/*
   *  Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
   *  JZ4740 platform IRQ support
   *
   *  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.
   *
   *  You should have received a copy of the GNU General Public License along
   *  with this program; if not, write to the Free Software Foundation, Inc.,
   *  675 Mass Ave, Cambridge, MA 02139, USA.
   *
   */
  
  #include <linux/errno.h>
  #include <linux/init.h>
  #include <linux/types.h>
  #include <linux/interrupt.h>
  #include <linux/ioport.h>
  #include <linux/timex.h>
  #include <linux/slab.h>
  #include <linux/delay.h>
  
  #include <linux/debugfs.h>
  #include <linux/seq_file.h>
  
  #include <asm/io.h>
  #include <asm/mipsregs.h>
  #include <asm/irq_cpu.h>
  
  #include <asm/mach-jz4740/base.h>
  
  static void __iomem *jz_intc_base;

  
  #define JZ_REG_INTC_STATUS	0x00
  #define JZ_REG_INTC_MASK	0x04
  #define JZ_REG_INTC_SET_MASK	0x08
  #define JZ_REG_INTC_CLEAR_MASK	0x0c
  #define JZ_REG_INTC_PENDING	0x10

  static irqreturn_t jz4740_cascade(int irq, void *data)

  {

  	uint32_t irq_reg;

  	irq_reg = readl(jz_intc_base + JZ_REG_INTC_PENDING);

  	if (irq_reg)
  		generic_handle_irq(__fls(irq_reg) + JZ4740_IRQ_BASE);
  
  	return IRQ_HANDLED;

  }

  static void jz4740_irq_set_mask(struct irq_chip_generic *gc, uint32_t mask)

  {

  	struct irq_chip_regs *regs = &gc->chip_types->regs;

  	writel(mask, gc->reg_base + regs->enable);
  	writel(~mask, gc->reg_base + regs->disable);

  }

  void jz4740_irq_suspend(struct irq_data *data)

  {

  	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
  	jz4740_irq_set_mask(gc, gc->wake_active);
  }

  void jz4740_irq_resume(struct irq_data *data)
  {
  	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
  	jz4740_irq_set_mask(gc, gc->mask_cache);

  }
  
  static struct irqaction jz4740_cascade_action = {
  	.handler = jz4740_cascade,
  	.name = "JZ4740 cascade interrupt",
  };
  
  void __init arch_init_irq(void)
  {

  	struct irq_chip_generic *gc;
  	struct irq_chip_type *ct;

  	mips_cpu_irq_init();
  
  	jz_intc_base = ioremap(JZ4740_INTC_BASE_ADDR, 0x14);

  	/* Mask all irqs */
  	writel(0xffffffff, jz_intc_base + JZ_REG_INTC_SET_MASK);

  	gc = irq_alloc_generic_chip("INTC", 1, JZ4740_IRQ_BASE, jz_intc_base,
  		handle_level_irq);
  
  	gc->wake_enabled = IRQ_MSK(32);
  
  	ct = gc->chip_types;
  	ct->regs.enable = JZ_REG_INTC_CLEAR_MASK;
  	ct->regs.disable = JZ_REG_INTC_SET_MASK;
  	ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
  	ct->chip.irq_mask = irq_gc_mask_disable_reg;
  	ct->chip.irq_mask_ack = irq_gc_mask_disable_reg;
  	ct->chip.irq_set_wake = irq_gc_set_wake;
  	ct->chip.irq_suspend = jz4740_irq_suspend;
  	ct->chip.irq_resume = jz4740_irq_resume;
  
  	irq_setup_generic_chip(gc, IRQ_MSK(32), 0, 0, IRQ_NOPROBE | IRQ_LEVEL);

  
  	setup_irq(2, &jz4740_cascade_action);
  }
  
  asmlinkage void plat_irq_dispatch(void)
  {
  	unsigned int pending = read_c0_status() & read_c0_cause() & ST0_IM;
  	if (pending & STATUSF_IP2)
  		do_IRQ(2);
  	else if (pending & STATUSF_IP3)
  		do_IRQ(3);
  	else
  		spurious_interrupt();
  }

  #ifdef CONFIG_DEBUG_FS
  
  static inline void intc_seq_reg(struct seq_file *s, const char *name,
  	unsigned int reg)
  {
  	seq_printf(s, "%s:\t\t%08x
  ", name, readl(jz_intc_base + reg));
  }
  
  static int intc_regs_show(struct seq_file *s, void *unused)
  {
  	intc_seq_reg(s, "Status", JZ_REG_INTC_STATUS);
  	intc_seq_reg(s, "Mask", JZ_REG_INTC_MASK);
  	intc_seq_reg(s, "Pending", JZ_REG_INTC_PENDING);
  
  	return 0;
  }
  
  static int intc_regs_open(struct inode *inode, struct file *file)
  {
  	return single_open(file, intc_regs_show, NULL);
  }
  
  static const struct file_operations intc_regs_operations = {
  	.open		= intc_regs_open,
  	.read		= seq_read,
  	.llseek		= seq_lseek,
  	.release	= single_release,
  };
  
  static int __init intc_debugfs_init(void)
  {
  	(void) debugfs_create_file("jz_regs_intc", S_IFREG | S_IRUGO,
  				NULL, NULL, &intc_regs_operations);
  	return 0;
  }
  subsys_initcall(intc_debugfs_init);
  
  #endif