/*
   * tps65910-irq.c  --  TI TPS6591x
   *
   * Copyright 2010 Texas Instruments Inc.
   *
   * Author: Graeme Gregory <gg@slimlogic.co.uk>
   * Author: Jorge Eduardo Candelaria <jedu@slimlogic.co.uk>
   *
   *  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/kernel.h>
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/bug.h>
  #include <linux/device.h>
  #include <linux/interrupt.h>
  #include <linux/irq.h>
  #include <linux/gpio.h>
  #include <linux/mfd/tps65910.h>
  
  static inline int irq_to_tps65910_irq(struct tps65910 *tps65910,
  							int irq)
  {
  	return (irq - tps65910->irq_base);
  }
  
  /*
   * This is a threaded IRQ handler so can access I2C/SPI.  Since all
   * interrupts are clear on read the IRQ line will be reasserted and
   * the physical IRQ will be handled again if another interrupt is
   * asserted while we run - in the normal course of events this is a
   * rare occurrence so we save I2C/SPI reads.  We're also assuming that
   * it's rare to get lots of interrupts firing simultaneously so try to
   * minimise I/O.
   */
  static irqreturn_t tps65910_irq(int irq, void *irq_data)
  {
  	struct tps65910 *tps65910 = irq_data;

  	u32 irq_sts;
  	u32 irq_mask;

  	u8 reg;
  	int i;
  
  	tps65910->read(tps65910, TPS65910_INT_STS, 1, &reg);
  	irq_sts = reg;
  	tps65910->read(tps65910, TPS65910_INT_STS2, 1, &reg);
  	irq_sts |= reg << 8;

  	switch (tps65910_chip_id(tps65910)) {
  	case TPS65911:
  		tps65910->read(tps65910, TPS65910_INT_STS3, 1, &reg);
  		irq_sts |= reg << 16;
  	}

  
  	tps65910->read(tps65910, TPS65910_INT_MSK, 1, &reg);
  	irq_mask = reg;
  	tps65910->read(tps65910, TPS65910_INT_MSK2, 1, &reg);
  	irq_mask |= reg << 8;

  	switch (tps65910_chip_id(tps65910)) {
  	case TPS65911:
  		tps65910->read(tps65910, TPS65910_INT_MSK3, 1, &reg);
  		irq_mask |= reg << 16;
  	}

  
  	irq_sts &= ~irq_mask;
  
  	if (!irq_sts)
  		return IRQ_NONE;

  	for (i = 0; i < tps65910->irq_num; i++) {

  
  		if (!(irq_sts & (1 << i)))
  			continue;
  
  		handle_nested_irq(tps65910->irq_base + i);
  	}
  
  	/* Write the STS register back to clear IRQs we handled */
  	reg = irq_sts & 0xFF;

  	irq_sts >>= 8;

  	tps65910->write(tps65910, TPS65910_INT_STS, 1, &reg);

  	reg = irq_sts & 0xFF;

  	tps65910->write(tps65910, TPS65910_INT_STS2, 1, &reg);

  	switch (tps65910_chip_id(tps65910)) {
  	case TPS65911:
  		reg = irq_sts >> 8;
  		tps65910->write(tps65910, TPS65910_INT_STS3, 1, &reg);
  	}

  
  	return IRQ_HANDLED;
  }
  
  static void tps65910_irq_lock(struct irq_data *data)
  {
  	struct tps65910 *tps65910 = irq_data_get_irq_chip_data(data);
  
  	mutex_lock(&tps65910->irq_lock);
  }
  
  static void tps65910_irq_sync_unlock(struct irq_data *data)
  {
  	struct tps65910 *tps65910 = irq_data_get_irq_chip_data(data);

  	u32 reg_mask;

  	u8 reg;
  
  	tps65910->read(tps65910, TPS65910_INT_MSK, 1, &reg);
  	reg_mask = reg;
  	tps65910->read(tps65910, TPS65910_INT_MSK2, 1, &reg);
  	reg_mask |= reg << 8;

  	switch (tps65910_chip_id(tps65910)) {
  	case TPS65911:
  		tps65910->read(tps65910, TPS65910_INT_MSK3, 1, &reg);
  		reg_mask |= reg << 16;
  	}

  
  	if (tps65910->irq_mask != reg_mask) {
  		reg = tps65910->irq_mask & 0xFF;
  		tps65910->write(tps65910, TPS65910_INT_MSK, 1, &reg);

  		reg = tps65910->irq_mask >> 8 & 0xFF;

  		tps65910->write(tps65910, TPS65910_INT_MSK2, 1, &reg);

  		switch (tps65910_chip_id(tps65910)) {
  		case TPS65911:
  			reg = tps65910->irq_mask >> 16;
  			tps65910->write(tps65910, TPS65910_INT_MSK3, 1, &reg);
  		}

  	}
  	mutex_unlock(&tps65910->irq_lock);
  }
  
  static void tps65910_irq_enable(struct irq_data *data)
  {
  	struct tps65910 *tps65910 = irq_data_get_irq_chip_data(data);
  
  	tps65910->irq_mask &= ~( 1 << irq_to_tps65910_irq(tps65910, data->irq));
  }
  
  static void tps65910_irq_disable(struct irq_data *data)
  {
  	struct tps65910 *tps65910 = irq_data_get_irq_chip_data(data);
  
  	tps65910->irq_mask |= ( 1 << irq_to_tps65910_irq(tps65910, data->irq));
  }
  
  static struct irq_chip tps65910_irq_chip = {
  	.name = "tps65910",
  	.irq_bus_lock = tps65910_irq_lock,
  	.irq_bus_sync_unlock = tps65910_irq_sync_unlock,
  	.irq_disable = tps65910_irq_disable,
  	.irq_enable = tps65910_irq_enable,
  };
  
  int tps65910_irq_init(struct tps65910 *tps65910, int irq,
  		    struct tps65910_platform_data *pdata)
  {
  	int ret, cur_irq;
  	int flags = IRQF_ONESHOT;

  
  	if (!irq) {
  		dev_warn(tps65910->dev, "No interrupt support, no core IRQ
  ");
  		return -EINVAL;
  	}
  
  	if (!pdata || !pdata->irq_base) {
  		dev_warn(tps65910->dev, "No interrupt support, no IRQ base
  ");
  		return -EINVAL;
  	}

  	tps65910->irq_mask = 0xFFFFFF;

  
  	mutex_init(&tps65910->irq_lock);
  	tps65910->chip_irq = irq;
  	tps65910->irq_base = pdata->irq_base;

  	switch (tps65910_chip_id(tps65910)) {
  	case TPS65910:
  		tps65910->irq_num = TPS65910_NUM_IRQ;

  		break;

  	case TPS65911:
  		tps65910->irq_num = TPS65911_NUM_IRQ;

  		break;

  	}

  	/* Register with genirq */
  	for (cur_irq = tps65910->irq_base;

  	     cur_irq < tps65910->irq_num + tps65910->irq_base;

  	     cur_irq++) {
  		irq_set_chip_data(cur_irq, tps65910);
  		irq_set_chip_and_handler(cur_irq, &tps65910_irq_chip,
  					 handle_edge_irq);
  		irq_set_nested_thread(cur_irq, 1);
  
  		/* ARM needs us to explicitly flag the IRQ as valid
  		 * and will set them noprobe when we do so. */
  #ifdef CONFIG_ARM
  		set_irq_flags(cur_irq, IRQF_VALID);
  #else
  		irq_set_noprobe(cur_irq);
  #endif
  	}
  
  	ret = request_threaded_irq(irq, NULL, tps65910_irq, flags,
  				   "tps65910", tps65910);

  
  	irq_set_irq_type(irq, IRQ_TYPE_LEVEL_LOW);

  	if (ret != 0)
  		dev_err(tps65910->dev, "Failed to request IRQ: %d
  ", ret);
  
  	return ret;
  }
  
  int tps65910_irq_exit(struct tps65910 *tps65910)
  {

  	if (tps65910->chip_irq)
  		free_irq(tps65910->chip_irq, tps65910);

  	return 0;
  }