/*
   * linux/arch/h8300/kernel/irq.c
   *
   * Copyright 2007 Yoshinori Sato <ysato@users.sourceforge.jp>
   */
  
  #include <linux/module.h>
  #include <linux/types.h>
  #include <linux/kernel.h>
  #include <linux/sched.h>
  #include <linux/kernel_stat.h>
  #include <linux/seq_file.h>
  #include <linux/init.h>
  #include <linux/random.h>
  #include <linux/bootmem.h>
  #include <linux/irq.h>

  #include <linux/interrupt.h>

  
  #include <asm/system.h>
  #include <asm/traps.h>
  #include <asm/io.h>
  #include <asm/setup.h>
  #include <asm/errno.h>
  
  /*#define DEBUG*/
  
  extern unsigned long *interrupt_redirect_table;
  extern const int h8300_saved_vectors[];

  extern const h8300_vector h8300_trap_table[];

  int h8300_enable_irq_pin(unsigned int irq);
  void h8300_disable_irq_pin(unsigned int irq);
  
  #define CPU_VECTOR ((unsigned long *)0x000000)
  #define ADDR_MASK (0xffffff)
  
  static inline int is_ext_irq(unsigned int irq)
  {
  	return (irq >= EXT_IRQ0 && irq <= (EXT_IRQ0 + EXT_IRQS));
  }

  static void h8300_enable_irq(struct irq_data *data)

  {

  	if (is_ext_irq(data->irq))
  		IER_REGS |= 1 << (data->irq - EXT_IRQ0);

  }

  static void h8300_disable_irq(struct irq_data *data)

  {

  	if (is_ext_irq(data->irq))
  		IER_REGS &= ~(1 << (data->irq - EXT_IRQ0));

  }

  static unsigned int h8300_startup_irq(struct irq_data *data)

  {

  	if (is_ext_irq(data->irq))
  		return h8300_enable_irq_pin(data->irq);

  	else
  		return 0;
  }

  static void h8300_shutdown_irq(struct irq_data *data)

  {

  	if (is_ext_irq(data->irq))
  		h8300_disable_irq_pin(data->irq);

  }
  
  /*

   * h8300 interrupt controller implementation

   */
  struct irq_chip h8300irq_chip = {
  	.name		= "H8300-INTC",

  	.irq_startup	= h8300_startup_irq,
  	.irq_shutdown	= h8300_shutdown_irq,
  	.irq_enable	= h8300_enable_irq,
  	.irq_disable	= h8300_disable_irq,

  };

  #if defined(CONFIG_RAMKERNEL)
  static unsigned long __init *get_vector_address(void)
  {
  	unsigned long *rom_vector = CPU_VECTOR;
  	unsigned long base,tmp;
  	int vec_no;
  
  	base = rom_vector[EXT_IRQ0] & ADDR_MASK;
  
  	/* check romvector format */
  	for (vec_no = EXT_IRQ1; vec_no <= EXT_IRQ0+EXT_IRQS; vec_no++) {
  		if ((base+(vec_no - EXT_IRQ0)*4) != (rom_vector[vec_no] & ADDR_MASK))
  			return NULL;
  	}
  
  	/* ramvector base address */
  	base -= EXT_IRQ0*4;
  
  	/* writerble check */
  	tmp = ~(*(volatile unsigned long *)base);
  	(*(volatile unsigned long *)base) = tmp;
  	if ((*(volatile unsigned long *)base) != tmp)
  		return NULL;
  	return (unsigned long *)base;
  }
  
  static void __init setup_vector(void)
  {
  	int i;
  	unsigned long *ramvec,*ramvec_p;

  	const h8300_vector *trap_entry;

  	const int *saved_vector;
  
  	ramvec = get_vector_address();
  	if (ramvec == NULL)
  		panic("interrupt vector serup failed.");
  	else
  		printk(KERN_INFO "virtual vector at 0x%08lx
  ",(unsigned long)ramvec);
  
  	/* create redirect table */
  	ramvec_p = ramvec;
  	trap_entry = h8300_trap_table;
  	saved_vector = h8300_saved_vectors;
  	for ( i = 0; i < NR_IRQS; i++) {
  		if (i == *saved_vector) {
  			ramvec_p++;
  			saved_vector++;
  		} else {
  			if ( i < NR_TRAPS ) {
  				if (*trap_entry)
  					*ramvec_p = VECTOR(*trap_entry);
  				ramvec_p++;
  				trap_entry++;
  			} else
  				*ramvec_p++ = REDIRECT(interrupt_entry);
  		}
  	}
  	interrupt_redirect_table = ramvec;
  #ifdef DEBUG
  	ramvec_p = ramvec;
  	for (i = 0; i < NR_IRQS; i++) {
  		if ((i % 8) == 0)
  			printk(KERN_DEBUG "
  %p: ",ramvec_p);
  		printk(KERN_DEBUG "%p ",*ramvec_p);
  		ramvec_p++;
  	}
  	printk(KERN_DEBUG "
  ");
  #endif
  }
  #else
  #define setup_vector() do { } while(0)
  #endif
  
  void __init init_IRQ(void)
  {
  	int c;
  
  	setup_vector();

  	for (c = 0; c < NR_IRQS; c++)

  		irq_set_chip_and_handler(c, &h8300irq_chip, handle_simple_irq);

  }
  
  asmlinkage void do_IRQ(int irq)
  {
  	irq_enter();

  	generic_handle_irq(irq);

  	irq_exit();
  }