drivers/gpio/gpio-mpc8xxx.c - kernel/common - Git at Google

 /*
  * GPIOs on MPC512x/8349/8572/8610 and compatible
  *
  * Copyright (C) 2008 Peter Korsgaard <[email protected]>
  *
  * This file is licensed under the terms of the GNU General Public License
  * version 2.  This program is licensed "as is" without any warranty of any
  * kind, whether express or implied.
  */

 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/spinlock.h>
 #include <linux/io.h>
 #include <linux/of.h>
 #include <linux/of_gpio.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
 #include <linux/gpio.h>
 #include <linux/slab.h>
 #include <linux/irq.h>

 #define MPC8XXX_GPIO_PINS	32

 #define GPIO_DIR		0x00
 #define GPIO_ODR		0x04
 #define GPIO_DAT		0x08
 #define GPIO_IER		0x0c
 #define GPIO_IMR		0x10
 #define GPIO_ICR		0x14
 #define GPIO_ICR2		0x18

 struct mpc8xxx_gpio_chip {
 	struct of_mm_gpio_chip mm_gc;
 	spinlock_t lock;

 	/*
 	 * shadowed data register to be able to clear/set output pins in
 	 * open drain mode safely
 	 */
 	u32 data;
 	struct irq_domain *irq;
 	unsigned int irqn;
 	const void *of_dev_id_data;
 };

 static inline u32 mpc8xxx_gpio2mask(unsigned int gpio)
 {
 	return 1u << (MPC8XXX_GPIO_PINS - 1 - gpio);
 }

 static inline struct mpc8xxx_gpio_chip *
 to_mpc8xxx_gpio_chip(struct of_mm_gpio_chip *mm)
 {
 	return container_of(mm, struct mpc8xxx_gpio_chip, mm_gc);
 }

 static void mpc8xxx_gpio_save_regs(struct of_mm_gpio_chip *mm)
 {
 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);

 	mpc8xxx_gc->data = in_be32(mm->regs + GPIO_DAT);
 }

 /* Workaround GPIO 1 errata on MPC8572/MPC8536. The status of GPIOs
  * defined as output cannot be determined by reading GPDAT register,
  * so we use shadow data register instead. The status of input pins
  * is determined by reading GPDAT register.
  */
 static int mpc8572_gpio_get(struct gpio_chip *gc, unsigned int gpio)
 {
 	u32 val;
 	struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
 	u32 out_mask, out_shadow;

 	out_mask = in_be32(mm->regs + GPIO_DIR);

 	val = in_be32(mm->regs + GPIO_DAT) & ~out_mask;
 	out_shadow = mpc8xxx_gc->data & out_mask;

 	return (val | out_shadow) & mpc8xxx_gpio2mask(gpio);
 }

 static int mpc8xxx_gpio_get(struct gpio_chip *gc, unsigned int gpio)
 {
 	struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);

 	return in_be32(mm->regs + GPIO_DAT) & mpc8xxx_gpio2mask(gpio);
 }

 static void mpc8xxx_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
 {
 	struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
 	unsigned long flags;

 	spin_lock_irqsave(&mpc8xxx_gc->lock, flags);

 	if (val)
 		mpc8xxx_gc->data |= mpc8xxx_gpio2mask(gpio);
 	else
 		mpc8xxx_gc->data &= ~mpc8xxx_gpio2mask(gpio);

 	out_be32(mm->regs + GPIO_DAT, mpc8xxx_gc->data);

 	spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
 }

 static void mpc8xxx_gpio_set_multiple(struct gpio_chip *gc,
 				      unsigned long *mask, unsigned long *bits)
 {
 	struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
 	unsigned long flags;
 	int i;

 	spin_lock_irqsave(&mpc8xxx_gc->lock, flags);

 	for (i = 0; i < gc->ngpio; i++) {
 		if (*mask == 0)
 			break;
 		if (__test_and_clear_bit(i, mask)) {
 			if (test_bit(i, bits))
 				mpc8xxx_gc->data |= mpc8xxx_gpio2mask(i);
 			else
 				mpc8xxx_gc->data &= ~mpc8xxx_gpio2mask(i);
 		}
 	}

 	out_be32(mm->regs + GPIO_DAT, mpc8xxx_gc->data);

 	spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
 }

 static int mpc8xxx_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
 {
 	struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
 	unsigned long flags;

 	spin_lock_irqsave(&mpc8xxx_gc->lock, flags);

 	clrbits32(mm->regs + GPIO_DIR, mpc8xxx_gpio2mask(gpio));

 	spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);

 	return 0;
 }

 static int mpc8xxx_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
 {
 	struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
 	unsigned long flags;

 	mpc8xxx_gpio_set(gc, gpio, val);

 	spin_lock_irqsave(&mpc8xxx_gc->lock, flags);

 	setbits32(mm->regs + GPIO_DIR, mpc8xxx_gpio2mask(gpio));

 	spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);

 	return 0;
 }

 static int mpc5121_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
 {
 	/* GPIO 28..31 are input only on MPC5121 */
 	if (gpio >= 28)
 		return -EINVAL;

 	return mpc8xxx_gpio_dir_out(gc, gpio, val);
 }

 static int mpc8xxx_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
 {
 	struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);

 	if (mpc8xxx_gc->irq && offset < MPC8XXX_GPIO_PINS)
 		return irq_create_mapping(mpc8xxx_gc->irq, offset);
 	else
 		return -ENXIO;
 }

 static void mpc8xxx_gpio_irq_cascade(unsigned int irq, struct irq_desc *desc)
 {
 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_desc_get_handler_data(desc);
 	struct irq_chip *chip = irq_desc_get_chip(desc);
 	struct of_mm_gpio_chip *mm = &mpc8xxx_gc->mm_gc;
 	unsigned int mask;

 	mask = in_be32(mm->regs + GPIO_IER) & in_be32(mm->regs + GPIO_IMR);
 	if (mask)
 		generic_handle_irq(irq_linear_revmap(mpc8xxx_gc->irq,
 						     32 - ffs(mask)));
 	if (chip->irq_eoi)
 		chip->irq_eoi(&desc->irq_data);
 }

 static void mpc8xxx_irq_unmask(struct irq_data *d)
 {
 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
 	struct of_mm_gpio_chip *mm = &mpc8xxx_gc->mm_gc;
 	unsigned long flags;

 	spin_lock_irqsave(&mpc8xxx_gc->lock, flags);

 	setbits32(mm->regs + GPIO_IMR, mpc8xxx_gpio2mask(irqd_to_hwirq(d)));

 	spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
 }

 static void mpc8xxx_irq_mask(struct irq_data *d)
 {
 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
 	struct of_mm_gpio_chip *mm = &mpc8xxx_gc->mm_gc;
 	unsigned long flags;

 	spin_lock_irqsave(&mpc8xxx_gc->lock, flags);

 	clrbits32(mm->regs + GPIO_IMR, mpc8xxx_gpio2mask(irqd_to_hwirq(d)));

 	spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
 }

 static void mpc8xxx_irq_ack(struct irq_data *d)
 {
 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
 	struct of_mm_gpio_chip *mm = &mpc8xxx_gc->mm_gc;

 	out_be32(mm->regs + GPIO_IER, mpc8xxx_gpio2mask(irqd_to_hwirq(d)));
 }

 static int mpc8xxx_irq_set_type(struct irq_data *d, unsigned int flow_type)
 {
 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
 	struct of_mm_gpio_chip *mm = &mpc8xxx_gc->mm_gc;
 	unsigned long flags;

 	switch (flow_type) {
 	case IRQ_TYPE_EDGE_FALLING:
 		spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
 		setbits32(mm->regs + GPIO_ICR,
 			  mpc8xxx_gpio2mask(irqd_to_hwirq(d)));
 		spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
 		break;

 	case IRQ_TYPE_EDGE_BOTH:
 		spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
 		clrbits32(mm->regs + GPIO_ICR,
 			  mpc8xxx_gpio2mask(irqd_to_hwirq(d)));
 		spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
 		break;

 	default:
 		return -EINVAL;
 	}

 	return 0;
 }

 static int mpc512x_irq_set_type(struct irq_data *d, unsigned int flow_type)
 {
 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
 	struct of_mm_gpio_chip *mm = &mpc8xxx_gc->mm_gc;
 	unsigned long gpio = irqd_to_hwirq(d);
 	void __iomem *reg;
 	unsigned int shift;
 	unsigned long flags;

 	if (gpio < 16) {
 		reg = mm->regs + GPIO_ICR;
 		shift = (15 - gpio) * 2;
 	} else {
 		reg = mm->regs + GPIO_ICR2;
 		shift = (15 - (gpio % 16)) * 2;
 	}

 	switch (flow_type) {
 	case IRQ_TYPE_EDGE_FALLING:
 	case IRQ_TYPE_LEVEL_LOW:
 		spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
 		clrsetbits_be32(reg, 3 << shift, 2 << shift);
 		spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
 		break;

 	case IRQ_TYPE_EDGE_RISING:
 	case IRQ_TYPE_LEVEL_HIGH:
 		spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
 		clrsetbits_be32(reg, 3 << shift, 1 << shift);
 		spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
 		break;

 	case IRQ_TYPE_EDGE_BOTH:
 		spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
 		clrbits32(reg, 3 << shift);
 		spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
 		break;

 	default:
 		return -EINVAL;
 	}

 	return 0;
 }

 static struct irq_chip mpc8xxx_irq_chip = {
 	.name		= "mpc8xxx-gpio",
 	.irq_unmask	= mpc8xxx_irq_unmask,
 	.irq_mask	= mpc8xxx_irq_mask,
 	.irq_ack	= mpc8xxx_irq_ack,
 	.irq_set_type	= mpc8xxx_irq_set_type,
 };

 static int mpc8xxx_gpio_irq_map(struct irq_domain *h, unsigned int irq,
 				irq_hw_number_t hwirq)
 {
 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = h->host_data;

 	if (mpc8xxx_gc->of_dev_id_data)
 		mpc8xxx_irq_chip.irq_set_type = mpc8xxx_gc->of_dev_id_data;

 	irq_set_chip_data(irq, h->host_data);
 	irq_set_chip_and_handler(irq, &mpc8xxx_irq_chip, handle_level_irq);

 	return 0;
 }

 static struct irq_domain_ops mpc8xxx_gpio_irq_ops = {
 	.map	= mpc8xxx_gpio_irq_map,
 	.xlate	= irq_domain_xlate_twocell,
 };

 static struct of_device_id mpc8xxx_gpio_ids[] = {
 	{ .compatible = "fsl,mpc8349-gpio", },
 	{ .compatible = "fsl,mpc8572-gpio", },
 	{ .compatible = "fsl,mpc8610-gpio", },
 	{ .compatible = "fsl,mpc5121-gpio", .data = mpc512x_irq_set_type, },
 	{ .compatible = "fsl,pq3-gpio",     },
 	{ .compatible = "fsl,qoriq-gpio",   },
 	{}
 };

 static int mpc8xxx_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
 	struct mpc8xxx_gpio_chip *mpc8xxx_gc;
 	struct of_mm_gpio_chip *mm_gc;
 	struct gpio_chip *gc;
 	const struct of_device_id *id;
 	int ret;

 	mpc8xxx_gc = devm_kzalloc(&pdev->dev, sizeof(*mpc8xxx_gc), GFP_KERNEL);
 	if (!mpc8xxx_gc)
 		return -ENOMEM;

 	platform_set_drvdata(pdev, mpc8xxx_gc);

 	spin_lock_init(&mpc8xxx_gc->lock);

 	mm_gc = &mpc8xxx_gc->mm_gc;
 	gc = &mm_gc->gc;

 	mm_gc->save_regs = mpc8xxx_gpio_save_regs;
 	gc->ngpio = MPC8XXX_GPIO_PINS;
 	gc->direction_input = mpc8xxx_gpio_dir_in;
 	gc->direction_output = of_device_is_compatible(np, "fsl,mpc5121-gpio") ?
 		mpc5121_gpio_dir_out : mpc8xxx_gpio_dir_out;
 	gc->get = of_device_is_compatible(np, "fsl,mpc8572-gpio") ?
 		mpc8572_gpio_get : mpc8xxx_gpio_get;
 	gc->set = mpc8xxx_gpio_set;
 	gc->set_multiple = mpc8xxx_gpio_set_multiple;
 	gc->to_irq = mpc8xxx_gpio_to_irq;

 	ret = of_mm_gpiochip_add(np, mm_gc);
 	if (ret)
 		return ret;

 	mpc8xxx_gc->irqn = irq_of_parse_and_map(np, 0);
 	if (mpc8xxx_gc->irqn == NO_IRQ)
 		return 0;

 	mpc8xxx_gc->irq = irq_domain_add_linear(np, MPC8XXX_GPIO_PINS,
 					&mpc8xxx_gpio_irq_ops, mpc8xxx_gc);
 	if (!mpc8xxx_gc->irq)
 		return 0;

 	id = of_match_node(mpc8xxx_gpio_ids, np);
 	if (id)
 		mpc8xxx_gc->of_dev_id_data = id->data;

 	/* ack and mask all irqs */
 	out_be32(mm_gc->regs + GPIO_IER, 0xffffffff);
 	out_be32(mm_gc->regs + GPIO_IMR, 0);

 	irq_set_handler_data(mpc8xxx_gc->irqn, mpc8xxx_gc);
 	irq_set_chained_handler(mpc8xxx_gc->irqn, mpc8xxx_gpio_irq_cascade);

 	return 0;
 }

 static int mpc8xxx_remove(struct platform_device *pdev)
 {
 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = platform_get_drvdata(pdev);

 	if (mpc8xxx_gc->irq) {
 		irq_set_handler_data(mpc8xxx_gc->irqn, NULL);
 		irq_set_chained_handler(mpc8xxx_gc->irqn, NULL);
 		irq_domain_remove(mpc8xxx_gc->irq);
 	}

 	of_mm_gpiochip_remove(&mpc8xxx_gc->mm_gc);

 	return 0;
 }

 static struct platform_driver mpc8xxx_plat_driver = {
 	.probe		= mpc8xxx_probe,
 	.remove		= mpc8xxx_remove,
 	.driver		= {
 		.name = "gpio-mpc8xxx",
 		.of_match_table	= mpc8xxx_gpio_ids,
 	},
 };

 static int __init mpc8xxx_init(void)
 {
 	return platform_driver_register(&mpc8xxx_plat_driver);
 }

 arch_initcall(mpc8xxx_init);
	/*
	* GPIOs on MPC512x/8349/8572/8610 and compatible
	*
	* Copyright (C) 2008 Peter Korsgaard <[email protected]>
	*
	* This file is licensed under the terms of the GNU General Public License
	* version 2. This program is licensed "as is" without any warranty of any
	* kind, whether express or implied.
	*/

	#include <linux/kernel.h>
	#include <linux/init.h>
	#include <linux/spinlock.h>
	#include <linux/io.h>
	#include <linux/of.h>
	#include <linux/of_gpio.h>
	#include <linux/of_irq.h>
	#include <linux/of_platform.h>
	#include <linux/gpio.h>
	#include <linux/slab.h>
	#include <linux/irq.h>

	#define MPC8XXX_GPIO_PINS 32

	#define GPIO_DIR 0x00
	#define GPIO_ODR 0x04
	#define GPIO_DAT 0x08
	#define GPIO_IER 0x0c
	#define GPIO_IMR 0x10
	#define GPIO_ICR 0x14
	#define GPIO_ICR2 0x18

	struct mpc8xxx_gpio_chip {
	struct of_mm_gpio_chip mm_gc;
	spinlock_t lock;

	/*
	* shadowed data register to be able to clear/set output pins in
	* open drain mode safely
	*/
	u32 data;
	struct irq_domain *irq;
	unsigned int irqn;
	const void *of_dev_id_data;
	};

	static inline u32 mpc8xxx_gpio2mask(unsigned int gpio)
	{
	return 1u << (MPC8XXX_GPIO_PINS - 1 - gpio);
	}

	static inline struct mpc8xxx_gpio_chip *
	to_mpc8xxx_gpio_chip(struct of_mm_gpio_chip *mm)
	{
	return container_of(mm, struct mpc8xxx_gpio_chip, mm_gc);
	}

	static void mpc8xxx_gpio_save_regs(struct of_mm_gpio_chip *mm)
	{
	struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);

	mpc8xxx_gc->data = in_be32(mm->regs + GPIO_DAT);
	}

	/* Workaround GPIO 1 errata on MPC8572/MPC8536. The status of GPIOs
	* defined as output cannot be determined by reading GPDAT register,
	* so we use shadow data register instead. The status of input pins
	* is determined by reading GPDAT register.
	*/
	static int mpc8572_gpio_get(struct gpio_chip *gc, unsigned int gpio)
	{
	u32 val;
	struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
	struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
	u32 out_mask, out_shadow;

	out_mask = in_be32(mm->regs + GPIO_DIR);

	val = in_be32(mm->regs + GPIO_DAT) & ~out_mask;
	out_shadow = mpc8xxx_gc->data & out_mask;

	return (val \| out_shadow) & mpc8xxx_gpio2mask(gpio);
	}

	static int mpc8xxx_gpio_get(struct gpio_chip *gc, unsigned int gpio)
	{
	struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);

	return in_be32(mm->regs + GPIO_DAT) & mpc8xxx_gpio2mask(gpio);
	}

	static void mpc8xxx_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
	{
	struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
	struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
	unsigned long flags;

	spin_lock_irqsave(&mpc8xxx_gc->lock, flags);

	if (val)
	mpc8xxx_gc->data \|= mpc8xxx_gpio2mask(gpio);
	else
	mpc8xxx_gc->data &= ~mpc8xxx_gpio2mask(gpio);

	out_be32(mm->regs + GPIO_DAT, mpc8xxx_gc->data);

	spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
	}

	static void mpc8xxx_gpio_set_multiple(struct gpio_chip *gc,
	unsigned long mask, unsigned long bits)
	{
	struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
	struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
	unsigned long flags;
	int i;

	spin_lock_irqsave(&mpc8xxx_gc->lock, flags);

	for (i = 0; i < gc->ngpio; i++) {
	if (*mask == 0)
	break;
	if (__test_and_clear_bit(i, mask)) {
	if (test_bit(i, bits))
	mpc8xxx_gc->data \|= mpc8xxx_gpio2mask(i);
	else
	mpc8xxx_gc->data &= ~mpc8xxx_gpio2mask(i);
	}
	}

	out_be32(mm->regs + GPIO_DAT, mpc8xxx_gc->data);

	spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
	}

	static int mpc8xxx_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
	{
	struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
	struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
	unsigned long flags;

	spin_lock_irqsave(&mpc8xxx_gc->lock, flags);

	clrbits32(mm->regs + GPIO_DIR, mpc8xxx_gpio2mask(gpio));

	spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);

	return 0;
	}

	static int mpc8xxx_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
	{
	struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
	struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
	unsigned long flags;

	mpc8xxx_gpio_set(gc, gpio, val);

	spin_lock_irqsave(&mpc8xxx_gc->lock, flags);

	setbits32(mm->regs + GPIO_DIR, mpc8xxx_gpio2mask(gpio));

	spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);

	return 0;
	}

	static int mpc5121_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
	{
	/* GPIO 28..31 are input only on MPC5121 */
	if (gpio >= 28)
	return -EINVAL;

	return mpc8xxx_gpio_dir_out(gc, gpio, val);
	}

	static int mpc8xxx_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
	{
	struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
	struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);

	if (mpc8xxx_gc->irq && offset < MPC8XXX_GPIO_PINS)
	return irq_create_mapping(mpc8xxx_gc->irq, offset);
	else
	return -ENXIO;
	}

	static void mpc8xxx_gpio_irq_cascade(unsigned int irq, struct irq_desc *desc)
	{
	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_desc_get_handler_data(desc);
	struct irq_chip *chip = irq_desc_get_chip(desc);
	struct of_mm_gpio_chip *mm = &mpc8xxx_gc->mm_gc;
	unsigned int mask;

	mask = in_be32(mm->regs + GPIO_IER) & in_be32(mm->regs + GPIO_IMR);
	if (mask)
	generic_handle_irq(irq_linear_revmap(mpc8xxx_gc->irq,
	32 - ffs(mask)));
	if (chip->irq_eoi)
	chip->irq_eoi(&desc->irq_data);
	}

	static void mpc8xxx_irq_unmask(struct irq_data *d)
	{
	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
	struct of_mm_gpio_chip *mm = &mpc8xxx_gc->mm_gc;
	unsigned long flags;

	spin_lock_irqsave(&mpc8xxx_gc->lock, flags);

	setbits32(mm->regs + GPIO_IMR, mpc8xxx_gpio2mask(irqd_to_hwirq(d)));

	spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
	}

	static void mpc8xxx_irq_mask(struct irq_data *d)
	{
	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
	struct of_mm_gpio_chip *mm = &mpc8xxx_gc->mm_gc;
	unsigned long flags;

	spin_lock_irqsave(&mpc8xxx_gc->lock, flags);

	clrbits32(mm->regs + GPIO_IMR, mpc8xxx_gpio2mask(irqd_to_hwirq(d)));

	spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
	}

	static void mpc8xxx_irq_ack(struct irq_data *d)
	{
	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
	struct of_mm_gpio_chip *mm = &mpc8xxx_gc->mm_gc;

	out_be32(mm->regs + GPIO_IER, mpc8xxx_gpio2mask(irqd_to_hwirq(d)));
	}

	static int mpc8xxx_irq_set_type(struct irq_data *d, unsigned int flow_type)
	{
	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
	struct of_mm_gpio_chip *mm = &mpc8xxx_gc->mm_gc;
	unsigned long flags;

	switch (flow_type) {
	case IRQ_TYPE_EDGE_FALLING:
	spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
	setbits32(mm->regs + GPIO_ICR,
	mpc8xxx_gpio2mask(irqd_to_hwirq(d)));
	spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
	break;

	case IRQ_TYPE_EDGE_BOTH:
	spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
	clrbits32(mm->regs + GPIO_ICR,
	mpc8xxx_gpio2mask(irqd_to_hwirq(d)));
	spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
	break;

	default:
	return -EINVAL;
	}

	return 0;
	}

	static int mpc512x_irq_set_type(struct irq_data *d, unsigned int flow_type)
	{
	struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
	struct of_mm_gpio_chip *mm = &mpc8xxx_gc->mm_gc;
	unsigned long gpio = irqd_to_hwirq(d);
	void __iomem *reg;
	unsigned int shift;
	unsigned long flags;

	if (gpio < 16) {
	reg = mm->regs + GPIO_ICR;
	shift = (15 - gpio) * 2;
	} else {
	reg = mm->regs + GPIO_ICR2;
	shift = (15 - (gpio % 16)) * 2;
	}

	switch (flow_type) {
	case IRQ_TYPE_EDGE_FALLING:
	case IRQ_TYPE_LEVEL_LOW:
	spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
	clrsetbits_be32(reg, 3 << shift, 2 << shift);
	spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
	break;

	case IRQ_TYPE_EDGE_RISING:
	case IRQ_TYPE_LEVEL_HIGH:
	spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
	clrsetbits_be32(reg, 3 << shift, 1 << shift);
	spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
	break;

	case IRQ_TYPE_EDGE_BOTH:
	spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
	clrbits32(reg, 3 << shift);
	spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
	break;

	default:
	return -EINVAL;
	}

	return 0;
	}

	static struct irq_chip mpc8xxx_irq_chip = {
	.name = "mpc8xxx-gpio",
	.irq_unmask = mpc8xxx_irq_unmask,
	.irq_mask = mpc8xxx_irq_mask,
	.irq_ack = mpc8xxx_irq_ack,
	.irq_set_type = mpc8xxx_irq_set_type,
	};

	static int mpc8xxx_gpio_irq_map(struct irq_domain *h, unsigned int irq,
	irq_hw_number_t hwirq)
	{
	struct mpc8xxx_gpio_chip *mpc8xxx_gc = h->host_data;

	if (mpc8xxx_gc->of_dev_id_data)
	mpc8xxx_irq_chip.irq_set_type = mpc8xxx_gc->of_dev_id_data;

	irq_set_chip_data(irq, h->host_data);
	irq_set_chip_and_handler(irq, &mpc8xxx_irq_chip, handle_level_irq);

	return 0;
	}

	static struct irq_domain_ops mpc8xxx_gpio_irq_ops = {
	.map = mpc8xxx_gpio_irq_map,
	.xlate = irq_domain_xlate_twocell,
	};

	static struct of_device_id mpc8xxx_gpio_ids[] = {
	{ .compatible = "fsl,mpc8349-gpio", },
	{ .compatible = "fsl,mpc8572-gpio", },
	{ .compatible = "fsl,mpc8610-gpio", },
	{ .compatible = "fsl,mpc5121-gpio", .data = mpc512x_irq_set_type, },
	{ .compatible = "fsl,pq3-gpio", },
	{ .compatible = "fsl,qoriq-gpio", },
	{}
	};

	static int mpc8xxx_probe(struct platform_device *pdev)
	{
	struct device_node *np = pdev->dev.of_node;
	struct mpc8xxx_gpio_chip *mpc8xxx_gc;
	struct of_mm_gpio_chip *mm_gc;
	struct gpio_chip *gc;
	const struct of_device_id *id;
	int ret;

	mpc8xxx_gc = devm_kzalloc(&pdev->dev, sizeof(*mpc8xxx_gc), GFP_KERNEL);
	if (!mpc8xxx_gc)
	return -ENOMEM;

	platform_set_drvdata(pdev, mpc8xxx_gc);

	spin_lock_init(&mpc8xxx_gc->lock);

	mm_gc = &mpc8xxx_gc->mm_gc;
	gc = &mm_gc->gc;

	mm_gc->save_regs = mpc8xxx_gpio_save_regs;
	gc->ngpio = MPC8XXX_GPIO_PINS;
	gc->direction_input = mpc8xxx_gpio_dir_in;
	gc->direction_output = of_device_is_compatible(np, "fsl,mpc5121-gpio") ?
	mpc5121_gpio_dir_out : mpc8xxx_gpio_dir_out;
	gc->get = of_device_is_compatible(np, "fsl,mpc8572-gpio") ?
	mpc8572_gpio_get : mpc8xxx_gpio_get;
	gc->set = mpc8xxx_gpio_set;
	gc->set_multiple = mpc8xxx_gpio_set_multiple;
	gc->to_irq = mpc8xxx_gpio_to_irq;

	ret = of_mm_gpiochip_add(np, mm_gc);
	if (ret)
	return ret;

	mpc8xxx_gc->irqn = irq_of_parse_and_map(np, 0);
	if (mpc8xxx_gc->irqn == NO_IRQ)
	return 0;

	mpc8xxx_gc->irq = irq_domain_add_linear(np, MPC8XXX_GPIO_PINS,
	&mpc8xxx_gpio_irq_ops, mpc8xxx_gc);
	if (!mpc8xxx_gc->irq)
	return 0;

	id = of_match_node(mpc8xxx_gpio_ids, np);
	if (id)
	mpc8xxx_gc->of_dev_id_data = id->data;

	/* ack and mask all irqs */
	out_be32(mm_gc->regs + GPIO_IER, 0xffffffff);
	out_be32(mm_gc->regs + GPIO_IMR, 0);

	irq_set_handler_data(mpc8xxx_gc->irqn, mpc8xxx_gc);
	irq_set_chained_handler(mpc8xxx_gc->irqn, mpc8xxx_gpio_irq_cascade);

	return 0;
	}

	static int mpc8xxx_remove(struct platform_device *pdev)
	{
	struct mpc8xxx_gpio_chip *mpc8xxx_gc = platform_get_drvdata(pdev);

	if (mpc8xxx_gc->irq) {
	irq_set_handler_data(mpc8xxx_gc->irqn, NULL);
	irq_set_chained_handler(mpc8xxx_gc->irqn, NULL);
	irq_domain_remove(mpc8xxx_gc->irq);
	}

	of_mm_gpiochip_remove(&mpc8xxx_gc->mm_gc);

	return 0;
	}

	static struct platform_driver mpc8xxx_plat_driver = {
	.probe = mpc8xxx_probe,
	.remove = mpc8xxx_remove,
	.driver = {
	.name = "gpio-mpc8xxx",
	.of_match_table = mpc8xxx_gpio_ids,
	},
	};

	static int __init mpc8xxx_init(void)
	{
	return platform_driver_register(&mpc8xxx_plat_driver);
	}

	arch_initcall(mpc8xxx_init);