/*
   * GPIO driver for Marvell SoCs
   *
   * Copyright (C) 2012 Marvell
   *
   * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
   * Andrew Lunn <andrew@lunn.ch>
   * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
   *
   * 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.
   *
   * This driver is a fairly straightforward GPIO driver for the
   * complete family of Marvell EBU SoC platforms (Orion, Dove,
   * Kirkwood, Discovery, Armada 370/XP). The only complexity of this
   * driver is the different register layout that exists between the
   * non-SMP platforms (Orion, Dove, Kirkwood, Armada 370) and the SMP
   * platforms (MV78200 from the Discovery family and the Armada
   * XP). Therefore, this driver handles three variants of the GPIO
   * block:
   * - the basic variant, called "orion-gpio", with the simplest
   *   register set. Used on Orion, Dove, Kirkwoord, Armada 370 and
   *   non-SMP Discovery systems
   * - the mv78200 variant for MV78200 Discovery systems. This variant
   *   turns the edge mask and level mask registers into CPU0 edge
   *   mask/level mask registers, and adds CPU1 edge mask/level mask
   *   registers.
   * - the armadaxp variant for Armada XP systems. This variant keeps
   *   the normal cause/edge mask/level mask registers when the global
   *   interrupts are used, but adds per-CPU cause/edge mask/level mask
   *   registers n a separate memory area for the per-CPU GPIO
   *   interrupts.
   */
  
  #include <linux/err.h>
  #include <linux/module.h>
  #include <linux/gpio.h>
  #include <linux/irq.h>
  #include <linux/slab.h>
  #include <linux/irqdomain.h>
  #include <linux/io.h>
  #include <linux/of_irq.h>
  #include <linux/of_device.h>
  #include <linux/clk.h>
  #include <linux/pinctrl/consumer.h>
  
  /*
   * GPIO unit register offsets.
   */
  #define GPIO_OUT_OFF		0x0000
  #define GPIO_IO_CONF_OFF	0x0004
  #define GPIO_BLINK_EN_OFF	0x0008
  #define GPIO_IN_POL_OFF		0x000c
  #define GPIO_DATA_IN_OFF	0x0010
  #define GPIO_EDGE_CAUSE_OFF	0x0014
  #define GPIO_EDGE_MASK_OFF	0x0018
  #define GPIO_LEVEL_MASK_OFF	0x001c
  
  /* The MV78200 has per-CPU registers for edge mask and level mask */
  #define GPIO_EDGE_MASK_MV78200_OFF(cpu)   ((cpu) ? 0x30 : 0x18)
  #define GPIO_LEVEL_MASK_MV78200_OFF(cpu)  ((cpu) ? 0x34 : 0x1C)
  
  /* The Armada XP has per-CPU registers for interrupt cause, interrupt
   * mask and interrupt level mask. Those are relative to the
   * percpu_membase. */
  #define GPIO_EDGE_CAUSE_ARMADAXP_OFF(cpu) ((cpu) * 0x4)
  #define GPIO_EDGE_MASK_ARMADAXP_OFF(cpu)  (0x10 + (cpu) * 0x4)
  #define GPIO_LEVEL_MASK_ARMADAXP_OFF(cpu) (0x20 + (cpu) * 0x4)
  
  #define MVEBU_GPIO_SOC_VARIANT_ORION    0x1
  #define MVEBU_GPIO_SOC_VARIANT_MV78200  0x2
  #define MVEBU_GPIO_SOC_VARIANT_ARMADAXP 0x3
  
  #define MVEBU_MAX_GPIO_PER_BANK         32
  
  struct mvebu_gpio_chip {
  	struct gpio_chip   chip;
  	spinlock_t	   lock;
  	void __iomem	  *membase;
  	void __iomem	  *percpu_membase;
  	int		   irqbase;
  	struct irq_domain *domain;
  	int                soc_variant;
  };
  
  /*
   * Functions returning addresses of individual registers for a given
   * GPIO controller.
   */
  static inline void __iomem *mvebu_gpioreg_out(struct mvebu_gpio_chip *mvchip)
  {
  	return mvchip->membase + GPIO_OUT_OFF;
  }
  
  static inline void __iomem *mvebu_gpioreg_blink(struct mvebu_gpio_chip *mvchip)
  {
  	return mvchip->membase + GPIO_BLINK_EN_OFF;
  }
  
  static inline void __iomem *mvebu_gpioreg_io_conf(struct mvebu_gpio_chip *mvchip)
  {
  	return mvchip->membase + GPIO_IO_CONF_OFF;
  }
  
  static inline void __iomem *mvebu_gpioreg_in_pol(struct mvebu_gpio_chip *mvchip)
  {
  	return mvchip->membase + GPIO_IN_POL_OFF;
  }
  
  static inline void __iomem *mvebu_gpioreg_data_in(struct mvebu_gpio_chip *mvchip)
  {
  	return mvchip->membase + GPIO_DATA_IN_OFF;
  }
  
  static inline void __iomem *mvebu_gpioreg_edge_cause(struct mvebu_gpio_chip *mvchip)
  {
  	int cpu;
  
  	switch (mvchip->soc_variant) {
  	case MVEBU_GPIO_SOC_VARIANT_ORION:
  	case MVEBU_GPIO_SOC_VARIANT_MV78200:
  		return mvchip->membase + GPIO_EDGE_CAUSE_OFF;
  	case MVEBU_GPIO_SOC_VARIANT_ARMADAXP:
  		cpu = smp_processor_id();
  		return mvchip->percpu_membase + GPIO_EDGE_CAUSE_ARMADAXP_OFF(cpu);
  	default:
  		BUG();
  	}
  }
  
  static inline void __iomem *mvebu_gpioreg_edge_mask(struct mvebu_gpio_chip *mvchip)
  {
  	int cpu;
  
  	switch (mvchip->soc_variant) {
  	case MVEBU_GPIO_SOC_VARIANT_ORION:
  		return mvchip->membase + GPIO_EDGE_MASK_OFF;
  	case MVEBU_GPIO_SOC_VARIANT_MV78200:
  		cpu = smp_processor_id();
  		return mvchip->membase + GPIO_EDGE_MASK_MV78200_OFF(cpu);
  	case MVEBU_GPIO_SOC_VARIANT_ARMADAXP:
  		cpu = smp_processor_id();
  		return mvchip->percpu_membase + GPIO_EDGE_MASK_ARMADAXP_OFF(cpu);
  	default:
  		BUG();
  	}
  }
  
  static void __iomem *mvebu_gpioreg_level_mask(struct mvebu_gpio_chip *mvchip)
  {
  	int cpu;
  
  	switch (mvchip->soc_variant) {
  	case MVEBU_GPIO_SOC_VARIANT_ORION:
  		return mvchip->membase + GPIO_LEVEL_MASK_OFF;
  	case MVEBU_GPIO_SOC_VARIANT_MV78200:
  		cpu = smp_processor_id();
  		return mvchip->membase + GPIO_LEVEL_MASK_MV78200_OFF(cpu);
  	case MVEBU_GPIO_SOC_VARIANT_ARMADAXP:
  		cpu = smp_processor_id();
  		return mvchip->percpu_membase + GPIO_LEVEL_MASK_ARMADAXP_OFF(cpu);
  	default:
  		BUG();
  	}
  }
  
  /*
   * Functions implementing the gpio_chip methods
   */
  
  static int mvebu_gpio_request(struct gpio_chip *chip, unsigned pin)
  {
  	return pinctrl_request_gpio(chip->base + pin);
  }
  
  static void mvebu_gpio_free(struct gpio_chip *chip, unsigned pin)
  {
  	pinctrl_free_gpio(chip->base + pin);
  }
  
  static void mvebu_gpio_set(struct gpio_chip *chip, unsigned pin, int value)
  {
  	struct mvebu_gpio_chip *mvchip =
  		container_of(chip, struct mvebu_gpio_chip, chip);
  	unsigned long flags;
  	u32 u;
  
  	spin_lock_irqsave(&mvchip->lock, flags);
  	u = readl_relaxed(mvebu_gpioreg_out(mvchip));
  	if (value)
  		u |= 1 << pin;
  	else
  		u &= ~(1 << pin);
  	writel_relaxed(u, mvebu_gpioreg_out(mvchip));
  	spin_unlock_irqrestore(&mvchip->lock, flags);
  }
  
  static int mvebu_gpio_get(struct gpio_chip *chip, unsigned pin)
  {
  	struct mvebu_gpio_chip *mvchip =
  		container_of(chip, struct mvebu_gpio_chip, chip);
  	u32 u;
  
  	if (readl_relaxed(mvebu_gpioreg_io_conf(mvchip)) & (1 << pin)) {
  		u = readl_relaxed(mvebu_gpioreg_data_in(mvchip)) ^
  			readl_relaxed(mvebu_gpioreg_in_pol(mvchip));
  	} else {
  		u = readl_relaxed(mvebu_gpioreg_out(mvchip));
  	}
  
  	return (u >> pin) & 1;
  }
  
  static void mvebu_gpio_blink(struct gpio_chip *chip, unsigned pin, int value)
  {
  	struct mvebu_gpio_chip *mvchip =
  		container_of(chip, struct mvebu_gpio_chip, chip);
  	unsigned long flags;
  	u32 u;
  
  	spin_lock_irqsave(&mvchip->lock, flags);
  	u = readl_relaxed(mvebu_gpioreg_blink(mvchip));
  	if (value)
  		u |= 1 << pin;
  	else
  		u &= ~(1 << pin);
  	writel_relaxed(u, mvebu_gpioreg_blink(mvchip));
  	spin_unlock_irqrestore(&mvchip->lock, flags);
  }
  
  static int mvebu_gpio_direction_input(struct gpio_chip *chip, unsigned pin)
  {
  	struct mvebu_gpio_chip *mvchip =
  		container_of(chip, struct mvebu_gpio_chip, chip);
  	unsigned long flags;
  	int ret;
  	u32 u;
  
  	/* Check with the pinctrl driver whether this pin is usable as
  	 * an input GPIO */
  	ret = pinctrl_gpio_direction_input(chip->base + pin);
  	if (ret)
  		return ret;
  
  	spin_lock_irqsave(&mvchip->lock, flags);
  	u = readl_relaxed(mvebu_gpioreg_io_conf(mvchip));
  	u |= 1 << pin;
  	writel_relaxed(u, mvebu_gpioreg_io_conf(mvchip));
  	spin_unlock_irqrestore(&mvchip->lock, flags);
  
  	return 0;
  }
  
  static int mvebu_gpio_direction_output(struct gpio_chip *chip, unsigned pin,
  				       int value)
  {
  	struct mvebu_gpio_chip *mvchip =
  		container_of(chip, struct mvebu_gpio_chip, chip);
  	unsigned long flags;
  	int ret;
  	u32 u;
  
  	/* Check with the pinctrl driver whether this pin is usable as
  	 * an output GPIO */
  	ret = pinctrl_gpio_direction_output(chip->base + pin);
  	if (ret)
  		return ret;
  
  	mvebu_gpio_blink(chip, pin, 0);
  	mvebu_gpio_set(chip, pin, value);
  
  	spin_lock_irqsave(&mvchip->lock, flags);
  	u = readl_relaxed(mvebu_gpioreg_io_conf(mvchip));
  	u &= ~(1 << pin);
  	writel_relaxed(u, mvebu_gpioreg_io_conf(mvchip));
  	spin_unlock_irqrestore(&mvchip->lock, flags);
  
  	return 0;
  }
  
  static int mvebu_gpio_to_irq(struct gpio_chip *chip, unsigned pin)
  {
  	struct mvebu_gpio_chip *mvchip =
  		container_of(chip, struct mvebu_gpio_chip, chip);
  	return irq_create_mapping(mvchip->domain, pin);
  }
  
  /*
   * Functions implementing the irq_chip methods
   */
  static void mvebu_gpio_irq_ack(struct irq_data *d)
  {
  	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
  	struct mvebu_gpio_chip *mvchip = gc->private;
  	u32 mask = ~(1 << (d->irq - gc->irq_base));
  
  	irq_gc_lock(gc);
  	writel_relaxed(mask, mvebu_gpioreg_edge_cause(mvchip));
  	irq_gc_unlock(gc);
  }
  
  static void mvebu_gpio_edge_irq_mask(struct irq_data *d)
  {
  	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
  	struct mvebu_gpio_chip *mvchip = gc->private;
  	u32 mask = 1 << (d->irq - gc->irq_base);
  
  	irq_gc_lock(gc);
  	gc->mask_cache &= ~mask;
  	writel_relaxed(gc->mask_cache, mvebu_gpioreg_edge_mask(mvchip));
  	irq_gc_unlock(gc);
  }
  
  static void mvebu_gpio_edge_irq_unmask(struct irq_data *d)
  {
  	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
  	struct mvebu_gpio_chip *mvchip = gc->private;
  	u32 mask = 1 << (d->irq - gc->irq_base);
  
  	irq_gc_lock(gc);
  	gc->mask_cache |= mask;
  	writel_relaxed(gc->mask_cache, mvebu_gpioreg_edge_mask(mvchip));
  	irq_gc_unlock(gc);
  }
  
  static void mvebu_gpio_level_irq_mask(struct irq_data *d)
  {
  	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
  	struct mvebu_gpio_chip *mvchip = gc->private;
  	u32 mask = 1 << (d->irq - gc->irq_base);
  
  	irq_gc_lock(gc);
  	gc->mask_cache &= ~mask;
  	writel_relaxed(gc->mask_cache, mvebu_gpioreg_level_mask(mvchip));
  	irq_gc_unlock(gc);
  }
  
  static void mvebu_gpio_level_irq_unmask(struct irq_data *d)
  {
  	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
  	struct mvebu_gpio_chip *mvchip = gc->private;
  	u32 mask = 1 << (d->irq - gc->irq_base);
  
  	irq_gc_lock(gc);
  	gc->mask_cache |= mask;
  	writel_relaxed(gc->mask_cache, mvebu_gpioreg_level_mask(mvchip));
  	irq_gc_unlock(gc);
  }
  
  /*****************************************************************************
   * MVEBU GPIO IRQ
   *
   * GPIO_IN_POL register controls whether GPIO_DATA_IN will hold the same
   * value of the line or the opposite value.
   *
   * Level IRQ handlers: DATA_IN is used directly as cause register.
   *                     Interrupt are masked by LEVEL_MASK registers.
   * Edge IRQ handlers:  Change in DATA_IN are latched in EDGE_CAUSE.
   *                     Interrupt are masked by EDGE_MASK registers.
   * Both-edge handlers: Similar to regular Edge handlers, but also swaps
   *                     the polarity to catch the next line transaction.
   *                     This is a race condition that might not perfectly
   *                     work on some use cases.
   *
   * Every eight GPIO lines are grouped (OR'ed) before going up to main
   * cause register.
   *
   *                    EDGE  cause    mask
   *        data-in   /--------| |-----| |----\
   *     -----| |-----                         ---- to main cause reg
   *           X      \----------------| |----/
   *        polarity    LEVEL          mask
   *
   ****************************************************************************/
  
  static int mvebu_gpio_irq_set_type(struct irq_data *d, unsigned int type)
  {
  	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
  	struct irq_chip_type *ct = irq_data_get_chip_type(d);
  	struct mvebu_gpio_chip *mvchip = gc->private;
  	int pin;
  	u32 u;
  
  	pin = d->hwirq;
  
  	u = readl_relaxed(mvebu_gpioreg_io_conf(mvchip)) & (1 << pin);
  	if (!u) {
  		return -EINVAL;
  	}
  
  	type &= IRQ_TYPE_SENSE_MASK;
  	if (type == IRQ_TYPE_NONE)
  		return -EINVAL;
  
  	/* Check if we need to change chip and handler */
  	if (!(ct->type & type))
  		if (irq_setup_alt_chip(d, type))
  			return -EINVAL;
  
  	/*
  	 * Configure interrupt polarity.
  	 */
  	switch (type) {
  	case IRQ_TYPE_EDGE_RISING:
  	case IRQ_TYPE_LEVEL_HIGH:
  		u = readl_relaxed(mvebu_gpioreg_in_pol(mvchip));
  		u &= ~(1 << pin);
  		writel_relaxed(u, mvebu_gpioreg_in_pol(mvchip));
  		break;
  	case IRQ_TYPE_EDGE_FALLING:
  	case IRQ_TYPE_LEVEL_LOW:
  		u = readl_relaxed(mvebu_gpioreg_in_pol(mvchip));
  		u |= 1 << pin;
  		writel_relaxed(u, mvebu_gpioreg_in_pol(mvchip));
  		break;
  	case IRQ_TYPE_EDGE_BOTH: {
  		u32 v;
  
  		v = readl_relaxed(mvebu_gpioreg_in_pol(mvchip)) ^
  			readl_relaxed(mvebu_gpioreg_data_in(mvchip));
  
  		/*
  		 * set initial polarity based on current input level
  		 */
  		u = readl_relaxed(mvebu_gpioreg_in_pol(mvchip));
  		if (v & (1 << pin))
  			u |= 1 << pin;		/* falling */
  		else
  			u &= ~(1 << pin);	/* rising */
  		writel_relaxed(u, mvebu_gpioreg_in_pol(mvchip));
  		break;
  	}
  	}
  	return 0;
  }
  
  static void mvebu_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
  {
  	struct mvebu_gpio_chip *mvchip = irq_get_handler_data(irq);
  	u32 cause, type;
  	int i;
  
  	if (mvchip == NULL)
  		return;
  
  	cause = readl_relaxed(mvebu_gpioreg_data_in(mvchip)) &
  		readl_relaxed(mvebu_gpioreg_level_mask(mvchip));
  	cause |= readl_relaxed(mvebu_gpioreg_edge_cause(mvchip)) &
  		readl_relaxed(mvebu_gpioreg_edge_mask(mvchip));
  
  	for (i = 0; i < mvchip->chip.ngpio; i++) {
  		int irq;
  
  		irq = mvchip->irqbase + i;
  
  		if (!(cause & (1 << i)))
  			continue;
  
  		type = irq_get_trigger_type(irq);
  		if ((type & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_BOTH) {
  			/* Swap polarity (race with GPIO line) */
  			u32 polarity;
  
  			polarity = readl_relaxed(mvebu_gpioreg_in_pol(mvchip));
  			polarity ^= 1 << i;
  			writel_relaxed(polarity, mvebu_gpioreg_in_pol(mvchip));
  		}
  		generic_handle_irq(irq);
  	}
  }
  
  #ifdef CONFIG_DEBUG_FS
  #include <linux/seq_file.h>
  
  static void mvebu_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
  {
  	struct mvebu_gpio_chip *mvchip =
  		container_of(chip, struct mvebu_gpio_chip, chip);
  	u32 out, io_conf, blink, in_pol, data_in, cause, edg_msk, lvl_msk;
  	int i;
  
  	out	= readl_relaxed(mvebu_gpioreg_out(mvchip));
  	io_conf	= readl_relaxed(mvebu_gpioreg_io_conf(mvchip));
  	blink	= readl_relaxed(mvebu_gpioreg_blink(mvchip));
  	in_pol	= readl_relaxed(mvebu_gpioreg_in_pol(mvchip));
  	data_in	= readl_relaxed(mvebu_gpioreg_data_in(mvchip));
  	cause	= readl_relaxed(mvebu_gpioreg_edge_cause(mvchip));
  	edg_msk	= readl_relaxed(mvebu_gpioreg_edge_mask(mvchip));
  	lvl_msk	= readl_relaxed(mvebu_gpioreg_level_mask(mvchip));
  
  	for (i = 0; i < chip->ngpio; i++) {
  		const char *label;
  		u32 msk;
  		bool is_out;
  
  		label = gpiochip_is_requested(chip, i);
  		if (!label)
  			continue;
  
  		msk = 1 << i;
  		is_out = !(io_conf & msk);
  
  		seq_printf(s, " gpio-%-3d (%-20.20s)", chip->base + i, label);
  
  		if (is_out) {
  			seq_printf(s, " out %s %s
  ",
  				   out & msk ? "hi" : "lo",
  				   blink & msk ? "(blink )" : "");
  			continue;
  		}
  
  		seq_printf(s, " in  %s (act %s) - IRQ",
  			   (data_in ^ in_pol) & msk  ? "hi" : "lo",
  			   in_pol & msk ? "lo" : "hi");
  		if (!((edg_msk | lvl_msk) & msk)) {
  			seq_printf(s, " disabled
  ");
  			continue;
  		}
  		if (edg_msk & msk)
  			seq_printf(s, " edge ");
  		if (lvl_msk & msk)
  			seq_printf(s, " level");
  		seq_printf(s, " (%s)
  ", cause & msk ? "pending" : "clear  ");
  	}
  }
  #else
  #define mvebu_gpio_dbg_show NULL
  #endif
  
  static struct of_device_id mvebu_gpio_of_match[] = {
  	{
  		.compatible = "marvell,orion-gpio",
  		.data       = (void *) MVEBU_GPIO_SOC_VARIANT_ORION,
  	},
  	{
  		.compatible = "marvell,mv78200-gpio",
  		.data       = (void *) MVEBU_GPIO_SOC_VARIANT_MV78200,
  	},
  	{
  		.compatible = "marvell,armadaxp-gpio",
  		.data       = (void *) MVEBU_GPIO_SOC_VARIANT_ARMADAXP,
  	},
  	{
  		/* sentinel */
  	},
  };
  MODULE_DEVICE_TABLE(of, mvebu_gpio_of_match);
  
  static int mvebu_gpio_probe(struct platform_device *pdev)
  {
  	struct mvebu_gpio_chip *mvchip;
  	const struct of_device_id *match;
  	struct device_node *np = pdev->dev.of_node;
  	struct resource *res;
  	struct irq_chip_generic *gc;
  	struct irq_chip_type *ct;
  	struct clk *clk;
  	unsigned int ngpios;
  	int soc_variant;
  	int i, cpu, id;
  
  	match = of_match_device(mvebu_gpio_of_match, &pdev->dev);
  	if (match)
  		soc_variant = (int) match->data;
  	else
  		soc_variant = MVEBU_GPIO_SOC_VARIANT_ORION;
  
  	mvchip = devm_kzalloc(&pdev->dev, sizeof(struct mvebu_gpio_chip), GFP_KERNEL);
  	if (!mvchip) {
  		dev_err(&pdev->dev, "Cannot allocate memory
  ");
  		return -ENOMEM;
  	}
  
  	if (of_property_read_u32(pdev->dev.of_node, "ngpios", &ngpios)) {
  		dev_err(&pdev->dev, "Missing ngpios OF property
  ");
  		return -ENODEV;
  	}
  
  	id = of_alias_get_id(pdev->dev.of_node, "gpio");
  	if (id < 0) {
  		dev_err(&pdev->dev, "Couldn't get OF id
  ");
  		return id;
  	}
  
  	clk = devm_clk_get(&pdev->dev, NULL);
  	/* Not all SoCs require a clock.*/
  	if (!IS_ERR(clk))
  		clk_prepare_enable(clk);
  
  	mvchip->soc_variant = soc_variant;
  	mvchip->chip.label = dev_name(&pdev->dev);
  	mvchip->chip.dev = &pdev->dev;
  	mvchip->chip.request = mvebu_gpio_request;
  	mvchip->chip.free = mvebu_gpio_free;
  	mvchip->chip.direction_input = mvebu_gpio_direction_input;
  	mvchip->chip.get = mvebu_gpio_get;
  	mvchip->chip.direction_output = mvebu_gpio_direction_output;
  	mvchip->chip.set = mvebu_gpio_set;
  	mvchip->chip.to_irq = mvebu_gpio_to_irq;
  	mvchip->chip.base = id * MVEBU_MAX_GPIO_PER_BANK;
  	mvchip->chip.ngpio = ngpios;
  	mvchip->chip.can_sleep = false;
  	mvchip->chip.of_node = np;
  	mvchip->chip.dbg_show = mvebu_gpio_dbg_show;
  
  	spin_lock_init(&mvchip->lock);
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	mvchip->membase = devm_ioremap_resource(&pdev->dev, res);
  	if (IS_ERR(mvchip->membase))
  		return PTR_ERR(mvchip->membase);
  
  	/* The Armada XP has a second range of registers for the
  	 * per-CPU registers */
  	if (soc_variant == MVEBU_GPIO_SOC_VARIANT_ARMADAXP) {
  		res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
  		mvchip->percpu_membase = devm_ioremap_resource(&pdev->dev,
  							       res);
  		if (IS_ERR(mvchip->percpu_membase))
  			return PTR_ERR(mvchip->percpu_membase);
  	}
  
  	/*
  	 * Mask and clear GPIO interrupts.
  	 */
  	switch (soc_variant) {
  	case MVEBU_GPIO_SOC_VARIANT_ORION:
  		writel_relaxed(0, mvchip->membase + GPIO_EDGE_CAUSE_OFF);
  		writel_relaxed(0, mvchip->membase + GPIO_EDGE_MASK_OFF);
  		writel_relaxed(0, mvchip->membase + GPIO_LEVEL_MASK_OFF);
  		break;
  	case MVEBU_GPIO_SOC_VARIANT_MV78200:
  		writel_relaxed(0, mvchip->membase + GPIO_EDGE_CAUSE_OFF);
  		for (cpu = 0; cpu < 2; cpu++) {
  			writel_relaxed(0, mvchip->membase +
  				       GPIO_EDGE_MASK_MV78200_OFF(cpu));
  			writel_relaxed(0, mvchip->membase +
  				       GPIO_LEVEL_MASK_MV78200_OFF(cpu));
  		}
  		break;
  	case MVEBU_GPIO_SOC_VARIANT_ARMADAXP:
  		writel_relaxed(0, mvchip->membase + GPIO_EDGE_CAUSE_OFF);
  		writel_relaxed(0, mvchip->membase + GPIO_EDGE_MASK_OFF);
  		writel_relaxed(0, mvchip->membase + GPIO_LEVEL_MASK_OFF);
  		for (cpu = 0; cpu < 4; cpu++) {
  			writel_relaxed(0, mvchip->percpu_membase +
  				       GPIO_EDGE_CAUSE_ARMADAXP_OFF(cpu));
  			writel_relaxed(0, mvchip->percpu_membase +
  				       GPIO_EDGE_MASK_ARMADAXP_OFF(cpu));
  			writel_relaxed(0, mvchip->percpu_membase +
  				       GPIO_LEVEL_MASK_ARMADAXP_OFF(cpu));
  		}
  		break;
  	default:
  		BUG();
  	}
  
  	gpiochip_add(&mvchip->chip);
  
  	/* Some gpio controllers do not provide irq support */
  	if (!of_irq_count(np))
  		return 0;
  
  	/* Setup the interrupt handlers. Each chip can have up to 4
  	 * interrupt handlers, with each handler dealing with 8 GPIO
  	 * pins. */
  	for (i = 0; i < 4; i++) {
  		int irq;
  		irq = platform_get_irq(pdev, i);
  		if (irq < 0)
  			continue;
  		irq_set_handler_data(irq, mvchip);
  		irq_set_chained_handler(irq, mvebu_gpio_irq_handler);
  	}
  
  	mvchip->irqbase = irq_alloc_descs(-1, 0, ngpios, -1);
  	if (mvchip->irqbase < 0) {
  		dev_err(&pdev->dev, "no irqs
  ");
  		return mvchip->irqbase;
  	}
  
  	gc = irq_alloc_generic_chip("mvebu_gpio_irq", 2, mvchip->irqbase,
  				    mvchip->membase, handle_level_irq);
  	if (!gc) {
  		dev_err(&pdev->dev, "Cannot allocate generic irq_chip
  ");
  		return -ENOMEM;
  	}
  
  	gc->private = mvchip;
  	ct = &gc->chip_types[0];
  	ct->type = IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW;
  	ct->chip.irq_mask = mvebu_gpio_level_irq_mask;
  	ct->chip.irq_unmask = mvebu_gpio_level_irq_unmask;
  	ct->chip.irq_set_type = mvebu_gpio_irq_set_type;
  	ct->chip.name = mvchip->chip.label;
  
  	ct = &gc->chip_types[1];
  	ct->type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
  	ct->chip.irq_ack = mvebu_gpio_irq_ack;
  	ct->chip.irq_mask = mvebu_gpio_edge_irq_mask;
  	ct->chip.irq_unmask = mvebu_gpio_edge_irq_unmask;
  	ct->chip.irq_set_type = mvebu_gpio_irq_set_type;
  	ct->handler = handle_edge_irq;
  	ct->chip.name = mvchip->chip.label;
  
  	irq_setup_generic_chip(gc, IRQ_MSK(ngpios), 0,
  			       IRQ_NOREQUEST, IRQ_LEVEL | IRQ_NOPROBE);
  
  	/* Setup irq domain on top of the generic chip. */
  	mvchip->domain = irq_domain_add_simple(np, mvchip->chip.ngpio,
  					       mvchip->irqbase,
  					       &irq_domain_simple_ops,
  					       mvchip);
  	if (!mvchip->domain) {
  		dev_err(&pdev->dev, "couldn't allocate irq domain %s (DT).
  ",
  			mvchip->chip.label);
  		irq_remove_generic_chip(gc, IRQ_MSK(ngpios), IRQ_NOREQUEST,
  					IRQ_LEVEL | IRQ_NOPROBE);
  		kfree(gc);
  		return -ENODEV;
  	}
  
  	return 0;
  }
  
  static struct platform_driver mvebu_gpio_driver = {
  	.driver		= {
  		.name	        = "mvebu-gpio",
  		.owner	        = THIS_MODULE,
  		.of_match_table = mvebu_gpio_of_match,
  	},
  	.probe		= mvebu_gpio_probe,
  };
  
  static int __init mvebu_gpio_init(void)
  {
  	return platform_driver_register(&mvebu_gpio_driver);
  }
  postcore_initcall(mvebu_gpio_init);