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-rw-r--r--cpu/nios2/interrupts.c229
1 files changed, 229 insertions, 0 deletions
diff --git a/cpu/nios2/interrupts.c b/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 */