linux/arch/mips/jz4740/gpio.c - nest-guard/1.0/linux - Git at Google

 /*
  *  Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
  *  JZ4740 platform GPIO support
  *
  *  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.
  *
  *  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.,
  *  675 Mass Ave, Cambridge, MA 02139, USA.
  *
  */

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>

 #include <linux/spinlock.h>
 #include <linux/sysdev.h>
 #include <linux/io.h>
 #include <linux/gpio.h>
 #include <linux/delay.h>
 #include <linux/interrupt.h>
 #include <linux/bitops.h>

 #include <linux/debugfs.h>
 #include <linux/seq_file.h>

 #include <asm/mach-jz4740/base.h>

 #define JZ4740_GPIO_BASE_A (32*0)
 #define JZ4740_GPIO_BASE_B (32*1)
 #define JZ4740_GPIO_BASE_C (32*2)
 #define JZ4740_GPIO_BASE_D (32*3)

 #define JZ4740_GPIO_NUM_A 32
 #define JZ4740_GPIO_NUM_B 32
 #define JZ4740_GPIO_NUM_C 31
 #define JZ4740_GPIO_NUM_D 32

 #define JZ4740_IRQ_GPIO_BASE_A (JZ4740_IRQ_GPIO(0) + JZ4740_GPIO_BASE_A)
 #define JZ4740_IRQ_GPIO_BASE_B (JZ4740_IRQ_GPIO(0) + JZ4740_GPIO_BASE_B)
 #define JZ4740_IRQ_GPIO_BASE_C (JZ4740_IRQ_GPIO(0) + JZ4740_GPIO_BASE_C)
 #define JZ4740_IRQ_GPIO_BASE_D (JZ4740_IRQ_GPIO(0) + JZ4740_GPIO_BASE_D)

 #define JZ_REG_GPIO_PIN			0x00
 #define JZ_REG_GPIO_DATA		0x10
 #define JZ_REG_GPIO_DATA_SET		0x14
 #define JZ_REG_GPIO_DATA_CLEAR		0x18
 #define JZ_REG_GPIO_MASK		0x20
 #define JZ_REG_GPIO_MASK_SET		0x24
 #define JZ_REG_GPIO_MASK_CLEAR		0x28
 #define JZ_REG_GPIO_PULL		0x30
 #define JZ_REG_GPIO_PULL_SET		0x34
 #define JZ_REG_GPIO_PULL_CLEAR		0x38
 #define JZ_REG_GPIO_FUNC		0x40
 #define JZ_REG_GPIO_FUNC_SET		0x44
 #define JZ_REG_GPIO_FUNC_CLEAR		0x48
 #define JZ_REG_GPIO_SELECT		0x50
 #define JZ_REG_GPIO_SELECT_SET		0x54
 #define JZ_REG_GPIO_SELECT_CLEAR	0x58
 #define JZ_REG_GPIO_DIRECTION		0x60
 #define JZ_REG_GPIO_DIRECTION_SET	0x64
 #define JZ_REG_GPIO_DIRECTION_CLEAR	0x68
 #define JZ_REG_GPIO_TRIGGER		0x70
 #define JZ_REG_GPIO_TRIGGER_SET		0x74
 #define JZ_REG_GPIO_TRIGGER_CLEAR	0x78
 #define JZ_REG_GPIO_FLAG		0x80
 #define JZ_REG_GPIO_FLAG_CLEAR		0x14

 #define GPIO_TO_BIT(gpio) BIT(gpio & 0x1f)
 #define GPIO_TO_REG(gpio, reg) (gpio_to_jz_gpio_chip(gpio)->base + (reg))
 #define CHIP_TO_REG(chip, reg) (gpio_chip_to_jz_gpio_chip(chip)->base + (reg))

 struct jz_gpio_chip {
 	unsigned int irq;
 	unsigned int irq_base;
 	uint32_t wakeup;
 	uint32_t suspend_mask;
 	uint32_t edge_trigger_both;

 	void __iomem *base;

 	spinlock_t lock;

 	struct gpio_chip gpio_chip;
 	struct irq_chip irq_chip;
 	struct sys_device sysdev;
 };

 static struct jz_gpio_chip jz4740_gpio_chips[];

 static inline struct jz_gpio_chip *gpio_to_jz_gpio_chip(unsigned int gpio)
 {
 	return &jz4740_gpio_chips[gpio >> 5];
 }

 static inline struct jz_gpio_chip *gpio_chip_to_jz_gpio_chip(struct gpio_chip *gpio_chip)
 {
 	return container_of(gpio_chip, struct jz_gpio_chip, gpio_chip);
 }

 static inline struct jz_gpio_chip *irq_to_jz_gpio_chip(unsigned int irq)
 {
 	return get_irq_chip_data(irq);
 }

 static inline void jz_gpio_write_bit(unsigned int gpio, unsigned int reg)
 {
 	writel(GPIO_TO_BIT(gpio), GPIO_TO_REG(gpio, reg));
 }

 int jz_gpio_set_function(int gpio, enum jz_gpio_function function)
 {
 	if (function == JZ_GPIO_FUNC_NONE) {
 		jz_gpio_write_bit(gpio, JZ_REG_GPIO_FUNC_CLEAR);
 		jz_gpio_write_bit(gpio, JZ_REG_GPIO_SELECT_CLEAR);
 		jz_gpio_write_bit(gpio, JZ_REG_GPIO_TRIGGER_CLEAR);
 	} else {
 		jz_gpio_write_bit(gpio, JZ_REG_GPIO_FUNC_SET);
 		jz_gpio_write_bit(gpio, JZ_REG_GPIO_TRIGGER_CLEAR);
 		switch (function) {
 		case JZ_GPIO_FUNC1:
 			jz_gpio_write_bit(gpio, JZ_REG_GPIO_SELECT_CLEAR);
 			break;
 		case JZ_GPIO_FUNC3:
 			jz_gpio_write_bit(gpio, JZ_REG_GPIO_TRIGGER_SET);
 		case JZ_GPIO_FUNC2: /* Falltrough */
 			jz_gpio_write_bit(gpio, JZ_REG_GPIO_SELECT_SET);
 			break;
 		default:
 			BUG();
 			break;
 		}
 	}

 	return 0;
 }
 EXPORT_SYMBOL_GPL(jz_gpio_set_function);

 int jz_gpio_bulk_request(const struct jz_gpio_bulk_request *request, size_t num)
 {
 	size_t i;
 	int ret;

 	for (i = 0; i < num; ++i, ++request) {
 		ret = gpio_request(request->gpio, request->name);
 		if (ret)
 			goto err;
 		jz_gpio_set_function(request->gpio, request->function);
 	}

 	return 0;

 err:
 	for (--request; i > 0; --i, --request) {
 		gpio_free(request->gpio);
 		jz_gpio_set_function(request->gpio, JZ_GPIO_FUNC_NONE);
 	}

 	return ret;
 }
 EXPORT_SYMBOL_GPL(jz_gpio_bulk_request);

 void jz_gpio_bulk_free(const struct jz_gpio_bulk_request *request, size_t num)
 {
 	size_t i;

 	for (i = 0; i < num; ++i, ++request) {
 		gpio_free(request->gpio);
 		jz_gpio_set_function(request->gpio, JZ_GPIO_FUNC_NONE);
 	}

 }
 EXPORT_SYMBOL_GPL(jz_gpio_bulk_free);

 void jz_gpio_bulk_suspend(const struct jz_gpio_bulk_request *request, size_t num)
 {
 	size_t i;

 	for (i = 0; i < num; ++i, ++request) {
 		jz_gpio_set_function(request->gpio, JZ_GPIO_FUNC_NONE);
 		jz_gpio_write_bit(request->gpio, JZ_REG_GPIO_DIRECTION_CLEAR);
 		jz_gpio_write_bit(request->gpio, JZ_REG_GPIO_PULL_SET);
 	}
 }
 EXPORT_SYMBOL_GPL(jz_gpio_bulk_suspend);

 void jz_gpio_bulk_resume(const struct jz_gpio_bulk_request *request, size_t num)
 {
 	size_t i;

 	for (i = 0; i < num; ++i, ++request)
 		jz_gpio_set_function(request->gpio, request->function);
 }
 EXPORT_SYMBOL_GPL(jz_gpio_bulk_resume);

 void jz_gpio_enable_pullup(unsigned gpio)
 {
 	jz_gpio_write_bit(gpio, JZ_REG_GPIO_PULL_CLEAR);
 }
 EXPORT_SYMBOL_GPL(jz_gpio_enable_pullup);

 void jz_gpio_disable_pullup(unsigned gpio)
 {
 	jz_gpio_write_bit(gpio, JZ_REG_GPIO_PULL_SET);
 }
 EXPORT_SYMBOL_GPL(jz_gpio_disable_pullup);

 static int jz_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
 {
 	return !!(readl(CHIP_TO_REG(chip, JZ_REG_GPIO_PIN)) & BIT(gpio));
 }

 static void jz_gpio_set_value(struct gpio_chip *chip, unsigned gpio, int value)
 {
 	uint32_t __iomem *reg = CHIP_TO_REG(chip, JZ_REG_GPIO_DATA_SET);
 	reg += !value;
 	writel(BIT(gpio), reg);
 }

 static int jz_gpio_direction_output(struct gpio_chip *chip, unsigned gpio,
 	int value)
 {
 	writel(BIT(gpio), CHIP_TO_REG(chip, JZ_REG_GPIO_DIRECTION_SET));
 	jz_gpio_set_value(chip, gpio, value);

 	return 0;
 }

 static int jz_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
 {
 	writel(BIT(gpio), CHIP_TO_REG(chip, JZ_REG_GPIO_DIRECTION_CLEAR));

 	return 0;
 }

 int jz_gpio_port_direction_input(int port, uint32_t mask)
 {
 	writel(mask, GPIO_TO_REG(port, JZ_REG_GPIO_DIRECTION_CLEAR));

 	return 0;
 }
 EXPORT_SYMBOL(jz_gpio_port_direction_input);

 int jz_gpio_port_direction_output(int port, uint32_t mask)
 {
 	writel(mask, GPIO_TO_REG(port, JZ_REG_GPIO_DIRECTION_SET));

 	return 0;
 }
 EXPORT_SYMBOL(jz_gpio_port_direction_output);

 void jz_gpio_port_set_value(int port, uint32_t value, uint32_t mask)
 {
 	writel(~value & mask, GPIO_TO_REG(port, JZ_REG_GPIO_DATA_CLEAR));
 	writel(value & mask, GPIO_TO_REG(port, JZ_REG_GPIO_DATA_SET));
 }
 EXPORT_SYMBOL(jz_gpio_port_set_value);

 uint32_t jz_gpio_port_get_value(int port, uint32_t mask)
 {
 	uint32_t value = readl(GPIO_TO_REG(port, JZ_REG_GPIO_PIN));

 	return value & mask;
 }
 EXPORT_SYMBOL(jz_gpio_port_get_value);

 int gpio_to_irq(unsigned gpio)
 {
 	return JZ4740_IRQ_GPIO(0) + gpio;
 }
 EXPORT_SYMBOL_GPL(gpio_to_irq);

 int irq_to_gpio(unsigned irq)
 {
 	return irq - JZ4740_IRQ_GPIO(0);
 }
 EXPORT_SYMBOL_GPL(irq_to_gpio);

 #define IRQ_TO_BIT(irq) BIT(irq_to_gpio(irq) & 0x1f)

 static void jz_gpio_check_trigger_both(struct jz_gpio_chip *chip, unsigned int irq)
 {
 	uint32_t value;
 	void __iomem *reg;
 	uint32_t mask = IRQ_TO_BIT(irq);

 	if (!(chip->edge_trigger_both & mask))
 		return;

 	reg = chip->base;

 	value = readl(chip->base + JZ_REG_GPIO_PIN);
 	if (value & mask)
 		reg += JZ_REG_GPIO_DIRECTION_CLEAR;
 	else
 		reg += JZ_REG_GPIO_DIRECTION_SET;

 	writel(mask, reg);
 }

 static void jz_gpio_irq_demux_handler(unsigned int irq, struct irq_desc *desc)
 {
 	uint32_t flag;
 	unsigned int gpio_irq;
 	unsigned int gpio_bank;
 	struct jz_gpio_chip *chip = get_irq_desc_data(desc);

 	gpio_bank = JZ4740_IRQ_GPIO0 - irq;

 	flag = readl(chip->base + JZ_REG_GPIO_FLAG);

 	if (!flag)
 		return;

 	gpio_irq = __fls(flag);

 	jz_gpio_check_trigger_both(chip, irq);

 	gpio_irq += (gpio_bank << 5) + JZ4740_IRQ_GPIO(0);

 	generic_handle_irq(gpio_irq);
 };

 static inline void jz_gpio_set_irq_bit(unsigned int irq, unsigned int reg)
 {
 	struct jz_gpio_chip *chip = irq_to_jz_gpio_chip(irq);
 	writel(IRQ_TO_BIT(irq), chip->base + reg);
 }

 static void jz_gpio_irq_mask(unsigned int irq)
 {
 	jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_MASK_SET);
 };

 static void jz_gpio_irq_unmask(unsigned int irq)
 {
 	struct jz_gpio_chip *chip = irq_to_jz_gpio_chip(irq);

 	jz_gpio_check_trigger_both(chip, irq);

 	jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_MASK_CLEAR);
 };

 /* TODO: Check if function is gpio */
 static unsigned int jz_gpio_irq_startup(unsigned int irq)
 {
 	struct irq_desc *desc = irq_to_desc(irq);

 	jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_SELECT_SET);

 	desc->status &= ~IRQ_MASKED;
 	jz_gpio_irq_unmask(irq);

 	return 0;
 }

 static void jz_gpio_irq_shutdown(unsigned int irq)
 {
 	struct irq_desc *desc = irq_to_desc(irq);

 	jz_gpio_irq_mask(irq);
 	desc->status |= IRQ_MASKED;

 	/* Set direction to input */
 	jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_DIRECTION_CLEAR);
 	jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_SELECT_CLEAR);
 }

 static void jz_gpio_irq_ack(unsigned int irq)
 {
 	jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_FLAG_CLEAR);
 };

 static int jz_gpio_irq_set_type(unsigned int irq, unsigned int flow_type)
 {
 	struct jz_gpio_chip *chip = irq_to_jz_gpio_chip(irq);
 	struct irq_desc *desc = irq_to_desc(irq);

 	jz_gpio_irq_mask(irq);

 	if (flow_type == IRQ_TYPE_EDGE_BOTH) {
 		uint32_t value = readl(chip->base + JZ_REG_GPIO_PIN);
 		if (value & IRQ_TO_BIT(irq))
 			flow_type = IRQ_TYPE_EDGE_FALLING;
 		else
 			flow_type = IRQ_TYPE_EDGE_RISING;
 		chip->edge_trigger_both |= IRQ_TO_BIT(irq);
 	} else {
 		chip->edge_trigger_both &= ~IRQ_TO_BIT(irq);
 	}

 	switch (flow_type) {
 	case IRQ_TYPE_EDGE_RISING:
 		jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_DIRECTION_SET);
 		jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_TRIGGER_SET);
 		break;
 	case IRQ_TYPE_EDGE_FALLING:
 		jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_DIRECTION_CLEAR);
 		jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_TRIGGER_SET);
 		break;
 	case IRQ_TYPE_LEVEL_HIGH:
 		jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_DIRECTION_SET);
 		jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_TRIGGER_CLEAR);
 		break;
 	case IRQ_TYPE_LEVEL_LOW:
 		jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_DIRECTION_CLEAR);
 		jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_TRIGGER_CLEAR);
 		break;
 	default:
 		return -EINVAL;
 	}

 	if (!(desc->status & IRQ_MASKED))
 		jz_gpio_irq_unmask(irq);

 	return 0;
 }

 static int jz_gpio_irq_set_wake(unsigned int irq, unsigned int on)
 {
 	struct jz_gpio_chip *chip = irq_to_jz_gpio_chip(irq);
 	spin_lock(&chip->lock);
 	if (on)
 		chip->wakeup |= IRQ_TO_BIT(irq);
 	else
 		chip->wakeup &= ~IRQ_TO_BIT(irq);
 	spin_unlock(&chip->lock);

 	set_irq_wake(chip->irq, on);
 	return 0;
 }

 /*
  * This lock class tells lockdep that GPIO irqs are in a different
  * category than their parents, so it won't report false recursion.
  */
 static struct lock_class_key gpio_lock_class;

 #define JZ4740_GPIO_CHIP(_bank) { \
 	.irq_base = JZ4740_IRQ_GPIO_BASE_ ## _bank, \
 	.gpio_chip = { \
 		.label = "Bank " # _bank, \
 		.owner = THIS_MODULE, \
 		.set = jz_gpio_set_value, \
 		.get = jz_gpio_get_value, \
 		.direction_output = jz_gpio_direction_output, \
 		.direction_input = jz_gpio_direction_input, \
 		.base = JZ4740_GPIO_BASE_ ## _bank, \
 		.ngpio = JZ4740_GPIO_NUM_ ## _bank, \
 	}, \
 	.irq_chip =  { \
 		.name = "GPIO Bank " # _bank, \
 		.mask = jz_gpio_irq_mask, \
 		.unmask = jz_gpio_irq_unmask, \
 		.ack = jz_gpio_irq_ack, \
 		.startup = jz_gpio_irq_startup, \
 		.shutdown = jz_gpio_irq_shutdown, \
 		.set_type = jz_gpio_irq_set_type, \
 		.set_wake = jz_gpio_irq_set_wake, \
 	}, \
 }

 static struct jz_gpio_chip jz4740_gpio_chips[] = {
 	JZ4740_GPIO_CHIP(A),
 	JZ4740_GPIO_CHIP(B),
 	JZ4740_GPIO_CHIP(C),
 	JZ4740_GPIO_CHIP(D),
 };

 static inline struct jz_gpio_chip *sysdev_to_chip(struct sys_device *dev)
 {
 	return container_of(dev, struct jz_gpio_chip, sysdev);
 }

 static int jz4740_gpio_suspend(struct sys_device *dev, pm_message_t state)
 {
 	struct jz_gpio_chip *chip = sysdev_to_chip(dev);

 	chip->suspend_mask = readl(chip->base + JZ_REG_GPIO_MASK);
 	writel(~(chip->wakeup), chip->base + JZ_REG_GPIO_MASK_SET);
 	writel(chip->wakeup, chip->base + JZ_REG_GPIO_MASK_CLEAR);

 	return 0;
 }

 static int jz4740_gpio_resume(struct sys_device *dev)
 {
 	struct jz_gpio_chip *chip = sysdev_to_chip(dev);
 	uint32_t mask = chip->suspend_mask;

 	writel(~mask, chip->base + JZ_REG_GPIO_MASK_CLEAR);
 	writel(mask, chip->base + JZ_REG_GPIO_MASK_SET);

 	return 0;
 }

 static struct sysdev_class jz4740_gpio_sysdev_class = {
 	.name = "gpio",
 	.suspend = jz4740_gpio_suspend,
 	.resume = jz4740_gpio_resume,
 };

 static int jz4740_gpio_chip_init(struct jz_gpio_chip *chip, unsigned int id)
 {
 	int ret, irq;

 	chip->sysdev.id = id;
 	chip->sysdev.cls = &jz4740_gpio_sysdev_class;
 	ret = sysdev_register(&chip->sysdev);

 	if (ret)
 		return ret;

 	spin_lock_init(&chip->lock);

 	chip->base = ioremap(JZ4740_GPIO_BASE_ADDR + (id * 0x100), 0x100);

 	gpiochip_add(&chip->gpio_chip);

 	chip->irq = JZ4740_IRQ_INTC_GPIO(id);
 	set_irq_data(chip->irq, chip);
 	set_irq_chained_handler(chip->irq, jz_gpio_irq_demux_handler);

 	for (irq = chip->irq_base; irq < chip->irq_base + chip->gpio_chip.ngpio; ++irq) {
 		lockdep_set_class(&irq_desc[irq].lock, &gpio_lock_class);
 		set_irq_chip_data(irq, chip);
 		set_irq_chip_and_handler(irq, &chip->irq_chip, handle_level_irq);
 	}

 	return 0;
 }

 static int __init jz4740_gpio_init(void)
 {
 	unsigned int i;
 	int ret;

 	ret = sysdev_class_register(&jz4740_gpio_sysdev_class);
 	if (ret)
 		return ret;

 	for (i = 0; i < ARRAY_SIZE(jz4740_gpio_chips); ++i)
 		jz4740_gpio_chip_init(&jz4740_gpio_chips[i], i);

 	printk(KERN_INFO "JZ4740 GPIO initalized\n");

 	return 0;
 }
 arch_initcall(jz4740_gpio_init);

 #ifdef CONFIG_DEBUG_FS

 static inline void gpio_seq_reg(struct seq_file *s, struct jz_gpio_chip *chip,
 	const char *name, unsigned int reg)
 {
 	seq_printf(s, "\t%s: %08x\n", name, readl(chip->base + reg));
 }

 static int gpio_regs_show(struct seq_file *s, void *unused)
 {
 	struct jz_gpio_chip *chip = jz4740_gpio_chips;
 	int i;

 	for (i = 0; i < ARRAY_SIZE(jz4740_gpio_chips); ++i, ++chip) {
 		seq_printf(s, "==GPIO %d==\n", i);
 		gpio_seq_reg(s, chip, "Pin", JZ_REG_GPIO_PIN);
 		gpio_seq_reg(s, chip, "Data", JZ_REG_GPIO_DATA);
 		gpio_seq_reg(s, chip, "Mask", JZ_REG_GPIO_MASK);
 		gpio_seq_reg(s, chip, "Pull", JZ_REG_GPIO_PULL);
 		gpio_seq_reg(s, chip, "Func", JZ_REG_GPIO_FUNC);
 		gpio_seq_reg(s, chip, "Select", JZ_REG_GPIO_SELECT);
 		gpio_seq_reg(s, chip, "Direction", JZ_REG_GPIO_DIRECTION);
 		gpio_seq_reg(s, chip, "Trigger", JZ_REG_GPIO_TRIGGER);
 		gpio_seq_reg(s, chip, "Flag", JZ_REG_GPIO_FLAG);
 	}

 	return 0;
 }

 static int gpio_regs_open(struct inode *inode, struct file *file)
 {
 	return single_open(file, gpio_regs_show, NULL);
 }

 static const struct file_operations gpio_regs_operations = {
 	.open		= gpio_regs_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };

 static int __init gpio_debugfs_init(void)
 {
 	(void) debugfs_create_file("jz_regs_gpio", S_IFREG | S_IRUGO,
 				NULL, NULL, &gpio_regs_operations);
 	return 0;
 }
 subsys_initcall(gpio_debugfs_init);

 #endif
	/*
	* Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
	* JZ4740 platform GPIO support
	*
	* 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.
	*
	* 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.,
	* 675 Mass Ave, Cambridge, MA 02139, USA.
	*
	*/

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/init.h>

	#include <linux/spinlock.h>
	#include <linux/sysdev.h>
	#include <linux/io.h>
	#include <linux/gpio.h>
	#include <linux/delay.h>
	#include <linux/interrupt.h>
	#include <linux/bitops.h>

	#include <linux/debugfs.h>
	#include <linux/seq_file.h>

	#include <asm/mach-jz4740/base.h>

	#define JZ4740_GPIO_BASE_A (32*0)
	#define JZ4740_GPIO_BASE_B (32*1)
	#define JZ4740_GPIO_BASE_C (32*2)
	#define JZ4740_GPIO_BASE_D (32*3)

	#define JZ4740_GPIO_NUM_A 32
	#define JZ4740_GPIO_NUM_B 32
	#define JZ4740_GPIO_NUM_C 31
	#define JZ4740_GPIO_NUM_D 32

	#define JZ4740_IRQ_GPIO_BASE_A (JZ4740_IRQ_GPIO(0) + JZ4740_GPIO_BASE_A)
	#define JZ4740_IRQ_GPIO_BASE_B (JZ4740_IRQ_GPIO(0) + JZ4740_GPIO_BASE_B)
	#define JZ4740_IRQ_GPIO_BASE_C (JZ4740_IRQ_GPIO(0) + JZ4740_GPIO_BASE_C)
	#define JZ4740_IRQ_GPIO_BASE_D (JZ4740_IRQ_GPIO(0) + JZ4740_GPIO_BASE_D)

	#define JZ_REG_GPIO_PIN 0x00
	#define JZ_REG_GPIO_DATA 0x10
	#define JZ_REG_GPIO_DATA_SET 0x14
	#define JZ_REG_GPIO_DATA_CLEAR 0x18
	#define JZ_REG_GPIO_MASK 0x20
	#define JZ_REG_GPIO_MASK_SET 0x24
	#define JZ_REG_GPIO_MASK_CLEAR 0x28
	#define JZ_REG_GPIO_PULL 0x30
	#define JZ_REG_GPIO_PULL_SET 0x34
	#define JZ_REG_GPIO_PULL_CLEAR 0x38
	#define JZ_REG_GPIO_FUNC 0x40
	#define JZ_REG_GPIO_FUNC_SET 0x44
	#define JZ_REG_GPIO_FUNC_CLEAR 0x48
	#define JZ_REG_GPIO_SELECT 0x50
	#define JZ_REG_GPIO_SELECT_SET 0x54
	#define JZ_REG_GPIO_SELECT_CLEAR 0x58
	#define JZ_REG_GPIO_DIRECTION 0x60
	#define JZ_REG_GPIO_DIRECTION_SET 0x64
	#define JZ_REG_GPIO_DIRECTION_CLEAR 0x68
	#define JZ_REG_GPIO_TRIGGER 0x70
	#define JZ_REG_GPIO_TRIGGER_SET 0x74
	#define JZ_REG_GPIO_TRIGGER_CLEAR 0x78
	#define JZ_REG_GPIO_FLAG 0x80
	#define JZ_REG_GPIO_FLAG_CLEAR 0x14

	#define GPIO_TO_BIT(gpio) BIT(gpio & 0x1f)
	#define GPIO_TO_REG(gpio, reg) (gpio_to_jz_gpio_chip(gpio)->base + (reg))
	#define CHIP_TO_REG(chip, reg) (gpio_chip_to_jz_gpio_chip(chip)->base + (reg))

	struct jz_gpio_chip {
	unsigned int irq;
	unsigned int irq_base;
	uint32_t wakeup;
	uint32_t suspend_mask;
	uint32_t edge_trigger_both;

	void __iomem *base;

	spinlock_t lock;

	struct gpio_chip gpio_chip;
	struct irq_chip irq_chip;
	struct sys_device sysdev;
	};

	static struct jz_gpio_chip jz4740_gpio_chips[];

	static inline struct jz_gpio_chip *gpio_to_jz_gpio_chip(unsigned int gpio)
	{
	return &jz4740_gpio_chips[gpio >> 5];
	}

	static inline struct jz_gpio_chip gpio_chip_to_jz_gpio_chip(struct gpio_chip gpio_chip)
	{
	return container_of(gpio_chip, struct jz_gpio_chip, gpio_chip);
	}

	static inline struct jz_gpio_chip *irq_to_jz_gpio_chip(unsigned int irq)
	{
	return get_irq_chip_data(irq);
	}

	static inline void jz_gpio_write_bit(unsigned int gpio, unsigned int reg)
	{
	writel(GPIO_TO_BIT(gpio), GPIO_TO_REG(gpio, reg));
	}

	int jz_gpio_set_function(int gpio, enum jz_gpio_function function)
	{
	if (function == JZ_GPIO_FUNC_NONE) {
	jz_gpio_write_bit(gpio, JZ_REG_GPIO_FUNC_CLEAR);
	jz_gpio_write_bit(gpio, JZ_REG_GPIO_SELECT_CLEAR);
	jz_gpio_write_bit(gpio, JZ_REG_GPIO_TRIGGER_CLEAR);
	} else {
	jz_gpio_write_bit(gpio, JZ_REG_GPIO_FUNC_SET);
	jz_gpio_write_bit(gpio, JZ_REG_GPIO_TRIGGER_CLEAR);
	switch (function) {
	case JZ_GPIO_FUNC1:
	jz_gpio_write_bit(gpio, JZ_REG_GPIO_SELECT_CLEAR);
	break;
	case JZ_GPIO_FUNC3:
	jz_gpio_write_bit(gpio, JZ_REG_GPIO_TRIGGER_SET);
	case JZ_GPIO_FUNC2: /* Falltrough */
	jz_gpio_write_bit(gpio, JZ_REG_GPIO_SELECT_SET);
	break;
	default:
	BUG();
	break;
	}
	}

	return 0;
	}
	EXPORT_SYMBOL_GPL(jz_gpio_set_function);

	int jz_gpio_bulk_request(const struct jz_gpio_bulk_request *request, size_t num)
	{
	size_t i;
	int ret;

	for (i = 0; i < num; ++i, ++request) {
	ret = gpio_request(request->gpio, request->name);
	if (ret)
	goto err;
	jz_gpio_set_function(request->gpio, request->function);
	}

	return 0;

	err:
	for (--request; i > 0; --i, --request) {
	gpio_free(request->gpio);
	jz_gpio_set_function(request->gpio, JZ_GPIO_FUNC_NONE);
	}

	return ret;
	}
	EXPORT_SYMBOL_GPL(jz_gpio_bulk_request);

	void jz_gpio_bulk_free(const struct jz_gpio_bulk_request *request, size_t num)
	{
	size_t i;

	for (i = 0; i < num; ++i, ++request) {
	gpio_free(request->gpio);
	jz_gpio_set_function(request->gpio, JZ_GPIO_FUNC_NONE);
	}

	}
	EXPORT_SYMBOL_GPL(jz_gpio_bulk_free);

	void jz_gpio_bulk_suspend(const struct jz_gpio_bulk_request *request, size_t num)
	{
	size_t i;

	for (i = 0; i < num; ++i, ++request) {
	jz_gpio_set_function(request->gpio, JZ_GPIO_FUNC_NONE);
	jz_gpio_write_bit(request->gpio, JZ_REG_GPIO_DIRECTION_CLEAR);
	jz_gpio_write_bit(request->gpio, JZ_REG_GPIO_PULL_SET);
	}
	}
	EXPORT_SYMBOL_GPL(jz_gpio_bulk_suspend);

	void jz_gpio_bulk_resume(const struct jz_gpio_bulk_request *request, size_t num)
	{
	size_t i;

	for (i = 0; i < num; ++i, ++request)
	jz_gpio_set_function(request->gpio, request->function);
	}
	EXPORT_SYMBOL_GPL(jz_gpio_bulk_resume);

	void jz_gpio_enable_pullup(unsigned gpio)
	{
	jz_gpio_write_bit(gpio, JZ_REG_GPIO_PULL_CLEAR);
	}
	EXPORT_SYMBOL_GPL(jz_gpio_enable_pullup);

	void jz_gpio_disable_pullup(unsigned gpio)
	{
	jz_gpio_write_bit(gpio, JZ_REG_GPIO_PULL_SET);
	}
	EXPORT_SYMBOL_GPL(jz_gpio_disable_pullup);

	static int jz_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
	{
	return !!(readl(CHIP_TO_REG(chip, JZ_REG_GPIO_PIN)) & BIT(gpio));
	}

	static void jz_gpio_set_value(struct gpio_chip *chip, unsigned gpio, int value)
	{
	uint32_t __iomem *reg = CHIP_TO_REG(chip, JZ_REG_GPIO_DATA_SET);
	reg += !value;
	writel(BIT(gpio), reg);
	}

	static int jz_gpio_direction_output(struct gpio_chip *chip, unsigned gpio,
	int value)
	{
	writel(BIT(gpio), CHIP_TO_REG(chip, JZ_REG_GPIO_DIRECTION_SET));
	jz_gpio_set_value(chip, gpio, value);

	return 0;
	}

	static int jz_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
	{
	writel(BIT(gpio), CHIP_TO_REG(chip, JZ_REG_GPIO_DIRECTION_CLEAR));

	return 0;
	}

	int jz_gpio_port_direction_input(int port, uint32_t mask)
	{
	writel(mask, GPIO_TO_REG(port, JZ_REG_GPIO_DIRECTION_CLEAR));

	return 0;
	}
	EXPORT_SYMBOL(jz_gpio_port_direction_input);

	int jz_gpio_port_direction_output(int port, uint32_t mask)
	{
	writel(mask, GPIO_TO_REG(port, JZ_REG_GPIO_DIRECTION_SET));

	return 0;
	}
	EXPORT_SYMBOL(jz_gpio_port_direction_output);

	void jz_gpio_port_set_value(int port, uint32_t value, uint32_t mask)
	{
	writel(~value & mask, GPIO_TO_REG(port, JZ_REG_GPIO_DATA_CLEAR));
	writel(value & mask, GPIO_TO_REG(port, JZ_REG_GPIO_DATA_SET));
	}
	EXPORT_SYMBOL(jz_gpio_port_set_value);

	uint32_t jz_gpio_port_get_value(int port, uint32_t mask)
	{
	uint32_t value = readl(GPIO_TO_REG(port, JZ_REG_GPIO_PIN));

	return value & mask;
	}
	EXPORT_SYMBOL(jz_gpio_port_get_value);

	int gpio_to_irq(unsigned gpio)
	{
	return JZ4740_IRQ_GPIO(0) + gpio;
	}
	EXPORT_SYMBOL_GPL(gpio_to_irq);

	int irq_to_gpio(unsigned irq)
	{
	return irq - JZ4740_IRQ_GPIO(0);
	}
	EXPORT_SYMBOL_GPL(irq_to_gpio);

	#define IRQ_TO_BIT(irq) BIT(irq_to_gpio(irq) & 0x1f)

	static void jz_gpio_check_trigger_both(struct jz_gpio_chip *chip, unsigned int irq)
	{
	uint32_t value;
	void __iomem *reg;
	uint32_t mask = IRQ_TO_BIT(irq);

	if (!(chip->edge_trigger_both & mask))
	return;

	reg = chip->base;

	value = readl(chip->base + JZ_REG_GPIO_PIN);
	if (value & mask)
	reg += JZ_REG_GPIO_DIRECTION_CLEAR;
	else
	reg += JZ_REG_GPIO_DIRECTION_SET;

	writel(mask, reg);
	}

	static void jz_gpio_irq_demux_handler(unsigned int irq, struct irq_desc *desc)
	{
	uint32_t flag;
	unsigned int gpio_irq;
	unsigned int gpio_bank;
	struct jz_gpio_chip *chip = get_irq_desc_data(desc);

	gpio_bank = JZ4740_IRQ_GPIO0 - irq;

	flag = readl(chip->base + JZ_REG_GPIO_FLAG);

	if (!flag)
	return;

	gpio_irq = __fls(flag);

	jz_gpio_check_trigger_both(chip, irq);

	gpio_irq += (gpio_bank << 5) + JZ4740_IRQ_GPIO(0);

	generic_handle_irq(gpio_irq);
	};

	static inline void jz_gpio_set_irq_bit(unsigned int irq, unsigned int reg)
	{
	struct jz_gpio_chip *chip = irq_to_jz_gpio_chip(irq);
	writel(IRQ_TO_BIT(irq), chip->base + reg);
	}

	static void jz_gpio_irq_mask(unsigned int irq)
	{
	jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_MASK_SET);
	};

	static void jz_gpio_irq_unmask(unsigned int irq)
	{
	struct jz_gpio_chip *chip = irq_to_jz_gpio_chip(irq);

	jz_gpio_check_trigger_both(chip, irq);

	jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_MASK_CLEAR);
	};

	/* TODO: Check if function is gpio */
	static unsigned int jz_gpio_irq_startup(unsigned int irq)
	{
	struct irq_desc *desc = irq_to_desc(irq);

	jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_SELECT_SET);

	desc->status &= ~IRQ_MASKED;
	jz_gpio_irq_unmask(irq);

	return 0;
	}

	static void jz_gpio_irq_shutdown(unsigned int irq)
	{
	struct irq_desc *desc = irq_to_desc(irq);

	jz_gpio_irq_mask(irq);
	desc->status \|= IRQ_MASKED;

	/* Set direction to input */
	jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_DIRECTION_CLEAR);
	jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_SELECT_CLEAR);
	}

	static void jz_gpio_irq_ack(unsigned int irq)
	{
	jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_FLAG_CLEAR);
	};

	static int jz_gpio_irq_set_type(unsigned int irq, unsigned int flow_type)
	{
	struct jz_gpio_chip *chip = irq_to_jz_gpio_chip(irq);
	struct irq_desc *desc = irq_to_desc(irq);

	jz_gpio_irq_mask(irq);

	if (flow_type == IRQ_TYPE_EDGE_BOTH) {
	uint32_t value = readl(chip->base + JZ_REG_GPIO_PIN);
	if (value & IRQ_TO_BIT(irq))
	flow_type = IRQ_TYPE_EDGE_FALLING;
	else
	flow_type = IRQ_TYPE_EDGE_RISING;
	chip->edge_trigger_both \|= IRQ_TO_BIT(irq);
	} else {
	chip->edge_trigger_both &= ~IRQ_TO_BIT(irq);
	}

	switch (flow_type) {
	case IRQ_TYPE_EDGE_RISING:
	jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_DIRECTION_SET);
	jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_TRIGGER_SET);
	break;
	case IRQ_TYPE_EDGE_FALLING:
	jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_DIRECTION_CLEAR);
	jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_TRIGGER_SET);
	break;
	case IRQ_TYPE_LEVEL_HIGH:
	jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_DIRECTION_SET);
	jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_TRIGGER_CLEAR);
	break;
	case IRQ_TYPE_LEVEL_LOW:
	jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_DIRECTION_CLEAR);
	jz_gpio_set_irq_bit(irq, JZ_REG_GPIO_TRIGGER_CLEAR);
	break;
	default:
	return -EINVAL;
	}

	if (!(desc->status & IRQ_MASKED))
	jz_gpio_irq_unmask(irq);

	return 0;
	}

	static int jz_gpio_irq_set_wake(unsigned int irq, unsigned int on)
	{
	struct jz_gpio_chip *chip = irq_to_jz_gpio_chip(irq);
	spin_lock(&chip->lock);
	if (on)
	chip->wakeup \|= IRQ_TO_BIT(irq);
	else
	chip->wakeup &= ~IRQ_TO_BIT(irq);
	spin_unlock(&chip->lock);

	set_irq_wake(chip->irq, on);
	return 0;
	}

	/*
	* This lock class tells lockdep that GPIO irqs are in a different
	* category than their parents, so it won't report false recursion.
	*/
	static struct lock_class_key gpio_lock_class;

	#define JZ4740_GPIO_CHIP(_bank) { \
	.irq_base = JZ4740_IRQ_GPIO_BASE_ ## _bank, \
	.gpio_chip = { \
	.label = "Bank " # _bank, \
	.owner = THIS_MODULE, \
	.set = jz_gpio_set_value, \
	.get = jz_gpio_get_value, \
	.direction_output = jz_gpio_direction_output, \
	.direction_input = jz_gpio_direction_input, \
	.base = JZ4740_GPIO_BASE_ ## _bank, \
	.ngpio = JZ4740_GPIO_NUM_ ## _bank, \
	}, \
	.irq_chip = { \
	.name = "GPIO Bank " # _bank, \
	.mask = jz_gpio_irq_mask, \
	.unmask = jz_gpio_irq_unmask, \
	.ack = jz_gpio_irq_ack, \
	.startup = jz_gpio_irq_startup, \
	.shutdown = jz_gpio_irq_shutdown, \
	.set_type = jz_gpio_irq_set_type, \
	.set_wake = jz_gpio_irq_set_wake, \
	}, \
	}

	static struct jz_gpio_chip jz4740_gpio_chips[] = {
	JZ4740_GPIO_CHIP(A),
	JZ4740_GPIO_CHIP(B),
	JZ4740_GPIO_CHIP(C),
	JZ4740_GPIO_CHIP(D),
	};

	static inline struct jz_gpio_chip sysdev_to_chip(struct sys_device dev)
	{
	return container_of(dev, struct jz_gpio_chip, sysdev);
	}

	static int jz4740_gpio_suspend(struct sys_device *dev, pm_message_t state)
	{
	struct jz_gpio_chip *chip = sysdev_to_chip(dev);

	chip->suspend_mask = readl(chip->base + JZ_REG_GPIO_MASK);
	writel(~(chip->wakeup), chip->base + JZ_REG_GPIO_MASK_SET);
	writel(chip->wakeup, chip->base + JZ_REG_GPIO_MASK_CLEAR);

	return 0;
	}

	static int jz4740_gpio_resume(struct sys_device *dev)
	{
	struct jz_gpio_chip *chip = sysdev_to_chip(dev);
	uint32_t mask = chip->suspend_mask;

	writel(~mask, chip->base + JZ_REG_GPIO_MASK_CLEAR);
	writel(mask, chip->base + JZ_REG_GPIO_MASK_SET);

	return 0;
	}

	static struct sysdev_class jz4740_gpio_sysdev_class = {
	.name = "gpio",
	.suspend = jz4740_gpio_suspend,
	.resume = jz4740_gpio_resume,
	};

	static int jz4740_gpio_chip_init(struct jz_gpio_chip *chip, unsigned int id)
	{
	int ret, irq;

	chip->sysdev.id = id;
	chip->sysdev.cls = &jz4740_gpio_sysdev_class;
	ret = sysdev_register(&chip->sysdev);

	if (ret)
	return ret;

	spin_lock_init(&chip->lock);

	chip->base = ioremap(JZ4740_GPIO_BASE_ADDR + (id * 0x100), 0x100);

	gpiochip_add(&chip->gpio_chip);

	chip->irq = JZ4740_IRQ_INTC_GPIO(id);
	set_irq_data(chip->irq, chip);
	set_irq_chained_handler(chip->irq, jz_gpio_irq_demux_handler);

	for (irq = chip->irq_base; irq < chip->irq_base + chip->gpio_chip.ngpio; ++irq) {
	lockdep_set_class(&irq_desc[irq].lock, &gpio_lock_class);
	set_irq_chip_data(irq, chip);
	set_irq_chip_and_handler(irq, &chip->irq_chip, handle_level_irq);
	}

	return 0;
	}

	static int __init jz4740_gpio_init(void)
	{
	unsigned int i;
	int ret;

	ret = sysdev_class_register(&jz4740_gpio_sysdev_class);
	if (ret)
	return ret;

	for (i = 0; i < ARRAY_SIZE(jz4740_gpio_chips); ++i)
	jz4740_gpio_chip_init(&jz4740_gpio_chips[i], i);

	printk(KERN_INFO "JZ4740 GPIO initalized\n");

	return 0;
	}
	arch_initcall(jz4740_gpio_init);

	#ifdef CONFIG_DEBUG_FS

	static inline void gpio_seq_reg(struct seq_file s, struct jz_gpio_chip chip,
	const char *name, unsigned int reg)
	{
	seq_printf(s, "\t%s: %08x\n", name, readl(chip->base + reg));
	}

	static int gpio_regs_show(struct seq_file s, void unused)
	{
	struct jz_gpio_chip *chip = jz4740_gpio_chips;
	int i;

	for (i = 0; i < ARRAY_SIZE(jz4740_gpio_chips); ++i, ++chip) {
	seq_printf(s, "==GPIO %d==\n", i);
	gpio_seq_reg(s, chip, "Pin", JZ_REG_GPIO_PIN);
	gpio_seq_reg(s, chip, "Data", JZ_REG_GPIO_DATA);
	gpio_seq_reg(s, chip, "Mask", JZ_REG_GPIO_MASK);
	gpio_seq_reg(s, chip, "Pull", JZ_REG_GPIO_PULL);
	gpio_seq_reg(s, chip, "Func", JZ_REG_GPIO_FUNC);
	gpio_seq_reg(s, chip, "Select", JZ_REG_GPIO_SELECT);
	gpio_seq_reg(s, chip, "Direction", JZ_REG_GPIO_DIRECTION);
	gpio_seq_reg(s, chip, "Trigger", JZ_REG_GPIO_TRIGGER);
	gpio_seq_reg(s, chip, "Flag", JZ_REG_GPIO_FLAG);
	}

	return 0;
	}

	static int gpio_regs_open(struct inode inode, struct file file)
	{
	return single_open(file, gpio_regs_show, NULL);
	}

	static const struct file_operations gpio_regs_operations = {
	.open = gpio_regs_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
	};

	static int __init gpio_debugfs_init(void)
	{
	(void) debugfs_create_file("jz_regs_gpio", S_IFREG \| S_IRUGO,
	NULL, NULL, &gpio_regs_operations);
	return 0;
	}
	subsys_initcall(gpio_debugfs_init);

	#endif