/*
   * Xilinx Zynq GPIO device driver
   *
   * Copyright (C) 2009 - 2014 Xilinx, Inc.
   *
   * This program is free software; you can redistribute it and/or modify it under
   * the terms of the GNU General Public License as published by the Free Software
   * Foundation; either version 2 of the License, or (at your option) any later
   * version.
   */
  
  #include <linux/bitops.h>
  #include <linux/clk.h>
  #include <linux/gpio/driver.h>
  #include <linux/init.h>
  #include <linux/interrupt.h>
  #include <linux/io.h>
  #include <linux/module.h>
  #include <linux/platform_device.h>
  #include <linux/pm_runtime.h>

  #include <linux/of.h>

  
  #define DRIVER_NAME "zynq-gpio"
  
  /* Maximum banks */
  #define ZYNQ_GPIO_MAX_BANK	4

  #define ZYNQMP_GPIO_MAX_BANK	6

  
  #define ZYNQ_GPIO_BANK0_NGPIO	32
  #define ZYNQ_GPIO_BANK1_NGPIO	22
  #define ZYNQ_GPIO_BANK2_NGPIO	32
  #define ZYNQ_GPIO_BANK3_NGPIO	32

  #define ZYNQMP_GPIO_BANK0_NGPIO 26
  #define ZYNQMP_GPIO_BANK1_NGPIO 26
  #define ZYNQMP_GPIO_BANK2_NGPIO 26
  #define ZYNQMP_GPIO_BANK3_NGPIO 32
  #define ZYNQMP_GPIO_BANK4_NGPIO 32
  #define ZYNQMP_GPIO_BANK5_NGPIO 32
  
  #define	ZYNQ_GPIO_NR_GPIOS	118
  #define	ZYNQMP_GPIO_NR_GPIOS	174
  
  #define ZYNQ_GPIO_BANK0_PIN_MIN(str)	0
  #define ZYNQ_GPIO_BANK0_PIN_MAX(str)	(ZYNQ_GPIO_BANK0_PIN_MIN(str) + \
  					ZYNQ##str##_GPIO_BANK0_NGPIO - 1)
  #define ZYNQ_GPIO_BANK1_PIN_MIN(str)	(ZYNQ_GPIO_BANK0_PIN_MAX(str) + 1)
  #define ZYNQ_GPIO_BANK1_PIN_MAX(str)	(ZYNQ_GPIO_BANK1_PIN_MIN(str) + \
  					ZYNQ##str##_GPIO_BANK1_NGPIO - 1)
  #define ZYNQ_GPIO_BANK2_PIN_MIN(str)	(ZYNQ_GPIO_BANK1_PIN_MAX(str) + 1)
  #define ZYNQ_GPIO_BANK2_PIN_MAX(str)	(ZYNQ_GPIO_BANK2_PIN_MIN(str) + \
  					ZYNQ##str##_GPIO_BANK2_NGPIO - 1)
  #define ZYNQ_GPIO_BANK3_PIN_MIN(str)	(ZYNQ_GPIO_BANK2_PIN_MAX(str) + 1)
  #define ZYNQ_GPIO_BANK3_PIN_MAX(str)	(ZYNQ_GPIO_BANK3_PIN_MIN(str) + \
  					ZYNQ##str##_GPIO_BANK3_NGPIO - 1)
  #define ZYNQ_GPIO_BANK4_PIN_MIN(str)	(ZYNQ_GPIO_BANK3_PIN_MAX(str) + 1)
  #define ZYNQ_GPIO_BANK4_PIN_MAX(str)	(ZYNQ_GPIO_BANK4_PIN_MIN(str) + \
  					ZYNQ##str##_GPIO_BANK4_NGPIO - 1)
  #define ZYNQ_GPIO_BANK5_PIN_MIN(str)	(ZYNQ_GPIO_BANK4_PIN_MAX(str) + 1)
  #define ZYNQ_GPIO_BANK5_PIN_MAX(str)	(ZYNQ_GPIO_BANK5_PIN_MIN(str) + \
  					ZYNQ##str##_GPIO_BANK5_NGPIO - 1)

  
  
  /* Register offsets for the GPIO device */
  /* LSW Mask & Data -WO */
  #define ZYNQ_GPIO_DATA_LSW_OFFSET(BANK)	(0x000 + (8 * BANK))
  /* MSW Mask & Data -WO */
  #define ZYNQ_GPIO_DATA_MSW_OFFSET(BANK)	(0x004 + (8 * BANK))
  /* Data Register-RW */
  #define ZYNQ_GPIO_DATA_RO_OFFSET(BANK)	(0x060 + (4 * BANK))
  /* Direction mode reg-RW */
  #define ZYNQ_GPIO_DIRM_OFFSET(BANK)	(0x204 + (0x40 * BANK))
  /* Output enable reg-RW */
  #define ZYNQ_GPIO_OUTEN_OFFSET(BANK)	(0x208 + (0x40 * BANK))
  /* Interrupt mask reg-RO */
  #define ZYNQ_GPIO_INTMASK_OFFSET(BANK)	(0x20C + (0x40 * BANK))
  /* Interrupt enable reg-WO */
  #define ZYNQ_GPIO_INTEN_OFFSET(BANK)	(0x210 + (0x40 * BANK))
  /* Interrupt disable reg-WO */
  #define ZYNQ_GPIO_INTDIS_OFFSET(BANK)	(0x214 + (0x40 * BANK))
  /* Interrupt status reg-RO */
  #define ZYNQ_GPIO_INTSTS_OFFSET(BANK)	(0x218 + (0x40 * BANK))
  /* Interrupt type reg-RW */
  #define ZYNQ_GPIO_INTTYPE_OFFSET(BANK)	(0x21C + (0x40 * BANK))
  /* Interrupt polarity reg-RW */
  #define ZYNQ_GPIO_INTPOL_OFFSET(BANK)	(0x220 + (0x40 * BANK))
  /* Interrupt on any, reg-RW */
  #define ZYNQ_GPIO_INTANY_OFFSET(BANK)	(0x224 + (0x40 * BANK))
  
  /* Disable all interrupts mask */
  #define ZYNQ_GPIO_IXR_DISABLE_ALL	0xFFFFFFFF
  
  /* Mid pin number of a bank */
  #define ZYNQ_GPIO_MID_PIN_NUM 16
  
  /* GPIO upper 16 bit mask */
  #define ZYNQ_GPIO_UPPER_MASK 0xFFFF0000

  /* For GPIO quirks */
  #define ZYNQ_GPIO_QUIRK_FOO	BIT(0)

  /**
   * struct zynq_gpio - gpio device private data structure
   * @chip:	instance of the gpio_chip
   * @base_addr:	base address of the GPIO device
   * @clk:	clock resource for this controller

   * @irq:	interrupt for the GPIO device

   * @p_data:	pointer to platform data

   */
  struct zynq_gpio {
  	struct gpio_chip chip;
  	void __iomem *base_addr;
  	struct clk *clk;

  	int irq;

  	const struct zynq_platform_data *p_data;
  };
  
  /**
   * struct zynq_platform_data -  zynq gpio platform data structure
   * @label:	string to store in gpio->label
   * @ngpio:	max number of gpio pins
   * @max_bank:	maximum number of gpio banks
   * @bank_min:	this array represents bank's min pin
   * @bank_max:	this array represents bank's max pin
  */
  struct zynq_platform_data {
  	const char *label;

  	u32 quirks;

  	u16 ngpio;
  	int max_bank;
  	int bank_min[ZYNQMP_GPIO_MAX_BANK];
  	int bank_max[ZYNQMP_GPIO_MAX_BANK];

  };

  static struct irq_chip zynq_gpio_level_irqchip;
  static struct irq_chip zynq_gpio_edge_irqchip;

  /**
   * zynq_gpio_get_bank_pin - Get the bank number and pin number within that bank
   * for a given pin in the GPIO device
   * @pin_num:	gpio pin number within the device
   * @bank_num:	an output parameter used to return the bank number of the gpio
   *		pin
   * @bank_pin_num: an output parameter used to return pin number within a bank
   *		  for the given gpio pin
   *
   * Returns the bank number and pin offset within the bank.
   */
  static inline void zynq_gpio_get_bank_pin(unsigned int pin_num,
  					  unsigned int *bank_num,

  					  unsigned int *bank_pin_num,
  					  struct zynq_gpio *gpio)

  {

  	int bank;
  
  	for (bank = 0; bank < gpio->p_data->max_bank; bank++) {
  		if ((pin_num >= gpio->p_data->bank_min[bank]) &&
  			(pin_num <= gpio->p_data->bank_max[bank])) {
  				*bank_num = bank;
  				*bank_pin_num = pin_num -
  						gpio->p_data->bank_min[bank];
  				return;
  		}

  	}

  	/* default */
  	WARN(true, "invalid GPIO pin number: %u", pin_num);
  	*bank_num = 0;
  	*bank_pin_num = 0;
  }

  /**
   * zynq_gpio_get_value - Get the state of the specified pin of GPIO device
   * @chip:	gpio_chip instance to be worked on
   * @pin:	gpio pin number within the device
   *
   * This function reads the state of the specified pin of the GPIO device.
   *
   * Return: 0 if the pin is low, 1 if pin is high.
   */
  static int zynq_gpio_get_value(struct gpio_chip *chip, unsigned int pin)
  {
  	u32 data;
  	unsigned int bank_num, bank_pin_num;

  	struct zynq_gpio *gpio = gpiochip_get_data(chip);

  	zynq_gpio_get_bank_pin(pin, &bank_num, &bank_pin_num, gpio);

  
  	data = readl_relaxed(gpio->base_addr +
  			     ZYNQ_GPIO_DATA_RO_OFFSET(bank_num));
  
  	return (data >> bank_pin_num) & 1;
  }
  
  /**
   * zynq_gpio_set_value - Modify the state of the pin with specified value
   * @chip:	gpio_chip instance to be worked on
   * @pin:	gpio pin number within the device
   * @state:	value used to modify the state of the specified pin
   *
   * This function calculates the register offset (i.e to lower 16 bits or
   * upper 16 bits) based on the given pin number and sets the state of a
   * gpio pin to the specified value. The state is either 0 or non-zero.
   */
  static void zynq_gpio_set_value(struct gpio_chip *chip, unsigned int pin,
  				int state)
  {
  	unsigned int reg_offset, bank_num, bank_pin_num;

  	struct zynq_gpio *gpio = gpiochip_get_data(chip);

  	zynq_gpio_get_bank_pin(pin, &bank_num, &bank_pin_num, gpio);

  
  	if (bank_pin_num >= ZYNQ_GPIO_MID_PIN_NUM) {
  		/* only 16 data bits in bit maskable reg */
  		bank_pin_num -= ZYNQ_GPIO_MID_PIN_NUM;
  		reg_offset = ZYNQ_GPIO_DATA_MSW_OFFSET(bank_num);
  	} else {
  		reg_offset = ZYNQ_GPIO_DATA_LSW_OFFSET(bank_num);
  	}
  
  	/*
  	 * get the 32 bit value to be written to the mask/data register where
  	 * the upper 16 bits is the mask and lower 16 bits is the data
  	 */
  	state = !!state;
  	state = ~(1 << (bank_pin_num + ZYNQ_GPIO_MID_PIN_NUM)) &
  		((state << bank_pin_num) | ZYNQ_GPIO_UPPER_MASK);
  
  	writel_relaxed(state, gpio->base_addr + reg_offset);
  }
  
  /**
   * zynq_gpio_dir_in - Set the direction of the specified GPIO pin as input
   * @chip:	gpio_chip instance to be worked on
   * @pin:	gpio pin number within the device
   *
   * This function uses the read-modify-write sequence to set the direction of
   * the gpio pin as input.
   *
   * Return: 0 always
   */
  static int zynq_gpio_dir_in(struct gpio_chip *chip, unsigned int pin)
  {
  	u32 reg;

  	bool is_zynq_gpio;

  	unsigned int bank_num, bank_pin_num;

  	struct zynq_gpio *gpio = gpiochip_get_data(chip);

  	is_zynq_gpio = gpio->p_data->quirks & ZYNQ_GPIO_QUIRK_FOO;

  	zynq_gpio_get_bank_pin(pin, &bank_num, &bank_pin_num, gpio);

  	/*
  	 * On zynq bank 0 pins 7 and 8 are special and cannot be used
  	 * as inputs.
  	 */
  	if (is_zynq_gpio && bank_num == 0 &&
  		(bank_pin_num == 7 || bank_pin_num == 8))

  		return -EINVAL;
  
  	/* clear the bit in direction mode reg to set the pin as input */
  	reg = readl_relaxed(gpio->base_addr + ZYNQ_GPIO_DIRM_OFFSET(bank_num));
  	reg &= ~BIT(bank_pin_num);
  	writel_relaxed(reg, gpio->base_addr + ZYNQ_GPIO_DIRM_OFFSET(bank_num));
  
  	return 0;
  }
  
  /**
   * zynq_gpio_dir_out - Set the direction of the specified GPIO pin as output
   * @chip:	gpio_chip instance to be worked on
   * @pin:	gpio pin number within the device
   * @state:	value to be written to specified pin
   *
   * This function sets the direction of specified GPIO pin as output, configures
   * the Output Enable register for the pin and uses zynq_gpio_set to set
   * the state of the pin to the value specified.
   *
   * Return: 0 always
   */
  static int zynq_gpio_dir_out(struct gpio_chip *chip, unsigned int pin,
  			     int state)
  {
  	u32 reg;
  	unsigned int bank_num, bank_pin_num;

  	struct zynq_gpio *gpio = gpiochip_get_data(chip);

  	zynq_gpio_get_bank_pin(pin, &bank_num, &bank_pin_num, gpio);

  
  	/* set the GPIO pin as output */
  	reg = readl_relaxed(gpio->base_addr + ZYNQ_GPIO_DIRM_OFFSET(bank_num));
  	reg |= BIT(bank_pin_num);
  	writel_relaxed(reg, gpio->base_addr + ZYNQ_GPIO_DIRM_OFFSET(bank_num));
  
  	/* configure the output enable reg for the pin */
  	reg = readl_relaxed(gpio->base_addr + ZYNQ_GPIO_OUTEN_OFFSET(bank_num));
  	reg |= BIT(bank_pin_num);
  	writel_relaxed(reg, gpio->base_addr + ZYNQ_GPIO_OUTEN_OFFSET(bank_num));
  
  	/* set the state of the pin */
  	zynq_gpio_set_value(chip, pin, state);
  	return 0;
  }
  
  /**
   * zynq_gpio_irq_mask - Disable the interrupts for a gpio pin
   * @irq_data:	per irq and chip data passed down to chip functions
   *
   * This function calculates gpio pin number from irq number and sets the
   * bit in the Interrupt Disable register of the corresponding bank to disable
   * interrupts for that pin.
   */
  static void zynq_gpio_irq_mask(struct irq_data *irq_data)
  {
  	unsigned int device_pin_num, bank_num, bank_pin_num;

  	struct zynq_gpio *gpio =

  		gpiochip_get_data(irq_data_get_irq_chip_data(irq_data));

  
  	device_pin_num = irq_data->hwirq;

  	zynq_gpio_get_bank_pin(device_pin_num, &bank_num, &bank_pin_num, gpio);

  	writel_relaxed(BIT(bank_pin_num),
  		       gpio->base_addr + ZYNQ_GPIO_INTDIS_OFFSET(bank_num));
  }
  
  /**
   * zynq_gpio_irq_unmask - Enable the interrupts for a gpio pin
   * @irq_data:	irq data containing irq number of gpio pin for the interrupt
   *		to enable
   *
   * This function calculates the gpio pin number from irq number and sets the
   * bit in the Interrupt Enable register of the corresponding bank to enable
   * interrupts for that pin.
   */
  static void zynq_gpio_irq_unmask(struct irq_data *irq_data)
  {
  	unsigned int device_pin_num, bank_num, bank_pin_num;

  	struct zynq_gpio *gpio =

  		gpiochip_get_data(irq_data_get_irq_chip_data(irq_data));

  
  	device_pin_num = irq_data->hwirq;

  	zynq_gpio_get_bank_pin(device_pin_num, &bank_num, &bank_pin_num, gpio);

  	writel_relaxed(BIT(bank_pin_num),
  		       gpio->base_addr + ZYNQ_GPIO_INTEN_OFFSET(bank_num));
  }
  
  /**

   * zynq_gpio_irq_ack - Acknowledge the interrupt of a gpio pin
   * @irq_data:	irq data containing irq number of gpio pin for the interrupt
   *		to ack
   *
   * This function calculates gpio pin number from irq number and sets the bit
   * in the Interrupt Status Register of the corresponding bank, to ACK the irq.
   */
  static void zynq_gpio_irq_ack(struct irq_data *irq_data)
  {
  	unsigned int device_pin_num, bank_num, bank_pin_num;

  	struct zynq_gpio *gpio =

  		gpiochip_get_data(irq_data_get_irq_chip_data(irq_data));

  
  	device_pin_num = irq_data->hwirq;

  	zynq_gpio_get_bank_pin(device_pin_num, &bank_num, &bank_pin_num, gpio);

  	writel_relaxed(BIT(bank_pin_num),
  		       gpio->base_addr + ZYNQ_GPIO_INTSTS_OFFSET(bank_num));
  }
  
  /**
   * zynq_gpio_irq_enable - Enable the interrupts for a gpio pin
   * @irq_data:	irq data containing irq number of gpio pin for the interrupt
   *		to enable
   *

   * Clears the INTSTS bit and unmasks the given interrupt.

   */
  static void zynq_gpio_irq_enable(struct irq_data *irq_data)
  {
  	/*
  	 * The Zynq GPIO controller does not disable interrupt detection when
  	 * the interrupt is masked and only disables the propagation of the
  	 * interrupt. This means when the controller detects an interrupt
  	 * condition while the interrupt is logically disabled it will propagate
  	 * that interrupt event once the interrupt is enabled. This will cause
  	 * the interrupt consumer to see spurious interrupts to prevent this
  	 * first make sure that the interrupt is not asserted and then enable
  	 * it.
  	 */
  	zynq_gpio_irq_ack(irq_data);
  	zynq_gpio_irq_unmask(irq_data);
  }
  
  /**

   * zynq_gpio_set_irq_type - Set the irq type for a gpio pin
   * @irq_data:	irq data containing irq number of gpio pin
   * @type:	interrupt type that is to be set for the gpio pin
   *
   * This function gets the gpio pin number and its bank from the gpio pin number
   * and configures the INT_TYPE, INT_POLARITY and INT_ANY registers.
   *
   * Return: 0, negative error otherwise.
   * TYPE-EDGE_RISING,  INT_TYPE - 1, INT_POLARITY - 1,  INT_ANY - 0;
   * TYPE-EDGE_FALLING, INT_TYPE - 1, INT_POLARITY - 0,  INT_ANY - 0;
   * TYPE-EDGE_BOTH,    INT_TYPE - 1, INT_POLARITY - NA, INT_ANY - 1;
   * TYPE-LEVEL_HIGH,   INT_TYPE - 0, INT_POLARITY - 1,  INT_ANY - NA;
   * TYPE-LEVEL_LOW,    INT_TYPE - 0, INT_POLARITY - 0,  INT_ANY - NA
   */
  static int zynq_gpio_set_irq_type(struct irq_data *irq_data, unsigned int type)
  {
  	u32 int_type, int_pol, int_any;
  	unsigned int device_pin_num, bank_num, bank_pin_num;

  	struct zynq_gpio *gpio =

  		gpiochip_get_data(irq_data_get_irq_chip_data(irq_data));

  
  	device_pin_num = irq_data->hwirq;

  	zynq_gpio_get_bank_pin(device_pin_num, &bank_num, &bank_pin_num, gpio);

  
  	int_type = readl_relaxed(gpio->base_addr +
  				 ZYNQ_GPIO_INTTYPE_OFFSET(bank_num));
  	int_pol = readl_relaxed(gpio->base_addr +
  				ZYNQ_GPIO_INTPOL_OFFSET(bank_num));
  	int_any = readl_relaxed(gpio->base_addr +
  				ZYNQ_GPIO_INTANY_OFFSET(bank_num));
  
  	/*
  	 * based on the type requested, configure the INT_TYPE, INT_POLARITY
  	 * and INT_ANY registers
  	 */
  	switch (type) {
  	case IRQ_TYPE_EDGE_RISING:
  		int_type |= BIT(bank_pin_num);
  		int_pol |= BIT(bank_pin_num);
  		int_any &= ~BIT(bank_pin_num);
  		break;
  	case IRQ_TYPE_EDGE_FALLING:
  		int_type |= BIT(bank_pin_num);
  		int_pol &= ~BIT(bank_pin_num);
  		int_any &= ~BIT(bank_pin_num);
  		break;
  	case IRQ_TYPE_EDGE_BOTH:
  		int_type |= BIT(bank_pin_num);
  		int_any |= BIT(bank_pin_num);
  		break;
  	case IRQ_TYPE_LEVEL_HIGH:
  		int_type &= ~BIT(bank_pin_num);
  		int_pol |= BIT(bank_pin_num);
  		break;
  	case IRQ_TYPE_LEVEL_LOW:
  		int_type &= ~BIT(bank_pin_num);
  		int_pol &= ~BIT(bank_pin_num);
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	writel_relaxed(int_type,
  		       gpio->base_addr + ZYNQ_GPIO_INTTYPE_OFFSET(bank_num));
  	writel_relaxed(int_pol,
  		       gpio->base_addr + ZYNQ_GPIO_INTPOL_OFFSET(bank_num));
  	writel_relaxed(int_any,
  		       gpio->base_addr + ZYNQ_GPIO_INTANY_OFFSET(bank_num));

  
  	if (type & IRQ_TYPE_LEVEL_MASK) {

  		irq_set_chip_handler_name_locked(irq_data,

  			&zynq_gpio_level_irqchip, handle_fasteoi_irq, NULL);
  	} else {

  		irq_set_chip_handler_name_locked(irq_data,

  			&zynq_gpio_edge_irqchip, handle_level_irq, NULL);
  	}

  	return 0;
  }
  
  static int zynq_gpio_set_wake(struct irq_data *data, unsigned int on)
  {

  	struct zynq_gpio *gpio =

  		gpiochip_get_data(irq_data_get_irq_chip_data(data));

  
  	irq_set_irq_wake(gpio->irq, on);

  
  	return 0;
  }
  
  /* irq chip descriptor */

  static struct irq_chip zynq_gpio_level_irqchip = {

  	.name		= DRIVER_NAME,

  	.irq_enable	= zynq_gpio_irq_enable,

  	.irq_eoi	= zynq_gpio_irq_ack,
  	.irq_mask	= zynq_gpio_irq_mask,
  	.irq_unmask	= zynq_gpio_irq_unmask,
  	.irq_set_type	= zynq_gpio_set_irq_type,
  	.irq_set_wake	= zynq_gpio_set_wake,

  	.flags		= IRQCHIP_EOI_THREADED | IRQCHIP_EOI_IF_HANDLED |
  			  IRQCHIP_MASK_ON_SUSPEND,

  };
  
  static struct irq_chip zynq_gpio_edge_irqchip = {
  	.name		= DRIVER_NAME,
  	.irq_enable	= zynq_gpio_irq_enable,
  	.irq_ack	= zynq_gpio_irq_ack,

  	.irq_mask	= zynq_gpio_irq_mask,
  	.irq_unmask	= zynq_gpio_irq_unmask,
  	.irq_set_type	= zynq_gpio_set_irq_type,
  	.irq_set_wake	= zynq_gpio_set_wake,

  	.flags		= IRQCHIP_MASK_ON_SUSPEND,

  };

  static void zynq_gpio_handle_bank_irq(struct zynq_gpio *gpio,
  				      unsigned int bank_num,
  				      unsigned long pending)
  {

  	unsigned int bank_offset = gpio->p_data->bank_min[bank_num];

  	struct irq_domain *irqdomain = gpio->chip.irqdomain;
  	int offset;
  
  	if (!pending)
  		return;
  
  	for_each_set_bit(offset, &pending, 32) {
  		unsigned int gpio_irq;

  		gpio_irq = irq_find_mapping(irqdomain, offset + bank_offset);

  		generic_handle_irq(gpio_irq);
  	}
  }

  /**
   * zynq_gpio_irqhandler - IRQ handler for the gpio banks of a gpio device
   * @irq:	irq number of the gpio bank where interrupt has occurred
   * @desc:	irq descriptor instance of the 'irq'
   *
   * This function reads the Interrupt Status Register of each bank to get the
   * gpio pin number which has triggered an interrupt. It then acks the triggered
   * interrupt and calls the pin specific handler set by the higher layer
   * application for that pin.
   * Note: A bug is reported if no handler is set for the gpio pin.
   */

  static void zynq_gpio_irqhandler(struct irq_desc *desc)

  {
  	u32 int_sts, int_enb;
  	unsigned int bank_num;

  	struct zynq_gpio *gpio =

  		gpiochip_get_data(irq_desc_get_handler_data(desc));

  	struct irq_chip *irqchip = irq_desc_get_chip(desc);
  
  	chained_irq_enter(irqchip, desc);

  	for (bank_num = 0; bank_num < gpio->p_data->max_bank; bank_num++) {

  		int_sts = readl_relaxed(gpio->base_addr +
  					ZYNQ_GPIO_INTSTS_OFFSET(bank_num));
  		int_enb = readl_relaxed(gpio->base_addr +
  					ZYNQ_GPIO_INTMASK_OFFSET(bank_num));

  		zynq_gpio_handle_bank_irq(gpio, bank_num, int_sts & ~int_enb);

  	}
  
  	chained_irq_exit(irqchip, desc);
  }
  
  static int __maybe_unused zynq_gpio_suspend(struct device *dev)
  {

  	struct platform_device *pdev = to_platform_device(dev);
  	int irq = platform_get_irq(pdev, 0);
  	struct irq_data *data = irq_get_irq_data(irq);
  
  	if (!irqd_is_wakeup_set(data))

  		return pm_runtime_force_suspend(dev);
  
  	return 0;
  }
  
  static int __maybe_unused zynq_gpio_resume(struct device *dev)
  {

  	struct platform_device *pdev = to_platform_device(dev);
  	int irq = platform_get_irq(pdev, 0);
  	struct irq_data *data = irq_get_irq_data(irq);
  
  	if (!irqd_is_wakeup_set(data))

  		return pm_runtime_force_resume(dev);
  
  	return 0;
  }
  
  static int __maybe_unused zynq_gpio_runtime_suspend(struct device *dev)
  {
  	struct platform_device *pdev = to_platform_device(dev);
  	struct zynq_gpio *gpio = platform_get_drvdata(pdev);
  
  	clk_disable_unprepare(gpio->clk);
  
  	return 0;
  }
  
  static int __maybe_unused zynq_gpio_runtime_resume(struct device *dev)
  {
  	struct platform_device *pdev = to_platform_device(dev);
  	struct zynq_gpio *gpio = platform_get_drvdata(pdev);
  
  	return clk_prepare_enable(gpio->clk);
  }
  
  static int zynq_gpio_request(struct gpio_chip *chip, unsigned offset)
  {
  	int ret;

  	ret = pm_runtime_get_sync(chip->parent);

  
  	/*
  	 * If the device is already active pm_runtime_get() will return 1 on
  	 * success, but gpio_request still needs to return 0.
  	 */
  	return ret < 0 ? ret : 0;
  }
  
  static void zynq_gpio_free(struct gpio_chip *chip, unsigned offset)
  {

  	pm_runtime_put(chip->parent);

  }
  
  static const struct dev_pm_ops zynq_gpio_dev_pm_ops = {
  	SET_SYSTEM_SLEEP_PM_OPS(zynq_gpio_suspend, zynq_gpio_resume)

  	SET_RUNTIME_PM_OPS(zynq_gpio_runtime_suspend,

  			zynq_gpio_runtime_resume, NULL)
  };

  static const struct zynq_platform_data zynqmp_gpio_def = {
  	.label = "zynqmp_gpio",
  	.ngpio = ZYNQMP_GPIO_NR_GPIOS,
  	.max_bank = ZYNQMP_GPIO_MAX_BANK,
  	.bank_min[0] = ZYNQ_GPIO_BANK0_PIN_MIN(MP),
  	.bank_max[0] = ZYNQ_GPIO_BANK0_PIN_MAX(MP),
  	.bank_min[1] = ZYNQ_GPIO_BANK1_PIN_MIN(MP),
  	.bank_max[1] = ZYNQ_GPIO_BANK1_PIN_MAX(MP),
  	.bank_min[2] = ZYNQ_GPIO_BANK2_PIN_MIN(MP),
  	.bank_max[2] = ZYNQ_GPIO_BANK2_PIN_MAX(MP),
  	.bank_min[3] = ZYNQ_GPIO_BANK3_PIN_MIN(MP),
  	.bank_max[3] = ZYNQ_GPIO_BANK3_PIN_MAX(MP),
  	.bank_min[4] = ZYNQ_GPIO_BANK4_PIN_MIN(MP),
  	.bank_max[4] = ZYNQ_GPIO_BANK4_PIN_MAX(MP),
  	.bank_min[5] = ZYNQ_GPIO_BANK5_PIN_MIN(MP),
  	.bank_max[5] = ZYNQ_GPIO_BANK5_PIN_MAX(MP),
  };
  
  static const struct zynq_platform_data zynq_gpio_def = {
  	.label = "zynq_gpio",

  	.quirks = ZYNQ_GPIO_QUIRK_FOO,

  	.ngpio = ZYNQ_GPIO_NR_GPIOS,
  	.max_bank = ZYNQ_GPIO_MAX_BANK,
  	.bank_min[0] = ZYNQ_GPIO_BANK0_PIN_MIN(),
  	.bank_max[0] = ZYNQ_GPIO_BANK0_PIN_MAX(),
  	.bank_min[1] = ZYNQ_GPIO_BANK1_PIN_MIN(),
  	.bank_max[1] = ZYNQ_GPIO_BANK1_PIN_MAX(),
  	.bank_min[2] = ZYNQ_GPIO_BANK2_PIN_MIN(),
  	.bank_max[2] = ZYNQ_GPIO_BANK2_PIN_MAX(),
  	.bank_min[3] = ZYNQ_GPIO_BANK3_PIN_MIN(),
  	.bank_max[3] = ZYNQ_GPIO_BANK3_PIN_MAX(),
  };
  
  static const struct of_device_id zynq_gpio_of_match[] = {
  	{ .compatible = "xlnx,zynq-gpio-1.0", .data = (void *)&zynq_gpio_def },
  	{ .compatible = "xlnx,zynqmp-gpio-1.0",
  					.data = (void *)&zynqmp_gpio_def },
  	{ /* end of table */ }
  };
  MODULE_DEVICE_TABLE(of, zynq_gpio_of_match);

  /**
   * zynq_gpio_probe - Initialization method for a zynq_gpio device
   * @pdev:	platform device instance
   *
   * This function allocates memory resources for the gpio device and registers
   * all the banks of the device. It will also set up interrupts for the gpio
   * pins.
   * Note: Interrupts are disabled for all the banks during initialization.
   *
   * Return: 0 on success, negative error otherwise.
   */
  static int zynq_gpio_probe(struct platform_device *pdev)
  {

  	int ret, bank_num;

  	struct zynq_gpio *gpio;
  	struct gpio_chip *chip;
  	struct resource *res;

  	const struct of_device_id *match;

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

  	match = of_match_node(zynq_gpio_of_match, pdev->dev.of_node);
  	if (!match) {
  		dev_err(&pdev->dev, "of_match_node() failed
  ");
  		return -EINVAL;
  	}
  	gpio->p_data = match->data;

  	platform_set_drvdata(pdev, gpio);
  
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	gpio->base_addr = devm_ioremap_resource(&pdev->dev, res);
  	if (IS_ERR(gpio->base_addr))
  		return PTR_ERR(gpio->base_addr);

  	gpio->irq = platform_get_irq(pdev, 0);
  	if (gpio->irq < 0) {

  		dev_err(&pdev->dev, "invalid IRQ
  ");

  		return gpio->irq;

  	}
  
  	/* configure the gpio chip */
  	chip = &gpio->chip;

  	chip->label = gpio->p_data->label;

  	chip->owner = THIS_MODULE;

  	chip->parent = &pdev->dev;

  	chip->get = zynq_gpio_get_value;
  	chip->set = zynq_gpio_set_value;
  	chip->request = zynq_gpio_request;
  	chip->free = zynq_gpio_free;
  	chip->direction_input = zynq_gpio_dir_in;
  	chip->direction_output = zynq_gpio_dir_out;
  	chip->base = -1;

  	chip->ngpio = gpio->p_data->ngpio;

  	/* Retrieve GPIO clock */

  	gpio->clk = devm_clk_get(&pdev->dev, NULL);
  	if (IS_ERR(gpio->clk)) {
  		dev_err(&pdev->dev, "input clock not found.
  ");
  		return PTR_ERR(gpio->clk);
  	}

  	ret = clk_prepare_enable(gpio->clk);
  	if (ret) {
  		dev_err(&pdev->dev, "Unable to enable clock.
  ");
  		return ret;
  	}

  	pm_runtime_set_active(&pdev->dev);

  	pm_runtime_enable(&pdev->dev);
  	ret = pm_runtime_get_sync(&pdev->dev);
  	if (ret < 0)

  		goto err_pm_dis;

  
  	/* report a bug if gpio chip registration fails */

  	ret = gpiochip_add_data(chip, gpio);

  	if (ret) {
  		dev_err(&pdev->dev, "Failed to add gpio chip
  ");

  		goto err_pm_put;

  	}
  
  	/* disable interrupts for all banks */

  	for (bank_num = 0; bank_num < gpio->p_data->max_bank; bank_num++)

  		writel_relaxed(ZYNQ_GPIO_IXR_DISABLE_ALL, gpio->base_addr +
  			       ZYNQ_GPIO_INTDIS_OFFSET(bank_num));

  	ret = gpiochip_irqchip_add(chip, &zynq_gpio_edge_irqchip, 0,
  				   handle_level_irq, IRQ_TYPE_NONE);

  	if (ret) {
  		dev_err(&pdev->dev, "Failed to add irq chip
  ");
  		goto err_rm_gpiochip;
  	}

  	gpiochip_set_chained_irqchip(chip, &zynq_gpio_edge_irqchip, gpio->irq,

  				     zynq_gpio_irqhandler);

  	pm_runtime_put(&pdev->dev);

  	return 0;
  
  err_rm_gpiochip:

  	gpiochip_remove(chip);

  err_pm_put:
  	pm_runtime_put(&pdev->dev);

  err_pm_dis:
  	pm_runtime_disable(&pdev->dev);

  	clk_disable_unprepare(gpio->clk);

  
  	return ret;
  }
  
  /**
   * zynq_gpio_remove - Driver removal function
   * @pdev:	platform device instance
   *
   * Return: 0 always
   */
  static int zynq_gpio_remove(struct platform_device *pdev)
  {

  	struct zynq_gpio *gpio = platform_get_drvdata(pdev);
  
  	pm_runtime_get_sync(&pdev->dev);

  	gpiochip_remove(&gpio->chip);

  	clk_disable_unprepare(gpio->clk);
  	device_set_wakeup_capable(&pdev->dev, 0);

  	pm_runtime_disable(&pdev->dev);

  	return 0;
  }

  static struct platform_driver zynq_gpio_driver = {
  	.driver	= {
  		.name = DRIVER_NAME,

  		.pm = &zynq_gpio_dev_pm_ops,
  		.of_match_table = zynq_gpio_of_match,
  	},
  	.probe = zynq_gpio_probe,
  	.remove = zynq_gpio_remove,
  };
  
  /**
   * zynq_gpio_init - Initial driver registration call
   *
   * Return: value from platform_driver_register
   */
  static int __init zynq_gpio_init(void)
  {
  	return platform_driver_register(&zynq_gpio_driver);
  }
  postcore_initcall(zynq_gpio_init);

  static void __exit zynq_gpio_exit(void)
  {
  	platform_driver_unregister(&zynq_gpio_driver);
  }
  module_exit(zynq_gpio_exit);

  MODULE_AUTHOR("Xilinx Inc.");
  MODULE_DESCRIPTION("Zynq GPIO driver");
  MODULE_LICENSE("GPL");