u-boot/arch/nios2/cpu/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>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <nios2.h>
#include <nios2-io.h>
#include <asm/types.h>
#include <asm/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(CONFIG_SYS_NIOS_TMRBASE) && !defined(CONFIG_SYS_NIOS_TMRIRQ)
#error CONFIG_SYS_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)
{
nios_timer_t *tmr =(nios_timer_t *)CONFIG_SYS_NIOS_TMRBASE;
/* From Embedded Peripherals Handbook:
*
* "When the hardware is configured with Writeable period
* disabled, writing to one of the period_n registers causes
* the counter to reset to the fixed Timeout Period specified
* at system generation time."
*
* Here we force a reload to prevent early timeouts from
* get_timer() when the interrupt period is greater than
* than 1 msec.
*
* Simply write to periodl with its own value to force an
* internal counter reload, THEN reset the timestamp.
*/
writel (readl (&tmr->periodl), &tmr->periodl);
timestamp = 0;
/* From Embedded Peripherals Handbook:
*
* "Writing to one of the period_n registers stops the internal
* counter, except when the hardware is configured with Start/Stop
* control bits off. If Start/Stop control bits is off, writing
* either register does not stop the counter."
*
* In order to accomodate either configuration, the control
* register is re-written. If the counter is stopped, it will
* be restarted. If it is running, the write is essentially
* a nop.
*/
writel (NIOS_TIMER_ITO | NIOS_TIMER_CONT | NIOS_TIMER_START,
&tmr->control);
}
ulong get_timer (ulong base)
{
WATCHDOG_RESET ();
return (timestamp - base);
}
/*
* This function is derived from Blackfin code (read timebase as long long).
* On Nios2 it just returns the timer value.
*/
unsigned long long get_ticks(void)
{
return get_timer(0);
}
/*
* This function is derived from Blackfin code.
* On Nios2 it returns the number of timer ticks per second.
*/
ulong get_tbclk(void)
{
ulong tbclk;
tbclk = CONFIG_SYS_HZ;
return tbclk;
}
/* The board must handle this interrupt if a timer is not
* provided.
*/
#if defined(CONFIG_SYS_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.
*/
writel (0, &tmr->status);
timestamp += CONFIG_SYS_NIOS_TMRMS;
#ifdef CONFIG_STATUS_LED
status_led_tick(timestamp);
#endif
}
static void tmr_init (void)
{
nios_timer_t *tmr =(nios_timer_t *)CONFIG_SYS_NIOS_TMRBASE;
writel (0, &tmr->status);
writel (0, &tmr->control);
writel (NIOS_TIMER_STOP, &tmr->control);
#if defined(CONFIG_SYS_NIOS_TMRCNT)
writel (CONFIG_SYS_NIOS_TMRCNT & 0xffff, &tmr->periodl);
writel ((CONFIG_SYS_NIOS_TMRCNT >> 16) & 0xffff, &tmr->periodh);
#endif
writel (NIOS_TIMER_ITO | NIOS_TIMER_CONT | NIOS_TIMER_START,
&tmr->control);
irq_install_handler (CONFIG_SYS_NIOS_TMRIRQ, tmr_isr, (void *)tmr);
}
#endif /* CONFIG_SYS_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(CONFIG_SYS_NIOS_TMRBASE)
tmr_init ();
#endif
enable_interrupts ();
return (0);
}
/*************************************************************************/
#if defined(CONFIG_CMD_IRQ)
int do_irqinfo (cmd_tbl_t *cmdtp, int flag, int argc, char * const 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