/*
* linux/arch/mips/kernel/irq.c
*
* Copyright (C) 1992 Linus Torvalds
*
* This file contains the code used by various IRQ handling routines:
* asking for different IRQ's should be done through these routines
* instead of just grabbing them. Thus setups with different IRQ numbers
* shouldn't result in any weird surprises, and installing new handlers
* should be easier.
*/
/*
* IRQ's are in fact implemented a bit like signal handlers for the kernel.
* Naturally it's not a 1:1 relation, but there are similarities.
*/
/*
* Mips support by Ralf Baechle and Andreas Busse
*
* The Deskstation Tyne is almost completely like an IBM compatible PC with
* another type of microprocessor. Therefore this code is almost completely
* the same. More work needs to be done to support Acer PICA and other
* machines.
*/
#include <linux/ptrace.h>
#include <linux/errno.h>
#include <linux/kernel_stat.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/timex.h>
#include <linux/malloc.h>
#include <linux/random.h>
#include <asm/bitops.h>
#include <asm/bootinfo.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/jazz.h>
#include <asm/mipsregs.h>
#include <asm/system.h>
#define TIMER_IRQ 0 /* Keep this in sync with time.c */
unsigned char cache_21 = 0xff;
unsigned char cache_A1 = 0xff;
unsigned long spurious_count = 0;
void disable_irq(unsigned int irq_nr)
{
unsigned long flags;
unsigned char mask;
mask = 1 << (irq_nr & 7);
save_flags(flags);
if (irq_nr < 8) {
cli();
cache_21 |= mask;
outb(cache_21,0x21);
restore_flags(flags);
return;
}
cli();
cache_A1 |= mask;
outb(cache_A1,0xA1);
restore_flags(flags);
}
void enable_irq(unsigned int irq_nr)
{
unsigned long flags;
unsigned char mask;
mask = ~(1 << (irq_nr & 7));
save_flags(flags);
if (irq_nr < 8) {
cli();
cache_21 &= mask;
outb(cache_21,0x21);
restore_flags(flags);
return;
}
cli();
cache_A1 &= mask;
outb(cache_A1,0xA1);
restore_flags(flags);
}
/*
* Pointers to the low-level handlers: first the general ones, then the
* fast ones, then the bad ones.
*/
extern void interrupt(void);
extern void fast_interrupt(void);
extern void bad_interrupt(void);
/*
* Initial irq handlers.
*/
static struct irqaction timer_irq = { NULL, 0, 0, NULL, NULL, NULL};
static struct irqaction cascade_irq = { NULL, 0, 0, NULL, NULL, NULL};
static struct irqaction math_irq = { NULL, 0, 0, NULL, NULL, NULL};
static struct irqaction *irq_action[16] = {
NULL, NULL, NULL, NULL, NULL, NULL , NULL, NULL,
NULL, NULL, NULL, NULL, NULL, NULL , NULL, NULL
};
int get_irq_list(char *buf)
{
int i, len = 0;
struct irqaction * action;
for (i = 0 ; i < 16 ; i++) {
action = *(i + irq_action);
if (!action)
continue;
len += sprintf(buf+len, "%2d: %8d %c %s",
i, kstat.interrupts[i],
(action->flags & SA_INTERRUPT) ? '+' : ' ',
action->name);
for (action=action->next; action; action = action->next) {
len += sprintf(buf+len, ",%s %s",
(action->flags & SA_INTERRUPT) ? " +" : "",
action->name);
}
len += sprintf(buf+len, "\n");
}
return len;
}
/*
* do_IRQ handles IRQ's that have been installed without the
* SA_INTERRUPT flag: it uses the full signal-handling return
* and runs with other interrupts enabled. All relatively slow
* IRQ's should use this format: notably the keyboard/timer
* routines.
*/
asmlinkage void do_IRQ(int irq, struct pt_regs * regs)
{
struct irqaction * action = *(irq + irq_action);
kstat.interrupts[irq]++;
if (action->flags & SA_SAMPLE_RANDOM)
add_interrupt_randomness(irq);
while (action) {
action->handler(irq, action->dev_id, regs);
action = action->next;
}
}
/*
* do_fast_IRQ handles IRQ's that don't need the fancy interrupt return
* stuff - the handler is also running with interrupts disabled unless
* it explicitly enables them later.
*/
asmlinkage void do_fast_IRQ(int irq)
{
struct irqaction * action = *(irq + irq_action);
kstat.interrupts[irq]++;
if (action->flags & SA_SAMPLE_RANDOM)
add_interrupt_randomness(irq);
while (action) {
action->handler(irq, action->dev_id, NULL);
action = action->next;
}
}
#define SA_PROBE SA_ONESHOT
int request_irq(unsigned int irq,
void (*handler)(int, void *, struct pt_regs *),
unsigned long irqflags,
const char * devname,
void *dev_id)
{
struct irqaction * action, *tmp = NULL;
unsigned long flags;
if (irq > 15)
return -EINVAL;
if (!handler)
return -EINVAL;
action = *(irq + irq_action);
if (action) {
if ((action->flags & SA_SHIRQ) && (irqflags & SA_SHIRQ)) {
for (tmp = action; tmp->next; tmp = tmp->next);
} else {
return -EBUSY;
}
if ((action->flags & SA_INTERRUPT) ^ (irqflags & SA_INTERRUPT)) {
printk("Attempt to mix fast and slow interrupts on IRQ%d denied\n", irq);
return -EBUSY;
}
}
if (irqflags & SA_SAMPLE_RANDOM)
rand_initialize_irq(irq);
save_flags(flags);
cli();
if (irq == 2)
action = &cascade_irq;
else if (irq == 13)
action = &math_irq;
else if (irq == TIMER_IRQ)
action = &timer_irq;
else
action = (struct irqaction *)kmalloc(sizeof(struct irqaction), GFP_KERNEL);
if (!action) {
restore_flags(flags);
return -ENOMEM;
}
action->handler = handler;
action->flags = irqflags;
action->mask = 0;
action->name = devname;
action->next = NULL;
action->dev_id = dev_id;
if (tmp) {
tmp->next = action;
} else {
*(irq + irq_action) = action;
if (!(action->flags & SA_PROBE)) {/* SA_ONESHOT used by probing */
/*
* FIXME: Does the SA_INTERRUPT flag make any sense on MIPS???
*/
if (action->flags & SA_INTERRUPT)
set_int_vector(irq,fast_interrupt);
else
set_int_vector(irq,interrupt);
}
if (irq < 8) {
cache_21 &= ~(1<<irq);
outb(cache_21,0x21);
} else {
cache_21 &= ~(1<<2);
cache_A1 &= ~(1<<(irq-8));
outb(cache_21,0x21);
outb(cache_A1,0xA1);
}
}
restore_flags(flags);
return 0;
}
void free_irq(unsigned int irq, void *dev_id)
{
struct irqaction * action = *(irq + irq_action);
struct irqaction * tmp = NULL;
unsigned long flags;
if (irq > 15) {
printk("Trying to free IRQ%d\n",irq);
return;
}
if (!action->handler) {
printk("Trying to free free IRQ%d\n",irq);
return;
}
if (dev_id) {
for (; action; action = action->next) {
if (action->dev_id == dev_id) break;
tmp = action;
}
if (!action) {
printk("Trying to free free shared IRQ%d\n",irq);
return;
}
} else if (action->flags & SA_SHIRQ) {
printk("Trying to free shared IRQ%d with NULL device ID\n", irq);
return;
}
save_flags(flags);
cli();
if (action && tmp) {
tmp->next = action->next;
} else {
*(irq + irq_action) = action->next;
}
if ((irq == 2) || (irq == 13) | (irq == TIMER_IRQ))
memset(action, 0, sizeof(struct irqaction));
else
kfree_s(action, sizeof(struct irqaction));
if (!(*(irq + irq_action))) {
if (irq < 8) {
cache_21 |= 1 << irq;
outb(cache_21,0x21);
} else {
cache_A1 |= 1 << (irq-8);
outb(cache_A1,0xA1);
}
set_int_vector(irq,bad_interrupt);
}
restore_flags(flags);
}
static void no_action(int cpl, void *dev_id, struct pt_regs * regs) { }
unsigned long probe_irq_on (void)
{
unsigned int i, irqs = 0, irqmask;
unsigned long delay;
/* first, snaffle up any unassigned irqs */
for (i = 15; i > 0; i--) {
if (!request_irq(i, no_action, SA_PROBE, "probe", NULL)) {
enable_irq(i);
irqs |= (1 << i);
}
}
/* wait for spurious interrupts to mask themselves out again */
for (delay = jiffies + 2; delay > jiffies; ); /* min 10ms delay */
/* now filter out any obviously spurious interrupts */
irqmask = (((unsigned int)cache_A1)<<8) | (unsigned int)cache_21;
for (i = 15; i > 0; i--) {
if (irqs & (1 << i) & irqmask) {
irqs ^= (1 << i);
free_irq(i, NULL);
}
}
#ifdef DEBUG
printk("probe_irq_on: irqs=0x%04x irqmask=0x%04x\n", irqs, irqmask);
#endif
return irqs;
}
int probe_irq_off (unsigned long irqs)
{
unsigned int i, irqmask;
irqmask = (((unsigned int)cache_A1)<<8) | (unsigned int)cache_21;
for (i = 15; i > 0; i--) {
if (irqs & (1 << i)) {
free_irq(i, NULL);
}
}
#ifdef DEBUG
printk("probe_irq_off: irqs=0x%04x irqmask=0x%04x\n", irqs, irqmask);
#endif
irqs &= irqmask;
if (!irqs)
return 0;
i = ffz(~irqs);
if (irqs != (irqs & (1 << i)))
i = -i;
return i;
}
void init_IRQ(void)
{
int i;
switch (boot_info.machtype) {
case MACH_MIPS_MAGNUM_4000:
case MACH_ACER_PICA_61:
r4030_write_reg16(JAZZ_IO_IRQ_ENABLE,
JAZZ_IE_ETHERNET |
JAZZ_IE_SERIAL1 |
JAZZ_IE_SERIAL2 |
JAZZ_IE_PARALLEL |
JAZZ_IE_FLOPPY);
r4030_read_reg16(JAZZ_IO_IRQ_SOURCE); /* clear pending IRQs */
set_cp0_status(ST0_IM, IE_IRQ4 | IE_IRQ1);
/* set the clock to 100 Hz */
r4030_write_reg32(JAZZ_TIMER_INTERVAL, 9);
break;
case MACH_DESKSTATION_TYNE:
/* set the clock to 100 Hz */
outb_p(0x34,0x43); /* binary, mode 2, LSB/MSB, ch 0 */
outb_p(LATCH & 0xff , 0x40); /* LSB */
outb(LATCH >> 8 , 0x40); /* MSB */
if (request_irq(2, no_action, SA_INTERRUPT, "cascade", NULL))
printk("Unable to get IRQ2 for cascade\n");
break;
default:
panic("Unknown machtype in init_IRQ");
}
for (i = 0; i < 16 ; i++)
set_int_vector(i, bad_interrupt);
/* initialize the bottom half routines. */
for (i = 0; i < 32; i++) {
bh_base[i].routine = NULL;
bh_base[i].data = NULL;
}
bh_active = 0;
intr_count = 0;
}
