drivers/char/vr41xx_giu.c - kernel/msm-4.9 - Gitiles

 /*
  *  Driver for NEC VR4100 series General-purpose I/O Unit.
  *
  *  Copyright (C) 2002 MontaVista Software Inc.
  *	Author: Yoichi Yuasa <yyuasa@mvista.com or source@mvista.com>
  *  Copyright (C) 2003-2007  Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
  *  the Free Software Foundation; either version 2 of the License, or
  *  (at your option) any later version.
  *
  *  This program is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  *  GNU General Public License for more details.
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program; if not, write to the Free Software
  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 #include <linux/errno.h>
 #include <linux/fs.h>
 #include <linux/init.h>
 #include <linux/interrupt.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/io.h>
 #include <asm/vr41xx/giu.h>
 #include <asm/vr41xx/irq.h>
 #include <asm/vr41xx/vr41xx.h>

 MODULE_AUTHOR("Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>");
 MODULE_DESCRIPTION("NEC VR4100 series General-purpose I/O Unit driver");
 MODULE_LICENSE("GPL");

 static int major;	/* default is dynamic major device number */
 module_param(major, int, 0);
 MODULE_PARM_DESC(major, "Major device number");

 #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

 static spinlock_t giu_lock;
 static unsigned long giu_flags;
 static unsigned int giu_nr_pins;

 static void __iomem *giu_base;

 #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 uint16_t giu_set(uint16_t offset, uint16_t set)
 {
 	uint16_t data;

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

 	return data;
 }

 static inline uint16_t giu_clear(uint16_t offset, uint16_t clear)
 {
 	uint16_t data;

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

 	return data;
 }

 static void ack_giuint_low(unsigned int irq)
 {
 	giu_write(GIUINTSTATL, 1 << GPIO_PIN_OF_IRQ(irq));
 }

 static void mask_giuint_low(unsigned int irq)
 {
 	giu_clear(GIUINTENL, 1 << GPIO_PIN_OF_IRQ(irq));
 }

 static void mask_ack_giuint_low(unsigned int irq)
 {
 	unsigned int pin;

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

 static void unmask_giuint_low(unsigned int irq)
 {
 	giu_set(GIUINTENL, 1 << GPIO_PIN_OF_IRQ(irq));
 }

 static struct irq_chip giuint_low_irq_chip = {
 	.name		= "GIUINTL",
 	.ack		= ack_giuint_low,
 	.mask		= mask_giuint_low,
 	.mask_ack	= mask_ack_giuint_low,
 	.unmask		= unmask_giuint_low,
 };

 static void ack_giuint_high(unsigned int irq)
 {
 	giu_write(GIUINTSTATH, 1 << (GPIO_PIN_OF_IRQ(irq) - GIUINT_HIGH_OFFSET));
 }

 static void mask_giuint_high(unsigned int irq)
 {
 	giu_clear(GIUINTENH, 1 << (GPIO_PIN_OF_IRQ(irq) - GIUINT_HIGH_OFFSET));
 }

 static void mask_ack_giuint_high(unsigned int irq)
 {
 	unsigned int pin;

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

 static void unmask_giuint_high(unsigned int irq)
 {
 	giu_set(GIUINTENH, 1 << (GPIO_PIN_OF_IRQ(irq) - GIUINT_HIGH_OFFSET));
 }

 static struct irq_chip giuint_high_irq_chip = {
 	.name		= "GIUINTH",
 	.ack		= ack_giuint_high,
 	.mask		= mask_giuint_high,
 	.mask_ack	= mask_ack_giuint_high,
 	.unmask		= unmask_giuint_high,
 };

 static int giu_get_irq(unsigned int irq)
 {
 	uint16_t 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)
 {
 	uint16_t 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;
 				}
 			}
 			set_irq_chip_and_handler(GIU_IRQ(pin),
 			                         &giuint_low_irq_chip,
 			                         handle_edge_irq);
 		} else {
 			giu_clear(GIUINTTYPL, mask);
 			giu_clear(GIUINTHTSELL, mask);
 			set_irq_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;
 				}
 			}
 			set_irq_chip_and_handler(GIU_IRQ(pin),
 			                         &giuint_high_irq_chip,
 			                         handle_edge_irq);
 		} else {
 			giu_clear(GIUINTTYPH, mask);
 			giu_clear(GIUINTHTSELH, mask);
 			set_irq_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)
 {
 	uint16_t 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);

 gpio_data_t vr41xx_gpio_get_pin(unsigned int pin)
 {
 	uint16_t reg, mask;

 	if (pin >= giu_nr_pins)
 		return GPIO_DATA_INVAL;

 	if (pin < 16) {
 		reg = giu_read(GIUPIODL);
 		mask = (uint16_t)1 << pin;
 	} else if (pin < 32) {
 		reg = giu_read(GIUPIODH);
 		mask = (uint16_t)1 << (pin - 16);
 	} else if (pin < 48) {
 		reg = giu_read(GIUPODATL);
 		mask = (uint16_t)1 << (pin - 32);
 	} else {
 		reg = giu_read(GIUPODATH);
 		mask = (uint16_t)1 << (pin - 48);
 	}

 	if (reg & mask)
 		return GPIO_DATA_HIGH;

 	return GPIO_DATA_LOW;
 }
 EXPORT_SYMBOL_GPL(vr41xx_gpio_get_pin);

 int vr41xx_gpio_set_pin(unsigned int pin, gpio_data_t data)
 {
 	uint16_t offset, mask, reg;
 	unsigned long flags;

 	if (pin >= giu_nr_pins)
 		return -EINVAL;

 	if (pin < 16) {
 		offset = GIUPIODL;
 		mask = (uint16_t)1 << pin;
 	} else if (pin < 32) {
 		offset = GIUPIODH;
 		mask = (uint16_t)1 << (pin - 16);
 	} else if (pin < 48) {
 		offset = GIUPODATL;
 		mask = (uint16_t)1 << (pin - 32);
 	} else {
 		offset = GIUPODATH;
 		mask = (uint16_t)1 << (pin - 48);
 	}

 	spin_lock_irqsave(&giu_lock, flags);

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

 	spin_unlock_irqrestore(&giu_lock, flags);

 	return 0;
 }
 EXPORT_SYMBOL_GPL(vr41xx_gpio_set_pin);

 int vr41xx_gpio_set_direction(unsigned int pin, gpio_direction_t dir)
 {
 	uint16_t offset, mask, reg;
 	unsigned long flags;

 	if (pin >= giu_nr_pins)
 		return -EINVAL;

 	if (pin < 16) {
 		offset = GIUIOSELL;
 		mask = (uint16_t)1 << pin;
 	} else if (pin < 32) {
 		offset = GIUIOSELH;
 		mask = (uint16_t)1 << (pin - 16);
 	} else {
 		if (giu_flags & GPIO_HAS_OUTPUT_ENABLE) {
 			offset = GIUPODATEN;
 			mask = (uint16_t)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;
 }
 EXPORT_SYMBOL_GPL(vr41xx_gpio_set_direction);

 int vr41xx_gpio_pullupdown(unsigned int pin, gpio_pull_t pull)
 {
 	uint16_t reg, mask;
 	unsigned long flags;

 	if ((giu_flags & GPIO_HAS_PULLUPDOWN_IO) != GPIO_HAS_PULLUPDOWN_IO)
 		return -EPERM;

 	if (pin >= 15)
 		return -EINVAL;

 	mask = (uint16_t)1 << pin;

 	spin_lock_irqsave(&giu_lock, flags);

 	if (pull == GPIO_PULL_UP || pull == GPIO_PULL_DOWN) {
 		reg = giu_read(GIUTERMUPDN);
 		if (pull == GPIO_PULL_UP)
 			reg |= mask;
 		else
 			reg &= ~mask;
 		giu_write(GIUTERMUPDN, reg);

 		reg = giu_read(GIUUSEUPDN);
 		reg |= mask;
 		giu_write(GIUUSEUPDN, reg);
 	} else {
 		reg = giu_read(GIUUSEUPDN);
 		reg &= ~mask;
 		giu_write(GIUUSEUPDN, reg);
 	}

 	spin_unlock_irqrestore(&giu_lock, flags);

 	return 0;
 }
 EXPORT_SYMBOL_GPL(vr41xx_gpio_pullupdown);

 static ssize_t gpio_read(struct file *file, char __user *buf, size_t len,
                          loff_t *ppos)
 {
 	unsigned int pin;
 	char value = '0';

 	pin = iminor(file->f_path.dentry->d_inode);
 	if (pin >= giu_nr_pins)
 		return -EBADF;

 	if (vr41xx_gpio_get_pin(pin) == GPIO_DATA_HIGH)
 		value = '1';

 	if (len <= 0)
 		return -EFAULT;

 	if (put_user(value, buf))
 		return -EFAULT;

 	return 1;
 }

 static ssize_t gpio_write(struct file *file, const char __user *data,
                           size_t len, loff_t *ppos)
 {
 	unsigned int pin;
 	size_t i;
 	char c;
 	int retval = 0;

 	pin = iminor(file->f_path.dentry->d_inode);
 	if (pin >= giu_nr_pins)
 		return -EBADF;

 	for (i = 0; i < len; i++) {
 		if (get_user(c, data + i))
 			return -EFAULT;

 		switch (c) {
 		case '0':
 			retval = vr41xx_gpio_set_pin(pin, GPIO_DATA_LOW);
 			break;
 		case '1':
 			retval = vr41xx_gpio_set_pin(pin, GPIO_DATA_HIGH);
 			break;
 		case 'D':
 			printk(KERN_INFO "GPIO%d: pull down\n", pin);
 			retval = vr41xx_gpio_pullupdown(pin, GPIO_PULL_DOWN);
 			break;
 		case 'd':
 			printk(KERN_INFO "GPIO%d: pull up/down disable\n", pin);
 			retval = vr41xx_gpio_pullupdown(pin, GPIO_PULL_DISABLE);
 			break;
 		case 'I':
 			printk(KERN_INFO "GPIO%d: input\n", pin);
 			retval = vr41xx_gpio_set_direction(pin, GPIO_INPUT);
 			break;
 		case 'O':
 			printk(KERN_INFO "GPIO%d: output\n", pin);
 			retval = vr41xx_gpio_set_direction(pin, GPIO_OUTPUT);
 			break;
 		case 'o':
 			printk(KERN_INFO "GPIO%d: output disable\n", pin);
 			retval = vr41xx_gpio_set_direction(pin, GPIO_OUTPUT_DISABLE);
 			break;
 		case 'P':
 			printk(KERN_INFO "GPIO%d: pull up\n", pin);
 			retval = vr41xx_gpio_pullupdown(pin, GPIO_PULL_UP);
 			break;
 		case 'p':
 			printk(KERN_INFO "GPIO%d: pull up/down disable\n", pin);
 			retval = vr41xx_gpio_pullupdown(pin, GPIO_PULL_DISABLE);
 			break;
 		default:
 			break;
 		}

 		if (retval < 0)
 			break;
 	}

 	return i;
 }

 /* No BKL needed here; only global (giu_nr_pins) is only set
    at probe time */
 static int gpio_open(struct inode *inode, struct file *file)
 {
 	unsigned int pin;

 	pin = iminor(inode);
 	if (pin >= giu_nr_pins)
 		return -EBADF;

 	return nonseekable_open(inode, file);
 }

 static int gpio_release(struct inode *inode, struct file *file)
 {
 	unsigned int pin;

 	pin = iminor(inode);
 	if (pin >= giu_nr_pins)
 		return -EBADF;

 	return 0;
 }

 static const struct file_operations gpio_fops = {
 	.owner		= THIS_MODULE,
 	.read		= gpio_read,
 	.write		= gpio_write,
 	.open		= gpio_open,
 	.release	= gpio_release,
 };

 static int __devinit giu_probe(struct platform_device *dev)
 {
 	struct resource *res;
 	unsigned int trigger, i, pin;
 	struct irq_chip *chip;
 	int irq, retval;

 	switch (dev->id) {
 	case GPIO_50PINS_PULLUPDOWN:
 		giu_flags = GPIO_HAS_PULLUPDOWN_IO;
 		giu_nr_pins = 50;
 		break;
 	case GPIO_36PINS:
 		giu_nr_pins = 36;
 		break;
 	case GPIO_48PINS_EDGE_SELECT:
 		giu_flags = GPIO_HAS_INTERRUPT_EDGE_SELECT;
 		giu_nr_pins = 48;
 		break;
 	default:
 		printk(KERN_ERR "GIU: unknown ID %d\n", dev->id);
 		return -ENODEV;
 	}

 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
 	if (!res)
 		return -EBUSY;

 	giu_base = ioremap(res->start, res->end - res->start + 1);
 	if (!giu_base)
 		return -ENOMEM;

 	retval = register_chrdev(major, "GIU", &gpio_fops);
 	if (retval < 0) {
 		iounmap(giu_base);
 		giu_base = NULL;
 		return retval;
 	}

 	if (major == 0) {
 		major = retval;
 		printk(KERN_INFO "GIU: major number %d\n", major);
 	}

 	spin_lock_init(&giu_lock);

 	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))
 			set_irq_chip_and_handler(i, chip, handle_edge_irq);
 		else
 			set_irq_chip_and_handler(i, chip, handle_level_irq);

 	}

 	irq = platform_get_irq(dev, 0);
 	if (irq < 0 || irq >= NR_IRQS)
 		return -EBUSY;

 	return cascade_irq(irq, giu_get_irq);
 }

 static int __devexit giu_remove(struct platform_device *dev)
 {
 	if (giu_base) {
 		iounmap(giu_base);
 		giu_base = NULL;
 	}

 	return 0;
 }

 static struct platform_driver giu_device_driver = {
 	.probe		= giu_probe,
 	.remove		= __devexit_p(giu_remove),
 	.driver		= {
 		.name	= "GIU",
 		.owner	= THIS_MODULE,
 	},
 };

 static int __init vr41xx_giu_init(void)
 {
 	return platform_driver_register(&giu_device_driver);
 }

 static void __exit vr41xx_giu_exit(void)
 {
 	platform_driver_unregister(&giu_device_driver);
 }

 module_init(vr41xx_giu_init);
 module_exit(vr41xx_giu_exit);
	/*
	* Driver for NEC VR4100 series General-purpose I/O Unit.
	*
	* Copyright (C) 2002 MontaVista Software Inc.
	* Author: Yoichi Yuasa <yyuasa@mvista.com or source@mvista.com>
	* Copyright (C) 2003-2007 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/
	#include <linux/errno.h>
	#include <linux/fs.h>
	#include <linux/init.h>
	#include <linux/interrupt.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/io.h>
	#include <asm/vr41xx/giu.h>
	#include <asm/vr41xx/irq.h>
	#include <asm/vr41xx/vr41xx.h>

	MODULE_AUTHOR("Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>");
	MODULE_DESCRIPTION("NEC VR4100 series General-purpose I/O Unit driver");
	MODULE_LICENSE("GPL");

	static int major; /* default is dynamic major device number */
	module_param(major, int, 0);
	MODULE_PARM_DESC(major, "Major device number");

	#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

	static spinlock_t giu_lock;
	static unsigned long giu_flags;
	static unsigned int giu_nr_pins;

	static void __iomem *giu_base;

	#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 uint16_t giu_set(uint16_t offset, uint16_t set)
	{
	uint16_t data;

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

	return data;
	}

	static inline uint16_t giu_clear(uint16_t offset, uint16_t clear)
	{
	uint16_t data;

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

	return data;
	}

	static void ack_giuint_low(unsigned int irq)
	{
	giu_write(GIUINTSTATL, 1 << GPIO_PIN_OF_IRQ(irq));
	}

	static void mask_giuint_low(unsigned int irq)
	{
	giu_clear(GIUINTENL, 1 << GPIO_PIN_OF_IRQ(irq));
	}

	static void mask_ack_giuint_low(unsigned int irq)
	{
	unsigned int pin;

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

	static void unmask_giuint_low(unsigned int irq)
	{
	giu_set(GIUINTENL, 1 << GPIO_PIN_OF_IRQ(irq));
	}

	static struct irq_chip giuint_low_irq_chip = {
	.name = "GIUINTL",
	.ack = ack_giuint_low,
	.mask = mask_giuint_low,
	.mask_ack = mask_ack_giuint_low,
	.unmask = unmask_giuint_low,
	};

	static void ack_giuint_high(unsigned int irq)
	{
	giu_write(GIUINTSTATH, 1 << (GPIO_PIN_OF_IRQ(irq) - GIUINT_HIGH_OFFSET));
	}

	static void mask_giuint_high(unsigned int irq)
	{
	giu_clear(GIUINTENH, 1 << (GPIO_PIN_OF_IRQ(irq) - GIUINT_HIGH_OFFSET));
	}

	static void mask_ack_giuint_high(unsigned int irq)
	{
	unsigned int pin;

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

	static void unmask_giuint_high(unsigned int irq)
	{
	giu_set(GIUINTENH, 1 << (GPIO_PIN_OF_IRQ(irq) - GIUINT_HIGH_OFFSET));
	}

	static struct irq_chip giuint_high_irq_chip = {
	.name = "GIUINTH",
	.ack = ack_giuint_high,
	.mask = mask_giuint_high,
	.mask_ack = mask_ack_giuint_high,
	.unmask = unmask_giuint_high,
	};

	static int giu_get_irq(unsigned int irq)
	{
	uint16_t 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)
	{
	uint16_t 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;
	}
	}
	set_irq_chip_and_handler(GIU_IRQ(pin),
	&giuint_low_irq_chip,
	handle_edge_irq);
	} else {
	giu_clear(GIUINTTYPL, mask);
	giu_clear(GIUINTHTSELL, mask);
	set_irq_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;
	}
	}
	set_irq_chip_and_handler(GIU_IRQ(pin),
	&giuint_high_irq_chip,
	handle_edge_irq);
	} else {
	giu_clear(GIUINTTYPH, mask);
	giu_clear(GIUINTHTSELH, mask);
	set_irq_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)
	{
	uint16_t 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);

	gpio_data_t vr41xx_gpio_get_pin(unsigned int pin)
	{
	uint16_t reg, mask;

	if (pin >= giu_nr_pins)
	return GPIO_DATA_INVAL;

	if (pin < 16) {
	reg = giu_read(GIUPIODL);
	mask = (uint16_t)1 << pin;
	} else if (pin < 32) {
	reg = giu_read(GIUPIODH);
	mask = (uint16_t)1 << (pin - 16);
	} else if (pin < 48) {
	reg = giu_read(GIUPODATL);
	mask = (uint16_t)1 << (pin - 32);
	} else {
	reg = giu_read(GIUPODATH);
	mask = (uint16_t)1 << (pin - 48);
	}

	if (reg & mask)
	return GPIO_DATA_HIGH;

	return GPIO_DATA_LOW;
	}
	EXPORT_SYMBOL_GPL(vr41xx_gpio_get_pin);

	int vr41xx_gpio_set_pin(unsigned int pin, gpio_data_t data)
	{
	uint16_t offset, mask, reg;
	unsigned long flags;

	if (pin >= giu_nr_pins)
	return -EINVAL;

	if (pin < 16) {
	offset = GIUPIODL;
	mask = (uint16_t)1 << pin;
	} else if (pin < 32) {
	offset = GIUPIODH;
	mask = (uint16_t)1 << (pin - 16);
	} else if (pin < 48) {
	offset = GIUPODATL;
	mask = (uint16_t)1 << (pin - 32);
	} else {
	offset = GIUPODATH;
	mask = (uint16_t)1 << (pin - 48);
	}

	spin_lock_irqsave(&giu_lock, flags);

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

	spin_unlock_irqrestore(&giu_lock, flags);

	return 0;
	}
	EXPORT_SYMBOL_GPL(vr41xx_gpio_set_pin);

	int vr41xx_gpio_set_direction(unsigned int pin, gpio_direction_t dir)
	{
	uint16_t offset, mask, reg;
	unsigned long flags;

	if (pin >= giu_nr_pins)
	return -EINVAL;

	if (pin < 16) {
	offset = GIUIOSELL;
	mask = (uint16_t)1 << pin;
	} else if (pin < 32) {
	offset = GIUIOSELH;
	mask = (uint16_t)1 << (pin - 16);
	} else {
	if (giu_flags & GPIO_HAS_OUTPUT_ENABLE) {
	offset = GIUPODATEN;
	mask = (uint16_t)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;
	}
	EXPORT_SYMBOL_GPL(vr41xx_gpio_set_direction);

	int vr41xx_gpio_pullupdown(unsigned int pin, gpio_pull_t pull)
	{
	uint16_t reg, mask;
	unsigned long flags;

	if ((giu_flags & GPIO_HAS_PULLUPDOWN_IO) != GPIO_HAS_PULLUPDOWN_IO)
	return -EPERM;

	if (pin >= 15)
	return -EINVAL;

	mask = (uint16_t)1 << pin;

	spin_lock_irqsave(&giu_lock, flags);

	if (pull == GPIO_PULL_UP \|\| pull == GPIO_PULL_DOWN) {
	reg = giu_read(GIUTERMUPDN);
	if (pull == GPIO_PULL_UP)
	reg \|= mask;
	else
	reg &= ~mask;
	giu_write(GIUTERMUPDN, reg);

	reg = giu_read(GIUUSEUPDN);
	reg \|= mask;
	giu_write(GIUUSEUPDN, reg);
	} else {
	reg = giu_read(GIUUSEUPDN);
	reg &= ~mask;
	giu_write(GIUUSEUPDN, reg);
	}

	spin_unlock_irqrestore(&giu_lock, flags);

	return 0;
	}
	EXPORT_SYMBOL_GPL(vr41xx_gpio_pullupdown);

	static ssize_t gpio_read(struct file file, char __user buf, size_t len,
	loff_t *ppos)
	{
	unsigned int pin;
	char value = '0';

	pin = iminor(file->f_path.dentry->d_inode);
	if (pin >= giu_nr_pins)
	return -EBADF;

	if (vr41xx_gpio_get_pin(pin) == GPIO_DATA_HIGH)
	value = '1';

	if (len <= 0)
	return -EFAULT;

	if (put_user(value, buf))
	return -EFAULT;

	return 1;
	}

	static ssize_t gpio_write(struct file file, const char __user data,
	size_t len, loff_t *ppos)
	{
	unsigned int pin;
	size_t i;
	char c;
	int retval = 0;

	pin = iminor(file->f_path.dentry->d_inode);
	if (pin >= giu_nr_pins)
	return -EBADF;

	for (i = 0; i < len; i++) {
	if (get_user(c, data + i))
	return -EFAULT;

	switch (c) {
	case '0':
	retval = vr41xx_gpio_set_pin(pin, GPIO_DATA_LOW);
	break;
	case '1':
	retval = vr41xx_gpio_set_pin(pin, GPIO_DATA_HIGH);
	break;
	case 'D':
	printk(KERN_INFO "GPIO%d: pull down\n", pin);
	retval = vr41xx_gpio_pullupdown(pin, GPIO_PULL_DOWN);
	break;
	case 'd':
	printk(KERN_INFO "GPIO%d: pull up/down disable\n", pin);
	retval = vr41xx_gpio_pullupdown(pin, GPIO_PULL_DISABLE);
	break;
	case 'I':
	printk(KERN_INFO "GPIO%d: input\n", pin);
	retval = vr41xx_gpio_set_direction(pin, GPIO_INPUT);
	break;
	case 'O':
	printk(KERN_INFO "GPIO%d: output\n", pin);
	retval = vr41xx_gpio_set_direction(pin, GPIO_OUTPUT);
	break;
	case 'o':
	printk(KERN_INFO "GPIO%d: output disable\n", pin);
	retval = vr41xx_gpio_set_direction(pin, GPIO_OUTPUT_DISABLE);
	break;
	case 'P':
	printk(KERN_INFO "GPIO%d: pull up\n", pin);
	retval = vr41xx_gpio_pullupdown(pin, GPIO_PULL_UP);
	break;
	case 'p':
	printk(KERN_INFO "GPIO%d: pull up/down disable\n", pin);
	retval = vr41xx_gpio_pullupdown(pin, GPIO_PULL_DISABLE);
	break;
	default:
	break;
	}

	if (retval < 0)
	break;
	}

	return i;
	}

	/* No BKL needed here; only global (giu_nr_pins) is only set
	at probe time */
	static int gpio_open(struct inode inode, struct file file)
	{
	unsigned int pin;

	pin = iminor(inode);
	if (pin >= giu_nr_pins)
	return -EBADF;

	return nonseekable_open(inode, file);
	}

	static int gpio_release(struct inode inode, struct file file)
	{
	unsigned int pin;

	pin = iminor(inode);
	if (pin >= giu_nr_pins)
	return -EBADF;

	return 0;
	}

	static const struct file_operations gpio_fops = {
	.owner = THIS_MODULE,
	.read = gpio_read,
	.write = gpio_write,
	.open = gpio_open,
	.release = gpio_release,
	};

	static int __devinit giu_probe(struct platform_device *dev)
	{
	struct resource *res;
	unsigned int trigger, i, pin;
	struct irq_chip *chip;
	int irq, retval;

	switch (dev->id) {
	case GPIO_50PINS_PULLUPDOWN:
	giu_flags = GPIO_HAS_PULLUPDOWN_IO;
	giu_nr_pins = 50;
	break;
	case GPIO_36PINS:
	giu_nr_pins = 36;
	break;
	case GPIO_48PINS_EDGE_SELECT:
	giu_flags = GPIO_HAS_INTERRUPT_EDGE_SELECT;
	giu_nr_pins = 48;
	break;
	default:
	printk(KERN_ERR "GIU: unknown ID %d\n", dev->id);
	return -ENODEV;
	}

	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
	if (!res)
	return -EBUSY;

	giu_base = ioremap(res->start, res->end - res->start + 1);
	if (!giu_base)
	return -ENOMEM;

	retval = register_chrdev(major, "GIU", &gpio_fops);
	if (retval < 0) {
	iounmap(giu_base);
	giu_base = NULL;
	return retval;
	}

	if (major == 0) {
	major = retval;
	printk(KERN_INFO "GIU: major number %d\n", major);
	}

	spin_lock_init(&giu_lock);

	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))
	set_irq_chip_and_handler(i, chip, handle_edge_irq);
	else
	set_irq_chip_and_handler(i, chip, handle_level_irq);

	}

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

	return cascade_irq(irq, giu_get_irq);
	}

	static int __devexit giu_remove(struct platform_device *dev)
	{
	if (giu_base) {
	iounmap(giu_base);
	giu_base = NULL;
	}

	return 0;
	}

	static struct platform_driver giu_device_driver = {
	.probe = giu_probe,
	.remove = __devexit_p(giu_remove),
	.driver = {
	.name = "GIU",
	.owner = THIS_MODULE,
	},
	};

	static int __init vr41xx_giu_init(void)
	{
	return platform_driver_register(&giu_device_driver);
	}

	static void __exit vr41xx_giu_exit(void)
	{
	platform_driver_unregister(&giu_device_driver);
	}

	module_init(vr41xx_giu_init);
	module_exit(vr41xx_giu_exit);