drivers/gpio/gpio-bcm-kona.c - kernel/msm-4.9 - Gitiles

 /*
  * Copyright (C) 2012-2014 Broadcom Corporation
  *
  * 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 version 2.
  *
  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  * kind, whether express or implied; without even the implied warranty
  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  */

 #include <linux/bitops.h>
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/gpio.h>
 #include <linux/of_device.h>
 #include <linux/of_irq.h>
 #include <linux/module.h>
 #include <linux/irqdomain.h>
 #include <linux/irqchip/chained_irq.h>

 #define BCM_GPIO_PASSWD				0x00a5a501
 #define GPIO_PER_BANK				32
 #define GPIO_MAX_BANK_NUM			8

 #define GPIO_BANK(gpio)				((gpio) >> 5)
 #define GPIO_BIT(gpio)				((gpio) & (GPIO_PER_BANK - 1))

 /* There is a GPIO control register for each GPIO */
 #define GPIO_CONTROL(gpio)			(0x00000100 + ((gpio) << 2))

 /* The remaining registers are per GPIO bank */
 #define GPIO_OUT_STATUS(bank)			(0x00000000 + ((bank) << 2))
 #define GPIO_IN_STATUS(bank)			(0x00000020 + ((bank) << 2))
 #define GPIO_OUT_SET(bank)			(0x00000040 + ((bank) << 2))
 #define GPIO_OUT_CLEAR(bank)			(0x00000060 + ((bank) << 2))
 #define GPIO_INT_STATUS(bank)			(0x00000080 + ((bank) << 2))
 #define GPIO_INT_MASK(bank)			(0x000000a0 + ((bank) << 2))
 #define GPIO_INT_MSKCLR(bank)			(0x000000c0 + ((bank) << 2))
 #define GPIO_PWD_STATUS(bank)			(0x00000500 + ((bank) << 2))

 #define GPIO_GPPWR_OFFSET			0x00000520

 #define GPIO_GPCTR0_DBR_SHIFT			5
 #define GPIO_GPCTR0_DBR_MASK			0x000001e0

 #define GPIO_GPCTR0_ITR_SHIFT			3
 #define GPIO_GPCTR0_ITR_MASK			0x00000018
 #define GPIO_GPCTR0_ITR_CMD_RISING_EDGE		0x00000001
 #define GPIO_GPCTR0_ITR_CMD_FALLING_EDGE	0x00000002
 #define GPIO_GPCTR0_ITR_CMD_BOTH_EDGE		0x00000003

 #define GPIO_GPCTR0_IOTR_MASK			0x00000001
 #define GPIO_GPCTR0_IOTR_CMD_0UTPUT		0x00000000
 #define GPIO_GPCTR0_IOTR_CMD_INPUT		0x00000001

 #define GPIO_GPCTR0_DB_ENABLE_MASK		0x00000100

 #define LOCK_CODE				0xffffffff
 #define UNLOCK_CODE				0x00000000

 struct bcm_kona_gpio {
 	void __iomem *reg_base;
 	int num_bank;
 	spinlock_t lock;
 	struct gpio_chip gpio_chip;
 	struct irq_domain *irq_domain;
 	struct bcm_kona_gpio_bank *banks;
 	struct platform_device *pdev;
 };

 struct bcm_kona_gpio_bank {
 	int id;
 	int irq;
 	/* Used in the interrupt handler */
 	struct bcm_kona_gpio *kona_gpio;
 };

 static inline struct bcm_kona_gpio *to_kona_gpio(struct gpio_chip *chip)
 {
 	return container_of(chip, struct bcm_kona_gpio, gpio_chip);
 }

 static inline void bcm_kona_gpio_write_lock_regs(void __iomem *reg_base,
 						int bank_id, u32 lockcode)
 {
 	writel(BCM_GPIO_PASSWD, reg_base + GPIO_GPPWR_OFFSET);
 	writel(lockcode, reg_base + GPIO_PWD_STATUS(bank_id));
 }

 static void bcm_kona_gpio_lock_gpio(struct bcm_kona_gpio *kona_gpio,
 					unsigned gpio)
 {
 	u32 val;
 	unsigned long flags;
 	int bank_id = GPIO_BANK(gpio);

 	spin_lock_irqsave(&kona_gpio->lock, flags);

 	val = readl(kona_gpio->reg_base + GPIO_PWD_STATUS(bank_id));
 	val |= BIT(gpio);
 	bcm_kona_gpio_write_lock_regs(kona_gpio->reg_base, bank_id, val);

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

 static void bcm_kona_gpio_unlock_gpio(struct bcm_kona_gpio *kona_gpio,
 					unsigned gpio)
 {
 	u32 val;
 	unsigned long flags;
 	int bank_id = GPIO_BANK(gpio);

 	spin_lock_irqsave(&kona_gpio->lock, flags);

 	val = readl(kona_gpio->reg_base + GPIO_PWD_STATUS(bank_id));
 	val &= ~BIT(gpio);
 	bcm_kona_gpio_write_lock_regs(kona_gpio->reg_base, bank_id, val);

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

 static int bcm_kona_gpio_get_dir(struct gpio_chip *chip, unsigned gpio)
 {
 	struct bcm_kona_gpio *kona_gpio = to_kona_gpio(chip);
 	void __iomem *reg_base = kona_gpio->reg_base;
 	u32 val;

 	val = readl(reg_base + GPIO_CONTROL(gpio)) & GPIO_GPCTR0_IOTR_MASK;
 	return val ? GPIOF_DIR_IN : GPIOF_DIR_OUT;
 }

 static void bcm_kona_gpio_set(struct gpio_chip *chip, unsigned gpio, int value)
 {
 	struct bcm_kona_gpio *kona_gpio;
 	void __iomem *reg_base;
 	int bank_id = GPIO_BANK(gpio);
 	int bit = GPIO_BIT(gpio);
 	u32 val, reg_offset;
 	unsigned long flags;

 	kona_gpio = to_kona_gpio(chip);
 	reg_base = kona_gpio->reg_base;
 	spin_lock_irqsave(&kona_gpio->lock, flags);

 	/* this function only applies to output pin */
 	if (bcm_kona_gpio_get_dir(chip, gpio) == GPIOF_DIR_IN)
 		goto out;

 	reg_offset = value ? GPIO_OUT_SET(bank_id) : GPIO_OUT_CLEAR(bank_id);

 	val = readl(reg_base + reg_offset);
 	val |= BIT(bit);
 	writel(val, reg_base + reg_offset);

 out:
 	spin_unlock_irqrestore(&kona_gpio->lock, flags);
 }

 static int bcm_kona_gpio_get(struct gpio_chip *chip, unsigned gpio)
 {
 	struct bcm_kona_gpio *kona_gpio;
 	void __iomem *reg_base;
 	int bank_id = GPIO_BANK(gpio);
 	int bit = GPIO_BIT(gpio);
 	u32 val, reg_offset;
 	unsigned long flags;

 	kona_gpio = to_kona_gpio(chip);
 	reg_base = kona_gpio->reg_base;
 	spin_lock_irqsave(&kona_gpio->lock, flags);

 	if (bcm_kona_gpio_get_dir(chip, gpio) == GPIOF_DIR_IN)
 		reg_offset = GPIO_IN_STATUS(bank_id);
 	else
 		reg_offset = GPIO_OUT_STATUS(bank_id);

 	/* read the GPIO bank status */
 	val = readl(reg_base + reg_offset);

 	spin_unlock_irqrestore(&kona_gpio->lock, flags);

 	/* return the specified bit status */
 	return !!(val & BIT(bit));
 }

 static int bcm_kona_gpio_request(struct gpio_chip *chip, unsigned gpio)
 {
 	struct bcm_kona_gpio *kona_gpio = to_kona_gpio(chip);

 	bcm_kona_gpio_unlock_gpio(kona_gpio, gpio);
 	return 0;
 }

 static void bcm_kona_gpio_free(struct gpio_chip *chip, unsigned gpio)
 {
 	struct bcm_kona_gpio *kona_gpio = to_kona_gpio(chip);

 	bcm_kona_gpio_lock_gpio(kona_gpio, gpio);
 }

 static int bcm_kona_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
 {
 	struct bcm_kona_gpio *kona_gpio;
 	void __iomem *reg_base;
 	u32 val;
 	unsigned long flags;

 	kona_gpio = to_kona_gpio(chip);
 	reg_base = kona_gpio->reg_base;
 	spin_lock_irqsave(&kona_gpio->lock, flags);

 	val = readl(reg_base + GPIO_CONTROL(gpio));
 	val &= ~GPIO_GPCTR0_IOTR_MASK;
 	val |= GPIO_GPCTR0_IOTR_CMD_INPUT;
 	writel(val, reg_base + GPIO_CONTROL(gpio));

 	spin_unlock_irqrestore(&kona_gpio->lock, flags);

 	return 0;
 }

 static int bcm_kona_gpio_direction_output(struct gpio_chip *chip,
 					  unsigned gpio, int value)
 {
 	struct bcm_kona_gpio *kona_gpio;
 	void __iomem *reg_base;
 	int bank_id = GPIO_BANK(gpio);
 	int bit = GPIO_BIT(gpio);
 	u32 val, reg_offset;
 	unsigned long flags;

 	kona_gpio = to_kona_gpio(chip);
 	reg_base = kona_gpio->reg_base;
 	spin_lock_irqsave(&kona_gpio->lock, flags);

 	val = readl(reg_base + GPIO_CONTROL(gpio));
 	val &= ~GPIO_GPCTR0_IOTR_MASK;
 	val |= GPIO_GPCTR0_IOTR_CMD_0UTPUT;
 	writel(val, reg_base + GPIO_CONTROL(gpio));
 	reg_offset = value ? GPIO_OUT_SET(bank_id) : GPIO_OUT_CLEAR(bank_id);

 	val = readl(reg_base + reg_offset);
 	val |= BIT(bit);
 	writel(val, reg_base + reg_offset);

 	spin_unlock_irqrestore(&kona_gpio->lock, flags);

 	return 0;
 }

 static int bcm_kona_gpio_to_irq(struct gpio_chip *chip, unsigned gpio)
 {
 	struct bcm_kona_gpio *kona_gpio;

 	kona_gpio = to_kona_gpio(chip);
 	if (gpio >= kona_gpio->gpio_chip.ngpio)
 		return -ENXIO;
 	return irq_create_mapping(kona_gpio->irq_domain, gpio);
 }

 static int bcm_kona_gpio_set_debounce(struct gpio_chip *chip, unsigned gpio,
 				      unsigned debounce)
 {
 	struct bcm_kona_gpio *kona_gpio;
 	void __iomem *reg_base;
 	u32 val, res;
 	unsigned long flags;

 	kona_gpio = to_kona_gpio(chip);
 	reg_base = kona_gpio->reg_base;
 	/* debounce must be 1-128ms (or 0) */
 	if ((debounce > 0 && debounce < 1000) || debounce > 128000) {
 		dev_err(chip->dev, "Debounce value %u not in range\n",
 			debounce);
 		return -EINVAL;
 	}

 	/* calculate debounce bit value */
 	if (debounce != 0) {
 		/* Convert to ms */
 		debounce /= 1000;
 		/* find the MSB */
 		res = fls(debounce) - 1;
 		/* Check if MSB-1 is set (round up or down) */
 		if (res > 0 && (debounce & BIT(res - 1)))
 			res++;
 	}

 	/* spin lock for read-modify-write of the GPIO register */
 	spin_lock_irqsave(&kona_gpio->lock, flags);

 	val = readl(reg_base + GPIO_CONTROL(gpio));
 	val &= ~GPIO_GPCTR0_DBR_MASK;

 	if (debounce == 0) {
 		/* disable debounce */
 		val &= ~GPIO_GPCTR0_DB_ENABLE_MASK;
 	} else {
 		val |= GPIO_GPCTR0_DB_ENABLE_MASK |
 		    (res << GPIO_GPCTR0_DBR_SHIFT);
 	}

 	writel(val, reg_base + GPIO_CONTROL(gpio));

 	spin_unlock_irqrestore(&kona_gpio->lock, flags);

 	return 0;
 }

 static struct gpio_chip template_chip = {
 	.label = "bcm-kona-gpio",
 	.owner = THIS_MODULE,
 	.request = bcm_kona_gpio_request,
 	.free = bcm_kona_gpio_free,
 	.get_direction = bcm_kona_gpio_get_dir,
 	.direction_input = bcm_kona_gpio_direction_input,
 	.get = bcm_kona_gpio_get,
 	.direction_output = bcm_kona_gpio_direction_output,
 	.set = bcm_kona_gpio_set,
 	.set_debounce = bcm_kona_gpio_set_debounce,
 	.to_irq = bcm_kona_gpio_to_irq,
 	.base = 0,
 };

 static void bcm_kona_gpio_irq_ack(struct irq_data *d)
 {
 	struct bcm_kona_gpio *kona_gpio;
 	void __iomem *reg_base;
 	unsigned gpio = d->hwirq;
 	int bank_id = GPIO_BANK(gpio);
 	int bit = GPIO_BIT(gpio);
 	u32 val;
 	unsigned long flags;

 	kona_gpio = irq_data_get_irq_chip_data(d);
 	reg_base = kona_gpio->reg_base;
 	spin_lock_irqsave(&kona_gpio->lock, flags);

 	val = readl(reg_base + GPIO_INT_STATUS(bank_id));
 	val |= BIT(bit);
 	writel(val, reg_base + GPIO_INT_STATUS(bank_id));

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

 static void bcm_kona_gpio_irq_mask(struct irq_data *d)
 {
 	struct bcm_kona_gpio *kona_gpio;
 	void __iomem *reg_base;
 	unsigned gpio = d->hwirq;
 	int bank_id = GPIO_BANK(gpio);
 	int bit = GPIO_BIT(gpio);
 	u32 val;
 	unsigned long flags;

 	kona_gpio = irq_data_get_irq_chip_data(d);
 	reg_base = kona_gpio->reg_base;
 	spin_lock_irqsave(&kona_gpio->lock, flags);

 	val = readl(reg_base + GPIO_INT_MASK(bank_id));
 	val |= BIT(bit);
 	writel(val, reg_base + GPIO_INT_MASK(bank_id));

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

 static void bcm_kona_gpio_irq_unmask(struct irq_data *d)
 {
 	struct bcm_kona_gpio *kona_gpio;
 	void __iomem *reg_base;
 	unsigned gpio = d->hwirq;
 	int bank_id = GPIO_BANK(gpio);
 	int bit = GPIO_BIT(gpio);
 	u32 val;
 	unsigned long flags;

 	kona_gpio = irq_data_get_irq_chip_data(d);
 	reg_base = kona_gpio->reg_base;
 	spin_lock_irqsave(&kona_gpio->lock, flags);

 	val = readl(reg_base + GPIO_INT_MSKCLR(bank_id));
 	val |= BIT(bit);
 	writel(val, reg_base + GPIO_INT_MSKCLR(bank_id));

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

 static int bcm_kona_gpio_irq_set_type(struct irq_data *d, unsigned int type)
 {
 	struct bcm_kona_gpio *kona_gpio;
 	void __iomem *reg_base;
 	unsigned gpio = d->hwirq;
 	u32 lvl_type;
 	u32 val;
 	unsigned long flags;

 	kona_gpio = irq_data_get_irq_chip_data(d);
 	reg_base = kona_gpio->reg_base;
 	switch (type & IRQ_TYPE_SENSE_MASK) {
 	case IRQ_TYPE_EDGE_RISING:
 		lvl_type = GPIO_GPCTR0_ITR_CMD_RISING_EDGE;
 		break;

 	case IRQ_TYPE_EDGE_FALLING:
 		lvl_type = GPIO_GPCTR0_ITR_CMD_FALLING_EDGE;
 		break;

 	case IRQ_TYPE_EDGE_BOTH:
 		lvl_type = GPIO_GPCTR0_ITR_CMD_BOTH_EDGE;
 		break;

 	case IRQ_TYPE_LEVEL_HIGH:
 	case IRQ_TYPE_LEVEL_LOW:
 		/* BCM GPIO doesn't support level triggering */
 	default:
 		dev_err(kona_gpio->gpio_chip.dev,
 			"Invalid BCM GPIO irq type 0x%x\n", type);
 		return -EINVAL;
 	}

 	spin_lock_irqsave(&kona_gpio->lock, flags);

 	val = readl(reg_base + GPIO_CONTROL(gpio));
 	val &= ~GPIO_GPCTR0_ITR_MASK;
 	val |= lvl_type << GPIO_GPCTR0_ITR_SHIFT;
 	writel(val, reg_base + GPIO_CONTROL(gpio));

 	spin_unlock_irqrestore(&kona_gpio->lock, flags);

 	return 0;
 }

 static void bcm_kona_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
 {
 	void __iomem *reg_base;
 	int bit, bank_id;
 	unsigned long sta;
 	struct bcm_kona_gpio_bank *bank = irq_get_handler_data(irq);
 	struct irq_chip *chip = irq_desc_get_chip(desc);

 	chained_irq_enter(chip, desc);

 	/*
 	 * For bank interrupts, we can't use chip_data to store the kona_gpio
 	 * pointer, since GIC needs it for its own purposes. Therefore, we get
 	 * our pointer from the bank structure.
 	 */
 	reg_base = bank->kona_gpio->reg_base;
 	bank_id = bank->id;

 	while ((sta = readl(reg_base + GPIO_INT_STATUS(bank_id)) &
 		    (~(readl(reg_base + GPIO_INT_MASK(bank_id)))))) {
 		for_each_set_bit(bit, &sta, 32) {
 			int hwirq = GPIO_PER_BANK * bank_id + bit;
 			int child_irq =
 				irq_find_mapping(bank->kona_gpio->irq_domain,
 						 hwirq);
 			/*
 			 * Clear interrupt before handler is called so we don't
 			 * miss any interrupt occurred during executing them.
 			 */
 			writel(readl(reg_base + GPIO_INT_STATUS(bank_id)) |
 			       BIT(bit), reg_base + GPIO_INT_STATUS(bank_id));
 			/* Invoke interrupt handler */
 			generic_handle_irq(child_irq);
 		}
 	}

 	chained_irq_exit(chip, desc);
 }

 static int bcm_kona_gpio_irq_reqres(struct irq_data *d)
 {
 	struct bcm_kona_gpio *kona_gpio = irq_data_get_irq_chip_data(d);

 	if (gpiochip_lock_as_irq(&kona_gpio->gpio_chip, d->hwirq)) {
 		dev_err(kona_gpio->gpio_chip.dev,
 			"unable to lock HW IRQ %lu for IRQ\n",
 			d->hwirq);
 		return -EINVAL;
 	}
 	return 0;
 }

 static void bcm_kona_gpio_irq_relres(struct irq_data *d)
 {
 	struct bcm_kona_gpio *kona_gpio = irq_data_get_irq_chip_data(d);

 	gpiochip_unlock_as_irq(&kona_gpio->gpio_chip, d->hwirq);
 }

 static struct irq_chip bcm_gpio_irq_chip = {
 	.name = "bcm-kona-gpio",
 	.irq_ack = bcm_kona_gpio_irq_ack,
 	.irq_mask = bcm_kona_gpio_irq_mask,
 	.irq_unmask = bcm_kona_gpio_irq_unmask,
 	.irq_set_type = bcm_kona_gpio_irq_set_type,
 	.irq_request_resources = bcm_kona_gpio_irq_reqres,
 	.irq_release_resources = bcm_kona_gpio_irq_relres,
 };

 static struct of_device_id const bcm_kona_gpio_of_match[] = {
 	{ .compatible = "brcm,kona-gpio" },
 	{}
 };

 MODULE_DEVICE_TABLE(of, bcm_kona_gpio_of_match);

 /*
  * 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;

 static int bcm_kona_gpio_irq_map(struct irq_domain *d, unsigned int irq,
 				 irq_hw_number_t hwirq)
 {
 	int ret;

 	ret = irq_set_chip_data(irq, d->host_data);
 	if (ret < 0)
 		return ret;
 	irq_set_lockdep_class(irq, &gpio_lock_class);
 	irq_set_chip_and_handler(irq, &bcm_gpio_irq_chip, handle_simple_irq);
 #ifdef CONFIG_ARM
 	set_irq_flags(irq, IRQF_VALID);
 #else
 	irq_set_noprobe(irq);
 #endif

 	return 0;
 }

 static void bcm_kona_gpio_irq_unmap(struct irq_domain *d, unsigned int irq)
 {
 	irq_set_chip_and_handler(irq, NULL, NULL);
 	irq_set_chip_data(irq, NULL);
 }

 static struct irq_domain_ops bcm_kona_irq_ops = {
 	.map = bcm_kona_gpio_irq_map,
 	.unmap = bcm_kona_gpio_irq_unmap,
 	.xlate = irq_domain_xlate_twocell,
 };

 static void bcm_kona_gpio_reset(struct bcm_kona_gpio *kona_gpio)
 {
 	void __iomem *reg_base;
 	int i;

 	reg_base = kona_gpio->reg_base;
 	/* disable interrupts and clear status */
 	for (i = 0; i < kona_gpio->num_bank; i++) {
 		/* Unlock the entire bank first */
 		bcm_kona_gpio_write_lock_regs(kona_gpio, i, UNLOCK_CODE);
 		writel(0xffffffff, reg_base + GPIO_INT_MASK(i));
 		writel(0xffffffff, reg_base + GPIO_INT_STATUS(i));
 		/* Now re-lock the bank */
 		bcm_kona_gpio_write_lock_regs(kona_gpio, i, LOCK_CODE);
 	}
 }

 static int bcm_kona_gpio_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	const struct of_device_id *match;
 	struct resource *res;
 	struct bcm_kona_gpio_bank *bank;
 	struct bcm_kona_gpio *kona_gpio;
 	struct gpio_chip *chip;
 	int ret;
 	int i;

 	match = of_match_device(bcm_kona_gpio_of_match, dev);
 	if (!match) {
 		dev_err(dev, "Failed to find gpio controller\n");
 		return -ENODEV;
 	}

 	kona_gpio = devm_kzalloc(dev, sizeof(*kona_gpio), GFP_KERNEL);
 	if (!kona_gpio)
 		return -ENOMEM;

 	kona_gpio->gpio_chip = template_chip;
 	chip = &kona_gpio->gpio_chip;
 	kona_gpio->num_bank = of_irq_count(dev->of_node);
 	if (kona_gpio->num_bank == 0) {
 		dev_err(dev, "Couldn't determine # GPIO banks\n");
 		return -ENOENT;
 	}
 	if (kona_gpio->num_bank > GPIO_MAX_BANK_NUM) {
 		dev_err(dev, "Too many GPIO banks configured (max=%d)\n",
 			GPIO_MAX_BANK_NUM);
 		return -ENXIO;
 	}
 	kona_gpio->banks = devm_kzalloc(dev,
 					kona_gpio->num_bank *
 					sizeof(*kona_gpio->banks), GFP_KERNEL);
 	if (!kona_gpio->banks)
 		return -ENOMEM;

 	kona_gpio->pdev = pdev;
 	platform_set_drvdata(pdev, kona_gpio);
 	chip->of_node = dev->of_node;
 	chip->ngpio = kona_gpio->num_bank * GPIO_PER_BANK;

 	kona_gpio->irq_domain = irq_domain_add_linear(dev->of_node,
 						      chip->ngpio,
 						      &bcm_kona_irq_ops,
 						      kona_gpio);
 	if (!kona_gpio->irq_domain) {
 		dev_err(dev, "Couldn't allocate IRQ domain\n");
 		return -ENXIO;
 	}

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	kona_gpio->reg_base = devm_ioremap_resource(dev, res);
 	if (IS_ERR(kona_gpio->reg_base)) {
 		ret = -ENXIO;
 		goto err_irq_domain;
 	}

 	for (i = 0; i < kona_gpio->num_bank; i++) {
 		bank = &kona_gpio->banks[i];
 		bank->id = i;
 		bank->irq = platform_get_irq(pdev, i);
 		bank->kona_gpio = kona_gpio;
 		if (bank->irq < 0) {
 			dev_err(dev, "Couldn't get IRQ for bank %d", i);
 			ret = -ENOENT;
 			goto err_irq_domain;
 		}
 	}

 	dev_info(&pdev->dev, "Setting up Kona GPIO\n");

 	bcm_kona_gpio_reset(kona_gpio);

 	ret = gpiochip_add(chip);
 	if (ret < 0) {
 		dev_err(dev, "Couldn't add GPIO chip -- %d\n", ret);
 		goto err_irq_domain;
 	}
 	for (i = 0; i < chip->ngpio; i++) {
 		int irq = bcm_kona_gpio_to_irq(chip, i);
 		irq_set_lockdep_class(irq, &gpio_lock_class);
 		irq_set_chip_and_handler(irq, &bcm_gpio_irq_chip,
 					 handle_simple_irq);
 #ifdef CONFIG_ARM
 		set_irq_flags(irq, IRQF_VALID);
 #else
 		irq_set_noprobe(irq);
 #endif
 	}
 	for (i = 0; i < kona_gpio->num_bank; i++) {
 		bank = &kona_gpio->banks[i];
 		irq_set_chained_handler(bank->irq, bcm_kona_gpio_irq_handler);
 		irq_set_handler_data(bank->irq, bank);
 	}

 	spin_lock_init(&kona_gpio->lock);

 	return 0;

 err_irq_domain:
 	irq_domain_remove(kona_gpio->irq_domain);

 	return ret;
 }

 static struct platform_driver bcm_kona_gpio_driver = {
 	.driver = {
 			.name = "bcm-kona-gpio",
 			.of_match_table = bcm_kona_gpio_of_match,
 	},
 	.probe = bcm_kona_gpio_probe,
 };

 module_platform_driver(bcm_kona_gpio_driver);

 MODULE_AUTHOR("Broadcom Corporation <bcm-kernel-feedback-list@broadcom.com>");
 MODULE_DESCRIPTION("Broadcom Kona GPIO Driver");
 MODULE_LICENSE("GPL v2");
	/*
	* Copyright (C) 2012-2014 Broadcom Corporation
	*
	* 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 version 2.
	*
	* This program is distributed "as is" WITHOUT ANY WARRANTY of any
	* kind, whether express or implied; without even the implied warranty
	* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*/

	#include <linux/bitops.h>
	#include <linux/err.h>
	#include <linux/io.h>
	#include <linux/gpio.h>
	#include <linux/of_device.h>
	#include <linux/of_irq.h>
	#include <linux/module.h>
	#include <linux/irqdomain.h>
	#include <linux/irqchip/chained_irq.h>

	#define BCM_GPIO_PASSWD 0x00a5a501
	#define GPIO_PER_BANK 32
	#define GPIO_MAX_BANK_NUM 8

	#define GPIO_BANK(gpio) ((gpio) >> 5)
	#define GPIO_BIT(gpio) ((gpio) & (GPIO_PER_BANK - 1))

	/* There is a GPIO control register for each GPIO */
	#define GPIO_CONTROL(gpio) (0x00000100 + ((gpio) << 2))

	/* The remaining registers are per GPIO bank */
	#define GPIO_OUT_STATUS(bank) (0x00000000 + ((bank) << 2))
	#define GPIO_IN_STATUS(bank) (0x00000020 + ((bank) << 2))
	#define GPIO_OUT_SET(bank) (0x00000040 + ((bank) << 2))
	#define GPIO_OUT_CLEAR(bank) (0x00000060 + ((bank) << 2))
	#define GPIO_INT_STATUS(bank) (0x00000080 + ((bank) << 2))
	#define GPIO_INT_MASK(bank) (0x000000a0 + ((bank) << 2))
	#define GPIO_INT_MSKCLR(bank) (0x000000c0 + ((bank) << 2))
	#define GPIO_PWD_STATUS(bank) (0x00000500 + ((bank) << 2))

	#define GPIO_GPPWR_OFFSET 0x00000520

	#define GPIO_GPCTR0_DBR_SHIFT 5
	#define GPIO_GPCTR0_DBR_MASK 0x000001e0

	#define GPIO_GPCTR0_ITR_SHIFT 3
	#define GPIO_GPCTR0_ITR_MASK 0x00000018
	#define GPIO_GPCTR0_ITR_CMD_RISING_EDGE 0x00000001
	#define GPIO_GPCTR0_ITR_CMD_FALLING_EDGE 0x00000002
	#define GPIO_GPCTR0_ITR_CMD_BOTH_EDGE 0x00000003

	#define GPIO_GPCTR0_IOTR_MASK 0x00000001
	#define GPIO_GPCTR0_IOTR_CMD_0UTPUT 0x00000000
	#define GPIO_GPCTR0_IOTR_CMD_INPUT 0x00000001

	#define GPIO_GPCTR0_DB_ENABLE_MASK 0x00000100

	#define LOCK_CODE 0xffffffff
	#define UNLOCK_CODE 0x00000000

	struct bcm_kona_gpio {
	void __iomem *reg_base;
	int num_bank;
	spinlock_t lock;
	struct gpio_chip gpio_chip;
	struct irq_domain *irq_domain;
	struct bcm_kona_gpio_bank *banks;
	struct platform_device *pdev;
	};

	struct bcm_kona_gpio_bank {
	int id;
	int irq;
	/* Used in the interrupt handler */
	struct bcm_kona_gpio *kona_gpio;
	};

	static inline struct bcm_kona_gpio to_kona_gpio(struct gpio_chip chip)
	{
	return container_of(chip, struct bcm_kona_gpio, gpio_chip);
	}

	static inline void bcm_kona_gpio_write_lock_regs(void __iomem *reg_base,
	int bank_id, u32 lockcode)
	{
	writel(BCM_GPIO_PASSWD, reg_base + GPIO_GPPWR_OFFSET);
	writel(lockcode, reg_base + GPIO_PWD_STATUS(bank_id));
	}

	static void bcm_kona_gpio_lock_gpio(struct bcm_kona_gpio *kona_gpio,
	unsigned gpio)
	{
	u32 val;
	unsigned long flags;
	int bank_id = GPIO_BANK(gpio);

	spin_lock_irqsave(&kona_gpio->lock, flags);

	val = readl(kona_gpio->reg_base + GPIO_PWD_STATUS(bank_id));
	val \|= BIT(gpio);
	bcm_kona_gpio_write_lock_regs(kona_gpio->reg_base, bank_id, val);

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

	static void bcm_kona_gpio_unlock_gpio(struct bcm_kona_gpio *kona_gpio,
	unsigned gpio)
	{
	u32 val;
	unsigned long flags;
	int bank_id = GPIO_BANK(gpio);

	spin_lock_irqsave(&kona_gpio->lock, flags);

	val = readl(kona_gpio->reg_base + GPIO_PWD_STATUS(bank_id));
	val &= ~BIT(gpio);
	bcm_kona_gpio_write_lock_regs(kona_gpio->reg_base, bank_id, val);

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

	static int bcm_kona_gpio_get_dir(struct gpio_chip *chip, unsigned gpio)
	{
	struct bcm_kona_gpio *kona_gpio = to_kona_gpio(chip);
	void __iomem *reg_base = kona_gpio->reg_base;
	u32 val;

	val = readl(reg_base + GPIO_CONTROL(gpio)) & GPIO_GPCTR0_IOTR_MASK;
	return val ? GPIOF_DIR_IN : GPIOF_DIR_OUT;
	}

	static void bcm_kona_gpio_set(struct gpio_chip *chip, unsigned gpio, int value)
	{
	struct bcm_kona_gpio *kona_gpio;
	void __iomem *reg_base;
	int bank_id = GPIO_BANK(gpio);
	int bit = GPIO_BIT(gpio);
	u32 val, reg_offset;
	unsigned long flags;

	kona_gpio = to_kona_gpio(chip);
	reg_base = kona_gpio->reg_base;
	spin_lock_irqsave(&kona_gpio->lock, flags);

	/* this function only applies to output pin */
	if (bcm_kona_gpio_get_dir(chip, gpio) == GPIOF_DIR_IN)
	goto out;

	reg_offset = value ? GPIO_OUT_SET(bank_id) : GPIO_OUT_CLEAR(bank_id);

	val = readl(reg_base + reg_offset);
	val \|= BIT(bit);
	writel(val, reg_base + reg_offset);

	out:
	spin_unlock_irqrestore(&kona_gpio->lock, flags);
	}

	static int bcm_kona_gpio_get(struct gpio_chip *chip, unsigned gpio)
	{
	struct bcm_kona_gpio *kona_gpio;
	void __iomem *reg_base;
	int bank_id = GPIO_BANK(gpio);
	int bit = GPIO_BIT(gpio);
	u32 val, reg_offset;
	unsigned long flags;

	kona_gpio = to_kona_gpio(chip);
	reg_base = kona_gpio->reg_base;
	spin_lock_irqsave(&kona_gpio->lock, flags);

	if (bcm_kona_gpio_get_dir(chip, gpio) == GPIOF_DIR_IN)
	reg_offset = GPIO_IN_STATUS(bank_id);
	else
	reg_offset = GPIO_OUT_STATUS(bank_id);

	/* read the GPIO bank status */
	val = readl(reg_base + reg_offset);

	spin_unlock_irqrestore(&kona_gpio->lock, flags);

	/* return the specified bit status */
	return !!(val & BIT(bit));
	}

	static int bcm_kona_gpio_request(struct gpio_chip *chip, unsigned gpio)
	{
	struct bcm_kona_gpio *kona_gpio = to_kona_gpio(chip);

	bcm_kona_gpio_unlock_gpio(kona_gpio, gpio);
	return 0;
	}

	static void bcm_kona_gpio_free(struct gpio_chip *chip, unsigned gpio)
	{
	struct bcm_kona_gpio *kona_gpio = to_kona_gpio(chip);

	bcm_kona_gpio_lock_gpio(kona_gpio, gpio);
	}

	static int bcm_kona_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
	{
	struct bcm_kona_gpio *kona_gpio;
	void __iomem *reg_base;
	u32 val;
	unsigned long flags;

	kona_gpio = to_kona_gpio(chip);
	reg_base = kona_gpio->reg_base;
	spin_lock_irqsave(&kona_gpio->lock, flags);

	val = readl(reg_base + GPIO_CONTROL(gpio));
	val &= ~GPIO_GPCTR0_IOTR_MASK;
	val \|= GPIO_GPCTR0_IOTR_CMD_INPUT;
	writel(val, reg_base + GPIO_CONTROL(gpio));

	spin_unlock_irqrestore(&kona_gpio->lock, flags);

	return 0;
	}

	static int bcm_kona_gpio_direction_output(struct gpio_chip *chip,
	unsigned gpio, int value)
	{
	struct bcm_kona_gpio *kona_gpio;
	void __iomem *reg_base;
	int bank_id = GPIO_BANK(gpio);
	int bit = GPIO_BIT(gpio);
	u32 val, reg_offset;
	unsigned long flags;

	kona_gpio = to_kona_gpio(chip);
	reg_base = kona_gpio->reg_base;
	spin_lock_irqsave(&kona_gpio->lock, flags);

	val = readl(reg_base + GPIO_CONTROL(gpio));
	val &= ~GPIO_GPCTR0_IOTR_MASK;
	val \|= GPIO_GPCTR0_IOTR_CMD_0UTPUT;
	writel(val, reg_base + GPIO_CONTROL(gpio));
	reg_offset = value ? GPIO_OUT_SET(bank_id) : GPIO_OUT_CLEAR(bank_id);

	val = readl(reg_base + reg_offset);
	val \|= BIT(bit);
	writel(val, reg_base + reg_offset);

	spin_unlock_irqrestore(&kona_gpio->lock, flags);

	return 0;
	}

	static int bcm_kona_gpio_to_irq(struct gpio_chip *chip, unsigned gpio)
	{
	struct bcm_kona_gpio *kona_gpio;

	kona_gpio = to_kona_gpio(chip);
	if (gpio >= kona_gpio->gpio_chip.ngpio)
	return -ENXIO;
	return irq_create_mapping(kona_gpio->irq_domain, gpio);
	}

	static int bcm_kona_gpio_set_debounce(struct gpio_chip *chip, unsigned gpio,
	unsigned debounce)
	{
	struct bcm_kona_gpio *kona_gpio;
	void __iomem *reg_base;
	u32 val, res;
	unsigned long flags;

	kona_gpio = to_kona_gpio(chip);
	reg_base = kona_gpio->reg_base;
	/* debounce must be 1-128ms (or 0) */
	if ((debounce > 0 && debounce < 1000) \|\| debounce > 128000) {
	dev_err(chip->dev, "Debounce value %u not in range\n",
	debounce);
	return -EINVAL;
	}

	/* calculate debounce bit value */
	if (debounce != 0) {
	/* Convert to ms */
	debounce /= 1000;
	/* find the MSB */
	res = fls(debounce) - 1;
	/* Check if MSB-1 is set (round up or down) */
	if (res > 0 && (debounce & BIT(res - 1)))
	res++;
	}

	/* spin lock for read-modify-write of the GPIO register */
	spin_lock_irqsave(&kona_gpio->lock, flags);

	val = readl(reg_base + GPIO_CONTROL(gpio));
	val &= ~GPIO_GPCTR0_DBR_MASK;

	if (debounce == 0) {
	/* disable debounce */
	val &= ~GPIO_GPCTR0_DB_ENABLE_MASK;
	} else {
	val \|= GPIO_GPCTR0_DB_ENABLE_MASK \|
	(res << GPIO_GPCTR0_DBR_SHIFT);
	}

	writel(val, reg_base + GPIO_CONTROL(gpio));

	spin_unlock_irqrestore(&kona_gpio->lock, flags);

	return 0;
	}

	static struct gpio_chip template_chip = {
	.label = "bcm-kona-gpio",
	.owner = THIS_MODULE,
	.request = bcm_kona_gpio_request,
	.free = bcm_kona_gpio_free,
	.get_direction = bcm_kona_gpio_get_dir,
	.direction_input = bcm_kona_gpio_direction_input,
	.get = bcm_kona_gpio_get,
	.direction_output = bcm_kona_gpio_direction_output,
	.set = bcm_kona_gpio_set,
	.set_debounce = bcm_kona_gpio_set_debounce,
	.to_irq = bcm_kona_gpio_to_irq,
	.base = 0,
	};

	static void bcm_kona_gpio_irq_ack(struct irq_data *d)
	{
	struct bcm_kona_gpio *kona_gpio;
	void __iomem *reg_base;
	unsigned gpio = d->hwirq;
	int bank_id = GPIO_BANK(gpio);
	int bit = GPIO_BIT(gpio);
	u32 val;
	unsigned long flags;

	kona_gpio = irq_data_get_irq_chip_data(d);
	reg_base = kona_gpio->reg_base;
	spin_lock_irqsave(&kona_gpio->lock, flags);

	val = readl(reg_base + GPIO_INT_STATUS(bank_id));
	val \|= BIT(bit);
	writel(val, reg_base + GPIO_INT_STATUS(bank_id));

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

	static void bcm_kona_gpio_irq_mask(struct irq_data *d)
	{
	struct bcm_kona_gpio *kona_gpio;
	void __iomem *reg_base;
	unsigned gpio = d->hwirq;
	int bank_id = GPIO_BANK(gpio);
	int bit = GPIO_BIT(gpio);
	u32 val;
	unsigned long flags;

	kona_gpio = irq_data_get_irq_chip_data(d);
	reg_base = kona_gpio->reg_base;
	spin_lock_irqsave(&kona_gpio->lock, flags);

	val = readl(reg_base + GPIO_INT_MASK(bank_id));
	val \|= BIT(bit);
	writel(val, reg_base + GPIO_INT_MASK(bank_id));

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

	static void bcm_kona_gpio_irq_unmask(struct irq_data *d)
	{
	struct bcm_kona_gpio *kona_gpio;
	void __iomem *reg_base;
	unsigned gpio = d->hwirq;
	int bank_id = GPIO_BANK(gpio);
	int bit = GPIO_BIT(gpio);
	u32 val;
	unsigned long flags;

	kona_gpio = irq_data_get_irq_chip_data(d);
	reg_base = kona_gpio->reg_base;
	spin_lock_irqsave(&kona_gpio->lock, flags);

	val = readl(reg_base + GPIO_INT_MSKCLR(bank_id));
	val \|= BIT(bit);
	writel(val, reg_base + GPIO_INT_MSKCLR(bank_id));

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

	static int bcm_kona_gpio_irq_set_type(struct irq_data *d, unsigned int type)
	{
	struct bcm_kona_gpio *kona_gpio;
	void __iomem *reg_base;
	unsigned gpio = d->hwirq;
	u32 lvl_type;
	u32 val;
	unsigned long flags;

	kona_gpio = irq_data_get_irq_chip_data(d);
	reg_base = kona_gpio->reg_base;
	switch (type & IRQ_TYPE_SENSE_MASK) {
	case IRQ_TYPE_EDGE_RISING:
	lvl_type = GPIO_GPCTR0_ITR_CMD_RISING_EDGE;
	break;

	case IRQ_TYPE_EDGE_FALLING:
	lvl_type = GPIO_GPCTR0_ITR_CMD_FALLING_EDGE;
	break;

	case IRQ_TYPE_EDGE_BOTH:
	lvl_type = GPIO_GPCTR0_ITR_CMD_BOTH_EDGE;
	break;

	case IRQ_TYPE_LEVEL_HIGH:
	case IRQ_TYPE_LEVEL_LOW:
	/* BCM GPIO doesn't support level triggering */
	default:
	dev_err(kona_gpio->gpio_chip.dev,
	"Invalid BCM GPIO irq type 0x%x\n", type);
	return -EINVAL;
	}

	spin_lock_irqsave(&kona_gpio->lock, flags);

	val = readl(reg_base + GPIO_CONTROL(gpio));
	val &= ~GPIO_GPCTR0_ITR_MASK;
	val \|= lvl_type << GPIO_GPCTR0_ITR_SHIFT;
	writel(val, reg_base + GPIO_CONTROL(gpio));

	spin_unlock_irqrestore(&kona_gpio->lock, flags);

	return 0;
	}

	static void bcm_kona_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
	{
	void __iomem *reg_base;
	int bit, bank_id;
	unsigned long sta;
	struct bcm_kona_gpio_bank *bank = irq_get_handler_data(irq);
	struct irq_chip *chip = irq_desc_get_chip(desc);

	chained_irq_enter(chip, desc);

	/*
	* For bank interrupts, we can't use chip_data to store the kona_gpio
	* pointer, since GIC needs it for its own purposes. Therefore, we get
	* our pointer from the bank structure.
	*/
	reg_base = bank->kona_gpio->reg_base;
	bank_id = bank->id;

	while ((sta = readl(reg_base + GPIO_INT_STATUS(bank_id)) &
	(~(readl(reg_base + GPIO_INT_MASK(bank_id)))))) {
	for_each_set_bit(bit, &sta, 32) {
	int hwirq = GPIO_PER_BANK * bank_id + bit;
	int child_irq =
	irq_find_mapping(bank->kona_gpio->irq_domain,
	hwirq);
	/*
	* Clear interrupt before handler is called so we don't
	* miss any interrupt occurred during executing them.
	*/
	writel(readl(reg_base + GPIO_INT_STATUS(bank_id)) \|
	BIT(bit), reg_base + GPIO_INT_STATUS(bank_id));
	/* Invoke interrupt handler */
	generic_handle_irq(child_irq);
	}
	}

	chained_irq_exit(chip, desc);
	}

	static int bcm_kona_gpio_irq_reqres(struct irq_data *d)
	{
	struct bcm_kona_gpio *kona_gpio = irq_data_get_irq_chip_data(d);

	if (gpiochip_lock_as_irq(&kona_gpio->gpio_chip, d->hwirq)) {
	dev_err(kona_gpio->gpio_chip.dev,
	"unable to lock HW IRQ %lu for IRQ\n",
	d->hwirq);
	return -EINVAL;
	}
	return 0;
	}

	static void bcm_kona_gpio_irq_relres(struct irq_data *d)
	{
	struct bcm_kona_gpio *kona_gpio = irq_data_get_irq_chip_data(d);

	gpiochip_unlock_as_irq(&kona_gpio->gpio_chip, d->hwirq);
	}

	static struct irq_chip bcm_gpio_irq_chip = {
	.name = "bcm-kona-gpio",
	.irq_ack = bcm_kona_gpio_irq_ack,
	.irq_mask = bcm_kona_gpio_irq_mask,
	.irq_unmask = bcm_kona_gpio_irq_unmask,
	.irq_set_type = bcm_kona_gpio_irq_set_type,
	.irq_request_resources = bcm_kona_gpio_irq_reqres,
	.irq_release_resources = bcm_kona_gpio_irq_relres,
	};

	static struct of_device_id const bcm_kona_gpio_of_match[] = {
	{ .compatible = "brcm,kona-gpio" },
	{}
	};

	MODULE_DEVICE_TABLE(of, bcm_kona_gpio_of_match);

	/*
	* 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;

	static int bcm_kona_gpio_irq_map(struct irq_domain *d, unsigned int irq,
	irq_hw_number_t hwirq)
	{
	int ret;

	ret = irq_set_chip_data(irq, d->host_data);
	if (ret < 0)
	return ret;
	irq_set_lockdep_class(irq, &gpio_lock_class);
	irq_set_chip_and_handler(irq, &bcm_gpio_irq_chip, handle_simple_irq);
	#ifdef CONFIG_ARM
	set_irq_flags(irq, IRQF_VALID);
	#else
	irq_set_noprobe(irq);
	#endif

	return 0;
	}

	static void bcm_kona_gpio_irq_unmap(struct irq_domain *d, unsigned int irq)
	{
	irq_set_chip_and_handler(irq, NULL, NULL);
	irq_set_chip_data(irq, NULL);
	}

	static struct irq_domain_ops bcm_kona_irq_ops = {
	.map = bcm_kona_gpio_irq_map,
	.unmap = bcm_kona_gpio_irq_unmap,
	.xlate = irq_domain_xlate_twocell,
	};

	static void bcm_kona_gpio_reset(struct bcm_kona_gpio *kona_gpio)
	{
	void __iomem *reg_base;
	int i;

	reg_base = kona_gpio->reg_base;
	/* disable interrupts and clear status */
	for (i = 0; i < kona_gpio->num_bank; i++) {
	/* Unlock the entire bank first */
	bcm_kona_gpio_write_lock_regs(kona_gpio, i, UNLOCK_CODE);
	writel(0xffffffff, reg_base + GPIO_INT_MASK(i));
	writel(0xffffffff, reg_base + GPIO_INT_STATUS(i));
	/* Now re-lock the bank */
	bcm_kona_gpio_write_lock_regs(kona_gpio, i, LOCK_CODE);
	}
	}

	static int bcm_kona_gpio_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	const struct of_device_id *match;
	struct resource *res;
	struct bcm_kona_gpio_bank *bank;
	struct bcm_kona_gpio *kona_gpio;
	struct gpio_chip *chip;
	int ret;
	int i;

	match = of_match_device(bcm_kona_gpio_of_match, dev);
	if (!match) {
	dev_err(dev, "Failed to find gpio controller\n");
	return -ENODEV;
	}

	kona_gpio = devm_kzalloc(dev, sizeof(*kona_gpio), GFP_KERNEL);
	if (!kona_gpio)
	return -ENOMEM;

	kona_gpio->gpio_chip = template_chip;
	chip = &kona_gpio->gpio_chip;
	kona_gpio->num_bank = of_irq_count(dev->of_node);
	if (kona_gpio->num_bank == 0) {
	dev_err(dev, "Couldn't determine # GPIO banks\n");
	return -ENOENT;
	}
	if (kona_gpio->num_bank > GPIO_MAX_BANK_NUM) {
	dev_err(dev, "Too many GPIO banks configured (max=%d)\n",
	GPIO_MAX_BANK_NUM);
	return -ENXIO;
	}
	kona_gpio->banks = devm_kzalloc(dev,
	kona_gpio->num_bank *
	sizeof(*kona_gpio->banks), GFP_KERNEL);
	if (!kona_gpio->banks)
	return -ENOMEM;

	kona_gpio->pdev = pdev;
	platform_set_drvdata(pdev, kona_gpio);
	chip->of_node = dev->of_node;
	chip->ngpio = kona_gpio->num_bank * GPIO_PER_BANK;

	kona_gpio->irq_domain = irq_domain_add_linear(dev->of_node,
	chip->ngpio,
	&bcm_kona_irq_ops,
	kona_gpio);
	if (!kona_gpio->irq_domain) {
	dev_err(dev, "Couldn't allocate IRQ domain\n");
	return -ENXIO;
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	kona_gpio->reg_base = devm_ioremap_resource(dev, res);
	if (IS_ERR(kona_gpio->reg_base)) {
	ret = -ENXIO;
	goto err_irq_domain;
	}

	for (i = 0; i < kona_gpio->num_bank; i++) {
	bank = &kona_gpio->banks[i];
	bank->id = i;
	bank->irq = platform_get_irq(pdev, i);
	bank->kona_gpio = kona_gpio;
	if (bank->irq < 0) {
	dev_err(dev, "Couldn't get IRQ for bank %d", i);
	ret = -ENOENT;
	goto err_irq_domain;
	}
	}

	dev_info(&pdev->dev, "Setting up Kona GPIO\n");

	bcm_kona_gpio_reset(kona_gpio);

	ret = gpiochip_add(chip);
	if (ret < 0) {
	dev_err(dev, "Couldn't add GPIO chip -- %d\n", ret);
	goto err_irq_domain;
	}
	for (i = 0; i < chip->ngpio; i++) {
	int irq = bcm_kona_gpio_to_irq(chip, i);
	irq_set_lockdep_class(irq, &gpio_lock_class);
	irq_set_chip_and_handler(irq, &bcm_gpio_irq_chip,
	handle_simple_irq);
	#ifdef CONFIG_ARM
	set_irq_flags(irq, IRQF_VALID);
	#else
	irq_set_noprobe(irq);
	#endif
	}
	for (i = 0; i < kona_gpio->num_bank; i++) {
	bank = &kona_gpio->banks[i];
	irq_set_chained_handler(bank->irq, bcm_kona_gpio_irq_handler);
	irq_set_handler_data(bank->irq, bank);
	}

	spin_lock_init(&kona_gpio->lock);

	return 0;

	err_irq_domain:
	irq_domain_remove(kona_gpio->irq_domain);

	return ret;
	}

	static struct platform_driver bcm_kona_gpio_driver = {
	.driver = {
	.name = "bcm-kona-gpio",
	.of_match_table = bcm_kona_gpio_of_match,
	},
	.probe = bcm_kona_gpio_probe,
	};

	module_platform_driver(bcm_kona_gpio_driver);

	MODULE_AUTHOR("Broadcom Corporation <bcm-kernel-feedback-list@broadcom.com>");
	MODULE_DESCRIPTION("Broadcom Kona GPIO Driver");
	MODULE_LICENSE("GPL v2");