc.ngpio = PL061_GPIO_NR;
	chip->gc.label = dev_name(dev);
	chip->gc.dev = dev;
	chip->gc.owner = THIS_MODULE;

	ret = gpiochip_add(&chip->gc);
	if (ret)
	return ret;

	/*
	* irq_chip support
	*/
	writeb(0, chip->base + GPIOIE); /* disable irqs */
	irq = adev->irq[0];
	if (irq < 0)
	return -ENODEV;

	irq_set_chained_handler(irq, pl061_irq_handler);
	irq_set_handler_data(irq, chip);

	chip->domain = irq_domain_add_simple(adev->dev.of_node, PL061_GPIO_NR,
	irq_base, &pl061_domain_ops, chip);
	if (!chip->domain)
	return -ENODEV;

	for (i = 0; i < PL061_GPIO_NR; i++) {
	if (pdata) {
	if (pdata->directions & (1 << i))
	pl061_direction_output(&chip->gc, i,
	pdata->values & (1 << i));
	else
	pl061_direction_input(&chip->gc, i);
	}
	}

	amba_set_drvdata(adev, chip);

	return 0;
	}

	#ifdef CONFIG_PM
	static int pl061_suspend(struct device *dev)
	{
	struct pl061_gpio *chip = dev_get_drvdata(dev);
	int offset;

	chip->csave_regs.gpio_data = 0;
	chip->csave_regs.gpio_dir = readb(chip->base + GPIODIR);
	chip->csave_regs.gpio_is = readb(chip->base + GPIOIS);
	chip->csave_regs.gpio_ibe = readb(chip->base + GPIOIBE);
	chip->csave_regs.gpio_iev = readb(chip->base + GPIOIEV);
	chip->csave_regs.gpio_ie = readb(chip->base + GPIOIE);

	for (offset = 0; offset < PL061_GPIO_NR; offset++) {
	if (chip->csave_regs.gpio_dir & (1 << offset))
	chip->csave_regs.gpio_data \|=
	pl061_get_value(&chip->gc, offset) << offset;
	}

	return 0;
	}

	static int pl061_resume(struct device *dev)
	{
	struct pl061_gpio *chip = dev_get_drvdata(dev);
	int offset;

	for (offset = 0; offset < PL061_GPIO_NR; offset++) {
	if (chip->csave_regs.gpio_dir & (1 << offset))
	pl061_direction_output(&chip->gc, offset,
	chip->csave_regs.gpio_data &
	(1 << offset));
	else
	pl061_direction_input(&chip->gc, offset);
	}

	writeb(chip->csave_regs.gpio_is, chip->base + GPIOIS);
	writeb(chip->csave_regs.gpio_ibe, chip->base + GPIOIBE);
	writeb(chip->csave_regs.gpio_iev, chip->base + GPIOIEV);
	writeb(chip->csave_regs.gpio_ie, chip->base + GPIOIE);

	return 0;
	}

	static const struct dev_pm_ops pl061_dev_pm_ops = {
	.suspend = pl061_suspend,
	.resume = pl061_resume,
	.freeze = pl061_suspend,
	.restore = pl061_resume,
	};
	#endif

	static struct amba_id pl061_ids[] = {
	{
	.id = 0x00041061,
	.mask = 0x000fffff,
	},
	{ 0, 0 },
	};

	MODULE_DEVICE_TABLE(amba, pl061_ids);

	static struct amba_driver pl061_gpio_driver = {
	.drv = {
	.name = "pl061_gpio",
	#ifdef CONFIG_PM
	.pm = &pl061_dev_pm_ops,
	#endif
	},
	.id_table = pl061_ids,
	.probe = pl061_probe,
	};

	static int __init pl061_gpio_init(void)
	{
	return amba_driver_register(&pl061_gpio_driver);
	}
	module_init(pl061_gpio_init);

	MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
	MODULE_DESCRIPTION("PL061 GPIO driver");
	MODULE_LICENSE("GPL");