[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 5ed6515ae01f..7ccf871d3c9d 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 e3f5c32aac55..1aff819f3832 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 000000000000..683278bc5241
--- /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);