drivers/gpio/gpio-vr41xx.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0+
 /*
  *  Driver for NEC VR4100 series General-purpose I/O Unit.
  *
  *  Copyright (C) 2002 MontaVista Software Inc.
  *	Author: Yoichi Yuasa <source@mvista.com>
  *  Copyright (C) 2003-2009  Yoichi Yuasa <yuasa@linux-mips.org>
  */
 #include <linux/errno.h>
 #include <linux/fs.h>
 #include <linux/gpio/driver.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/irq.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/spinlock.h>
 #include <linux/types.h>

 #include <asm/vr41xx/giu.h>
 #include <asm/vr41xx/irq.h>
 #include <asm/vr41xx/vr41xx.h>

 MODULE_AUTHOR("Yoichi Yuasa <yuasa@linux-mips.org>");
 MODULE_DESCRIPTION("NEC VR4100 series General-purpose I/O Unit driver");
 MODULE_LICENSE("GPL");

 #define GIUIOSELL	0x00
 #define GIUIOSELH	0x02
 #define GIUPIODL	0x04
 #define GIUPIODH	0x06
 #define GIUINTSTATL	0x08
 #define GIUINTSTATH	0x0a
 #define GIUINTENL	0x0c
 #define GIUINTENH	0x0e
 #define GIUINTTYPL	0x10
 #define GIUINTTYPH	0x12
 #define GIUINTALSELL	0x14
 #define GIUINTALSELH	0x16
 #define GIUINTHTSELL	0x18
 #define GIUINTHTSELH	0x1a
 #define GIUPODATL	0x1c
 #define GIUPODATEN	0x1c
 #define GIUPODATH	0x1e
  #define PIOEN0		0x0100
  #define PIOEN1		0x0200
 #define GIUPODAT	0x1e
 #define GIUFEDGEINHL	0x20
 #define GIUFEDGEINHH	0x22
 #define GIUREDGEINHL	0x24
 #define GIUREDGEINHH	0x26

 #define GIUUSEUPDN	0x1e0
 #define GIUTERMUPDN	0x1e2

 #define GPIO_HAS_PULLUPDOWN_IO		0x0001
 #define GPIO_HAS_OUTPUT_ENABLE		0x0002
 #define GPIO_HAS_INTERRUPT_EDGE_SELECT	0x0100

 enum {
 	GPIO_INPUT,
 	GPIO_OUTPUT,
 };

 static DEFINE_SPINLOCK(giu_lock);
 static unsigned long giu_flags;

 static void __iomem *giu_base;
 static struct gpio_chip vr41xx_gpio_chip;

 #define giu_read(offset)		readw(giu_base + (offset))
 #define giu_write(offset, value)	writew((value), giu_base + (offset))

 #define GPIO_PIN_OF_IRQ(irq)	((irq) - GIU_IRQ_BASE)
 #define GIUINT_HIGH_OFFSET	16
 #define GIUINT_HIGH_MAX		32

 static inline u16 giu_set(u16 offset, u16 set)
 {
 	u16 data;

 	data = giu_read(offset);
 	data |= set;
 	giu_write(offset, data);

 	return data;
 }

 static inline u16 giu_clear(u16 offset, u16 clear)
 {
 	u16 data;

 	data = giu_read(offset);
 	data &= ~clear;
 	giu_write(offset, data);

 	return data;
 }

 static void ack_giuint_low(struct irq_data *d)
 {
 	giu_write(GIUINTSTATL, 1 << GPIO_PIN_OF_IRQ(d->irq));
 }

 static void mask_giuint_low(struct irq_data *d)
 {
 	giu_clear(GIUINTENL, 1 << GPIO_PIN_OF_IRQ(d->irq));
 }

 static void mask_ack_giuint_low(struct irq_data *d)
 {
 	unsigned int pin;

 	pin = GPIO_PIN_OF_IRQ(d->irq);
 	giu_clear(GIUINTENL, 1 << pin);
 	giu_write(GIUINTSTATL, 1 << pin);
 }

 static void unmask_giuint_low(struct irq_data *d)
 {
 	giu_set(GIUINTENL, 1 << GPIO_PIN_OF_IRQ(d->irq));
 }

 static unsigned int startup_giuint(struct irq_data *data)
 {
 	int ret;

 	ret = gpiochip_lock_as_irq(&vr41xx_gpio_chip, irqd_to_hwirq(data));
 	if (ret) {
 		dev_err(vr41xx_gpio_chip.parent,
 			"unable to lock HW IRQ %lu for IRQ\n",
 			data->hwirq);
 		return ret;
 	}

 	/* Satisfy the .enable semantics by unmasking the line */
 	unmask_giuint_low(data);
 	return 0;
 }

 static void shutdown_giuint(struct irq_data *data)
 {
 	mask_giuint_low(data);
 	gpiochip_unlock_as_irq(&vr41xx_gpio_chip, data->hwirq);
 }

 static struct irq_chip giuint_low_irq_chip = {
 	.name		= "GIUINTL",
 	.irq_ack	= ack_giuint_low,
 	.irq_mask	= mask_giuint_low,
 	.irq_mask_ack	= mask_ack_giuint_low,
 	.irq_unmask	= unmask_giuint_low,
 	.irq_startup	= startup_giuint,
 	.irq_shutdown	= shutdown_giuint,
 };

 static void ack_giuint_high(struct irq_data *d)
 {
 	giu_write(GIUINTSTATH,
 		  1 << (GPIO_PIN_OF_IRQ(d->irq) - GIUINT_HIGH_OFFSET));
 }

 static void mask_giuint_high(struct irq_data *d)
 {
 	giu_clear(GIUINTENH, 1 << (GPIO_PIN_OF_IRQ(d->irq) - GIUINT_HIGH_OFFSET));
 }

 static void mask_ack_giuint_high(struct irq_data *d)
 {
 	unsigned int pin;

 	pin = GPIO_PIN_OF_IRQ(d->irq) - GIUINT_HIGH_OFFSET;
 	giu_clear(GIUINTENH, 1 << pin);
 	giu_write(GIUINTSTATH, 1 << pin);
 }

 static void unmask_giuint_high(struct irq_data *d)
 {
 	giu_set(GIUINTENH, 1 << (GPIO_PIN_OF_IRQ(d->irq) - GIUINT_HIGH_OFFSET));
 }

 static struct irq_chip giuint_high_irq_chip = {
 	.name		= "GIUINTH",
 	.irq_ack	= ack_giuint_high,
 	.irq_mask	= mask_giuint_high,
 	.irq_mask_ack	= mask_ack_giuint_high,
 	.irq_unmask	= unmask_giuint_high,
 };

 static int giu_get_irq(unsigned int irq)
 {
 	u16 pendl, pendh, maskl, maskh;
 	int i;

 	pendl = giu_read(GIUINTSTATL);
 	pendh = giu_read(GIUINTSTATH);
 	maskl = giu_read(GIUINTENL);
 	maskh = giu_read(GIUINTENH);

 	maskl &= pendl;
 	maskh &= pendh;

 	if (maskl) {
 		for (i = 0; i < 16; i++) {
 			if (maskl & (1 << i))
 				return GIU_IRQ(i);
 		}
 	} else if (maskh) {
 		for (i = 0; i < 16; i++) {
 			if (maskh & (1 << i))
 				return GIU_IRQ(i + GIUINT_HIGH_OFFSET);
 		}
 	}

 	printk(KERN_ERR "spurious GIU interrupt: %04x(%04x),%04x(%04x)\n",
 	       maskl, pendl, maskh, pendh);

 	atomic_inc(&irq_err_count);

 	return -EINVAL;
 }

 void vr41xx_set_irq_trigger(unsigned int pin, irq_trigger_t trigger,
 			    irq_signal_t signal)
 {
 	u16 mask;

 	if (pin < GIUINT_HIGH_OFFSET) {
 		mask = 1 << pin;
 		if (trigger != IRQ_TRIGGER_LEVEL) {
 			giu_set(GIUINTTYPL, mask);
 			if (signal == IRQ_SIGNAL_HOLD)
 				giu_set(GIUINTHTSELL, mask);
 			else
 				giu_clear(GIUINTHTSELL, mask);
 			if (giu_flags & GPIO_HAS_INTERRUPT_EDGE_SELECT) {
 				switch (trigger) {
 				case IRQ_TRIGGER_EDGE_FALLING:
 					giu_set(GIUFEDGEINHL, mask);
 					giu_clear(GIUREDGEINHL, mask);
 					break;
 				case IRQ_TRIGGER_EDGE_RISING:
 					giu_clear(GIUFEDGEINHL, mask);
 					giu_set(GIUREDGEINHL, mask);
 					break;
 				default:
 					giu_set(GIUFEDGEINHL, mask);
 					giu_set(GIUREDGEINHL, mask);
 					break;
 				}
 			}
 			irq_set_chip_and_handler(GIU_IRQ(pin),
 						 &giuint_low_irq_chip,
 						 handle_edge_irq);
 		} else {
 			giu_clear(GIUINTTYPL, mask);
 			giu_clear(GIUINTHTSELL, mask);
 			irq_set_chip_and_handler(GIU_IRQ(pin),
 						 &giuint_low_irq_chip,
 						 handle_level_irq);
 		}
 		giu_write(GIUINTSTATL, mask);
 	} else if (pin < GIUINT_HIGH_MAX) {
 		mask = 1 << (pin - GIUINT_HIGH_OFFSET);
 		if (trigger != IRQ_TRIGGER_LEVEL) {
 			giu_set(GIUINTTYPH, mask);
 			if (signal == IRQ_SIGNAL_HOLD)
 				giu_set(GIUINTHTSELH, mask);
 			else
 				giu_clear(GIUINTHTSELH, mask);
 			if (giu_flags & GPIO_HAS_INTERRUPT_EDGE_SELECT) {
 				switch (trigger) {
 				case IRQ_TRIGGER_EDGE_FALLING:
 					giu_set(GIUFEDGEINHH, mask);
 					giu_clear(GIUREDGEINHH, mask);
 					break;
 				case IRQ_TRIGGER_EDGE_RISING:
 					giu_clear(GIUFEDGEINHH, mask);
 					giu_set(GIUREDGEINHH, mask);
 					break;
 				default:
 					giu_set(GIUFEDGEINHH, mask);
 					giu_set(GIUREDGEINHH, mask);
 					break;
 				}
 			}
 			irq_set_chip_and_handler(GIU_IRQ(pin),
 						 &giuint_high_irq_chip,
 						 handle_edge_irq);
 		} else {
 			giu_clear(GIUINTTYPH, mask);
 			giu_clear(GIUINTHTSELH, mask);
 			irq_set_chip_and_handler(GIU_IRQ(pin),
 						 &giuint_high_irq_chip,
 						 handle_level_irq);
 		}
 		giu_write(GIUINTSTATH, mask);
 	}
 }
 EXPORT_SYMBOL_GPL(vr41xx_set_irq_trigger);

 void vr41xx_set_irq_level(unsigned int pin, irq_level_t level)
 {
 	u16 mask;

 	if (pin < GIUINT_HIGH_OFFSET) {
 		mask = 1 << pin;
 		if (level == IRQ_LEVEL_HIGH)
 			giu_set(GIUINTALSELL, mask);
 		else
 			giu_clear(GIUINTALSELL, mask);
 		giu_write(GIUINTSTATL, mask);
 	} else if (pin < GIUINT_HIGH_MAX) {
 		mask = 1 << (pin - GIUINT_HIGH_OFFSET);
 		if (level == IRQ_LEVEL_HIGH)
 			giu_set(GIUINTALSELH, mask);
 		else
 			giu_clear(GIUINTALSELH, mask);
 		giu_write(GIUINTSTATH, mask);
 	}
 }
 EXPORT_SYMBOL_GPL(vr41xx_set_irq_level);

 static int giu_set_direction(struct gpio_chip *chip, unsigned pin, int dir)
 {
 	u16 offset, mask, reg;
 	unsigned long flags;

 	if (pin >= chip->ngpio)
 		return -EINVAL;

 	if (pin < 16) {
 		offset = GIUIOSELL;
 		mask = 1 << pin;
 	} else if (pin < 32) {
 		offset = GIUIOSELH;
 		mask = 1 << (pin - 16);
 	} else {
 		if (giu_flags & GPIO_HAS_OUTPUT_ENABLE) {
 			offset = GIUPODATEN;
 			mask = 1 << (pin - 32);
 		} else {
 			switch (pin) {
 			case 48:
 				offset = GIUPODATH;
 				mask = PIOEN0;
 				break;
 			case 49:
 				offset = GIUPODATH;
 				mask = PIOEN1;
 				break;
 			default:
 				return -EINVAL;
 			}
 		}
 	}

 	spin_lock_irqsave(&giu_lock, flags);

 	reg = giu_read(offset);
 	if (dir == GPIO_OUTPUT)
 		reg |= mask;
 	else
 		reg &= ~mask;
 	giu_write(offset, reg);

 	spin_unlock_irqrestore(&giu_lock, flags);

 	return 0;
 }

 static int vr41xx_gpio_get(struct gpio_chip *chip, unsigned pin)
 {
 	u16 reg, mask;

 	if (pin >= chip->ngpio)
 		return -EINVAL;

 	if (pin < 16) {
 		reg = giu_read(GIUPIODL);
 		mask = 1 << pin;
 	} else if (pin < 32) {
 		reg = giu_read(GIUPIODH);
 		mask = 1 << (pin - 16);
 	} else if (pin < 48) {
 		reg = giu_read(GIUPODATL);
 		mask = 1 << (pin - 32);
 	} else {
 		reg = giu_read(GIUPODATH);
 		mask = 1 << (pin - 48);
 	}

 	if (reg & mask)
 		return 1;

 	return 0;
 }

 static void vr41xx_gpio_set(struct gpio_chip *chip, unsigned pin,
 			    int value)
 {
 	u16 offset, mask, reg;
 	unsigned long flags;

 	if (pin >= chip->ngpio)
 		return;

 	if (pin < 16) {
 		offset = GIUPIODL;
 		mask = 1 << pin;
 	} else if (pin < 32) {
 		offset = GIUPIODH;
 		mask = 1 << (pin - 16);
 	} else if (pin < 48) {
 		offset = GIUPODATL;
 		mask = 1 << (pin - 32);
 	} else {
 		offset = GIUPODATH;
 		mask = 1 << (pin - 48);
 	}

 	spin_lock_irqsave(&giu_lock, flags);

 	reg = giu_read(offset);
 	if (value)
 		reg |= mask;
 	else
 		reg &= ~mask;
 	giu_write(offset, reg);

 	spin_unlock_irqrestore(&giu_lock, flags);
 }


 static int vr41xx_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
 {
 	return giu_set_direction(chip, offset, GPIO_INPUT);
 }

 static int vr41xx_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
 				int value)
 {
 	vr41xx_gpio_set(chip, offset, value);

 	return giu_set_direction(chip, offset, GPIO_OUTPUT);
 }

 static int vr41xx_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 {
 	if (offset >= chip->ngpio)
 		return -EINVAL;

 	return GIU_IRQ_BASE + offset;
 }

 static struct gpio_chip vr41xx_gpio_chip = {
 	.label			= "vr41xx",
 	.owner			= THIS_MODULE,
 	.direction_input	= vr41xx_gpio_direction_input,
 	.get			= vr41xx_gpio_get,
 	.direction_output	= vr41xx_gpio_direction_output,
 	.set			= vr41xx_gpio_set,
 	.to_irq			= vr41xx_gpio_to_irq,
 };

 static int giu_probe(struct platform_device *pdev)
 {
 	unsigned int trigger, i, pin;
 	struct irq_chip *chip;
 	int irq;

 	switch (pdev->id) {
 	case GPIO_50PINS_PULLUPDOWN:
 		giu_flags = GPIO_HAS_PULLUPDOWN_IO;
 		vr41xx_gpio_chip.ngpio = 50;
 		break;
 	case GPIO_36PINS:
 		vr41xx_gpio_chip.ngpio = 36;
 		break;
 	case GPIO_48PINS_EDGE_SELECT:
 		giu_flags = GPIO_HAS_INTERRUPT_EDGE_SELECT;
 		vr41xx_gpio_chip.ngpio = 48;
 		break;
 	default:
 		dev_err(&pdev->dev, "GIU: unknown ID %d\n", pdev->id);
 		return -ENODEV;
 	}

 	giu_base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(giu_base))
 		return PTR_ERR(giu_base);

 	vr41xx_gpio_chip.parent = &pdev->dev;

 	if (gpiochip_add_data(&vr41xx_gpio_chip, NULL))
 		return -ENODEV;

 	giu_write(GIUINTENL, 0);
 	giu_write(GIUINTENH, 0);

 	trigger = giu_read(GIUINTTYPH) << 16;
 	trigger |= giu_read(GIUINTTYPL);
 	for (i = GIU_IRQ_BASE; i <= GIU_IRQ_LAST; i++) {
 		pin = GPIO_PIN_OF_IRQ(i);
 		if (pin < GIUINT_HIGH_OFFSET)
 			chip = &giuint_low_irq_chip;
 		else
 			chip = &giuint_high_irq_chip;

 		if (trigger & (1 << pin))
 			irq_set_chip_and_handler(i, chip, handle_edge_irq);
 		else
 			irq_set_chip_and_handler(i, chip, handle_level_irq);

 	}

 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0 || irq >= nr_irqs)
 		return -EBUSY;

 	return cascade_irq(irq, giu_get_irq);
 }

 static int giu_remove(struct platform_device *pdev)
 {
 	if (giu_base) {
 		giu_base = NULL;
 	}

 	return 0;
 }

 static struct platform_driver giu_device_driver = {
 	.probe		= giu_probe,
 	.remove		= giu_remove,
 	.driver		= {
 		.name	= "GIU",
 	},
 };

 module_platform_driver(giu_device_driver);
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* Driver for NEC VR4100 series General-purpose I/O Unit.
	*
	* Copyright (C) 2002 MontaVista Software Inc.
	* Author: Yoichi Yuasa <source@mvista.com>
	* Copyright (C) 2003-2009 Yoichi Yuasa <yuasa@linux-mips.org>
	*/
	#include <linux/errno.h>
	#include <linux/fs.h>
	#include <linux/gpio/driver.h>
	#include <linux/init.h>
	#include <linux/interrupt.h>
	#include <linux/io.h>
	#include <linux/irq.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/spinlock.h>
	#include <linux/types.h>

	#include <asm/vr41xx/giu.h>
	#include <asm/vr41xx/irq.h>
	#include <asm/vr41xx/vr41xx.h>

	MODULE_AUTHOR("Yoichi Yuasa <yuasa@linux-mips.org>");
	MODULE_DESCRIPTION("NEC VR4100 series General-purpose I/O Unit driver");
	MODULE_LICENSE("GPL");

	#define GIUIOSELL 0x00
	#define GIUIOSELH 0x02
	#define GIUPIODL 0x04
	#define GIUPIODH 0x06
	#define GIUINTSTATL 0x08
	#define GIUINTSTATH 0x0a
	#define GIUINTENL 0x0c
	#define GIUINTENH 0x0e
	#define GIUINTTYPL 0x10
	#define GIUINTTYPH 0x12
	#define GIUINTALSELL 0x14
	#define GIUINTALSELH 0x16
	#define GIUINTHTSELL 0x18
	#define GIUINTHTSELH 0x1a
	#define GIUPODATL 0x1c
	#define GIUPODATEN 0x1c
	#define GIUPODATH 0x1e
	#define PIOEN0 0x0100
	#define PIOEN1 0x0200
	#define GIUPODAT 0x1e
	#define GIUFEDGEINHL 0x20
	#define GIUFEDGEINHH 0x22
	#define GIUREDGEINHL 0x24
	#define GIUREDGEINHH 0x26

	#define GIUUSEUPDN 0x1e0
	#define GIUTERMUPDN 0x1e2

	#define GPIO_HAS_PULLUPDOWN_IO 0x0001
	#define GPIO_HAS_OUTPUT_ENABLE 0x0002
	#define GPIO_HAS_INTERRUPT_EDGE_SELECT 0x0100

	enum {
	GPIO_INPUT,
	GPIO_OUTPUT,
	};

	static DEFINE_SPINLOCK(giu_lock);
	static unsigned long giu_flags;

	static void __iomem *giu_base;
	static struct gpio_chip vr41xx_gpio_chip;

	#define giu_read(offset) readw(giu_base + (offset))
	#define giu_write(offset, value) writew((value), giu_base + (offset))

	#define GPIO_PIN_OF_IRQ(irq) ((irq) - GIU_IRQ_BASE)
	#define GIUINT_HIGH_OFFSET 16
	#define GIUINT_HIGH_MAX 32

	static inline u16 giu_set(u16 offset, u16 set)
	{
	u16 data;

	data = giu_read(offset);
	data \|= set;
	giu_write(offset, data);

	return data;
	}

	static inline u16 giu_clear(u16 offset, u16 clear)
	{
	u16 data;

	data = giu_read(offset);
	data &= ~clear;
	giu_write(offset, data);

	return data;
	}

	static void ack_giuint_low(struct irq_data *d)
	{
	giu_write(GIUINTSTATL, 1 << GPIO_PIN_OF_IRQ(d->irq));
	}

	static void mask_giuint_low(struct irq_data *d)
	{
	giu_clear(GIUINTENL, 1 << GPIO_PIN_OF_IRQ(d->irq));
	}

	static void mask_ack_giuint_low(struct irq_data *d)
	{
	unsigned int pin;

	pin = GPIO_PIN_OF_IRQ(d->irq);
	giu_clear(GIUINTENL, 1 << pin);
	giu_write(GIUINTSTATL, 1 << pin);
	}

	static void unmask_giuint_low(struct irq_data *d)
	{
	giu_set(GIUINTENL, 1 << GPIO_PIN_OF_IRQ(d->irq));
	}

	static unsigned int startup_giuint(struct irq_data *data)
	{
	int ret;

	ret = gpiochip_lock_as_irq(&vr41xx_gpio_chip, irqd_to_hwirq(data));
	if (ret) {
	dev_err(vr41xx_gpio_chip.parent,
	"unable to lock HW IRQ %lu for IRQ\n",
	data->hwirq);
	return ret;
	}

	/* Satisfy the .enable semantics by unmasking the line */
	unmask_giuint_low(data);
	return 0;
	}

	static void shutdown_giuint(struct irq_data *data)
	{
	mask_giuint_low(data);
	gpiochip_unlock_as_irq(&vr41xx_gpio_chip, data->hwirq);
	}

	static struct irq_chip giuint_low_irq_chip = {
	.name = "GIUINTL",
	.irq_ack = ack_giuint_low,
	.irq_mask = mask_giuint_low,
	.irq_mask_ack = mask_ack_giuint_low,
	.irq_unmask = unmask_giuint_low,
	.irq_startup = startup_giuint,
	.irq_shutdown = shutdown_giuint,
	};

	static void ack_giuint_high(struct irq_data *d)
	{
	giu_write(GIUINTSTATH,
	1 << (GPIO_PIN_OF_IRQ(d->irq) - GIUINT_HIGH_OFFSET));
	}

	static void mask_giuint_high(struct irq_data *d)
	{
	giu_clear(GIUINTENH, 1 << (GPIO_PIN_OF_IRQ(d->irq) - GIUINT_HIGH_OFFSET));
	}

	static void mask_ack_giuint_high(struct irq_data *d)
	{
	unsigned int pin;

	pin = GPIO_PIN_OF_IRQ(d->irq) - GIUINT_HIGH_OFFSET;
	giu_clear(GIUINTENH, 1 << pin);
	giu_write(GIUINTSTATH, 1 << pin);
	}

	static void unmask_giuint_high(struct irq_data *d)
	{
	giu_set(GIUINTENH, 1 << (GPIO_PIN_OF_IRQ(d->irq) - GIUINT_HIGH_OFFSET));
	}

	static struct irq_chip giuint_high_irq_chip = {
	.name = "GIUINTH",
	.irq_ack = ack_giuint_high,
	.irq_mask = mask_giuint_high,
	.irq_mask_ack = mask_ack_giuint_high,
	.irq_unmask = unmask_giuint_high,
	};

	static int giu_get_irq(unsigned int irq)
	{
	u16 pendl, pendh, maskl, maskh;
	int i;

	pendl = giu_read(GIUINTSTATL);
	pendh = giu_read(GIUINTSTATH);
	maskl = giu_read(GIUINTENL);
	maskh = giu_read(GIUINTENH);

	maskl &= pendl;
	maskh &= pendh;

	if (maskl) {
	for (i = 0; i < 16; i++) {
	if (maskl & (1 << i))
	return GIU_IRQ(i);
	}
	} else if (maskh) {
	for (i = 0; i < 16; i++) {
	if (maskh & (1 << i))
	return GIU_IRQ(i + GIUINT_HIGH_OFFSET);
	}
	}

	printk(KERN_ERR "spurious GIU interrupt: %04x(%04x),%04x(%04x)\n",
	maskl, pendl, maskh, pendh);

	atomic_inc(&irq_err_count);

	return -EINVAL;
	}

	void vr41xx_set_irq_trigger(unsigned int pin, irq_trigger_t trigger,
	irq_signal_t signal)
	{
	u16 mask;

	if (pin < GIUINT_HIGH_OFFSET) {
	mask = 1 << pin;
	if (trigger != IRQ_TRIGGER_LEVEL) {
	giu_set(GIUINTTYPL, mask);
	if (signal == IRQ_SIGNAL_HOLD)
	giu_set(GIUINTHTSELL, mask);
	else
	giu_clear(GIUINTHTSELL, mask);
	if (giu_flags & GPIO_HAS_INTERRUPT_EDGE_SELECT) {
	switch (trigger) {
	case IRQ_TRIGGER_EDGE_FALLING:
	giu_set(GIUFEDGEINHL, mask);
	giu_clear(GIUREDGEINHL, mask);
	break;
	case IRQ_TRIGGER_EDGE_RISING:
	giu_clear(GIUFEDGEINHL, mask);
	giu_set(GIUREDGEINHL, mask);
	break;
	default:
	giu_set(GIUFEDGEINHL, mask);
	giu_set(GIUREDGEINHL, mask);
	break;
	}
	}
	irq_set_chip_and_handler(GIU_IRQ(pin),
	&giuint_low_irq_chip,
	handle_edge_irq);
	} else {
	giu_clear(GIUINTTYPL, mask);
	giu_clear(GIUINTHTSELL, mask);
	irq_set_chip_and_handler(GIU_IRQ(pin),
	&giuint_low_irq_chip,
	handle_level_irq);
	}
	giu_write(GIUINTSTATL, mask);
	} else if (pin < GIUINT_HIGH_MAX) {
	mask = 1 << (pin - GIUINT_HIGH_OFFSET);
	if (trigger != IRQ_TRIGGER_LEVEL) {
	giu_set(GIUINTTYPH, mask);
	if (signal == IRQ_SIGNAL_HOLD)
	giu_set(GIUINTHTSELH, mask);
	else
	giu_clear(GIUINTHTSELH, mask);
	if (giu_flags & GPIO_HAS_INTERRUPT_EDGE_SELECT) {
	switch (trigger) {
	case IRQ_TRIGGER_EDGE_FALLING:
	giu_set(GIUFEDGEINHH, mask);
	giu_clear(GIUREDGEINHH, mask);
	break;
	case IRQ_TRIGGER_EDGE_RISING:
	giu_clear(GIUFEDGEINHH, mask);
	giu_set(GIUREDGEINHH, mask);
	break;
	default:
	giu_set(GIUFEDGEINHH, mask);
	giu_set(GIUREDGEINHH, mask);
	break;
	}
	}
	irq_set_chip_and_handler(GIU_IRQ(pin),
	&giuint_high_irq_chip,
	handle_edge_irq);
	} else {
	giu_clear(GIUINTTYPH, mask);
	giu_clear(GIUINTHTSELH, mask);
	irq_set_chip_and_handler(GIU_IRQ(pin),
	&giuint_high_irq_chip,
	handle_level_irq);
	}
	giu_write(GIUINTSTATH, mask);
	}
	}
	EXPORT_SYMBOL_GPL(vr41xx_set_irq_trigger);

	void vr41xx_set_irq_level(unsigned int pin, irq_level_t level)
	{
	u16 mask;

	if (pin < GIUINT_HIGH_OFFSET) {
	mask = 1 << pin;
	if (level == IRQ_LEVEL_HIGH)
	giu_set(GIUINTALSELL, mask);
	else
	giu_clear(GIUINTALSELL, mask);
	giu_write(GIUINTSTATL, mask);
	} else if (pin < GIUINT_HIGH_MAX) {
	mask = 1 << (pin - GIUINT_HIGH_OFFSET);
	if (level == IRQ_LEVEL_HIGH)
	giu_set(GIUINTALSELH, mask);
	else
	giu_clear(GIUINTALSELH, mask);
	giu_write(GIUINTSTATH, mask);
	}
	}
	EXPORT_SYMBOL_GPL(vr41xx_set_irq_level);

	static int giu_set_direction(struct gpio_chip *chip, unsigned pin, int dir)
	{
	u16 offset, mask, reg;
	unsigned long flags;

	if (pin >= chip->ngpio)
	return -EINVAL;

	if (pin < 16) {
	offset = GIUIOSELL;
	mask = 1 << pin;
	} else if (pin < 32) {
	offset = GIUIOSELH;
	mask = 1 << (pin - 16);
	} else {
	if (giu_flags & GPIO_HAS_OUTPUT_ENABLE) {
	offset = GIUPODATEN;
	mask = 1 << (pin - 32);
	} else {
	switch (pin) {
	case 48:
	offset = GIUPODATH;
	mask = PIOEN0;
	break;
	case 49:
	offset = GIUPODATH;
	mask = PIOEN1;
	break;
	default:
	return -EINVAL;
	}
	}
	}

	spin_lock_irqsave(&giu_lock, flags);

	reg = giu_read(offset);
	if (dir == GPIO_OUTPUT)
	reg \|= mask;
	else
	reg &= ~mask;
	giu_write(offset, reg);

	spin_unlock_irqrestore(&giu_lock, flags);

	return 0;
	}

	static int vr41xx_gpio_get(struct gpio_chip *chip, unsigned pin)
	{
	u16 reg, mask;

	if (pin >= chip->ngpio)
	return -EINVAL;

	if (pin < 16) {
	reg = giu_read(GIUPIODL);
	mask = 1 << pin;
	} else if (pin < 32) {
	reg = giu_read(GIUPIODH);
	mask = 1 << (pin - 16);
	} else if (pin < 48) {
	reg = giu_read(GIUPODATL);
	mask = 1 << (pin - 32);
	} else {
	reg = giu_read(GIUPODATH);
	mask = 1 << (pin - 48);
	}

	if (reg & mask)
	return 1;

	return 0;
	}

	static void vr41xx_gpio_set(struct gpio_chip *chip, unsigned pin,
	int value)
	{
	u16 offset, mask, reg;
	unsigned long flags;

	if (pin >= chip->ngpio)
	return;

	if (pin < 16) {
	offset = GIUPIODL;
	mask = 1 << pin;
	} else if (pin < 32) {
	offset = GIUPIODH;
	mask = 1 << (pin - 16);
	} else if (pin < 48) {
	offset = GIUPODATL;
	mask = 1 << (pin - 32);
	} else {
	offset = GIUPODATH;
	mask = 1 << (pin - 48);
	}

	spin_lock_irqsave(&giu_lock, flags);

	reg = giu_read(offset);
	if (value)
	reg \|= mask;
	else
	reg &= ~mask;
	giu_write(offset, reg);

	spin_unlock_irqrestore(&giu_lock, flags);
	}


	static int vr41xx_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
	{
	return giu_set_direction(chip, offset, GPIO_INPUT);
	}

	static int vr41xx_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
	int value)
	{
	vr41xx_gpio_set(chip, offset, value);

	return giu_set_direction(chip, offset, GPIO_OUTPUT);
	}

	static int vr41xx_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
	{
	if (offset >= chip->ngpio)
	return -EINVAL;

	return GIU_IRQ_BASE + offset;
	}

	static struct gpio_chip vr41xx_gpio_chip = {
	.label = "vr41xx",
	.owner = THIS_MODULE,
	.direction_input = vr41xx_gpio_direction_input,
	.get = vr41xx_gpio_get,
	.direction_output = vr41xx_gpio_direction_output,
	.set = vr41xx_gpio_set,
	.to_irq = vr41xx_gpio_to_irq,
	};

	static int giu_probe(struct platform_device *pdev)
	{
	unsigned int trigger, i, pin;
	struct irq_chip *chip;
	int irq;

	switch (pdev->id) {
	case GPIO_50PINS_PULLUPDOWN:
	giu_flags = GPIO_HAS_PULLUPDOWN_IO;
	vr41xx_gpio_chip.ngpio = 50;
	break;
	case GPIO_36PINS:
	vr41xx_gpio_chip.ngpio = 36;
	break;
	case GPIO_48PINS_EDGE_SELECT:
	giu_flags = GPIO_HAS_INTERRUPT_EDGE_SELECT;
	vr41xx_gpio_chip.ngpio = 48;
	break;
	default:
	dev_err(&pdev->dev, "GIU: unknown ID %d\n", pdev->id);
	return -ENODEV;
	}

	giu_base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(giu_base))
	return PTR_ERR(giu_base);

	vr41xx_gpio_chip.parent = &pdev->dev;

	if (gpiochip_add_data(&vr41xx_gpio_chip, NULL))
	return -ENODEV;

	giu_write(GIUINTENL, 0);
	giu_write(GIUINTENH, 0);

	trigger = giu_read(GIUINTTYPH) << 16;
	trigger \|= giu_read(GIUINTTYPL);
	for (i = GIU_IRQ_BASE; i <= GIU_IRQ_LAST; i++) {
	pin = GPIO_PIN_OF_IRQ(i);
	if (pin < GIUINT_HIGH_OFFSET)
	chip = &giuint_low_irq_chip;
	else
	chip = &giuint_high_irq_chip;

	if (trigger & (1 << pin))
	irq_set_chip_and_handler(i, chip, handle_edge_irq);
	else
	irq_set_chip_and_handler(i, chip, handle_level_irq);

	}

	irq = platform_get_irq(pdev, 0);
	if (irq < 0 \|\| irq >= nr_irqs)
	return -EBUSY;

	return cascade_irq(irq, giu_get_irq);
	}

	static int giu_remove(struct platform_device *pdev)
	{
	if (giu_base) {
	giu_base = NULL;
	}

	return 0;
	}

	static struct platform_driver giu_device_driver = {
	.probe = giu_probe,
	.remove = giu_remove,
	.driver = {
	.name = "GIU",
	},
	};

	module_platform_driver(giu_device_driver);