drivers/gpio/gpio-pl061.c - kernel/msm-4.19 - Gitiles

 /*
  * Copyright (C) 2008, 2009 Provigent Ltd.
  *
  * Author: Baruch Siach <baruch@tkos.co.il>
  *
  * 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/init.h>
 #include <linux/io.h>
 #include <linux/ioport.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/irqchip/chained_irq.h>
 #include <linux/bitops.h>
 #include <linux/gpio.h>
 #include <linux/device.h>
 #include <linux/amba/bus.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 {
 	spinlock_t		lock;

 	void __iomem		*base;
 	struct gpio_chip	gc;
 	int			parent_irq;

 #ifdef CONFIG_PM
 	struct pl061_context_save_regs csave_regs;
 #endif
 };

 static int pl061_get_direction(struct gpio_chip *gc, unsigned offset)
 {
 	struct pl061 *pl061 = gpiochip_get_data(gc);

 	return !(readb(pl061->base + GPIODIR) & BIT(offset));
 }

 static int pl061_direction_input(struct gpio_chip *gc, unsigned offset)
 {
 	struct pl061 *pl061 = gpiochip_get_data(gc);
 	unsigned long flags;
 	unsigned char gpiodir;

 	spin_lock_irqsave(&pl061->lock, flags);
 	gpiodir = readb(pl061->base + GPIODIR);
 	gpiodir &= ~(BIT(offset));
 	writeb(gpiodir, pl061->base + GPIODIR);
 	spin_unlock_irqrestore(&pl061->lock, flags);

 	return 0;
 }

 static int pl061_direction_output(struct gpio_chip *gc, unsigned offset,
 		int value)
 {
 	struct pl061 *pl061 = gpiochip_get_data(gc);
 	unsigned long flags;
 	unsigned char gpiodir;

 	spin_lock_irqsave(&pl061->lock, flags);
 	writeb(!!value << offset, pl061->base + (BIT(offset + 2)));
 	gpiodir = readb(pl061->base + GPIODIR);
 	gpiodir |= BIT(offset);
 	writeb(gpiodir, pl061->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, pl061->base + (BIT(offset + 2)));
 	spin_unlock_irqrestore(&pl061->lock, flags);

 	return 0;
 }

 static int pl061_get_value(struct gpio_chip *gc, unsigned offset)
 {
 	struct pl061 *pl061 = gpiochip_get_data(gc);

 	return !!readb(pl061->base + (BIT(offset + 2)));
 }

 static void pl061_set_value(struct gpio_chip *gc, unsigned offset, int value)
 {
 	struct pl061 *pl061 = gpiochip_get_data(gc);

 	writeb(!!value << offset, pl061->base + (BIT(offset + 2)));
 }

 static int pl061_irq_type(struct irq_data *d, unsigned trigger)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 	struct pl061 *pl061 = gpiochip_get_data(gc);
 	int offset = irqd_to_hwirq(d);
 	unsigned long flags;
 	u8 gpiois, gpioibe, gpioiev;
 	u8 bit = BIT(offset);

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

 	if ((trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) &&
 	    (trigger & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING)))
 	{
 		dev_err(gc->parent,
 			"trying to configure line %d for both level and edge "
 			"detection, choose one!\n",
 			offset);
 		return -EINVAL;
 	}


 	spin_lock_irqsave(&pl061->lock, flags);

 	gpioiev = readb(pl061->base + GPIOIEV);
 	gpiois = readb(pl061->base + GPIOIS);
 	gpioibe = readb(pl061->base + GPIOIBE);

 	if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
 		bool polarity = trigger & IRQ_TYPE_LEVEL_HIGH;

 		/* Disable edge detection */
 		gpioibe &= ~bit;
 		/* Enable level detection */
 		gpiois |= bit;
 		/* Select polarity */
 		if (polarity)
 			gpioiev |= bit;
 		else
 			gpioiev &= ~bit;
 		irq_set_handler_locked(d, handle_level_irq);
 		dev_dbg(gc->parent, "line %d: IRQ on %s level\n",
 			offset,
 			polarity ? "HIGH" : "LOW");
 	} else if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
 		/* Disable level detection */
 		gpiois &= ~bit;
 		/* Select both edges, setting this makes GPIOEV be ignored */
 		gpioibe |= bit;
 		irq_set_handler_locked(d, handle_edge_irq);
 		dev_dbg(gc->parent, "line %d: IRQ on both edges\n", offset);
 	} else if ((trigger & IRQ_TYPE_EDGE_RISING) ||
 		   (trigger & IRQ_TYPE_EDGE_FALLING)) {
 		bool rising = trigger & IRQ_TYPE_EDGE_RISING;

 		/* Disable level detection */
 		gpiois &= ~bit;
 		/* Clear detection on both edges */
 		gpioibe &= ~bit;
 		/* Select edge */
 		if (rising)
 			gpioiev |= bit;
 		else
 			gpioiev &= ~bit;
 		irq_set_handler_locked(d, handle_edge_irq);
 		dev_dbg(gc->parent, "line %d: IRQ on %s edge\n",
 			offset,
 			rising ? "RISING" : "FALLING");
 	} else {
 		/* No trigger: disable everything */
 		gpiois &= ~bit;
 		gpioibe &= ~bit;
 		gpioiev &= ~bit;
 		irq_set_handler_locked(d, handle_bad_irq);
 		dev_warn(gc->parent, "no trigger selected for line %d\n",
 			 offset);
 	}

 	writeb(gpiois, pl061->base + GPIOIS);
 	writeb(gpioibe, pl061->base + GPIOIBE);
 	writeb(gpioiev, pl061->base + GPIOIEV);

 	spin_unlock_irqrestore(&pl061->lock, flags);

 	return 0;
 }

 static void pl061_irq_handler(struct irq_desc *desc)
 {
 	unsigned long pending;
 	int offset;
 	struct gpio_chip *gc = irq_desc_get_handler_data(desc);
 	struct pl061 *pl061 = gpiochip_get_data(gc);
 	struct irq_chip *irqchip = irq_desc_get_chip(desc);

 	chained_irq_enter(irqchip, desc);

 	pending = readb(pl061->base + GPIOMIS);
 	if (pending) {
 		for_each_set_bit(offset, &pending, PL061_GPIO_NR)
 			generic_handle_irq(irq_find_mapping(gc->irqdomain,
 							    offset));
 	}

 	chained_irq_exit(irqchip, desc);
 }

 static void pl061_irq_mask(struct irq_data *d)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 	struct pl061 *pl061 = gpiochip_get_data(gc);
 	u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);
 	u8 gpioie;

 	spin_lock(&pl061->lock);
 	gpioie = readb(pl061->base + GPIOIE) & ~mask;
 	writeb(gpioie, pl061->base + GPIOIE);
 	spin_unlock(&pl061->lock);
 }

 static void pl061_irq_unmask(struct irq_data *d)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 	struct pl061 *pl061 = gpiochip_get_data(gc);
 	u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);
 	u8 gpioie;

 	spin_lock(&pl061->lock);
 	gpioie = readb(pl061->base + GPIOIE) | mask;
 	writeb(gpioie, pl061->base + GPIOIE);
 	spin_unlock(&pl061->lock);
 }

 /**
  * pl061_irq_ack() - ACK an edge IRQ
  * @d: IRQ data for this IRQ
  *
  * This gets called from the edge IRQ handler to ACK the edge IRQ
  * in the GPIOIC (interrupt-clear) register. For level IRQs this is
  * not needed: these go away when the level signal goes away.
  */
 static void pl061_irq_ack(struct irq_data *d)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 	struct pl061 *pl061 = gpiochip_get_data(gc);
 	u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);

 	spin_lock(&pl061->lock);
 	writeb(mask, pl061->base + GPIOIC);
 	spin_unlock(&pl061->lock);
 }

 static int pl061_irq_set_wake(struct irq_data *d, unsigned int state)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 	struct pl061 *pl061 = gpiochip_get_data(gc);

 	return irq_set_irq_wake(pl061->parent_irq, state);
 }

 static struct irq_chip pl061_irqchip = {
 	.name		= "pl061",
 	.irq_ack	= pl061_irq_ack,
 	.irq_mask	= pl061_irq_mask,
 	.irq_unmask	= pl061_irq_unmask,
 	.irq_set_type	= pl061_irq_type,
 	.irq_set_wake	= pl061_irq_set_wake,
 };

 static int pl061_probe(struct amba_device *adev, const struct amba_id *id)
 {
 	struct device *dev = &adev->dev;
 	struct pl061 *pl061;
 	int ret, irq;

 	pl061 = devm_kzalloc(dev, sizeof(*pl061), GFP_KERNEL);
 	if (pl061 == NULL)
 		return -ENOMEM;

 	pl061->base = devm_ioremap_resource(dev, &adev->res);
 	if (IS_ERR(pl061->base))
 		return PTR_ERR(pl061->base);

 	spin_lock_init(&pl061->lock);
 	if (of_property_read_bool(dev->of_node, "gpio-ranges")) {
 		pl061->gc.request = gpiochip_generic_request;
 		pl061->gc.free = gpiochip_generic_free;
 	}

 	pl061->gc.base = -1;
 	pl061->gc.get_direction = pl061_get_direction;
 	pl061->gc.direction_input = pl061_direction_input;
 	pl061->gc.direction_output = pl061_direction_output;
 	pl061->gc.get = pl061_get_value;
 	pl061->gc.set = pl061_set_value;
 	pl061->gc.ngpio = PL061_GPIO_NR;
 	pl061->gc.label = dev_name(dev);
 	pl061->gc.parent = dev;
 	pl061->gc.owner = THIS_MODULE;

 	ret = gpiochip_add_data(&pl061->gc, pl061);
 	if (ret)
 		return ret;

 	/*
 	 * irq_chip support
 	 */
 	writeb(0, pl061->base + GPIOIE); /* disable irqs */
 	irq = adev->irq[0];
 	if (irq < 0) {
 		dev_err(&adev->dev, "invalid IRQ\n");
 		return -ENODEV;
 	}
 	pl061->parent_irq = irq;

 	ret = gpiochip_irqchip_add(&pl061->gc, &pl061_irqchip,
 				   0, handle_bad_irq,
 				   IRQ_TYPE_NONE);
 	if (ret) {
 		dev_info(&adev->dev, "could not add irqchip\n");
 		return ret;
 	}
 	gpiochip_set_chained_irqchip(&pl061->gc, &pl061_irqchip,
 				     irq, pl061_irq_handler);

 	amba_set_drvdata(adev, pl061);
 	dev_info(&adev->dev, "PL061 GPIO chip @%pa registered\n",
 		 &adev->res.start);

 	return 0;
 }

 #ifdef CONFIG_PM
 static int pl061_suspend(struct device *dev)
 {
 	struct pl061 *pl061 = dev_get_drvdata(dev);
 	int offset;

 	pl061->csave_regs.gpio_data = 0;
 	pl061->csave_regs.gpio_dir = readb(pl061->base + GPIODIR);
 	pl061->csave_regs.gpio_is = readb(pl061->base + GPIOIS);
 	pl061->csave_regs.gpio_ibe = readb(pl061->base + GPIOIBE);
 	pl061->csave_regs.gpio_iev = readb(pl061->base + GPIOIEV);
 	pl061->csave_regs.gpio_ie = readb(pl061->base + GPIOIE);

 	for (offset = 0; offset < PL061_GPIO_NR; offset++) {
 		if (pl061->csave_regs.gpio_dir & (BIT(offset)))
 			pl061->csave_regs.gpio_data |=
 				pl061_get_value(&pl061->gc, offset) << offset;
 	}

 	return 0;
 }

 static int pl061_resume(struct device *dev)
 {
 	struct pl061 *pl061 = dev_get_drvdata(dev);
 	int offset;

 	for (offset = 0; offset < PL061_GPIO_NR; offset++) {
 		if (pl061->csave_regs.gpio_dir & (BIT(offset)))
 			pl061_direction_output(&pl061->gc, offset,
 					pl061->csave_regs.gpio_data &
 					(BIT(offset)));
 		else
 			pl061_direction_input(&pl061->gc, offset);
 	}

 	writeb(pl061->csave_regs.gpio_is, pl061->base + GPIOIS);
 	writeb(pl061->csave_regs.gpio_ibe, pl061->base + GPIOIBE);
 	writeb(pl061->csave_regs.gpio_iev, pl061->base + GPIOIEV);
 	writeb(pl061->csave_regs.gpio_ie, pl061->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 },
 };

 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);
 }
 device_initcall(pl061_gpio_init);
	/*
	* Copyright (C) 2008, 2009 Provigent Ltd.
	*
	* Author: Baruch Siach <baruch@tkos.co.il>
	*
	* 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/init.h>
	#include <linux/io.h>
	#include <linux/ioport.h>
	#include <linux/interrupt.h>
	#include <linux/irq.h>
	#include <linux/irqchip/chained_irq.h>
	#include <linux/bitops.h>
	#include <linux/gpio.h>
	#include <linux/device.h>
	#include <linux/amba/bus.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 {
	spinlock_t lock;

	void __iomem *base;
	struct gpio_chip gc;
	int parent_irq;

	#ifdef CONFIG_PM
	struct pl061_context_save_regs csave_regs;
	#endif
	};

	static int pl061_get_direction(struct gpio_chip *gc, unsigned offset)
	{
	struct pl061 *pl061 = gpiochip_get_data(gc);

	return !(readb(pl061->base + GPIODIR) & BIT(offset));
	}

	static int pl061_direction_input(struct gpio_chip *gc, unsigned offset)
	{
	struct pl061 *pl061 = gpiochip_get_data(gc);
	unsigned long flags;
	unsigned char gpiodir;

	spin_lock_irqsave(&pl061->lock, flags);
	gpiodir = readb(pl061->base + GPIODIR);
	gpiodir &= ~(BIT(offset));
	writeb(gpiodir, pl061->base + GPIODIR);
	spin_unlock_irqrestore(&pl061->lock, flags);

	return 0;
	}

	static int pl061_direction_output(struct gpio_chip *gc, unsigned offset,
	int value)
	{
	struct pl061 *pl061 = gpiochip_get_data(gc);
	unsigned long flags;
	unsigned char gpiodir;

	spin_lock_irqsave(&pl061->lock, flags);
	writeb(!!value << offset, pl061->base + (BIT(offset + 2)));
	gpiodir = readb(pl061->base + GPIODIR);
	gpiodir \|= BIT(offset);
	writeb(gpiodir, pl061->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, pl061->base + (BIT(offset + 2)));
	spin_unlock_irqrestore(&pl061->lock, flags);

	return 0;
	}

	static int pl061_get_value(struct gpio_chip *gc, unsigned offset)
	{
	struct pl061 *pl061 = gpiochip_get_data(gc);

	return !!readb(pl061->base + (BIT(offset + 2)));
	}

	static void pl061_set_value(struct gpio_chip *gc, unsigned offset, int value)
	{
	struct pl061 *pl061 = gpiochip_get_data(gc);

	writeb(!!value << offset, pl061->base + (BIT(offset + 2)));
	}

	static int pl061_irq_type(struct irq_data *d, unsigned trigger)
	{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
	struct pl061 *pl061 = gpiochip_get_data(gc);
	int offset = irqd_to_hwirq(d);
	unsigned long flags;
	u8 gpiois, gpioibe, gpioiev;
	u8 bit = BIT(offset);

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

	if ((trigger & (IRQ_TYPE_LEVEL_HIGH \| IRQ_TYPE_LEVEL_LOW)) &&
	(trigger & (IRQ_TYPE_EDGE_RISING \| IRQ_TYPE_EDGE_FALLING)))
	{
	dev_err(gc->parent,
	"trying to configure line %d for both level and edge "
	"detection, choose one!\n",
	offset);
	return -EINVAL;
	}


	spin_lock_irqsave(&pl061->lock, flags);

	gpioiev = readb(pl061->base + GPIOIEV);
	gpiois = readb(pl061->base + GPIOIS);
	gpioibe = readb(pl061->base + GPIOIBE);

	if (trigger & (IRQ_TYPE_LEVEL_HIGH \| IRQ_TYPE_LEVEL_LOW)) {
	bool polarity = trigger & IRQ_TYPE_LEVEL_HIGH;

	/* Disable edge detection */
	gpioibe &= ~bit;
	/* Enable level detection */
	gpiois \|= bit;
	/* Select polarity */
	if (polarity)
	gpioiev \|= bit;
	else
	gpioiev &= ~bit;
	irq_set_handler_locked(d, handle_level_irq);
	dev_dbg(gc->parent, "line %d: IRQ on %s level\n",
	offset,
	polarity ? "HIGH" : "LOW");
	} else if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
	/* Disable level detection */
	gpiois &= ~bit;
	/* Select both edges, setting this makes GPIOEV be ignored */
	gpioibe \|= bit;
	irq_set_handler_locked(d, handle_edge_irq);
	dev_dbg(gc->parent, "line %d: IRQ on both edges\n", offset);
	} else if ((trigger & IRQ_TYPE_EDGE_RISING) \|\|
	(trigger & IRQ_TYPE_EDGE_FALLING)) {
	bool rising = trigger & IRQ_TYPE_EDGE_RISING;

	/* Disable level detection */
	gpiois &= ~bit;
	/* Clear detection on both edges */
	gpioibe &= ~bit;
	/* Select edge */
	if (rising)
	gpioiev \|= bit;
	else
	gpioiev &= ~bit;
	irq_set_handler_locked(d, handle_edge_irq);
	dev_dbg(gc->parent, "line %d: IRQ on %s edge\n",
	offset,
	rising ? "RISING" : "FALLING");
	} else {
	/* No trigger: disable everything */
	gpiois &= ~bit;
	gpioibe &= ~bit;
	gpioiev &= ~bit;
	irq_set_handler_locked(d, handle_bad_irq);
	dev_warn(gc->parent, "no trigger selected for line %d\n",
	offset);
	}

	writeb(gpiois, pl061->base + GPIOIS);
	writeb(gpioibe, pl061->base + GPIOIBE);
	writeb(gpioiev, pl061->base + GPIOIEV);

	spin_unlock_irqrestore(&pl061->lock, flags);

	return 0;
	}

	static void pl061_irq_handler(struct irq_desc *desc)
	{
	unsigned long pending;
	int offset;
	struct gpio_chip *gc = irq_desc_get_handler_data(desc);
	struct pl061 *pl061 = gpiochip_get_data(gc);
	struct irq_chip *irqchip = irq_desc_get_chip(desc);

	chained_irq_enter(irqchip, desc);

	pending = readb(pl061->base + GPIOMIS);
	if (pending) {
	for_each_set_bit(offset, &pending, PL061_GPIO_NR)
	generic_handle_irq(irq_find_mapping(gc->irqdomain,
	offset));
	}

	chained_irq_exit(irqchip, desc);
	}

	static void pl061_irq_mask(struct irq_data *d)
	{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
	struct pl061 *pl061 = gpiochip_get_data(gc);
	u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);
	u8 gpioie;

	spin_lock(&pl061->lock);
	gpioie = readb(pl061->base + GPIOIE) & ~mask;
	writeb(gpioie, pl061->base + GPIOIE);
	spin_unlock(&pl061->lock);
	}

	static void pl061_irq_unmask(struct irq_data *d)
	{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
	struct pl061 *pl061 = gpiochip_get_data(gc);
	u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);
	u8 gpioie;

	spin_lock(&pl061->lock);
	gpioie = readb(pl061->base + GPIOIE) \| mask;
	writeb(gpioie, pl061->base + GPIOIE);
	spin_unlock(&pl061->lock);
	}

	/**
	* pl061_irq_ack() - ACK an edge IRQ
	* @d: IRQ data for this IRQ
	*
	* This gets called from the edge IRQ handler to ACK the edge IRQ
	* in the GPIOIC (interrupt-clear) register. For level IRQs this is
	* not needed: these go away when the level signal goes away.
	*/
	static void pl061_irq_ack(struct irq_data *d)
	{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
	struct pl061 *pl061 = gpiochip_get_data(gc);
	u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR);

	spin_lock(&pl061->lock);
	writeb(mask, pl061->base + GPIOIC);
	spin_unlock(&pl061->lock);
	}

	static int pl061_irq_set_wake(struct irq_data *d, unsigned int state)
	{
	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
	struct pl061 *pl061 = gpiochip_get_data(gc);

	return irq_set_irq_wake(pl061->parent_irq, state);
	}

	static struct irq_chip pl061_irqchip = {
	.name = "pl061",
	.irq_ack = pl061_irq_ack,
	.irq_mask = pl061_irq_mask,
	.irq_unmask = pl061_irq_unmask,
	.irq_set_type = pl061_irq_type,
	.irq_set_wake = pl061_irq_set_wake,
	};

	static int pl061_probe(struct amba_device adev, const struct amba_id id)
	{
	struct device *dev = &adev->dev;
	struct pl061 *pl061;
	int ret, irq;

	pl061 = devm_kzalloc(dev, sizeof(*pl061), GFP_KERNEL);
	if (pl061 == NULL)
	return -ENOMEM;

	pl061->base = devm_ioremap_resource(dev, &adev->res);
	if (IS_ERR(pl061->base))
	return PTR_ERR(pl061->base);

	spin_lock_init(&pl061->lock);
	if (of_property_read_bool(dev->of_node, "gpio-ranges")) {
	pl061->gc.request = gpiochip_generic_request;
	pl061->gc.free = gpiochip_generic_free;
	}

	pl061->gc.base = -1;
	pl061->gc.get_direction = pl061_get_direction;
	pl061->gc.direction_input = pl061_direction_input;
	pl061->gc.direction_output = pl061_direction_output;
	pl061->gc.get = pl061_get_value;
	pl061->gc.set = pl061_set_value;
	pl061->gc.ngpio = PL061_GPIO_NR;
	pl061->gc.label = dev_name(dev);
	pl061->gc.parent = dev;
	pl061->gc.owner = THIS_MODULE;

	ret = gpiochip_add_data(&pl061->gc, pl061);
	if (ret)
	return ret;

	/*
	* irq_chip support
	*/
	writeb(0, pl061->base + GPIOIE); /* disable irqs */
	irq = adev->irq[0];
	if (irq < 0) {
	dev_err(&adev->dev, "invalid IRQ\n");
	return -ENODEV;
	}
	pl061->parent_irq = irq;

	ret = gpiochip_irqchip_add(&pl061->gc, &pl061_irqchip,
	0, handle_bad_irq,
	IRQ_TYPE_NONE);
	if (ret) {
	dev_info(&adev->dev, "could not add irqchip\n");
	return ret;
	}
	gpiochip_set_chained_irqchip(&pl061->gc, &pl061_irqchip,
	irq, pl061_irq_handler);

	amba_set_drvdata(adev, pl061);
	dev_info(&adev->dev, "PL061 GPIO chip @%pa registered\n",
	&adev->res.start);

	return 0;
	}

	#ifdef CONFIG_PM
	static int pl061_suspend(struct device *dev)
	{
	struct pl061 *pl061 = dev_get_drvdata(dev);
	int offset;

	pl061->csave_regs.gpio_data = 0;
	pl061->csave_regs.gpio_dir = readb(pl061->base + GPIODIR);
	pl061->csave_regs.gpio_is = readb(pl061->base + GPIOIS);
	pl061->csave_regs.gpio_ibe = readb(pl061->base + GPIOIBE);
	pl061->csave_regs.gpio_iev = readb(pl061->base + GPIOIEV);
	pl061->csave_regs.gpio_ie = readb(pl061->base + GPIOIE);

	for (offset = 0; offset < PL061_GPIO_NR; offset++) {
	if (pl061->csave_regs.gpio_dir & (BIT(offset)))
	pl061->csave_regs.gpio_data \|=
	pl061_get_value(&pl061->gc, offset) << offset;
	}

	return 0;
	}

	static int pl061_resume(struct device *dev)
	{
	struct pl061 *pl061 = dev_get_drvdata(dev);
	int offset;

	for (offset = 0; offset < PL061_GPIO_NR; offset++) {
	if (pl061->csave_regs.gpio_dir & (BIT(offset)))
	pl061_direction_output(&pl061->gc, offset,
	pl061->csave_regs.gpio_data &
	(BIT(offset)));
	else
	pl061_direction_input(&pl061->gc, offset);
	}

	writeb(pl061->csave_regs.gpio_is, pl061->base + GPIOIS);
	writeb(pl061->csave_regs.gpio_ibe, pl061->base + GPIOIBE);
	writeb(pl061->csave_regs.gpio_iev, pl061->base + GPIOIEV);
	writeb(pl061->csave_regs.gpio_ie, pl061->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 },
	};

	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);
	}
	device_initcall(pl061_gpio_init);