drivers/gpio/gpio-mpc8xxx.c - linux - Git at Google

 /*
  * GPIOs on MPC512x/8349/8572/8610/QorIQ and compatible
  *
  * Copyright (C) 2008 Peter Korsgaard <jacmet@sunsite.dk>
  * Copyright (C) 2016 Freescale Semiconductor Inc.
  *
  * 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_address.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
 #include <linux/slab.h>
 #include <linux/irq.h>
 #include <linux/gpio/driver.h>
 #include <linux/bitops.h>
 #include <linux/interrupt.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
 #define GPIO_IBE		0x18

 struct mpc8xxx_gpio_chip {
 	struct gpio_chip	gc;
 	void __iomem *regs;
 	raw_spinlock_t lock;

 	int (*direction_output)(struct gpio_chip *chip,
 				unsigned offset, int value);

 	struct irq_domain *irq;
 	unsigned int irqn;
 };

 /* The GPIO Input Buffer Enable register(GPIO_IBE) is used to
  * control the input enable of each individual GPIO port.
  * When an individual GPIO port’s direction is set to
  * input (GPIO_GPDIR[DRn=0]), the associated input enable must be
  * set (GPIOxGPIE[IEn]=1) to propagate the port value to the GPIO
  * Data Register.
  */
 static int ls1028a_gpio_dir_in_init(struct gpio_chip *gc)
 {
 	unsigned long flags;
 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);

 	spin_lock_irqsave(&gc->bgpio_lock, flags);

 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IBE, 0xffffffff);

 	spin_unlock_irqrestore(&gc->bgpio_lock, flags);

 	return 0;
 }

 /*
  * This hardware has a big endian bit assignment such that GPIO line 0 is
  * connected to bit 31, line 1 to bit 30 ... line 31 to bit 0.
  * This inline helper give the right bitmask for a certain line.
  */
 static inline u32 mpc_pin2mask(unsigned int offset)
 {
 	return BIT(31 - offset);
 }

 /* 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 mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
 	u32 out_mask, out_shadow;

 	out_mask = gc->read_reg(mpc8xxx_gc->regs + GPIO_DIR);
 	val = gc->read_reg(mpc8xxx_gc->regs + GPIO_DAT) & ~out_mask;
 	out_shadow = gc->bgpio_data & out_mask;

 	return !!((val | out_shadow) & mpc_pin2mask(gpio));
 }

 static int mpc5121_gpio_dir_out(struct gpio_chip *gc,
 				unsigned int gpio, int val)
 {
 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
 	/* GPIO 28..31 are input only on MPC5121 */
 	if (gpio >= 28)
 		return -EINVAL;

 	return mpc8xxx_gc->direction_output(gc, gpio, val);
 }

 static int mpc5125_gpio_dir_out(struct gpio_chip *gc,
 				unsigned int gpio, int val)
 {
 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
 	/* GPIO 0..3 are input only on MPC5125 */
 	if (gpio <= 3)
 		return -EINVAL;

 	return mpc8xxx_gc->direction_output(gc, gpio, val);
 }

 static int mpc8xxx_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
 {
 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);

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

 static irqreturn_t mpc8xxx_gpio_irq_cascade(int irq, void *data)
 {
 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = data;
 	struct gpio_chip *gc = &mpc8xxx_gc->gc;
 	unsigned long mask;
 	int i;

 	mask = gc->read_reg(mpc8xxx_gc->regs + GPIO_IER)
 		& gc->read_reg(mpc8xxx_gc->regs + GPIO_IMR);
 	for_each_set_bit(i, &mask, 32)
 		generic_handle_irq(irq_linear_revmap(mpc8xxx_gc->irq, 31 - i));

 	return IRQ_HANDLED;
 }

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

 	raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);

 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IMR,
 		gc->read_reg(mpc8xxx_gc->regs + GPIO_IMR)
 		| mpc_pin2mask(irqd_to_hwirq(d)));

 	raw_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 gpio_chip *gc = &mpc8xxx_gc->gc;
 	unsigned long flags;

 	raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);

 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IMR,
 		gc->read_reg(mpc8xxx_gc->regs + GPIO_IMR)
 		& ~mpc_pin2mask(irqd_to_hwirq(d)));

 	raw_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 gpio_chip *gc = &mpc8xxx_gc->gc;

 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IER,
 		      mpc_pin2mask(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 gpio_chip *gc = &mpc8xxx_gc->gc;
 	unsigned long flags;

 	switch (flow_type) {
 	case IRQ_TYPE_EDGE_FALLING:
 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
 		gc->write_reg(mpc8xxx_gc->regs + GPIO_ICR,
 			gc->read_reg(mpc8xxx_gc->regs + GPIO_ICR)
 			| mpc_pin2mask(irqd_to_hwirq(d)));
 		raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
 		break;

 	case IRQ_TYPE_EDGE_BOTH:
 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
 		gc->write_reg(mpc8xxx_gc->regs + GPIO_ICR,
 			gc->read_reg(mpc8xxx_gc->regs + GPIO_ICR)
 			& ~mpc_pin2mask(irqd_to_hwirq(d)));
 		raw_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 gpio_chip *gc = &mpc8xxx_gc->gc;
 	unsigned long gpio = irqd_to_hwirq(d);
 	void __iomem *reg;
 	unsigned int shift;
 	unsigned long flags;

 	if (gpio < 16) {
 		reg = mpc8xxx_gc->regs + GPIO_ICR;
 		shift = (15 - gpio) * 2;
 	} else {
 		reg = mpc8xxx_gc->regs + GPIO_ICR2;
 		shift = (15 - (gpio % 16)) * 2;
 	}

 	switch (flow_type) {
 	case IRQ_TYPE_EDGE_FALLING:
 	case IRQ_TYPE_LEVEL_LOW:
 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
 		gc->write_reg(reg, (gc->read_reg(reg) & ~(3 << shift))
 			| (2 << shift));
 		raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
 		break;

 	case IRQ_TYPE_EDGE_RISING:
 	case IRQ_TYPE_LEVEL_HIGH:
 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
 		gc->write_reg(reg, (gc->read_reg(reg) & ~(3 << shift))
 			| (1 << shift));
 		raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
 		break;

 	case IRQ_TYPE_EDGE_BOTH:
 		raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
 		gc->write_reg(reg, (gc->read_reg(reg) & ~(3 << shift)));
 		raw_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,
 	/* this might get overwritten in mpc8xxx_probe() */
 	.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)
 {
 	irq_set_chip_data(irq, h->host_data);
 	irq_set_chip_and_handler(irq, &mpc8xxx_irq_chip, handle_edge_irq);

 	return 0;
 }

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

 struct mpc8xxx_gpio_devtype {
 	int (*gpio_dir_in_init)(struct gpio_chip *chip);
 	int (*gpio_dir_out)(struct gpio_chip *, unsigned int, int);
 	int (*gpio_get)(struct gpio_chip *, unsigned int);
 	int (*irq_set_type)(struct irq_data *, unsigned int);
 };

 static const struct mpc8xxx_gpio_devtype mpc512x_gpio_devtype = {
 	.gpio_dir_out = mpc5121_gpio_dir_out,
 	.irq_set_type = mpc512x_irq_set_type,
 };

 static const struct mpc8xxx_gpio_devtype ls1028a_gpio_devtype = {
 	.gpio_dir_in_init = ls1028a_gpio_dir_in_init,
 	.irq_set_type = mpc8xxx_irq_set_type,
 };

 static const struct mpc8xxx_gpio_devtype mpc5125_gpio_devtype = {
 	.gpio_dir_out = mpc5125_gpio_dir_out,
 	.irq_set_type = mpc512x_irq_set_type,
 };

 static const struct mpc8xxx_gpio_devtype mpc8572_gpio_devtype = {
 	.gpio_get = mpc8572_gpio_get,
 };

 static const struct mpc8xxx_gpio_devtype mpc8xxx_gpio_devtype_default = {
 	.irq_set_type = mpc8xxx_irq_set_type,
 };

 static const struct of_device_id mpc8xxx_gpio_ids[] = {
 	{ .compatible = "fsl,mpc8349-gpio", },
 	{ .compatible = "fsl,mpc8572-gpio", .data = &mpc8572_gpio_devtype, },
 	{ .compatible = "fsl,mpc8610-gpio", },
 	{ .compatible = "fsl,mpc5121-gpio", .data = &mpc512x_gpio_devtype, },
 	{ .compatible = "fsl,mpc5125-gpio", .data = &mpc5125_gpio_devtype, },
 	{ .compatible = "fsl,pq3-gpio",     },
 	{ .compatible = "fsl,ls1028a-gpio", .data = &ls1028a_gpio_devtype, },
 	{ .compatible = "fsl,ls1088a-gpio", .data = &ls1028a_gpio_devtype, },
 	{ .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 gpio_chip	*gc;
 	const struct mpc8xxx_gpio_devtype *devtype =
 		of_device_get_match_data(&pdev->dev);
 	int ret;

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

 	platform_set_drvdata(pdev, mpc8xxx_gc);

 	raw_spin_lock_init(&mpc8xxx_gc->lock);

 	mpc8xxx_gc->regs = of_iomap(np, 0);
 	if (!mpc8xxx_gc->regs)
 		return -ENOMEM;

 	gc = &mpc8xxx_gc->gc;
 	gc->parent = &pdev->dev;

 	if (of_property_read_bool(np, "little-endian")) {
 		ret = bgpio_init(gc, &pdev->dev, 4,
 				 mpc8xxx_gc->regs + GPIO_DAT,
 				 NULL, NULL,
 				 mpc8xxx_gc->regs + GPIO_DIR, NULL,
 				 BGPIOF_BIG_ENDIAN);
 		if (ret)
 			goto err;
 		dev_dbg(&pdev->dev, "GPIO registers are LITTLE endian\n");
 	} else {
 		ret = bgpio_init(gc, &pdev->dev, 4,
 				 mpc8xxx_gc->regs + GPIO_DAT,
 				 NULL, NULL,
 				 mpc8xxx_gc->regs + GPIO_DIR, NULL,
 				 BGPIOF_BIG_ENDIAN
 				 | BGPIOF_BIG_ENDIAN_BYTE_ORDER);
 		if (ret)
 			goto err;
 		dev_dbg(&pdev->dev, "GPIO registers are BIG endian\n");
 	}

 	mpc8xxx_gc->direction_output = gc->direction_output;

 	if (!devtype)
 		devtype = &mpc8xxx_gpio_devtype_default;

 	/*
 	 * It's assumed that only a single type of gpio controller is available
 	 * on the current machine, so overwriting global data is fine.
 	 */
 	if (devtype->irq_set_type)
 		mpc8xxx_irq_chip.irq_set_type = devtype->irq_set_type;

 	if (devtype->gpio_dir_out)
 		gc->direction_output = devtype->gpio_dir_out;
 	if (devtype->gpio_get)
 		gc->get = devtype->gpio_get;

 	gc->to_irq = mpc8xxx_gpio_to_irq;

 	if (of_device_is_compatible(np, "fsl,qoriq-gpio"))
 		gc->write_reg(mpc8xxx_gc->regs + GPIO_IBE, 0xffffffff);

 	ret = gpiochip_add_data(gc, mpc8xxx_gc);
 	if (ret) {
 		pr_err("%pOF: GPIO chip registration failed with status %d\n",
 		       np, ret);
 		goto err;
 	}

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

 	/* ack and mask all irqs */
 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IER, 0xffffffff);
 	gc->write_reg(mpc8xxx_gc->regs + GPIO_IMR, 0);
 	/* enable input buffer  */
 	if (devtype->gpio_dir_in_init)
 		devtype->gpio_dir_in_init(gc);

 	ret = devm_request_irq(&pdev->dev, mpc8xxx_gc->irqn,
 			       mpc8xxx_gpio_irq_cascade,
 			       IRQF_NO_THREAD | IRQF_SHARED, "gpio-cascade",
 			       mpc8xxx_gc);
 	if (ret) {
 		dev_err(&pdev->dev, "%s: failed to devm_request_irq(%d), ret = %d\n",
 			np->full_name, mpc8xxx_gc->irqn, ret);
 		goto err;
 	}

 	return 0;
 err:
 	iounmap(mpc8xxx_gc->regs);
 	return ret;
 }

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

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

 	gpiochip_remove(&mpc8xxx_gc->gc);
 	iounmap(mpc8xxx_gc->regs);

 	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/QorIQ and compatible
	*
	* Copyright (C) 2008 Peter Korsgaard <jacmet@sunsite.dk>
	* Copyright (C) 2016 Freescale Semiconductor Inc.
	*
	* 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_address.h>
	#include <linux/of_irq.h>
	#include <linux/of_platform.h>
	#include <linux/slab.h>
	#include <linux/irq.h>
	#include <linux/gpio/driver.h>
	#include <linux/bitops.h>
	#include <linux/interrupt.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
	#define GPIO_IBE 0x18

	struct mpc8xxx_gpio_chip {
	struct gpio_chip gc;
	void __iomem *regs;
	raw_spinlock_t lock;

	int (direction_output)(struct gpio_chip chip,
	unsigned offset, int value);

	struct irq_domain *irq;
	unsigned int irqn;
	};

	/* The GPIO Input Buffer Enable register(GPIO_IBE) is used to
	* control the input enable of each individual GPIO port.
	* When an individual GPIO port’s direction is set to
	* input (GPIO_GPDIR[DRn=0]), the associated input enable must be
	* set (GPIOxGPIE[IEn]=1) to propagate the port value to the GPIO
	* Data Register.
	*/
	static int ls1028a_gpio_dir_in_init(struct gpio_chip *gc)
	{
	unsigned long flags;
	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);

	spin_lock_irqsave(&gc->bgpio_lock, flags);

	gc->write_reg(mpc8xxx_gc->regs + GPIO_IBE, 0xffffffff);

	spin_unlock_irqrestore(&gc->bgpio_lock, flags);

	return 0;
	}

	/*
	* This hardware has a big endian bit assignment such that GPIO line 0 is
	* connected to bit 31, line 1 to bit 30 ... line 31 to bit 0.
	* This inline helper give the right bitmask for a certain line.
	*/
	static inline u32 mpc_pin2mask(unsigned int offset)
	{
	return BIT(31 - offset);
	}

	/* 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 mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
	u32 out_mask, out_shadow;

	out_mask = gc->read_reg(mpc8xxx_gc->regs + GPIO_DIR);
	val = gc->read_reg(mpc8xxx_gc->regs + GPIO_DAT) & ~out_mask;
	out_shadow = gc->bgpio_data & out_mask;

	return !!((val \| out_shadow) & mpc_pin2mask(gpio));
	}

	static int mpc5121_gpio_dir_out(struct gpio_chip *gc,
	unsigned int gpio, int val)
	{
	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
	/* GPIO 28..31 are input only on MPC5121 */
	if (gpio >= 28)
	return -EINVAL;

	return mpc8xxx_gc->direction_output(gc, gpio, val);
	}

	static int mpc5125_gpio_dir_out(struct gpio_chip *gc,
	unsigned int gpio, int val)
	{
	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);
	/* GPIO 0..3 are input only on MPC5125 */
	if (gpio <= 3)
	return -EINVAL;

	return mpc8xxx_gc->direction_output(gc, gpio, val);
	}

	static int mpc8xxx_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
	{
	struct mpc8xxx_gpio_chip *mpc8xxx_gc = gpiochip_get_data(gc);

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

	static irqreturn_t mpc8xxx_gpio_irq_cascade(int irq, void *data)
	{
	struct mpc8xxx_gpio_chip *mpc8xxx_gc = data;
	struct gpio_chip *gc = &mpc8xxx_gc->gc;
	unsigned long mask;
	int i;

	mask = gc->read_reg(mpc8xxx_gc->regs + GPIO_IER)
	& gc->read_reg(mpc8xxx_gc->regs + GPIO_IMR);
	for_each_set_bit(i, &mask, 32)
	generic_handle_irq(irq_linear_revmap(mpc8xxx_gc->irq, 31 - i));

	return IRQ_HANDLED;
	}

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

	raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);

	gc->write_reg(mpc8xxx_gc->regs + GPIO_IMR,
	gc->read_reg(mpc8xxx_gc->regs + GPIO_IMR)
	\| mpc_pin2mask(irqd_to_hwirq(d)));

	raw_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 gpio_chip *gc = &mpc8xxx_gc->gc;
	unsigned long flags;

	raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);

	gc->write_reg(mpc8xxx_gc->regs + GPIO_IMR,
	gc->read_reg(mpc8xxx_gc->regs + GPIO_IMR)
	& ~mpc_pin2mask(irqd_to_hwirq(d)));

	raw_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 gpio_chip *gc = &mpc8xxx_gc->gc;

	gc->write_reg(mpc8xxx_gc->regs + GPIO_IER,
	mpc_pin2mask(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 gpio_chip *gc = &mpc8xxx_gc->gc;
	unsigned long flags;

	switch (flow_type) {
	case IRQ_TYPE_EDGE_FALLING:
	raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
	gc->write_reg(mpc8xxx_gc->regs + GPIO_ICR,
	gc->read_reg(mpc8xxx_gc->regs + GPIO_ICR)
	\| mpc_pin2mask(irqd_to_hwirq(d)));
	raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
	break;

	case IRQ_TYPE_EDGE_BOTH:
	raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
	gc->write_reg(mpc8xxx_gc->regs + GPIO_ICR,
	gc->read_reg(mpc8xxx_gc->regs + GPIO_ICR)
	& ~mpc_pin2mask(irqd_to_hwirq(d)));
	raw_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 gpio_chip *gc = &mpc8xxx_gc->gc;
	unsigned long gpio = irqd_to_hwirq(d);
	void __iomem *reg;
	unsigned int shift;
	unsigned long flags;

	if (gpio < 16) {
	reg = mpc8xxx_gc->regs + GPIO_ICR;
	shift = (15 - gpio) * 2;
	} else {
	reg = mpc8xxx_gc->regs + GPIO_ICR2;
	shift = (15 - (gpio % 16)) * 2;
	}

	switch (flow_type) {
	case IRQ_TYPE_EDGE_FALLING:
	case IRQ_TYPE_LEVEL_LOW:
	raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
	gc->write_reg(reg, (gc->read_reg(reg) & ~(3 << shift))
	\| (2 << shift));
	raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
	break;

	case IRQ_TYPE_EDGE_RISING:
	case IRQ_TYPE_LEVEL_HIGH:
	raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
	gc->write_reg(reg, (gc->read_reg(reg) & ~(3 << shift))
	\| (1 << shift));
	raw_spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
	break;

	case IRQ_TYPE_EDGE_BOTH:
	raw_spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
	gc->write_reg(reg, (gc->read_reg(reg) & ~(3 << shift)));
	raw_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,
	/* this might get overwritten in mpc8xxx_probe() */
	.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)
	{
	irq_set_chip_data(irq, h->host_data);
	irq_set_chip_and_handler(irq, &mpc8xxx_irq_chip, handle_edge_irq);

	return 0;
	}

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

	struct mpc8xxx_gpio_devtype {
	int (gpio_dir_in_init)(struct gpio_chip chip);
	int (gpio_dir_out)(struct gpio_chip , unsigned int, int);
	int (gpio_get)(struct gpio_chip , unsigned int);
	int (irq_set_type)(struct irq_data , unsigned int);
	};

	static const struct mpc8xxx_gpio_devtype mpc512x_gpio_devtype = {
	.gpio_dir_out = mpc5121_gpio_dir_out,
	.irq_set_type = mpc512x_irq_set_type,
	};

	static const struct mpc8xxx_gpio_devtype ls1028a_gpio_devtype = {
	.gpio_dir_in_init = ls1028a_gpio_dir_in_init,
	.irq_set_type = mpc8xxx_irq_set_type,
	};

	static const struct mpc8xxx_gpio_devtype mpc5125_gpio_devtype = {
	.gpio_dir_out = mpc5125_gpio_dir_out,
	.irq_set_type = mpc512x_irq_set_type,
	};

	static const struct mpc8xxx_gpio_devtype mpc8572_gpio_devtype = {
	.gpio_get = mpc8572_gpio_get,
	};

	static const struct mpc8xxx_gpio_devtype mpc8xxx_gpio_devtype_default = {
	.irq_set_type = mpc8xxx_irq_set_type,
	};

	static const struct of_device_id mpc8xxx_gpio_ids[] = {
	{ .compatible = "fsl,mpc8349-gpio", },
	{ .compatible = "fsl,mpc8572-gpio", .data = &mpc8572_gpio_devtype, },
	{ .compatible = "fsl,mpc8610-gpio", },
	{ .compatible = "fsl,mpc5121-gpio", .data = &mpc512x_gpio_devtype, },
	{ .compatible = "fsl,mpc5125-gpio", .data = &mpc5125_gpio_devtype, },
	{ .compatible = "fsl,pq3-gpio", },
	{ .compatible = "fsl,ls1028a-gpio", .data = &ls1028a_gpio_devtype, },
	{ .compatible = "fsl,ls1088a-gpio", .data = &ls1028a_gpio_devtype, },
	{ .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 gpio_chip *gc;
	const struct mpc8xxx_gpio_devtype *devtype =
	of_device_get_match_data(&pdev->dev);
	int ret;

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

	platform_set_drvdata(pdev, mpc8xxx_gc);

	raw_spin_lock_init(&mpc8xxx_gc->lock);

	mpc8xxx_gc->regs = of_iomap(np, 0);
	if (!mpc8xxx_gc->regs)
	return -ENOMEM;

	gc = &mpc8xxx_gc->gc;
	gc->parent = &pdev->dev;

	if (of_property_read_bool(np, "little-endian")) {
	ret = bgpio_init(gc, &pdev->dev, 4,
	mpc8xxx_gc->regs + GPIO_DAT,
	NULL, NULL,
	mpc8xxx_gc->regs + GPIO_DIR, NULL,
	BGPIOF_BIG_ENDIAN);
	if (ret)
	goto err;
	dev_dbg(&pdev->dev, "GPIO registers are LITTLE endian\n");
	} else {
	ret = bgpio_init(gc, &pdev->dev, 4,
	mpc8xxx_gc->regs + GPIO_DAT,
	NULL, NULL,
	mpc8xxx_gc->regs + GPIO_DIR, NULL,
	BGPIOF_BIG_ENDIAN
	\| BGPIOF_BIG_ENDIAN_BYTE_ORDER);
	if (ret)
	goto err;
	dev_dbg(&pdev->dev, "GPIO registers are BIG endian\n");
	}

	mpc8xxx_gc->direction_output = gc->direction_output;

	if (!devtype)
	devtype = &mpc8xxx_gpio_devtype_default;

	/*
	* It's assumed that only a single type of gpio controller is available
	* on the current machine, so overwriting global data is fine.
	*/
	if (devtype->irq_set_type)
	mpc8xxx_irq_chip.irq_set_type = devtype->irq_set_type;

	if (devtype->gpio_dir_out)
	gc->direction_output = devtype->gpio_dir_out;
	if (devtype->gpio_get)
	gc->get = devtype->gpio_get;

	gc->to_irq = mpc8xxx_gpio_to_irq;

	if (of_device_is_compatible(np, "fsl,qoriq-gpio"))
	gc->write_reg(mpc8xxx_gc->regs + GPIO_IBE, 0xffffffff);

	ret = gpiochip_add_data(gc, mpc8xxx_gc);
	if (ret) {
	pr_err("%pOF: GPIO chip registration failed with status %d\n",
	np, ret);
	goto err;
	}

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

	/* ack and mask all irqs */
	gc->write_reg(mpc8xxx_gc->regs + GPIO_IER, 0xffffffff);
	gc->write_reg(mpc8xxx_gc->regs + GPIO_IMR, 0);
	/* enable input buffer */
	if (devtype->gpio_dir_in_init)
	devtype->gpio_dir_in_init(gc);

	ret = devm_request_irq(&pdev->dev, mpc8xxx_gc->irqn,
	mpc8xxx_gpio_irq_cascade,
	IRQF_NO_THREAD \| IRQF_SHARED, "gpio-cascade",
	mpc8xxx_gc);
	if (ret) {
	dev_err(&pdev->dev, "%s: failed to devm_request_irq(%d), ret = %d\n",
	np->full_name, mpc8xxx_gc->irqn, ret);
	goto err;
	}

	return 0;
	err:
	iounmap(mpc8xxx_gc->regs);
	return ret;
	}

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

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

	gpiochip_remove(&mpc8xxx_gc->gc);
	iounmap(mpc8xxx_gc->regs);

	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);