[PATCH] mips: add vr41xx gpio support

Add vr41xx gpio support.

Signed-off-by: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 748 insertions, 0 deletions

diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index 5ed6515..7ccf871 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -929,6 +929,10 @@ config SCx200_GPIO
 
 	  If compiled as a module, it will be called scx200_gpio.
 
+config GPIO_VR41XX
+	tristate "NEC VR4100 series General-purpose I/O Unit support"
+	depends on CPU_VR41XX
+
 config RAW_DRIVER
 	tristate "RAW driver (/dev/raw/rawN) (OBSOLETE)"
 	help
diff --git a/drivers/char/Makefile b/drivers/char/Makefile
index e3f5c32..1aff819 100644
--- a/drivers/char/Makefile
+++ b/drivers/char/Makefile
@@ -80,6 +80,7 @@ obj-$(CONFIG_PPDEV) += ppdev.o
 obj-$(CONFIG_NWBUTTON) += nwbutton.o
 obj-$(CONFIG_NWFLASH) += nwflash.o
 obj-$(CONFIG_SCx200_GPIO) += scx200_gpio.o
+obj-$(CONFIG_GPIO_VR41XX) += vr41xx_giu.o
 obj-$(CONFIG_TANBAC_TB0219) += tb0219.o
 
 obj-$(CONFIG_WATCHDOG)	+= watchdog/
diff --git a/drivers/char/vr41xx_giu.c b/drivers/char/vr41xx_giu.c
new file mode 100644
index 0000000..683278b
--- /dev/null
+++ b/drivers/char/vr41xx_giu.c
@@ -0,0 +1,743 @@
+/*
+ *  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) 2003-2005  Yoichi Yuasa <yuasa@hh.iij4u.or.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/device.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#include <asm/cpu.h>
+#include <asm/io.h>
+#include <asm/vr41xx/giu.h>
+#include <asm/vr41xx/vr41xx.h>
+
+MODULE_AUTHOR("Yoichi Yuasa <yuasa@hh.iij4u.or.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 GIU_TYPE1_START		0x0b000100UL
+#define GIU_TYPE1_SIZE		0x20UL
+
+#define GIU_TYPE2_START		0x0f000140UL
+#define GIU_TYPE2_SIZE		0x20UL
+
+#define GIU_TYPE3_START		0x0f000140UL
+#define GIU_TYPE3_SIZE		0x28UL
+
+#define GIU_PULLUPDOWN_START	0x0b0002e0UL
+#define GIU_PULLUPDOWN_SIZE	0x04UL
+
+#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 struct resource *giu_resource1;
+static struct resource *giu_resource2;
+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 unsigned int startup_giuint_low_irq(unsigned int irq)
+{
+	unsigned int pin;
+
+	pin = GPIO_PIN_OF_IRQ(irq);
+	giu_write(GIUINTSTATL, 1 << pin);
+	giu_set(GIUINTENL, 1 << pin);
+
+	return 0;
+}
+
+static void shutdown_giuint_low_irq(unsigned int irq)
+{
+	giu_clear(GIUINTENL, 1 << GPIO_PIN_OF_IRQ(irq));
+}
+
+static void enable_giuint_low_irq(unsigned int irq)
+{
+	giu_set(GIUINTENL, 1 << GPIO_PIN_OF_IRQ(irq));
+}
+
+#define disable_giuint_low_irq	shutdown_giuint_low_irq
+
+static void ack_giuint_low_irq(unsigned int irq)
+{
+	unsigned int pin;
+
+	pin = GPIO_PIN_OF_IRQ(irq);
+	giu_clear(GIUINTENL, 1 << pin);
+	giu_write(GIUINTSTATL, 1 << pin);
+}
+
+static void end_giuint_low_irq(unsigned int irq)
+{
+	if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS)))
+		giu_set(GIUINTENL, 1 << GPIO_PIN_OF_IRQ(irq));
+}
+
+static struct hw_interrupt_type giuint_low_irq_type = {
+	.typename	= "GIUINTL",
+	.startup	= startup_giuint_low_irq,
+	.shutdown	= shutdown_giuint_low_irq,
+	.enable		= enable_giuint_low_irq,
+	.disable	= disable_giuint_low_irq,
+	.ack		= ack_giuint_low_irq,
+	.end		= end_giuint_low_irq,
+};
+
+static unsigned int startup_giuint_high_irq(unsigned int irq)
+{
+	unsigned int pin;
+
+	pin = GPIO_PIN_OF_IRQ(irq) - GIUINT_HIGH_OFFSET;
+	giu_write(GIUINTSTATH, 1 << pin);
+	giu_set(GIUINTENH, 1 << pin);
+
+	return 0;
+}
+
+static void shutdown_giuint_high_irq(unsigned int irq)
+{
+	giu_clear(GIUINTENH, 1 << (GPIO_PIN_OF_IRQ(irq) - GIUINT_HIGH_OFFSET));
+}
+
+static void enable_giuint_high_irq(unsigned int irq)
+{
+	giu_set(GIUINTENH, 1 << (GPIO_PIN_OF_IRQ(irq) - GIUINT_HIGH_OFFSET));
+}
+
+#define disable_giuint_high_irq	shutdown_giuint_high_irq
+
+static void ack_giuint_high_irq(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 end_giuint_high_irq(unsigned int irq)
+{
+	if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS)))
+		giu_set(GIUINTENH, 1 << (GPIO_PIN_OF_IRQ(irq) - GIUINT_HIGH_OFFSET));
+}
+
+static struct hw_interrupt_type giuint_high_irq_type = {
+	.typename	= "GIUINTH",
+	.startup	= startup_giuint_high_irq,
+	.shutdown	= shutdown_giuint_high_irq,
+	.enable		= enable_giuint_high_irq,
+	.disable	= disable_giuint_high_irq,
+	.ack		= ack_giuint_high_irq,
+	.end		= end_giuint_high_irq,
+};
+
+static int giu_get_irq(unsigned int irq, struct pt_regs *regs)
+{
+	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 (current_cpu_data.cputype == CPU_VR4133) {
+				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;
+				}
+			}
+		} else {
+			giu_clear(GIUINTTYPL, mask);
+			giu_clear(GIUINTHTSELL, mask);
+		}
+		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 (current_cpu_data.cputype == CPU_VR4133) {
+				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;
+				}
+			}
+		} else {
+			giu_clear(GIUINTTYPH, mask);
+			giu_clear(GIUINTHTSELH, mask);
+		}
+		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_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_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;
+}
+
+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 struct file_operations gpio_fops = {
+	.owner		= THIS_MODULE,
+	.read		= gpio_read,
+	.write		= gpio_write,
+	.open		= gpio_open,
+	.release	= gpio_release,
+};
+
+static int giu_probe(struct device *dev)
+{
+	unsigned long start, size, flags = 0;
+	unsigned int nr_pins = 0;
+	struct resource *res1, *res2 = NULL;
+	void *base;
+	int retval, i;
+
+	switch (current_cpu_data.cputype) {
+	case CPU_VR4111:
+	case CPU_VR4121:
+		start = GIU_TYPE1_START;
+		size = GIU_TYPE1_SIZE;
+		flags = GPIO_HAS_PULLUPDOWN_IO;
+		nr_pins = 50;
+		break;
+	case CPU_VR4122:
+	case CPU_VR4131:
+		start = GIU_TYPE2_START;
+		size = GIU_TYPE2_SIZE;
+		nr_pins = 36;
+		break;
+	case CPU_VR4133:
+		start = GIU_TYPE3_START;
+		size = GIU_TYPE3_SIZE;
+		flags = GPIO_HAS_INTERRUPT_EDGE_SELECT;
+		nr_pins = 48;
+		break;
+	default:
+		return -ENODEV;
+	}
+
+	res1 = request_mem_region(start, size, "GIU");
+	if (res1 == NULL)
+		return -EBUSY;
+
+	base = ioremap(start, size);
+	if (base == NULL) {
+		release_resource(res1);
+		return -ENOMEM;
+	}
+
+	if (flags & GPIO_HAS_PULLUPDOWN_IO) {
+		res2 = request_mem_region(GIU_PULLUPDOWN_START, GIU_PULLUPDOWN_SIZE, "GIU");
+		if (res2 == NULL) {
+			iounmap(base);
+			release_resource(res1);
+			return -EBUSY;
+		}
+	}
+
+	retval = register_chrdev(major, "GIU", &gpio_fops);
+	if (retval < 0) {
+		iounmap(base);
+		release_resource(res1);
+		release_resource(res2);
+		return retval;
+	}
+
+	if (major == 0) {
+		major = retval;
+		printk(KERN_INFO "GIU: major number %d\n", major);
+	}
+
+	spin_lock_init(&giu_lock);
+	giu_base = base;
+	giu_resource1 = res1;
+	giu_resource2 = res2;
+	giu_flags = flags;
+	giu_nr_pins = nr_pins;
+
+	giu_write(GIUINTENL, 0);
+	giu_write(GIUINTENH, 0);
+
+	for (i = GIU_IRQ_BASE; i <= GIU_IRQ_LAST; i++) {
+		if (i < GIU_IRQ(GIUINT_HIGH_OFFSET))
+			irq_desc[i].handler = &giuint_low_irq_type;
+		else
+			irq_desc[i].handler = &giuint_high_irq_type;
+	}
+
+	return cascade_irq(GIUINT_IRQ, giu_get_irq);
+}
+
+static int giu_remove(struct device *dev)
+{
+	iounmap(giu_base);
+
+	release_resource(giu_resource1);
+	if (giu_flags & GPIO_HAS_PULLUPDOWN_IO)
+		release_resource(giu_resource2);
+
+	return 0;
+}
+
+static struct platform_device *giu_platform_device;
+
+static struct device_driver giu_device_driver = {
+	.name		= "GIU",
+	.bus		= &platform_bus_type,
+	.probe		= giu_probe,
+	.remove		= giu_remove,
+};
+
+static int __devinit vr41xx_giu_init(void)
+{
+	int retval;
+
+	giu_platform_device = platform_device_register_simple("GIU", -1, NULL, 0);
+	if (IS_ERR(giu_platform_device))
+		return PTR_ERR(giu_platform_device);
+
+	retval = driver_register(&giu_device_driver);
+	if (retval < 0)
+		platform_device_unregister(giu_platform_device);
+
+	return retval;
+}
+
+static void __devexit vr41xx_giu_exit(void)
+{
+	driver_unregister(&giu_device_driver);
+
+	platform_device_unregister(giu_platform_device);
+}
+
+module_init(vr41xx_giu_init);
+module_exit(vr41xx_giu_exit);