u-boot/cpu/nios2/interrupts.c

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/*
* (C) Copyright 2000-2002
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* (C) Copyright 2004, 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 <nios2.h>
#include <nios2-io.h>
#include <asm/ptrace.h>
#include <common.h>
#include <command.h>
#include <watchdog.h>
#ifdef CONFIG_STATUS_LED
#include <status_led.h>
#endif
#if defined(CFG_NIOS_TMRBASE) && !defined(CFG_NIOS_TMRIRQ)
#error CFG_NIOS_TMRIRQ not defined (see documentation)
#endif
/****************************************************************************/
struct irq_action {
interrupt_handler_t *handler;
void *arg;
int count;
};
static struct irq_action vecs[32];
/*************************************************************************/
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 tmr_isr (void *arg)
{
nios_timer_t *tmr = (nios_timer_t *)arg;
/* Interrupt is cleared by writing anything to the
* status register.
*/
tmr->status = 0;
timestamp += CFG_NIOS_TMRMS;
#ifdef CONFIG_STATUS_LED
status_led_tick(timestamp);
#endif
}
static void tmr_init (void)
{
nios_timer_t *tmr =(nios_timer_t *)CACHE_BYPASS(CFG_NIOS_TMRBASE);
tmr->control &= ~(NIOS_TIMER_START | 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
tmr->control |= ( NIOS_TIMER_ITO |
NIOS_TIMER_CONT |
NIOS_TIMER_START );
irq_install_handler (CFG_NIOS_TMRIRQ, tmr_isr, (void *)tmr);
}
#endif /* CFG_NIOS_TMRBASE */
/*************************************************************************/
int disable_interrupts (void)
{
int val = rdctl (CTL_STATUS);
wrctl (CTL_STATUS, val & ~STATUS_IE);
return (val & STATUS_IE);
}
void enable_interrupts( void )
{
int val = rdctl (CTL_STATUS);
wrctl (CTL_STATUS, val | STATUS_IE);
}
void external_interrupt (struct pt_regs *regs)
{
unsigned irqs;
struct irq_action *act;
/* Evaluate only irqs that are both enabled AND pending */
irqs = rdctl (CTL_IENABLE) & rdctl (CTL_IPENDING);
act = vecs;
/* Assume (as does the Nios2 HAL) that bit 0 is highest
* priority. NOTE: There is ALWAYS a handler assigned
* (the default if no other).
*/
while (irqs) {
if (irqs & 1) {
act->handler (act->arg);
act->count++;
}
irqs >>=1;
act++;
}
}
static void def_hdlr (void *arg)
{
unsigned irqs = rdctl (CTL_IENABLE);
/* Disable the individual interrupt -- with gratuitous
* warning.
*/
irqs &= ~(1 << (int)arg);
wrctl (CTL_IENABLE, irqs);
printf ("WARNING: Disabling unhandled interrupt: %d\n",
(int)arg);
}
/*************************************************************************/
void irq_install_handler (int irq, interrupt_handler_t *hdlr, void *arg)
{
int flag;
struct irq_action *act;
unsigned ena = rdctl (CTL_IENABLE);
if ((irq < 0) || (irq > 31))
return;
act = &vecs[irq];
flag = disable_interrupts ();
if (hdlr) {
act->handler = hdlr;
act->arg = arg;
ena |= (1 << irq); /* enable */
} else {
act->handler = def_hdlr;
act->arg = (void *)irq;
ena &= ~(1 << irq); /* disable */
}
wrctl (CTL_IENABLE, ena);
if (flag) enable_interrupts ();
}
int interrupt_init (void)
{
int i;
/* Assign the default handler to all */
for (i = 0; i < 32; i++) {
vecs[i].handler = def_hdlr;
vecs[i].arg = (void *)i;
vecs[i].count = 0;
}
#if defined(CFG_NIOS_TMRBASE)
tmr_init ();
#endif
enable_interrupts ();
return (0);
}
/*************************************************************************/
#if (CONFIG_COMMANDS & CFG_CMD_IRQ)
int do_irqinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
{
int i;
struct irq_action *act = vecs;
printf ("\nInterrupt-Information:\n\n");
printf ("Nr Routine Arg Count\n");
printf ("-----------------------------\n");
for (i=0; i<32; i++) {
if (act->handler != def_hdlr) {
printf ("%02d %08lx %08lx %d\n",
i,
(ulong)act->handler,
(ulong)act->arg,
act->count);
}
act++;
}
printf ("\n");
return (0);
}
#endif /* CONFIG_COMMANDS & CFG_CMD_IRQ */