u-boot/cpu/nios/interrupts.c

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/*
* (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(CFG_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 *)CFG_NIOS_TMRBASE;
tmr->status = 0;
timestamp += CFG_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(CFG_NIOS_TMRBASE)
nios_timer_t *tmr = (nios_timer_t *)CFG_NIOS_TMRBASE;
tmr->control &= ~NIOS_TIMER_ITO;
tmr->control |= NIOS_TIMER_STOP;
#if defined(CFG_NIOS_TMRCNT)
tmr->periodl = CFG_NIOS_TMRCNT & 0xffff;
tmr->periodh = (CFG_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(CFG_NIOS_TMRBASE)
tmr->control |= ( NIOS_TIMER_ITO |
NIOS_TIMER_CONT |
NIOS_TIMER_START );
ipri (CFG_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