/*
   *  linux/arch/arm/mach-mmp/irq.c
   *
   *  Generic IRQ handling, GPIO IRQ demultiplexing, etc.
   *  Copyright (C) 2008 - 2012 Marvell Technology Group Ltd.
   *
   *  Author:	Bin Yang <bin.yang@marvell.com>
   *              Haojian Zhuang <haojian.zhuang@gmail.com>
   *
   *  This program is free software; you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License version 2 as
   *  published by the Free Software Foundation.
   */
  
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/irq.h>

  #include <linux/irqchip.h>

  #include <linux/irqdomain.h>
  #include <linux/io.h>
  #include <linux/ioport.h>
  #include <linux/of_address.h>
  #include <linux/of_irq.h>

  #include <asm/exception.h>

  #include <asm/hardirq.h>

  #define MAX_ICU_NR		16

  #define PJ1_INT_SEL		0x10c
  #define PJ4_INT_SEL		0x104
  
  /* bit fields in PJ1_INT_SEL and PJ4_INT_SEL */
  #define SEL_INT_PENDING		(1 << 6)
  #define SEL_INT_NUM_MASK	0x3f

  struct icu_chip_data {
  	int			nr_irqs;
  	unsigned int		virq_base;
  	unsigned int		cascade_irq;
  	void __iomem		*reg_status;
  	void __iomem		*reg_mask;
  	unsigned int		conf_enable;
  	unsigned int		conf_disable;
  	unsigned int		conf_mask;
  	unsigned int		clr_mfp_irq_base;
  	unsigned int		clr_mfp_hwirq;
  	struct irq_domain	*domain;
  };
  
  struct mmp_intc_conf {
  	unsigned int	conf_enable;
  	unsigned int	conf_disable;
  	unsigned int	conf_mask;
  };

  static void __iomem *mmp_icu_base;

  static struct icu_chip_data icu_data[MAX_ICU_NR];
  static int max_icu_nr;
  
  extern void mmp2_clear_pmic_int(void);
  
  static void icu_mask_ack_irq(struct irq_data *d)
  {
  	struct irq_domain *domain = d->domain;
  	struct icu_chip_data *data = (struct icu_chip_data *)domain->host_data;
  	int hwirq;
  	u32 r;
  
  	hwirq = d->irq - data->virq_base;
  	if (data == &icu_data[0]) {
  		r = readl_relaxed(mmp_icu_base + (hwirq << 2));
  		r &= ~data->conf_mask;
  		r |= data->conf_disable;
  		writel_relaxed(r, mmp_icu_base + (hwirq << 2));
  	} else {
  #ifdef CONFIG_CPU_MMP2
  		if ((data->virq_base == data->clr_mfp_irq_base)
  			&& (hwirq == data->clr_mfp_hwirq))
  			mmp2_clear_pmic_int();
  #endif
  		r = readl_relaxed(data->reg_mask) | (1 << hwirq);
  		writel_relaxed(r, data->reg_mask);
  	}
  }
  
  static void icu_mask_irq(struct irq_data *d)
  {
  	struct irq_domain *domain = d->domain;
  	struct icu_chip_data *data = (struct icu_chip_data *)domain->host_data;
  	int hwirq;
  	u32 r;
  
  	hwirq = d->irq - data->virq_base;
  	if (data == &icu_data[0]) {
  		r = readl_relaxed(mmp_icu_base + (hwirq << 2));
  		r &= ~data->conf_mask;
  		r |= data->conf_disable;
  		writel_relaxed(r, mmp_icu_base + (hwirq << 2));
  	} else {
  		r = readl_relaxed(data->reg_mask) | (1 << hwirq);
  		writel_relaxed(r, data->reg_mask);
  	}
  }
  
  static void icu_unmask_irq(struct irq_data *d)
  {
  	struct irq_domain *domain = d->domain;
  	struct icu_chip_data *data = (struct icu_chip_data *)domain->host_data;
  	int hwirq;
  	u32 r;
  
  	hwirq = d->irq - data->virq_base;
  	if (data == &icu_data[0]) {
  		r = readl_relaxed(mmp_icu_base + (hwirq << 2));
  		r &= ~data->conf_mask;
  		r |= data->conf_enable;
  		writel_relaxed(r, mmp_icu_base + (hwirq << 2));
  	} else {
  		r = readl_relaxed(data->reg_mask) & ~(1 << hwirq);
  		writel_relaxed(r, data->reg_mask);
  	}
  }

  struct irq_chip icu_irq_chip = {

  	.name		= "icu_irq",
  	.irq_mask	= icu_mask_irq,
  	.irq_mask_ack	= icu_mask_ack_irq,
  	.irq_unmask	= icu_unmask_irq,
  };

  static void icu_mux_irq_demux(struct irq_desc *desc)

  {

  	unsigned int irq = irq_desc_get_irq(desc);

  	struct irq_domain *domain;
  	struct icu_chip_data *data;
  	int i;
  	unsigned long mask, status, n;
  
  	for (i = 1; i < max_icu_nr; i++) {
  		if (irq == icu_data[i].cascade_irq) {
  			domain = icu_data[i].domain;
  			data = (struct icu_chip_data *)domain->host_data;
  			break;
  		}
  	}
  	if (i >= max_icu_nr) {
  		pr_err("Spurious irq %d in MMP INTC
  ", irq);
  		return;
  	}
  
  	mask = readl_relaxed(data->reg_mask);
  	while (1) {
  		status = readl_relaxed(data->reg_status) & ~mask;
  		if (status == 0)
  			break;

  		for_each_set_bit(n, &status, BITS_PER_LONG) {

  			generic_handle_irq(icu_data[i].virq_base + n);

  		}
  	}
  }
  
  static int mmp_irq_domain_map(struct irq_domain *d, unsigned int irq,
  			      irq_hw_number_t hw)
  {
  	irq_set_chip_and_handler(irq, &icu_irq_chip, handle_level_irq);

  	return 0;
  }
  
  static int mmp_irq_domain_xlate(struct irq_domain *d, struct device_node *node,
  				const u32 *intspec, unsigned int intsize,
  				unsigned long *out_hwirq,
  				unsigned int *out_type)
  {
  	*out_hwirq = intspec[0];
  	return 0;
  }
  
  const struct irq_domain_ops mmp_irq_domain_ops = {
  	.map		= mmp_irq_domain_map,
  	.xlate		= mmp_irq_domain_xlate,
  };
  
  static struct mmp_intc_conf mmp_conf = {
  	.conf_enable	= 0x51,
  	.conf_disable	= 0x0,
  	.conf_mask	= 0x7f,
  };
  
  static struct mmp_intc_conf mmp2_conf = {
  	.conf_enable	= 0x20,
  	.conf_disable	= 0x0,
  	.conf_mask	= 0x7f,
  };

  static void __exception_irq_entry mmp_handle_irq(struct pt_regs *regs)

  {

  	int hwirq;

  
  	hwirq = readl_relaxed(mmp_icu_base + PJ1_INT_SEL);
  	if (!(hwirq & SEL_INT_PENDING))
  		return;
  	hwirq &= SEL_INT_NUM_MASK;

  	handle_domain_irq(icu_data[0].domain, hwirq, regs);

  }

  static void __exception_irq_entry mmp2_handle_irq(struct pt_regs *regs)

  {

  	int hwirq;

  
  	hwirq = readl_relaxed(mmp_icu_base + PJ4_INT_SEL);
  	if (!(hwirq & SEL_INT_PENDING))
  		return;
  	hwirq &= SEL_INT_NUM_MASK;

  	handle_domain_irq(icu_data[0].domain, hwirq, regs);

  }

  /* MMP (ARMv5) */
  void __init icu_init_irq(void)
  {
  	int irq;
  
  	max_icu_nr = 1;
  	mmp_icu_base = ioremap(0xd4282000, 0x1000);
  	icu_data[0].conf_enable = mmp_conf.conf_enable;
  	icu_data[0].conf_disable = mmp_conf.conf_disable;
  	icu_data[0].conf_mask = mmp_conf.conf_mask;
  	icu_data[0].nr_irqs = 64;
  	icu_data[0].virq_base = 0;
  	icu_data[0].domain = irq_domain_add_legacy(NULL, 64, 0, 0,
  						   &irq_domain_simple_ops,
  						   &icu_data[0]);
  	for (irq = 0; irq < 64; irq++) {
  		icu_mask_irq(irq_get_irq_data(irq));
  		irq_set_chip_and_handler(irq, &icu_irq_chip, handle_level_irq);

  	}
  	irq_set_default_host(icu_data[0].domain);

  	set_handle_irq(mmp_handle_irq);

  }
  
  /* MMP2 (ARMv7) */
  void __init mmp2_init_icu(void)
  {

  	int irq, end;

  
  	max_icu_nr = 8;
  	mmp_icu_base = ioremap(0xd4282000, 0x1000);
  	icu_data[0].conf_enable = mmp2_conf.conf_enable;
  	icu_data[0].conf_disable = mmp2_conf.conf_disable;
  	icu_data[0].conf_mask = mmp2_conf.conf_mask;
  	icu_data[0].nr_irqs = 64;
  	icu_data[0].virq_base = 0;
  	icu_data[0].domain = irq_domain_add_legacy(NULL, 64, 0, 0,
  						   &irq_domain_simple_ops,
  						   &icu_data[0]);
  	icu_data[1].reg_status = mmp_icu_base + 0x150;
  	icu_data[1].reg_mask = mmp_icu_base + 0x168;

  	icu_data[1].clr_mfp_irq_base = icu_data[0].virq_base +
  				icu_data[0].nr_irqs;
  	icu_data[1].clr_mfp_hwirq = 1;		/* offset to IRQ_MMP2_PMIC_BASE */

  	icu_data[1].nr_irqs = 2;

  	icu_data[1].cascade_irq = 4;

  	icu_data[1].virq_base = icu_data[0].virq_base + icu_data[0].nr_irqs;

  	icu_data[1].domain = irq_domain_add_legacy(NULL, icu_data[1].nr_irqs,
  						   icu_data[1].virq_base, 0,
  						   &irq_domain_simple_ops,
  						   &icu_data[1]);
  	icu_data[2].reg_status = mmp_icu_base + 0x154;
  	icu_data[2].reg_mask = mmp_icu_base + 0x16c;
  	icu_data[2].nr_irqs = 2;

  	icu_data[2].cascade_irq = 5;

  	icu_data[2].virq_base = icu_data[1].virq_base + icu_data[1].nr_irqs;

  	icu_data[2].domain = irq_domain_add_legacy(NULL, icu_data[2].nr_irqs,
  						   icu_data[2].virq_base, 0,
  						   &irq_domain_simple_ops,
  						   &icu_data[2]);
  	icu_data[3].reg_status = mmp_icu_base + 0x180;
  	icu_data[3].reg_mask = mmp_icu_base + 0x17c;
  	icu_data[3].nr_irqs = 3;

  	icu_data[3].cascade_irq = 9;

  	icu_data[3].virq_base = icu_data[2].virq_base + icu_data[2].nr_irqs;

  	icu_data[3].domain = irq_domain_add_legacy(NULL, icu_data[3].nr_irqs,
  						   icu_data[3].virq_base, 0,
  						   &irq_domain_simple_ops,
  						   &icu_data[3]);
  	icu_data[4].reg_status = mmp_icu_base + 0x158;
  	icu_data[4].reg_mask = mmp_icu_base + 0x170;
  	icu_data[4].nr_irqs = 5;

  	icu_data[4].cascade_irq = 17;

  	icu_data[4].virq_base = icu_data[3].virq_base + icu_data[3].nr_irqs;

  	icu_data[4].domain = irq_domain_add_legacy(NULL, icu_data[4].nr_irqs,
  						   icu_data[4].virq_base, 0,
  						   &irq_domain_simple_ops,
  						   &icu_data[4]);
  	icu_data[5].reg_status = mmp_icu_base + 0x15c;
  	icu_data[5].reg_mask = mmp_icu_base + 0x174;
  	icu_data[5].nr_irqs = 15;

  	icu_data[5].cascade_irq = 35;

  	icu_data[5].virq_base = icu_data[4].virq_base + icu_data[4].nr_irqs;

  	icu_data[5].domain = irq_domain_add_legacy(NULL, icu_data[5].nr_irqs,
  						   icu_data[5].virq_base, 0,
  						   &irq_domain_simple_ops,
  						   &icu_data[5]);
  	icu_data[6].reg_status = mmp_icu_base + 0x160;
  	icu_data[6].reg_mask = mmp_icu_base + 0x178;
  	icu_data[6].nr_irqs = 2;

  	icu_data[6].cascade_irq = 51;

  	icu_data[6].virq_base = icu_data[5].virq_base + icu_data[5].nr_irqs;

  	icu_data[6].domain = irq_domain_add_legacy(NULL, icu_data[6].nr_irqs,
  						   icu_data[6].virq_base, 0,
  						   &irq_domain_simple_ops,
  						   &icu_data[6]);
  	icu_data[7].reg_status = mmp_icu_base + 0x188;
  	icu_data[7].reg_mask = mmp_icu_base + 0x184;
  	icu_data[7].nr_irqs = 2;

  	icu_data[7].cascade_irq = 55;

  	icu_data[7].virq_base = icu_data[6].virq_base + icu_data[6].nr_irqs;

  	icu_data[7].domain = irq_domain_add_legacy(NULL, icu_data[7].nr_irqs,
  						   icu_data[7].virq_base, 0,
  						   &irq_domain_simple_ops,
  						   &icu_data[7]);

  	end = icu_data[7].virq_base + icu_data[7].nr_irqs;
  	for (irq = 0; irq < end; irq++) {

  		icu_mask_irq(irq_get_irq_data(irq));

  		if (irq == icu_data[1].cascade_irq ||
  		    irq == icu_data[2].cascade_irq ||
  		    irq == icu_data[3].cascade_irq ||
  		    irq == icu_data[4].cascade_irq ||
  		    irq == icu_data[5].cascade_irq ||
  		    irq == icu_data[6].cascade_irq ||
  		    irq == icu_data[7].cascade_irq) {

  			irq_set_chip(irq, &icu_irq_chip);
  			irq_set_chained_handler(irq, icu_mux_irq_demux);

  		} else {

  			irq_set_chip_and_handler(irq, &icu_irq_chip,
  						 handle_level_irq);

  		}

  	}
  	irq_set_default_host(icu_data[0].domain);

  	set_handle_irq(mmp2_handle_irq);

  }
  
  #ifdef CONFIG_OF

  static int __init mmp_init_bases(struct device_node *node)

  {

  	int ret, nr_irqs, irq, i = 0;

  	ret = of_property_read_u32(node, "mrvl,intc-nr-irqs", &nr_irqs);
  	if (ret) {
  		pr_err("Not found mrvl,intc-nr-irqs property
  ");
  		return ret;
  	}

  	mmp_icu_base = of_iomap(node, 0);
  	if (!mmp_icu_base) {
  		pr_err("Failed to get interrupt controller register
  ");
  		return -ENOMEM;
  	}
  
  	icu_data[0].virq_base = 0;
  	icu_data[0].domain = irq_domain_add_linear(node, nr_irqs,
  						   &mmp_irq_domain_ops,
  						   &icu_data[0]);
  	for (irq = 0; irq < nr_irqs; irq++) {
  		ret = irq_create_mapping(icu_data[0].domain, irq);
  		if (!ret) {
  			pr_err("Failed to mapping hwirq
  ");

  			goto err;
  		}

  		if (!irq)
  			icu_data[0].virq_base = ret;

  	}

  	icu_data[0].nr_irqs = nr_irqs;

  	return 0;
  err:

  	if (icu_data[0].virq_base) {
  		for (i = 0; i < irq; i++)
  			irq_dispose_mapping(icu_data[0].virq_base + i);
  	}
  	irq_domain_remove(icu_data[0].domain);
  	iounmap(mmp_icu_base);
  	return -EINVAL;

  }

  static int __init mmp_of_init(struct device_node *node,
  			      struct device_node *parent)

  {

  	int ret;

  	ret = mmp_init_bases(node);
  	if (ret < 0)
  		return ret;
  
  	icu_data[0].conf_enable = mmp_conf.conf_enable;
  	icu_data[0].conf_disable = mmp_conf.conf_disable;
  	icu_data[0].conf_mask = mmp_conf.conf_mask;
  	irq_set_default_host(icu_data[0].domain);
  	set_handle_irq(mmp_handle_irq);
  	max_icu_nr = 1;
  	return 0;
  }
  IRQCHIP_DECLARE(mmp_intc, "mrvl,mmp-intc", mmp_of_init);
  
  static int __init mmp2_of_init(struct device_node *node,
  			       struct device_node *parent)
  {
  	int ret;
  
  	ret = mmp_init_bases(node);
  	if (ret < 0)
  		return ret;
  
  	icu_data[0].conf_enable = mmp2_conf.conf_enable;
  	icu_data[0].conf_disable = mmp2_conf.conf_disable;
  	icu_data[0].conf_mask = mmp2_conf.conf_mask;
  	irq_set_default_host(icu_data[0].domain);
  	set_handle_irq(mmp2_handle_irq);
  	max_icu_nr = 1;
  	return 0;
  }
  IRQCHIP_DECLARE(mmp2_intc, "mrvl,mmp2-intc", mmp2_of_init);
  
  static int __init mmp2_mux_of_init(struct device_node *node,
  				   struct device_node *parent)
  {
  	struct resource res;
  	int i, ret, irq, j = 0;
  	u32 nr_irqs, mfp_irq;
  
  	if (!parent)
  		return -ENODEV;
  
  	i = max_icu_nr;
  	ret = of_property_read_u32(node, "mrvl,intc-nr-irqs",
  				   &nr_irqs);

  	if (ret) {
  		pr_err("Not found mrvl,intc-nr-irqs property
  ");

  		return -EINVAL;

  	}

  	ret = of_address_to_resource(node, 0, &res);
  	if (ret < 0) {
  		pr_err("Not found reg property
  ");
  		return -EINVAL;

  	}

  	icu_data[i].reg_status = mmp_icu_base + res.start;
  	ret = of_address_to_resource(node, 1, &res);
  	if (ret < 0) {
  		pr_err("Not found reg property
  ");
  		return -EINVAL;

  	}

  	icu_data[i].reg_mask = mmp_icu_base + res.start;
  	icu_data[i].cascade_irq = irq_of_parse_and_map(node, 0);
  	if (!icu_data[i].cascade_irq)
  		return -EINVAL;
  
  	icu_data[i].virq_base = 0;
  	icu_data[i].domain = irq_domain_add_linear(node, nr_irqs,

  						   &mmp_irq_domain_ops,

  						   &icu_data[i]);
  	for (irq = 0; irq < nr_irqs; irq++) {
  		ret = irq_create_mapping(icu_data[i].domain, irq);
  		if (!ret) {
  			pr_err("Failed to mapping hwirq
  ");
  			goto err;
  		}
  		if (!irq)
  			icu_data[i].virq_base = ret;
  	}
  	icu_data[i].nr_irqs = nr_irqs;
  	if (!of_property_read_u32(node, "mrvl,clr-mfp-irq",
  				  &mfp_irq)) {
  		icu_data[i].clr_mfp_irq_base = icu_data[i].virq_base;
  		icu_data[i].clr_mfp_hwirq = mfp_irq;
  	}
  	irq_set_chained_handler(icu_data[i].cascade_irq,
  				icu_mux_irq_demux);
  	max_icu_nr++;
  	return 0;

  err:

  	if (icu_data[i].virq_base) {
  		for (j = 0; j < irq; j++)
  			irq_dispose_mapping(icu_data[i].virq_base + j);
  	}
  	irq_domain_remove(icu_data[i].domain);
  	return -EINVAL;

  }

  IRQCHIP_DECLARE(mmp2_mux_intc, "mrvl,mmp2-mux-intc", mmp2_mux_of_init);

  #endif