/*
 * (C) Copyright 2000
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 * Rob Taylor, Flying Pig Systems. robt@flyingpig.com
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * 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., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <ppcboot.h>
#include <mpc824x.h>
#include <asm/processor.h>
#include <asm/pci_io.h>
#include <commproc.h>
#include "drivers/epic.h"

/****************************************************************************/

unsigned decrementer_count;		/* count val for 1e6/HZ microseconds */

static __inline__ unsigned long get_msr(void)
{
    unsigned long msr;

    asm volatile("mfmsr %0" : "=r" (msr) :);
    return msr;
}

static __inline__ void set_msr(unsigned long msr)
{
    asm volatile("mtmsr %0" : : "r" (msr));
}

static __inline__ unsigned long get_dec(void)
{
    unsigned long val;

    asm volatile("mfdec %0" : "=r" (val) :);
    return val;
}


static __inline__ void set_dec(unsigned long val)
{
    asm volatile("mtdec %0" : : "r" (val));
}


void enable_interrupts (void)
{
    set_msr (get_msr() | MSR_EE);
}

/* returns flag if MSR_EE was set before */
int disable_interrupts (void)
{
    ulong msr = get_msr();
    set_msr (msr & ~MSR_EE);
    return ((msr & MSR_EE) != 0);
}

/****************************************************************************/

void
interrupt_init (bd_t *bd)
{
    decrementer_count = (get_bus_freq(0) / 4) / CFG_HZ;

  /* it's all broken at the moment and I currently don't need interrupts
     if you want to fix it, have a look at the epic drivers in dink32 v12
     they do everthing and motorola said I could use the dink source in this project
     as long as copyright notices remain intact. */
    epicInit(EPIC_DIRECT_IRQ,0);

    set_dec (decrementer_count);

    set_msr (get_msr() | MSR_EE);
    
}

/****************************************************************************/

/*
 * Handle external interrupts
 */
void external_interrupt(struct pt_regs *regs)
{
  register unsigned long temp;
  pci_readl(CFG_EUMB_ADDR + EPIC_PROC_INT_ACK_REG, temp);
  sync();                 /* i'm not convinced this is needed, but dink source has it */
  temp &= 0xff;   /*get vector*/

  /*TODO: handle them -...*/
  epicEOI();
}

/****************************************************************************/

/*
 * blank int handlers.
 */

void
irq_install_handler(int vec, interrupt_handler_t *handler, void *arg)
{
}

void
irq_free_handler(int vec)
{

}

/*TODO: some handlers for winbond and 87308 interrupts
 and what about generic pci inteerupts?
 vga?
 */

volatile ulong timestamp = 0;

 void timer_interrupt(struct pt_regs *regs)
 {
    /* Restore Decrementer Count */
    set_dec (decrementer_count);

    timestamp++;
 }

 void reset_timer (void)
 {
  timestamp = 0;
 }

 ulong get_timer (ulong base)
 {
  return (timestamp - base);
 }

 void set_timer (ulong t)
 {
  timestamp = t;
 }
