/*
* arch/m68k/q40/q40ints.c
*
* Copyright (C) 1999,2001 Richard Zidlicky
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of this archive
* for more details.
*
* .. used to be loosely based on bvme6000ints.c
*
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <asm/machdep.h>
#include <asm/ptrace.h>
#include <asm/traps.h>
#include <asm/q40_master.h>
#include <asm/q40ints.h>
#include "q40.h"
/*
* Q40 IRQs are defined as follows:
* 3,4,5,6,7,10,11,14,15 : ISA dev IRQs
* 16-31: reserved
* 32 : keyboard int
* 33 : frame int (50/200 Hz periodic timer)
* 34 : sample int (10/20 KHz periodic timer)
*
*/
static void q40_irq_handler(unsigned int, struct pt_regs *fp);
static void q40_irq_enable(struct irq_data *data);
static void q40_irq_disable(struct irq_data *data);
unsigned short q40_ablecount[35];
unsigned short q40_state[35];
static unsigned int q40_irq_startup(struct irq_data *data)
{
unsigned int irq = data->irq;
/* test for ISA ints not implemented by HW */
switch (irq) {
case 1: case 2: case 8: case 9:
case 11: case 12: case 13:
pr_warn("%s: ISA IRQ %d not implemented by HW\n", __func__,
irq);
/* FIXME return -ENXIO; */
}
return 0;
}
static void q40_irq_shutdown(struct irq_data *data)
{
}
static struct irq_chip q40_irq_chip = {
.name = "q40",
.irq_startup = q40_irq_startup,
.irq_shutdown = q40_irq_shutdown,
.irq_enable = q40_irq_enable,
.irq_disable = q40_irq_disable,
};
/*
* void q40_init_IRQ (void)
*
* Parameters: None
*
* Returns: Nothing
*
* This function is called during kernel startup to initialize
* the q40 IRQ handling routines.
*/
static int disabled;
void __init q40_init_IRQ(void)
{
m68k_setup_irq_controller(&q40_irq_chip, handle_simple_irq, 1,
Q40_IRQ_MAX);
/* setup handler for ISA ints */
m68k_setup_auto_interrupt(q40_irq_handler);
m68k_irq_startup_irq(IRQ_AUTO_2);
m68k_irq_startup_irq(IRQ_AUTO_4);
/* now enable some ints.. */
master_outb(1, EXT_ENABLE_REG); /* ISA IRQ 5-15 */
/* make sure keyboard IRQ is disabled */
master_outb(0, KEY_IRQ_ENABLE_REG);
}
/*
* this stuff doesn't really belong here..
*/
int ql_ticks; /* 200Hz ticks since last jiffie */
static int sound_ticks;
#define SVOL 45
void q40_mksound(unsigned int hz, unsigned int ticks)
{
/* for now ignore hz, except that hz==0 switches off sound */
/* simply alternate the ampl (128-SVOL)-(128+SVOL)-..-.. at 200Hz */
if (hz == 0) {
if (sound_ticks)
sound_ticks = 1;
*DAC_LEFT = 128;
*DAC_RIGHT = 128;
return;
}
/* sound itself is done in q40_timer_int */
if (sound_ticks == 0)
sound_ticks = 1000; /* pretty long beep */
sound_ticks = ticks << 1;
}
static irqreturn_t q40_timer_int(int irq, void *dev_id)
{
ql_ticks = ql_ticks ? 0 : 1;
if (sound_ticks) {
unsigned char sval=(sound_ticks & 1) ? 128-SVOL : 128+SVOL;
sound_ticks--;
*DAC_LEFT=sval;
*DAC_RIGHT=sval;
}
if (!ql_ticks) {
unsigned long flags;
local_irq_save(flags);
legacy_timer_tick(1);
timer_heartbeat();
local_irq_restore(flags);
}
return IRQ_HANDLED;
}
void q40_sched_init (void)
{
int timer_irq;
timer_irq = Q40_IRQ_FRAME;
if (request_irq(timer_irq, q40_timer_int, 0, "timer", NULL))
panic("Couldn't register timer int");
master_outb(-1, FRAME_CLEAR_REG);
master_outb( 1, FRAME_RATE_REG);
}
/*
* tables to translate bits into IRQ numbers
* it is a good idea to order the entries by priority
*
*/
struct IRQ_TABLE{ unsigned mask; int irq ;};
#if 0
static struct IRQ_TABLE iirqs[]={
{Q40_IRQ_FRAME_MASK,Q40_IRQ_FRAME},
{Q40_IRQ_KEYB_MASK,Q40_IRQ_KEYBOARD},
{0,0}};
#endif
static struct IRQ_TABLE eirqs[] = {
{ .mask = Q40_IRQ3_MASK, .irq = 3 }, /* ser 1 */
{ .mask = Q40_IRQ4_MASK, .irq = 4 }, /* ser 2 */
{ .mask = Q40_IRQ14_MASK, .irq = 14 }, /* IDE 1 */
{ .mask = Q40_IRQ15_MASK, .irq = 15 }, /* IDE 2 */
{ .mask = Q40_IRQ6_MASK, .irq = 6 }, /* floppy, handled elsewhere */
{ .mask = Q40_IRQ7_MASK, .irq = 7 }, /* par */
{ .mask = Q40_IRQ5_MASK, .irq = 5 },
{ .mask = Q40_IRQ10_MASK, .irq = 10 },
{0,0}
};
/* complain only this many times about spurious ints : */
static int ccleirq=60; /* ISA dev IRQs*/
/*static int cclirq=60;*/ /* internal */
/* FIXME: add shared ints,mask,unmask,probing.... */
#define IRQ_INPROGRESS 1
/*static unsigned short saved_mask;*/
//static int do_tint=0;
#define DEBUG_Q40INT
/*#define IP_USE_DISABLE *//* would be nice, but crashes ???? */
static int mext_disabled; /* ext irq disabled by master chip? */
static int aliased_irq; /* how many times inside handler ?*/
/* got interrupt, dispatch to ISA or keyboard/timer IRQs */
static void q40_irq_handler(unsigned int irq, struct pt_regs *fp)
{
unsigned mir, mer;
int i;
//repeat:
mir = master_inb(IIRQ_REG);
#ifdef CONFIG_BLK_DEV_FD
if ((mir & Q40_IRQ_EXT_MASK) &&
(master_inb(EIRQ_REG) & Q40_IRQ6_MASK)) {
floppy_hardint();
return;
}
#endif
switch (irq) {
case 4:
case 6:
do_IRQ(Q40_IRQ_SAMPLE, fp);
return;
}
if (mir & Q40_IRQ_FRAME_MASK) {
do_IRQ(Q40_IRQ_FRAME, fp);
master_outb(-1, FRAME_CLEAR_REG);
}
if ((mir & Q40_IRQ_SER_MASK) || (mir & Q40_IRQ_EXT_MASK)) {
mer = master_inb(EIRQ_REG);
for (i = 0; eirqs[i].mask; i++) {
if (mer & eirqs[i].mask) {
irq = eirqs[i].irq;
/*
* There is a little mess wrt which IRQ really caused this irq request. The
* main problem is that IIRQ_REG and EIRQ_REG reflect the state when they
* are read - which is long after the request came in. In theory IRQs should
* not just go away but they occasionally do
*/
if (irq > 4 && irq <= 15 && mext_disabled) {
/*aliased_irq++;*/
goto iirq;
}
if (q40_state[irq] & IRQ_INPROGRESS) {
/* some handlers do local_irq_enable() for irq latency reasons, */
/* however reentering an active irq handler is not permitted */
#ifdef IP_USE_DISABLE
/* in theory this is the better way to do it because it still */
/* lets through eg the serial irqs, unfortunately it crashes */
disable_irq(irq);
disabled = 1;
#else
/*pr_warn("IRQ_INPROGRESS detected for irq %d, disabling - %s disabled\n",
irq, disabled ? "already" : "not yet"); */
fp->sr = (((fp->sr) & (~0x700))+0x200);
disabled = 1;
#endif
goto iirq;
}
q40_state[irq] |= IRQ_INPROGRESS;
do_IRQ(irq, fp);
q40_state[irq] &= ~IRQ_INPROGRESS;
/* naively enable everything, if that fails than */
/* this function will be reentered immediately thus */
/* getting another chance to disable the IRQ */
if (disabled) {
#ifdef IP_USE_DISABLE
if (irq > 4) {
disabled = 0;
enable_irq(irq);
}
#else
disabled = 0;
/*pr_info("reenabling irq %d\n", irq); */
#endif
}
// used to do 'goto repeat;' here, this delayed bh processing too long
return;
}
}
if (mer && ccleirq > 0 && !aliased_irq) {
pr_warn("ISA interrupt from unknown source? EIRQ_REG = %x\n",
mer);
ccleirq--;
}
}
iirq:
mir = master_inb(IIRQ_REG);
/* should test whether keyboard irq is really enabled, doing it in defhand */
if (mir & Q40_IRQ_KEYB_MASK)
do_IRQ(Q40_IRQ_KEYBOARD, fp);
return;
}
void q40_irq_enable(struct irq_data *data)
{
unsigned int irq = data->irq;
if (irq >= 5 && irq <= 15) {
mext_disabled--;
if (mext_disabled > 0)
pr_warn("q40_irq_enable : nested disable/enable\n");
if (mext_disabled == 0)
master_outb(1, EXT_ENABLE_REG);
}
}
void q40_irq_disable(struct irq_data *data)
{
unsigned int irq = data->irq;
/* disable ISA iqs : only do something if the driver has been
* verified to be Q40 "compatible" - right now IDE, NE2K
* Any driver should not attempt to sleep across disable_irq !!
*/
if (irq >= 5 && irq <= 15) {
master_outb(0, EXT_ENABLE_REG);
mext_disabled++;
if (mext_disabled > 1)
pr_info("disable_irq nesting count %d\n",
mext_disabled);
}
}
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