// SPDX-License-Identifier: GPL-2.0-only

  /*
   * GPIO driver for AMD
   *
   * Copyright (c) 2014,2015 AMD Corporation.
   * Authors: Ken Xue <Ken.Xue@amd.com>
   *      Wu, Jeff <Jeff.Wu@amd.com>
   *

   * Contact Information: Nehal Shah <Nehal-bakulchandra.Shah@amd.com>
   *			Shyam Sundar S K <Shyam-sundar.S-k@amd.com>

   */
  
  #include <linux/err.h>
  #include <linux/bug.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/spinlock.h>
  #include <linux/compiler.h>
  #include <linux/types.h>
  #include <linux/errno.h>
  #include <linux/log2.h>
  #include <linux/io.h>

  #include <linux/gpio/driver.h>

  #include <linux/slab.h>
  #include <linux/platform_device.h>
  #include <linux/mutex.h>
  #include <linux/acpi.h>
  #include <linux/seq_file.h>
  #include <linux/interrupt.h>
  #include <linux/list.h>
  #include <linux/bitops.h>

  #include <linux/pinctrl/pinconf.h>
  #include <linux/pinctrl/pinconf-generic.h>

  #include "core.h"

  #include "pinctrl-utils.h"
  #include "pinctrl-amd.h"

  static int amd_gpio_get_direction(struct gpio_chip *gc, unsigned offset)
  {
  	unsigned long flags;
  	u32 pin_reg;
  	struct amd_gpio *gpio_dev = gpiochip_get_data(gc);
  
  	raw_spin_lock_irqsave(&gpio_dev->lock, flags);
  	pin_reg = readl(gpio_dev->base + offset * 4);
  	raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);
  
  	return !(pin_reg & BIT(OUTPUT_ENABLE_OFF));
  }

  static int amd_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
  {
  	unsigned long flags;
  	u32 pin_reg;

  	struct amd_gpio *gpio_dev = gpiochip_get_data(gc);

  	raw_spin_lock_irqsave(&gpio_dev->lock, flags);

  	pin_reg = readl(gpio_dev->base + offset * 4);

  	pin_reg &= ~BIT(OUTPUT_ENABLE_OFF);
  	writel(pin_reg, gpio_dev->base + offset * 4);

  	raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

  
  	return 0;
  }
  
  static int amd_gpio_direction_output(struct gpio_chip *gc, unsigned offset,
  		int value)
  {
  	u32 pin_reg;
  	unsigned long flags;

  	struct amd_gpio *gpio_dev = gpiochip_get_data(gc);

  	raw_spin_lock_irqsave(&gpio_dev->lock, flags);

  	pin_reg = readl(gpio_dev->base + offset * 4);
  	pin_reg |= BIT(OUTPUT_ENABLE_OFF);
  	if (value)
  		pin_reg |= BIT(OUTPUT_VALUE_OFF);
  	else
  		pin_reg &= ~BIT(OUTPUT_VALUE_OFF);
  	writel(pin_reg, gpio_dev->base + offset * 4);

  	raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

  
  	return 0;
  }
  
  static int amd_gpio_get_value(struct gpio_chip *gc, unsigned offset)
  {
  	u32 pin_reg;
  	unsigned long flags;

  	struct amd_gpio *gpio_dev = gpiochip_get_data(gc);

  	raw_spin_lock_irqsave(&gpio_dev->lock, flags);

  	pin_reg = readl(gpio_dev->base + offset * 4);

  	raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

  
  	return !!(pin_reg & BIT(PIN_STS_OFF));
  }
  
  static void amd_gpio_set_value(struct gpio_chip *gc, unsigned offset, int value)
  {
  	u32 pin_reg;
  	unsigned long flags;

  	struct amd_gpio *gpio_dev = gpiochip_get_data(gc);

  	raw_spin_lock_irqsave(&gpio_dev->lock, flags);

  	pin_reg = readl(gpio_dev->base + offset * 4);
  	if (value)
  		pin_reg |= BIT(OUTPUT_VALUE_OFF);
  	else
  		pin_reg &= ~BIT(OUTPUT_VALUE_OFF);
  	writel(pin_reg, gpio_dev->base + offset * 4);

  	raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

  }
  
  static int amd_gpio_set_debounce(struct gpio_chip *gc, unsigned offset,
  		unsigned debounce)
  {

  	u32 time;

  	u32 pin_reg;
  	int ret = 0;

  	unsigned long flags;

  	struct amd_gpio *gpio_dev = gpiochip_get_data(gc);

  	raw_spin_lock_irqsave(&gpio_dev->lock, flags);

  	pin_reg = readl(gpio_dev->base + offset * 4);
  
  	if (debounce) {
  		pin_reg |= DB_TYPE_REMOVE_GLITCH << DB_CNTRL_OFF;
  		pin_reg &= ~DB_TMR_OUT_MASK;
  		/*
  		Debounce	Debounce	Timer	Max
  		TmrLarge	TmrOutUnit	Unit	Debounce
  							Time
  		0	0	61 usec (2 RtcClk)	976 usec
  		0	1	244 usec (8 RtcClk)	3.9 msec
  		1	0	15.6 msec (512 RtcClk)	250 msec
  		1	1	62.5 msec (2048 RtcClk)	1 sec
  		*/
  
  		if (debounce < 61) {
  			pin_reg |= 1;
  			pin_reg &= ~BIT(DB_TMR_OUT_UNIT_OFF);
  			pin_reg &= ~BIT(DB_TMR_LARGE_OFF);
  		} else if (debounce < 976) {
  			time = debounce / 61;
  			pin_reg |= time & DB_TMR_OUT_MASK;
  			pin_reg &= ~BIT(DB_TMR_OUT_UNIT_OFF);
  			pin_reg &= ~BIT(DB_TMR_LARGE_OFF);
  		} else if (debounce < 3900) {
  			time = debounce / 244;
  			pin_reg |= time & DB_TMR_OUT_MASK;
  			pin_reg |= BIT(DB_TMR_OUT_UNIT_OFF);
  			pin_reg &= ~BIT(DB_TMR_LARGE_OFF);
  		} else if (debounce < 250000) {
  			time = debounce / 15600;
  			pin_reg |= time & DB_TMR_OUT_MASK;
  			pin_reg &= ~BIT(DB_TMR_OUT_UNIT_OFF);
  			pin_reg |= BIT(DB_TMR_LARGE_OFF);
  		} else if (debounce < 1000000) {
  			time = debounce / 62500;
  			pin_reg |= time & DB_TMR_OUT_MASK;
  			pin_reg |= BIT(DB_TMR_OUT_UNIT_OFF);
  			pin_reg |= BIT(DB_TMR_LARGE_OFF);
  		} else {
  			pin_reg &= ~DB_CNTRl_MASK;

  			ret = -EINVAL;

  		}
  	} else {
  		pin_reg &= ~BIT(DB_TMR_OUT_UNIT_OFF);
  		pin_reg &= ~BIT(DB_TMR_LARGE_OFF);
  		pin_reg &= ~DB_TMR_OUT_MASK;
  		pin_reg &= ~DB_CNTRl_MASK;
  	}
  	writel(pin_reg, gpio_dev->base + offset * 4);

  	raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

  	return ret;

  }

  static int amd_gpio_set_config(struct gpio_chip *gc, unsigned offset,
  			       unsigned long config)
  {
  	u32 debounce;
  
  	if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
  		return -ENOTSUPP;
  
  	debounce = pinconf_to_config_argument(config);
  	return amd_gpio_set_debounce(gc, offset, debounce);
  }

  #ifdef CONFIG_DEBUG_FS
  static void amd_gpio_dbg_show(struct seq_file *s, struct gpio_chip *gc)
  {
  	u32 pin_reg;
  	unsigned long flags;
  	unsigned int bank, i, pin_num;

  	struct amd_gpio *gpio_dev = gpiochip_get_data(gc);

  
  	char *level_trig;
  	char *active_level;
  	char *interrupt_enable;
  	char *interrupt_mask;
  	char *wake_cntrl0;
  	char *wake_cntrl1;
  	char *wake_cntrl2;
  	char *pin_sts;
  	char *pull_up_sel;
  	char *pull_up_enable;
  	char *pull_down_enable;
  	char *output_value;
  	char *output_enable;

  	for (bank = 0; bank < gpio_dev->hwbank_num; bank++) {

  		seq_printf(s, "GPIO bank%d\t", bank);
  
  		switch (bank) {
  		case 0:
  			i = 0;
  			pin_num = AMD_GPIO_PINS_BANK0;
  			break;
  		case 1:
  			i = 64;
  			pin_num = AMD_GPIO_PINS_BANK1 + i;
  			break;
  		case 2:
  			i = 128;
  			pin_num = AMD_GPIO_PINS_BANK2 + i;
  			break;

  		case 3:
  			i = 192;
  			pin_num = AMD_GPIO_PINS_BANK3 + i;
  			break;

  		default:
  			/* Illegal bank number, ignore */
  			continue;

  		}

  		for (; i < pin_num; i++) {
  			seq_printf(s, "pin%d\t", i);

  			raw_spin_lock_irqsave(&gpio_dev->lock, flags);

  			pin_reg = readl(gpio_dev->base + i * 4);

  			raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

  
  			if (pin_reg & BIT(INTERRUPT_ENABLE_OFF)) {

  				u8 level = (pin_reg >> ACTIVE_LEVEL_OFF) &
  						ACTIVE_LEVEL_MASK;

  				interrupt_enable = "interrupt is enabled|";

  				if (level == ACTIVE_LEVEL_HIGH)

  					active_level = "Active high|";

  				else if (level == ACTIVE_LEVEL_LOW)
  					active_level = "Active low|";
  				else if (!(pin_reg & BIT(LEVEL_TRIG_OFF)) &&
  					 level == ACTIVE_LEVEL_BOTH)

  					active_level = "Active on both|";
  				else

  					active_level = "Unknown Active level|";

  
  				if (pin_reg & BIT(LEVEL_TRIG_OFF))
  					level_trig = "Level trigger|";
  				else
  					level_trig = "Edge trigger|";
  
  			} else {
  				interrupt_enable =
  					"interrupt is disabled|";
  				active_level = " ";
  				level_trig = " ";
  			}
  
  			if (pin_reg & BIT(INTERRUPT_MASK_OFF))
  				interrupt_mask =
  					"interrupt is unmasked|";
  			else
  				interrupt_mask =
  					"interrupt is masked|";

  			if (pin_reg & BIT(WAKE_CNTRL_OFF_S0I3))

  				wake_cntrl0 = "enable wakeup in S0i3 state|";
  			else
  				wake_cntrl0 = "disable wakeup in S0i3 state|";

  			if (pin_reg & BIT(WAKE_CNTRL_OFF_S3))

  				wake_cntrl1 = "enable wakeup in S3 state|";
  			else
  				wake_cntrl1 = "disable wakeup in S3 state|";

  			if (pin_reg & BIT(WAKE_CNTRL_OFF_S4))

  				wake_cntrl2 = "enable wakeup in S4/S5 state|";
  			else
  				wake_cntrl2 = "disable wakeup in S4/S5 state|";
  
  			if (pin_reg & BIT(PULL_UP_ENABLE_OFF)) {
  				pull_up_enable = "pull-up is enabled|";
  				if (pin_reg & BIT(PULL_UP_SEL_OFF))
  					pull_up_sel = "8k pull-up|";
  				else
  					pull_up_sel = "4k pull-up|";
  			} else {
  				pull_up_enable = "pull-up is disabled|";
  				pull_up_sel = " ";
  			}
  
  			if (pin_reg & BIT(PULL_DOWN_ENABLE_OFF))
  				pull_down_enable = "pull-down is enabled|";
  			else
  				pull_down_enable = "Pull-down is disabled|";
  
  			if (pin_reg & BIT(OUTPUT_ENABLE_OFF)) {
  				pin_sts = " ";
  				output_enable = "output is enabled|";
  				if (pin_reg & BIT(OUTPUT_VALUE_OFF))
  					output_value = "output is high|";
  				else
  					output_value = "output is low|";
  			} else {
  				output_enable = "output is disabled|";
  				output_value = " ";
  
  				if (pin_reg & BIT(PIN_STS_OFF))
  					pin_sts = "input is high|";
  				else
  					pin_sts = "input is low|";
  			}
  
  			seq_printf(s, "%s %s %s %s %s %s
  "
  				" %s %s %s %s %s %s %s 0x%x
  ",
  				level_trig, active_level, interrupt_enable,
  				interrupt_mask, wake_cntrl0, wake_cntrl1,
  				wake_cntrl2, pin_sts, pull_up_sel,
  				pull_up_enable, pull_down_enable,
  				output_value, output_enable, pin_reg);
  		}
  	}
  }
  #else
  #define amd_gpio_dbg_show NULL
  #endif
  
  static void amd_gpio_irq_enable(struct irq_data *d)
  {
  	u32 pin_reg;
  	unsigned long flags;
  	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);

  	struct amd_gpio *gpio_dev = gpiochip_get_data(gc);

  	raw_spin_lock_irqsave(&gpio_dev->lock, flags);

  	pin_reg = readl(gpio_dev->base + (d->hwirq)*4);

  	pin_reg |= BIT(INTERRUPT_ENABLE_OFF);
  	pin_reg |= BIT(INTERRUPT_MASK_OFF);
  	writel(pin_reg, gpio_dev->base + (d->hwirq)*4);

  	raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

  }
  
  static void amd_gpio_irq_disable(struct irq_data *d)
  {
  	u32 pin_reg;
  	unsigned long flags;
  	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);

  	struct amd_gpio *gpio_dev = gpiochip_get_data(gc);

  	raw_spin_lock_irqsave(&gpio_dev->lock, flags);

  	pin_reg = readl(gpio_dev->base + (d->hwirq)*4);
  	pin_reg &= ~BIT(INTERRUPT_ENABLE_OFF);
  	pin_reg &= ~BIT(INTERRUPT_MASK_OFF);
  	writel(pin_reg, gpio_dev->base + (d->hwirq)*4);

  	raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

  }
  
  static void amd_gpio_irq_mask(struct irq_data *d)
  {
  	u32 pin_reg;
  	unsigned long flags;
  	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);

  	struct amd_gpio *gpio_dev = gpiochip_get_data(gc);

  	raw_spin_lock_irqsave(&gpio_dev->lock, flags);

  	pin_reg = readl(gpio_dev->base + (d->hwirq)*4);
  	pin_reg &= ~BIT(INTERRUPT_MASK_OFF);
  	writel(pin_reg, gpio_dev->base + (d->hwirq)*4);

  	raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

  }
  
  static void amd_gpio_irq_unmask(struct irq_data *d)
  {
  	u32 pin_reg;
  	unsigned long flags;
  	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);

  	struct amd_gpio *gpio_dev = gpiochip_get_data(gc);

  	raw_spin_lock_irqsave(&gpio_dev->lock, flags);

  	pin_reg = readl(gpio_dev->base + (d->hwirq)*4);
  	pin_reg |= BIT(INTERRUPT_MASK_OFF);
  	writel(pin_reg, gpio_dev->base + (d->hwirq)*4);

  	raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

  }
  
  static void amd_gpio_irq_eoi(struct irq_data *d)
  {
  	u32 reg;
  	unsigned long flags;
  	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);

  	struct amd_gpio *gpio_dev = gpiochip_get_data(gc);

  	raw_spin_lock_irqsave(&gpio_dev->lock, flags);

  	reg = readl(gpio_dev->base + WAKE_INT_MASTER_REG);
  	reg |= EOI_MASK;
  	writel(reg, gpio_dev->base + WAKE_INT_MASTER_REG);

  	raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

  }
  
  static int amd_gpio_irq_set_type(struct irq_data *d, unsigned int type)
  {
  	int ret = 0;

  	u32 pin_reg, pin_reg_irq_en, mask;

  	unsigned long flags, irq_flags;

  	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);

  	struct amd_gpio *gpio_dev = gpiochip_get_data(gc);

  	raw_spin_lock_irqsave(&gpio_dev->lock, flags);

  	pin_reg = readl(gpio_dev->base + (d->hwirq)*4);

  	/* Ignore the settings coming from the client and
  	 * read the values from the ACPI tables
  	 * while setting the trigger type

  	 */

  	irq_flags = irq_get_trigger_type(d->irq);
  	if (irq_flags != IRQ_TYPE_NONE)
  		type = irq_flags;

  	switch (type & IRQ_TYPE_SENSE_MASK) {
  	case IRQ_TYPE_EDGE_RISING:
  		pin_reg &= ~BIT(LEVEL_TRIG_OFF);
  		pin_reg &= ~(ACTIVE_LEVEL_MASK << ACTIVE_LEVEL_OFF);
  		pin_reg |= ACTIVE_HIGH << ACTIVE_LEVEL_OFF;
  		pin_reg |= DB_TYPE_REMOVE_GLITCH << DB_CNTRL_OFF;

  		irq_set_handler_locked(d, handle_edge_irq);

  		break;
  
  	case IRQ_TYPE_EDGE_FALLING:
  		pin_reg &= ~BIT(LEVEL_TRIG_OFF);
  		pin_reg &= ~(ACTIVE_LEVEL_MASK << ACTIVE_LEVEL_OFF);
  		pin_reg |= ACTIVE_LOW << ACTIVE_LEVEL_OFF;
  		pin_reg |= DB_TYPE_REMOVE_GLITCH << DB_CNTRL_OFF;

  		irq_set_handler_locked(d, handle_edge_irq);

  		break;
  
  	case IRQ_TYPE_EDGE_BOTH:
  		pin_reg &= ~BIT(LEVEL_TRIG_OFF);
  		pin_reg &= ~(ACTIVE_LEVEL_MASK << ACTIVE_LEVEL_OFF);
  		pin_reg |= BOTH_EADGE << ACTIVE_LEVEL_OFF;
  		pin_reg |= DB_TYPE_REMOVE_GLITCH << DB_CNTRL_OFF;

  		irq_set_handler_locked(d, handle_edge_irq);

  		break;
  
  	case IRQ_TYPE_LEVEL_HIGH:
  		pin_reg |= LEVEL_TRIGGER << LEVEL_TRIG_OFF;
  		pin_reg &= ~(ACTIVE_LEVEL_MASK << ACTIVE_LEVEL_OFF);
  		pin_reg |= ACTIVE_HIGH << ACTIVE_LEVEL_OFF;
  		pin_reg &= ~(DB_CNTRl_MASK << DB_CNTRL_OFF);
  		pin_reg |= DB_TYPE_PRESERVE_LOW_GLITCH << DB_CNTRL_OFF;

  		irq_set_handler_locked(d, handle_level_irq);

  		break;
  
  	case IRQ_TYPE_LEVEL_LOW:
  		pin_reg |= LEVEL_TRIGGER << LEVEL_TRIG_OFF;
  		pin_reg &= ~(ACTIVE_LEVEL_MASK << ACTIVE_LEVEL_OFF);
  		pin_reg |= ACTIVE_LOW << ACTIVE_LEVEL_OFF;
  		pin_reg &= ~(DB_CNTRl_MASK << DB_CNTRL_OFF);
  		pin_reg |= DB_TYPE_PRESERVE_HIGH_GLITCH << DB_CNTRL_OFF;

  		irq_set_handler_locked(d, handle_level_irq);

  		break;
  
  	case IRQ_TYPE_NONE:
  		break;
  
  	default:
  		dev_err(&gpio_dev->pdev->dev, "Invalid type value
  ");
  		ret = -EINVAL;

  	}
  
  	pin_reg |= CLR_INTR_STAT << INTERRUPT_STS_OFF;

  	/*
  	 * If WAKE_INT_MASTER_REG.MaskStsEn is set, a software write to the
  	 * debounce registers of any GPIO will block wake/interrupt status

  	 * generation for *all* GPIOs for a length of time that depends on

  	 * WAKE_INT_MASTER_REG.MaskStsLength[11:0].  During this period the
  	 * INTERRUPT_ENABLE bit will read as 0.
  	 *
  	 * We temporarily enable irq for the GPIO whose configuration is
  	 * changing, and then wait for it to read back as 1 to know when
  	 * debounce has settled and then disable the irq again.
  	 * We do this polling with the spinlock held to ensure other GPIO
  	 * access routines do not read an incorrect value for the irq enable
  	 * bit of other GPIOs.  We keep the GPIO masked while polling to avoid
  	 * spurious irqs, and disable the irq again after polling.
  	 */
  	mask = BIT(INTERRUPT_ENABLE_OFF);
  	pin_reg_irq_en = pin_reg;
  	pin_reg_irq_en |= mask;
  	pin_reg_irq_en &= ~BIT(INTERRUPT_MASK_OFF);
  	writel(pin_reg_irq_en, gpio_dev->base + (d->hwirq)*4);
  	while ((readl(gpio_dev->base + (d->hwirq)*4) & mask) != mask)
  		continue;

  	writel(pin_reg, gpio_dev->base + (d->hwirq)*4);

  	raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

  	return ret;
  }
  
  static void amd_irq_ack(struct irq_data *d)
  {
  	/*
  	 * based on HW design,there is no need to ack HW
  	 * before handle current irq. But this routine is
  	 * necessary for handle_edge_irq
  	*/
  }
  
  static struct irq_chip amd_gpio_irqchip = {
  	.name         = "amd_gpio",
  	.irq_ack      = amd_irq_ack,
  	.irq_enable   = amd_gpio_irq_enable,
  	.irq_disable  = amd_gpio_irq_disable,
  	.irq_mask     = amd_gpio_irq_mask,
  	.irq_unmask   = amd_gpio_irq_unmask,
  	.irq_eoi      = amd_gpio_irq_eoi,
  	.irq_set_type = amd_gpio_irq_set_type,

  	.flags        = IRQCHIP_SKIP_SET_WAKE,

  };

  #define PIN_IRQ_PENDING	(BIT(INTERRUPT_STS_OFF) | BIT(WAKE_STS_OFF))
  
  static irqreturn_t amd_gpio_irq_handler(int irq, void *dev_id)

  {

  	struct amd_gpio *gpio_dev = dev_id;
  	struct gpio_chip *gc = &gpio_dev->gc;
  	irqreturn_t ret = IRQ_NONE;
  	unsigned int i, irqnr;

  	unsigned long flags;

  	u32 __iomem *regs;
  	u32  regval;

  	u64 status, mask;

  	/* Read the wake status */

  	raw_spin_lock_irqsave(&gpio_dev->lock, flags);

  	status = readl(gpio_dev->base + WAKE_INT_STATUS_REG1);
  	status <<= 32;
  	status |= readl(gpio_dev->base + WAKE_INT_STATUS_REG0);

  	raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

  	/* Bit 0-45 contain the relevant status bits */
  	status &= (1ULL << 46) - 1;
  	regs = gpio_dev->base;
  	for (mask = 1, irqnr = 0; status; mask <<= 1, regs += 4, irqnr += 4) {
  		if (!(status & mask))
  			continue;
  		status &= ~mask;
  
  		/* Each status bit covers four pins */
  		for (i = 0; i < 4; i++) {
  			regval = readl(regs + i);

  			if (!(regval & PIN_IRQ_PENDING) ||
  			    !(regval & BIT(INTERRUPT_MASK_OFF)))

  				continue;

  			irq = irq_find_mapping(gc->irq.domain, irqnr + i);

  			if (irq != 0)
  				generic_handle_irq(irq);

  
  			/* Clear interrupt.
  			 * We must read the pin register again, in case the
  			 * value was changed while executing
  			 * generic_handle_irq() above.

  			 * If we didn't find a mapping for the interrupt,
  			 * disable it in order to avoid a system hang caused
  			 * by an interrupt storm.

  			 */
  			raw_spin_lock_irqsave(&gpio_dev->lock, flags);
  			regval = readl(regs + i);

  			if (irq == 0) {
  				regval &= ~BIT(INTERRUPT_ENABLE_OFF);
  				dev_dbg(&gpio_dev->pdev->dev,
  					"Disabling spurious GPIO IRQ %d
  ",
  					irqnr + i);
  			}

  			writel(regval, regs + i);

  			raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

  			ret = IRQ_HANDLED;

  		}
  	}

  	/* Signal EOI to the GPIO unit */

  	raw_spin_lock_irqsave(&gpio_dev->lock, flags);

  	regval = readl(gpio_dev->base + WAKE_INT_MASTER_REG);
  	regval |= EOI_MASK;
  	writel(regval, gpio_dev->base + WAKE_INT_MASTER_REG);

  	raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

  	return ret;

  }
  
  static int amd_get_groups_count(struct pinctrl_dev *pctldev)
  {
  	struct amd_gpio *gpio_dev = pinctrl_dev_get_drvdata(pctldev);
  
  	return gpio_dev->ngroups;
  }
  
  static const char *amd_get_group_name(struct pinctrl_dev *pctldev,
  				      unsigned group)
  {
  	struct amd_gpio *gpio_dev = pinctrl_dev_get_drvdata(pctldev);
  
  	return gpio_dev->groups[group].name;
  }
  
  static int amd_get_group_pins(struct pinctrl_dev *pctldev,
  			      unsigned group,
  			      const unsigned **pins,
  			      unsigned *num_pins)
  {
  	struct amd_gpio *gpio_dev = pinctrl_dev_get_drvdata(pctldev);
  
  	*pins = gpio_dev->groups[group].pins;
  	*num_pins = gpio_dev->groups[group].npins;
  	return 0;
  }
  
  static const struct pinctrl_ops amd_pinctrl_ops = {
  	.get_groups_count	= amd_get_groups_count,
  	.get_group_name		= amd_get_group_name,
  	.get_group_pins		= amd_get_group_pins,
  #ifdef CONFIG_OF
  	.dt_node_to_map		= pinconf_generic_dt_node_to_map_group,

  	.dt_free_map		= pinctrl_utils_free_map,

  #endif
  };
  
  static int amd_pinconf_get(struct pinctrl_dev *pctldev,
  			  unsigned int pin,
  			  unsigned long *config)
  {
  	u32 pin_reg;
  	unsigned arg;
  	unsigned long flags;
  	struct amd_gpio *gpio_dev = pinctrl_dev_get_drvdata(pctldev);
  	enum pin_config_param param = pinconf_to_config_param(*config);

  	raw_spin_lock_irqsave(&gpio_dev->lock, flags);

  	pin_reg = readl(gpio_dev->base + pin*4);

  	raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

  	switch (param) {
  	case PIN_CONFIG_INPUT_DEBOUNCE:
  		arg = pin_reg & DB_TMR_OUT_MASK;
  		break;
  
  	case PIN_CONFIG_BIAS_PULL_DOWN:
  		arg = (pin_reg >> PULL_DOWN_ENABLE_OFF) & BIT(0);
  		break;
  
  	case PIN_CONFIG_BIAS_PULL_UP:
  		arg = (pin_reg >> PULL_UP_SEL_OFF) & (BIT(0) | BIT(1));
  		break;
  
  	case PIN_CONFIG_DRIVE_STRENGTH:
  		arg = (pin_reg >> DRV_STRENGTH_SEL_OFF) & DRV_STRENGTH_SEL_MASK;
  		break;
  
  	default:
  		dev_err(&gpio_dev->pdev->dev, "Invalid config param %04x
  ",
  			param);
  		return -ENOTSUPP;
  	}
  
  	*config = pinconf_to_config_packed(param, arg);
  
  	return 0;
  }
  
  static int amd_pinconf_set(struct pinctrl_dev *pctldev, unsigned int pin,
  				unsigned long *configs, unsigned num_configs)
  {
  	int i;

  	u32 arg;

  	int ret = 0;
  	u32 pin_reg;

  	unsigned long flags;
  	enum pin_config_param param;
  	struct amd_gpio *gpio_dev = pinctrl_dev_get_drvdata(pctldev);

  	raw_spin_lock_irqsave(&gpio_dev->lock, flags);

  	for (i = 0; i < num_configs; i++) {
  		param = pinconf_to_config_param(configs[i]);
  		arg = pinconf_to_config_argument(configs[i]);
  		pin_reg = readl(gpio_dev->base + pin*4);
  
  		switch (param) {
  		case PIN_CONFIG_INPUT_DEBOUNCE:
  			pin_reg &= ~DB_TMR_OUT_MASK;
  			pin_reg |= arg & DB_TMR_OUT_MASK;
  			break;
  
  		case PIN_CONFIG_BIAS_PULL_DOWN:
  			pin_reg &= ~BIT(PULL_DOWN_ENABLE_OFF);
  			pin_reg |= (arg & BIT(0)) << PULL_DOWN_ENABLE_OFF;
  			break;
  
  		case PIN_CONFIG_BIAS_PULL_UP:
  			pin_reg &= ~BIT(PULL_UP_SEL_OFF);
  			pin_reg |= (arg & BIT(0)) << PULL_UP_SEL_OFF;
  			pin_reg &= ~BIT(PULL_UP_ENABLE_OFF);
  			pin_reg |= ((arg>>1) & BIT(0)) << PULL_UP_ENABLE_OFF;
  			break;
  
  		case PIN_CONFIG_DRIVE_STRENGTH:
  			pin_reg &= ~(DRV_STRENGTH_SEL_MASK
  					<< DRV_STRENGTH_SEL_OFF);
  			pin_reg |= (arg & DRV_STRENGTH_SEL_MASK)
  					<< DRV_STRENGTH_SEL_OFF;
  			break;
  
  		default:
  			dev_err(&gpio_dev->pdev->dev,
  				"Invalid config param %04x
  ", param);

  			ret = -ENOTSUPP;

  		}
  
  		writel(pin_reg, gpio_dev->base + pin*4);
  	}

  	raw_spin_unlock_irqrestore(&gpio_dev->lock, flags);

  	return ret;

  }
  
  static int amd_pinconf_group_get(struct pinctrl_dev *pctldev,
  				unsigned int group,
  				unsigned long *config)
  {
  	const unsigned *pins;
  	unsigned npins;
  	int ret;
  
  	ret = amd_get_group_pins(pctldev, group, &pins, &npins);
  	if (ret)
  		return ret;
  
  	if (amd_pinconf_get(pctldev, pins[0], config))
  			return -ENOTSUPP;
  
  	return 0;
  }
  
  static int amd_pinconf_group_set(struct pinctrl_dev *pctldev,
  				unsigned group, unsigned long *configs,
  				unsigned num_configs)
  {
  	const unsigned *pins;
  	unsigned npins;
  	int i, ret;
  
  	ret = amd_get_group_pins(pctldev, group, &pins, &npins);
  	if (ret)
  		return ret;
  	for (i = 0; i < npins; i++) {
  		if (amd_pinconf_set(pctldev, pins[i], configs, num_configs))
  			return -ENOTSUPP;
  	}
  	return 0;
  }
  
  static const struct pinconf_ops amd_pinconf_ops = {
  	.pin_config_get		= amd_pinconf_get,
  	.pin_config_set		= amd_pinconf_set,
  	.pin_config_group_get = amd_pinconf_group_get,
  	.pin_config_group_set = amd_pinconf_group_set,
  };

  #ifdef CONFIG_PM_SLEEP
  static bool amd_gpio_should_save(struct amd_gpio *gpio_dev, unsigned int pin)
  {
  	const struct pin_desc *pd = pin_desc_get(gpio_dev->pctrl, pin);
  
  	if (!pd)
  		return false;
  
  	/*
  	 * Only restore the pin if it is actually in use by the kernel (or
  	 * by userspace).
  	 */
  	if (pd->mux_owner || pd->gpio_owner ||
  	    gpiochip_line_is_irq(&gpio_dev->gc, pin))
  		return true;
  
  	return false;
  }

  static int amd_gpio_suspend(struct device *dev)

  {

  	struct amd_gpio *gpio_dev = dev_get_drvdata(dev);

  	struct pinctrl_desc *desc = gpio_dev->pctrl->desc;
  	int i;
  
  	for (i = 0; i < desc->npins; i++) {
  		int pin = desc->pins[i].number;
  
  		if (!amd_gpio_should_save(gpio_dev, pin))
  			continue;
  
  		gpio_dev->saved_regs[i] = readl(gpio_dev->base + pin*4);
  	}
  
  	return 0;
  }

  static int amd_gpio_resume(struct device *dev)

  {

  	struct amd_gpio *gpio_dev = dev_get_drvdata(dev);

  	struct pinctrl_desc *desc = gpio_dev->pctrl->desc;
  	int i;
  
  	for (i = 0; i < desc->npins; i++) {
  		int pin = desc->pins[i].number;
  
  		if (!amd_gpio_should_save(gpio_dev, pin))
  			continue;
  
  		writel(gpio_dev->saved_regs[i], gpio_dev->base + pin*4);
  	}
  
  	return 0;
  }
  
  static const struct dev_pm_ops amd_gpio_pm_ops = {
  	SET_LATE_SYSTEM_SLEEP_PM_OPS(amd_gpio_suspend,
  				     amd_gpio_resume)
  };
  #endif

  static struct pinctrl_desc amd_pinctrl_desc = {
  	.pins	= kerncz_pins,
  	.npins = ARRAY_SIZE(kerncz_pins),
  	.pctlops = &amd_pinctrl_ops,
  	.confops = &amd_pinconf_ops,
  	.owner = THIS_MODULE,
  };
  
  static int amd_gpio_probe(struct platform_device *pdev)
  {
  	int ret = 0;

  	int irq_base;

  	struct resource *res;
  	struct amd_gpio *gpio_dev;
  
  	gpio_dev = devm_kzalloc(&pdev->dev,
  				sizeof(struct amd_gpio), GFP_KERNEL);
  	if (!gpio_dev)
  		return -ENOMEM;

  	raw_spin_lock_init(&gpio_dev->lock);

  
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	if (!res) {
  		dev_err(&pdev->dev, "Failed to get gpio io resource.
  ");
  		return -EINVAL;
  	}
  
  	gpio_dev->base = devm_ioremap_nocache(&pdev->dev, res->start,
  						resource_size(res));

  	if (!gpio_dev->base)
  		return -ENOMEM;

  
  	irq_base = platform_get_irq(pdev, 0);

  	if (irq_base < 0)

  		return irq_base;

  #ifdef CONFIG_PM_SLEEP
  	gpio_dev->saved_regs = devm_kcalloc(&pdev->dev, amd_pinctrl_desc.npins,
  					    sizeof(*gpio_dev->saved_regs),
  					    GFP_KERNEL);
  	if (!gpio_dev->saved_regs)
  		return -ENOMEM;
  #endif

  	gpio_dev->pdev = pdev;

  	gpio_dev->gc.get_direction	= amd_gpio_get_direction;

  	gpio_dev->gc.direction_input	= amd_gpio_direction_input;
  	gpio_dev->gc.direction_output	= amd_gpio_direction_output;
  	gpio_dev->gc.get			= amd_gpio_get_value;
  	gpio_dev->gc.set			= amd_gpio_set_value;

  	gpio_dev->gc.set_config		= amd_gpio_set_config;

  	gpio_dev->gc.dbg_show		= amd_gpio_dbg_show;

  	gpio_dev->gc.base		= -1;

  	gpio_dev->gc.label			= pdev->name;
  	gpio_dev->gc.owner			= THIS_MODULE;

  	gpio_dev->gc.parent			= &pdev->dev;

  	gpio_dev->gc.ngpio			= resource_size(res) / 4;

  #if defined(CONFIG_OF_GPIO)
  	gpio_dev->gc.of_node			= pdev->dev.of_node;
  #endif

  	gpio_dev->hwbank_num = gpio_dev->gc.ngpio / 64;

  	gpio_dev->groups = kerncz_groups;
  	gpio_dev->ngroups = ARRAY_SIZE(kerncz_groups);
  
  	amd_pinctrl_desc.name = dev_name(&pdev->dev);

  	gpio_dev->pctrl = devm_pinctrl_register(&pdev->dev, &amd_pinctrl_desc,
  						gpio_dev);

  	if (IS_ERR(gpio_dev->pctrl)) {

  		dev_err(&pdev->dev, "Couldn't register pinctrl driver
  ");

  		return PTR_ERR(gpio_dev->pctrl);

  	}

  	ret = gpiochip_add_data(&gpio_dev->gc, gpio_dev);

  	if (ret)

  		return ret;

  
  	ret = gpiochip_add_pin_range(&gpio_dev->gc, dev_name(&pdev->dev),

  				0, 0, gpio_dev->gc.ngpio);

  	if (ret) {
  		dev_err(&pdev->dev, "Failed to add pin range
  ");
  		goto out2;
  	}
  
  	ret = gpiochip_irqchip_add(&gpio_dev->gc,
  				&amd_gpio_irqchip,
  				0,
  				handle_simple_irq,
  				IRQ_TYPE_NONE);
  	if (ret) {
  		dev_err(&pdev->dev, "could not add irqchip
  ");
  		ret = -ENODEV;
  		goto out2;
  	}

  	ret = devm_request_irq(&pdev->dev, irq_base, amd_gpio_irq_handler,
  			       IRQF_SHARED, KBUILD_MODNAME, gpio_dev);

  	if (ret)
  		goto out2;

  	platform_set_drvdata(pdev, gpio_dev);
  
  	dev_dbg(&pdev->dev, "amd gpio driver loaded
  ");
  	return ret;
  
  out2:
  	gpiochip_remove(&gpio_dev->gc);

  	return ret;
  }
  
  static int amd_gpio_remove(struct platform_device *pdev)
  {
  	struct amd_gpio *gpio_dev;
  
  	gpio_dev = platform_get_drvdata(pdev);
  
  	gpiochip_remove(&gpio_dev->gc);

  
  	return 0;
  }
  
  static const struct acpi_device_id amd_gpio_acpi_match[] = {
  	{ "AMD0030", 0 },

  	{ "AMDI0030", 0},

  	{ },
  };
  MODULE_DEVICE_TABLE(acpi, amd_gpio_acpi_match);
  
  static struct platform_driver amd_gpio_driver = {
  	.driver		= {
  		.name	= "amd_gpio",

  		.acpi_match_table = ACPI_PTR(amd_gpio_acpi_match),

  #ifdef CONFIG_PM_SLEEP
  		.pm	= &amd_gpio_pm_ops,
  #endif

  	},
  	.probe		= amd_gpio_probe,
  	.remove		= amd_gpio_remove,
  };
  
  module_platform_driver(amd_gpio_driver);
  
  MODULE_LICENSE("GPL v2");
  MODULE_AUTHOR("Ken Xue <Ken.Xue@amd.com>, Jeff Wu <Jeff.Wu@amd.com>");
  MODULE_DESCRIPTION("AMD GPIO pinctrl driver");