/*
 * (C) Copyright 2000-2002
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * (C) Copyright 2003, Psyent Corporation <www.psyent.com>
 * Scott McNutt <smcnutt@psyent.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 <nios.h>
#include <nios-io.h>
#include <asm/ptrace.h>
#include <common.h>
#include <command.h>
#include <watchdog.h>
#ifdef CONFIG_STATUS_LED
#include <status_led.h>
#endif

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

struct  irq_action {
        interrupt_handler_t *handler;
        void *arg;
        int count;
};

static struct irq_action irq_vecs[64];

/*************************************************************************/
volatile ulong timestamp = 0;

void reset_timer (void)
{
        timestamp = 0;
}

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

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


/* The board must handle this interrupt if a timer is not
 * provided.
 */
#if defined(CONFIG_SYS_NIOS_TMRBASE)
void timer_interrupt (struct pt_regs *regs)
{
        /* Interrupt is cleared by writing anything to the
         * status register.
         */
        nios_timer_t *tmr = (nios_timer_t *)CONFIG_SYS_NIOS_TMRBASE;
        tmr->status = 0;
        timestamp += CONFIG_SYS_NIOS_TMRMS;
#ifdef CONFIG_STATUS_LED
        status_led_tick(timestamp);
#endif
}
#endif

/*************************************************************************/
int disable_interrupts (void)
{
        int val = 0;

        /* Writing anything to CLR_IE disables interrupts */
        val = rdctl (CTL_STATUS);
        wrctl (CTL_CLR_IE, 0);
        return (val & STATUS_IE);
}

void enable_interrupts( void )
{
        /* Writing anything SET_IE enables interrupts */
        wrctl (CTL_SET_IE, 0);
}

void external_interrupt (struct pt_regs *regs)
{
        unsigned vec;

        vec = (regs->status & STATUS_IPRI) >> 9;        /* ipri */

        irq_vecs[vec].count++;
        if (irq_vecs[vec].handler != NULL) {
                (*irq_vecs[vec].handler)(irq_vecs[vec].arg);
        } else {
                /* A sad side-effect of masking a bogus interrupt is
                 * that lower priority interrupts will also be disabled.
                 * This is probably not what we want ... so hang insted.
                 */
                printf ("Unhandled interrupt: 0x%x\n", vec);
                disable_interrupts ();
                hang ();
        }
}

/*************************************************************************/
int interrupt_init (void)
{
        int vec;

#if defined(CONFIG_SYS_NIOS_TMRBASE)
        nios_timer_t *tmr = (nios_timer_t *)CONFIG_SYS_NIOS_TMRBASE;

        tmr->control &= ~NIOS_TIMER_ITO;
        tmr->control |= NIOS_TIMER_STOP;
#if defined(CONFIG_SYS_NIOS_TMRCNT)
        tmr->periodl = CONFIG_SYS_NIOS_TMRCNT & 0xffff;
        tmr->periodh = (CONFIG_SYS_NIOS_TMRCNT >> 16) & 0xffff;
#endif
#endif

        for (vec=0; vec<64; vec++ ) {
                irq_vecs[vec].handler = NULL;
                irq_vecs[vec].arg = NULL;
                irq_vecs[vec].count = 0;
        }

        /* Need timus interruptus -- start the lopri timer */
#if defined(CONFIG_SYS_NIOS_TMRBASE)
        tmr->control |= ( NIOS_TIMER_ITO |
                          NIOS_TIMER_CONT |
                          NIOS_TIMER_START );
        ipri (CONFIG_SYS_NIOS_TMRIRQ + 1);
#endif
        enable_interrupts ();
        return (0);
}

void irq_install_handler (int vec, interrupt_handler_t *handler, void *arg)
{
        struct irq_action *irqa = irq_vecs;
        int   i = vec;
        int flag;

        if (irqa[i].handler != NULL) {
                printf ("Interrupt vector %d: handler 0x%x "
                        "replacing 0x%x\n",
                        vec, (uint)handler, (uint)irqa[i].handler);
        }

        flag = disable_interrupts ();
        irqa[i].handler = handler;
        irqa[i].arg = arg;
        if (flag )
                enable_interrupts ();
}

/*************************************************************************/
#if defined(CONFIG_CMD_IRQ)
int do_irqinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
{
        int vec;

        printf ("\nInterrupt-Information:\n");
        printf ("Nr  Routine   Arg       Count\n");

        for (vec=0; vec<64; vec++) {
                if (irq_vecs[vec].handler != NULL) {
                        printf ("%02d  %08lx  %08lx  %d\n",
                                vec,
                                (ulong)irq_vecs[vec].handler<<1,
                                (ulong)irq_vecs[vec].arg,
                                irq_vecs[vec].count);
                }
        }

        return (0);
}
#endif