// SPDX-License-Identifier: GPL-2.0
  //
  // Copyright (c) 2019 MediaTek Inc.
  
  #include <linux/interrupt.h>
  #include <linux/module.h>
  #include <linux/of.h>
  #include <linux/of_device.h>
  #include <linux/of_irq.h>
  #include <linux/platform_device.h>
  #include <linux/regmap.h>

  #include <linux/suspend.h>

  #include <linux/mfd/mt6323/core.h>
  #include <linux/mfd/mt6323/registers.h>
  #include <linux/mfd/mt6397/core.h>
  #include <linux/mfd/mt6397/registers.h>
  
  static void mt6397_irq_lock(struct irq_data *data)
  {
  	struct mt6397_chip *mt6397 = irq_data_get_irq_chip_data(data);
  
  	mutex_lock(&mt6397->irqlock);
  }
  
  static void mt6397_irq_sync_unlock(struct irq_data *data)
  {
  	struct mt6397_chip *mt6397 = irq_data_get_irq_chip_data(data);
  
  	regmap_write(mt6397->regmap, mt6397->int_con[0],
  		     mt6397->irq_masks_cur[0]);
  	regmap_write(mt6397->regmap, mt6397->int_con[1],
  		     mt6397->irq_masks_cur[1]);
  
  	mutex_unlock(&mt6397->irqlock);
  }
  
  static void mt6397_irq_disable(struct irq_data *data)
  {
  	struct mt6397_chip *mt6397 = irq_data_get_irq_chip_data(data);
  	int shift = data->hwirq & 0xf;
  	int reg = data->hwirq >> 4;
  
  	mt6397->irq_masks_cur[reg] &= ~BIT(shift);
  }
  
  static void mt6397_irq_enable(struct irq_data *data)
  {
  	struct mt6397_chip *mt6397 = irq_data_get_irq_chip_data(data);
  	int shift = data->hwirq & 0xf;
  	int reg = data->hwirq >> 4;
  
  	mt6397->irq_masks_cur[reg] |= BIT(shift);
  }
  
  #ifdef CONFIG_PM_SLEEP
  static int mt6397_irq_set_wake(struct irq_data *irq_data, unsigned int on)
  {
  	struct mt6397_chip *mt6397 = irq_data_get_irq_chip_data(irq_data);
  	int shift = irq_data->hwirq & 0xf;
  	int reg = irq_data->hwirq >> 4;
  
  	if (on)
  		mt6397->wake_mask[reg] |= BIT(shift);
  	else
  		mt6397->wake_mask[reg] &= ~BIT(shift);
  
  	return 0;
  }
  #else
  #define mt6397_irq_set_wake NULL
  #endif
  
  static struct irq_chip mt6397_irq_chip = {
  	.name = "mt6397-irq",
  	.irq_bus_lock = mt6397_irq_lock,
  	.irq_bus_sync_unlock = mt6397_irq_sync_unlock,
  	.irq_enable = mt6397_irq_enable,
  	.irq_disable = mt6397_irq_disable,
  	.irq_set_wake = mt6397_irq_set_wake,
  };
  
  static void mt6397_irq_handle_reg(struct mt6397_chip *mt6397, int reg,
  				  int irqbase)
  {

  	unsigned int status = 0;

  	int i, irq, ret;
  
  	ret = regmap_read(mt6397->regmap, reg, &status);
  	if (ret) {
  		dev_err(mt6397->dev, "Failed to read irq status: %d
  ", ret);
  		return;
  	}
  
  	for (i = 0; i < 16; i++) {
  		if (status & BIT(i)) {
  			irq = irq_find_mapping(mt6397->irq_domain, irqbase + i);
  			if (irq)
  				handle_nested_irq(irq);
  		}
  	}
  
  	regmap_write(mt6397->regmap, reg, status);
  }
  
  static irqreturn_t mt6397_irq_thread(int irq, void *data)
  {
  	struct mt6397_chip *mt6397 = data;
  
  	mt6397_irq_handle_reg(mt6397, mt6397->int_status[0], 0);
  	mt6397_irq_handle_reg(mt6397, mt6397->int_status[1], 16);
  
  	return IRQ_HANDLED;
  }
  
  static int mt6397_irq_domain_map(struct irq_domain *d, unsigned int irq,
  				 irq_hw_number_t hw)
  {
  	struct mt6397_chip *mt6397 = d->host_data;
  
  	irq_set_chip_data(irq, mt6397);
  	irq_set_chip_and_handler(irq, &mt6397_irq_chip, handle_level_irq);
  	irq_set_nested_thread(irq, 1);
  	irq_set_noprobe(irq);
  
  	return 0;
  }
  
  static const struct irq_domain_ops mt6397_irq_domain_ops = {
  	.map = mt6397_irq_domain_map,
  };

  static int mt6397_irq_pm_notifier(struct notifier_block *notifier,
  				  unsigned long pm_event, void *unused)
  {
  	struct mt6397_chip *chip =
  		container_of(notifier, struct mt6397_chip, pm_nb);
  
  	switch (pm_event) {
  	case PM_SUSPEND_PREPARE:
  		regmap_write(chip->regmap,
  			     chip->int_con[0], chip->wake_mask[0]);
  		regmap_write(chip->regmap,
  			     chip->int_con[1], chip->wake_mask[1]);
  		enable_irq_wake(chip->irq);
  		break;
  
  	case PM_POST_SUSPEND:
  		regmap_write(chip->regmap,
  			     chip->int_con[0], chip->irq_masks_cur[0]);
  		regmap_write(chip->regmap,
  			     chip->int_con[1], chip->irq_masks_cur[1]);
  		disable_irq_wake(chip->irq);
  		break;
  
  	default:
  		break;
  	}
  
  	return NOTIFY_DONE;
  }

  int mt6397_irq_init(struct mt6397_chip *chip)
  {
  	int ret;
  
  	mutex_init(&chip->irqlock);
  
  	switch (chip->chip_id) {
  	case MT6323_CHIP_ID:
  		chip->int_con[0] = MT6323_INT_CON0;
  		chip->int_con[1] = MT6323_INT_CON1;
  		chip->int_status[0] = MT6323_INT_STATUS0;
  		chip->int_status[1] = MT6323_INT_STATUS1;
  		break;
  
  	case MT6391_CHIP_ID:
  	case MT6397_CHIP_ID:
  		chip->int_con[0] = MT6397_INT_CON0;
  		chip->int_con[1] = MT6397_INT_CON1;
  		chip->int_status[0] = MT6397_INT_STATUS0;
  		chip->int_status[1] = MT6397_INT_STATUS1;
  		break;
  
  	default:
  		dev_err(chip->dev, "unsupported chip: 0x%x
  ", chip->chip_id);
  		return -ENODEV;
  	}
  
  	/* Mask all interrupt sources */
  	regmap_write(chip->regmap, chip->int_con[0], 0x0);
  	regmap_write(chip->regmap, chip->int_con[1], 0x0);

  	chip->pm_nb.notifier_call = mt6397_irq_pm_notifier;

  	chip->irq_domain = irq_domain_add_linear(chip->dev->of_node,
  						 MT6397_IRQ_NR,
  						 &mt6397_irq_domain_ops,
  						 chip);
  	if (!chip->irq_domain) {
  		dev_err(chip->dev, "could not create irq domain
  ");
  		return -ENOMEM;
  	}
  
  	ret = devm_request_threaded_irq(chip->dev, chip->irq, NULL,
  					mt6397_irq_thread, IRQF_ONESHOT,
  					"mt6397-pmic", chip);
  	if (ret) {
  		dev_err(chip->dev, "failed to register irq=%d; err: %d
  ",
  			chip->irq, ret);
  		return ret;
  	}

  	register_pm_notifier(&chip->pm_nb);

  	return 0;
  }