LXR linux/arch/m68k/q40/q40ints.c

   1/*
   2 * arch/m68k/q40/q40ints.c
   3 *
   4 * Copyright (C) 1999,2001 Richard Zidlicky
   5 *
   6 * This file is subject to the terms and conditions of the GNU General Public
   7 * License.  See the file COPYING in the main directory of this archive
   8 * for more details.
   9 *
  10 * .. used to be loosely based on bvme6000ints.c
  11 *
  12 */
  13
  14#include <linux/types.h>
  15#include <linux/kernel.h>
  16#include <linux/errno.h>
  17#include <linux/interrupt.h>
  18#include <linux/irq.h>
  19
  20#include <asm/ptrace.h>
  21#include <asm/traps.h>
  22
  23#include <asm/q40_master.h>
  24#include <asm/q40ints.h>
  25
  26/*
  27 * Q40 IRQs are defined as follows:
  28 *            3,4,5,6,7,10,11,14,15 : ISA dev IRQs
  29 *            16-31: reserved
  30 *            32   : keyboard int
  31 *            33   : frame int (50/200 Hz periodic timer)
  32 *            34   : sample int (10/20 KHz periodic timer)
  33 *
  34*/
  35
  36static void q40_irq_handler(unsigned int, struct pt_regs *fp);
  37static void q40_irq_enable(struct irq_data *data);
  38static void q40_irq_disable(struct irq_data *data);
  39
  40unsigned short q40_ablecount[35];
  41unsigned short q40_state[35];
  42
  43static unsigned int q40_irq_startup(struct irq_data *data)
  44{
  45        unsigned int irq = data->irq;
  46
  47        /* test for ISA ints not implemented by HW */
  48        switch (irq) {
  49        case 1: case 2: case 8: case 9:
  50        case 11: case 12: case 13:
  51                printk("%s: ISA IRQ %d not implemented by HW\n", __func__, irq);
  52                /* FIXME return -ENXIO; */
  53        }
  54        return 0;
  55}
  56
  57static void q40_irq_shutdown(struct irq_data *data)
  58{
  59}
  60
  61static struct irq_chip q40_irq_chip = {
  62        .name           = "q40",
  63        .irq_startup    = q40_irq_startup,
  64        .irq_shutdown   = q40_irq_shutdown,
  65        .irq_enable     = q40_irq_enable,
  66        .irq_disable    = q40_irq_disable,
  67};
  68
  69/*
  70 * void q40_init_IRQ (void)
  71 *
  72 * Parameters:  None
  73 *
  74 * Returns:     Nothing
  75 *
  76 * This function is called during kernel startup to initialize
  77 * the q40 IRQ handling routines.
  78 */
  79
  80static int disabled;
  81
  82void __init q40_init_IRQ(void)
  83{
  84        m68k_setup_irq_controller(&q40_irq_chip, handle_simple_irq, 1,
  85                                  Q40_IRQ_MAX);
  86
  87        /* setup handler for ISA ints */
  88        m68k_setup_auto_interrupt(q40_irq_handler);
  89
  90        m68k_irq_startup_irq(IRQ_AUTO_2);
  91        m68k_irq_startup_irq(IRQ_AUTO_4);
  92
  93        /* now enable some ints.. */
  94        master_outb(1, EXT_ENABLE_REG);  /* ISA IRQ 5-15 */
  95
  96        /* make sure keyboard IRQ is disabled */
  97        master_outb(0, KEY_IRQ_ENABLE_REG);
  98}
  99
 100
 101/*
 102 * this stuff doesn't really belong here..
 103 */
 104
 105int ql_ticks;              /* 200Hz ticks since last jiffie */
 106static int sound_ticks;
 107
 108#define SVOL 45
 109
 110void q40_mksound(unsigned int hz, unsigned int ticks)
 111{
 112        /* for now ignore hz, except that hz==0 switches off sound */
 113        /* simply alternate the ampl (128-SVOL)-(128+SVOL)-..-.. at 200Hz */
 114        if (hz == 0) {
 115                if (sound_ticks)
 116                        sound_ticks = 1;
 117
 118                *DAC_LEFT = 128;
 119                *DAC_RIGHT = 128;
 120
 121                return;
 122        }
 123        /* sound itself is done in q40_timer_int */
 124        if (sound_ticks == 0)
 125                sound_ticks = 1000; /* pretty long beep */
 126        sound_ticks = ticks << 1;
 127}
 128
 129static irq_handler_t q40_timer_routine;
 130
 131static irqreturn_t q40_timer_int (int irq, void * dev)
 132{
 133        ql_ticks = ql_ticks ? 0 : 1;
 134        if (sound_ticks) {
 135                unsigned char sval=(sound_ticks & 1) ? 128-SVOL : 128+SVOL;
 136                sound_ticks--;
 137                *DAC_LEFT=sval;
 138                *DAC_RIGHT=sval;
 139        }
 140
 141        if (!ql_ticks)
 142                q40_timer_routine(irq, dev);
 143        return IRQ_HANDLED;
 144}
 145
 146void q40_sched_init (irq_handler_t timer_routine)
 147{
 148        int timer_irq;
 149
 150        q40_timer_routine = timer_routine;
 151        timer_irq = Q40_IRQ_FRAME;
 152
 153        if (request_irq(timer_irq, q40_timer_int, 0,
 154                                "timer", q40_timer_int))
 155                panic("Couldn't register timer int");
 156
 157        master_outb(-1, FRAME_CLEAR_REG);
 158        master_outb( 1, FRAME_RATE_REG);
 159}
 160
 161
 162/*
 163 * tables to translate bits into IRQ numbers
 164 * it is a good idea to order the entries by priority
 165 *
 166*/
 167
 168struct IRQ_TABLE{ unsigned mask; int irq ;};
 169#if 0
 170static struct IRQ_TABLE iirqs[]={
 171  {Q40_IRQ_FRAME_MASK,Q40_IRQ_FRAME},
 172  {Q40_IRQ_KEYB_MASK,Q40_IRQ_KEYBOARD},
 173  {0,0}};
 174#endif
 175static struct IRQ_TABLE eirqs[] = {
 176  { .mask = Q40_IRQ3_MASK,      .irq = 3 },     /* ser 1 */
 177  { .mask = Q40_IRQ4_MASK,      .irq = 4 },     /* ser 2 */
 178  { .mask = Q40_IRQ14_MASK,     .irq = 14 },    /* IDE 1 */
 179  { .mask = Q40_IRQ15_MASK,     .irq = 15 },    /* IDE 2 */
 180  { .mask = Q40_IRQ6_MASK,      .irq = 6 },     /* floppy, handled elsewhere */
 181  { .mask = Q40_IRQ7_MASK,      .irq = 7 },     /* par */
 182  { .mask = Q40_IRQ5_MASK,      .irq = 5 },
 183  { .mask = Q40_IRQ10_MASK,     .irq = 10 },
 184  {0,0}
 185};
 186
 187/* complain only this many times about spurious ints : */
 188static int ccleirq=60;    /* ISA dev IRQs*/
 189/*static int cclirq=60;*/     /* internal */
 190
 191/* FIXME: add shared ints,mask,unmask,probing.... */
 192
 193#define IRQ_INPROGRESS 1
 194/*static unsigned short saved_mask;*/
 195//static int do_tint=0;
 196
 197#define DEBUG_Q40INT
 198/*#define IP_USE_DISABLE *//* would be nice, but crashes ???? */
 199
 200static int mext_disabled=0;  /* ext irq disabled by master chip? */
 201static int aliased_irq=0;  /* how many times inside handler ?*/
 202
 203
 204/* got interrupt, dispatch to ISA or keyboard/timer IRQs */
 205static void q40_irq_handler(unsigned int irq, struct pt_regs *fp)
 206{
 207        unsigned mir, mer;
 208        int i;
 209
 210//repeat:
 211        mir = master_inb(IIRQ_REG);
 212#ifdef CONFIG_BLK_DEV_FD
 213        if ((mir & Q40_IRQ_EXT_MASK) &&
 214            (master_inb(EIRQ_REG) & Q40_IRQ6_MASK)) {
 215                floppy_hardint();
 216                return;
 217        }
 218#endif
 219        switch (irq) {
 220        case 4:
 221        case 6:
 222                do_IRQ(Q40_IRQ_SAMPLE, fp);
 223                return;
 224        }
 225        if (mir & Q40_IRQ_FRAME_MASK) {
 226                do_IRQ(Q40_IRQ_FRAME, fp);
 227                master_outb(-1, FRAME_CLEAR_REG);
 228        }
 229        if ((mir & Q40_IRQ_SER_MASK) || (mir & Q40_IRQ_EXT_MASK)) {
 230                mer = master_inb(EIRQ_REG);
 231                for (i = 0; eirqs[i].mask; i++) {
 232                        if (mer & eirqs[i].mask) {
 233                                irq = eirqs[i].irq;
 234/*
 235 * There is a little mess wrt which IRQ really caused this irq request. The
 236 * main problem is that IIRQ_REG and EIRQ_REG reflect the state when they
 237 * are read - which is long after the request came in. In theory IRQs should
 238 * not just go away but they occasionally do
 239 */
 240                                if (irq > 4 && irq <= 15 && mext_disabled) {
 241                                        /*aliased_irq++;*/
 242                                        goto iirq;
 243                                }
 244                                if (q40_state[irq] & IRQ_INPROGRESS) {
 245                                        /* some handlers do local_irq_enable() for irq latency reasons, */
 246                                        /* however reentering an active irq handler is not permitted */
 247#ifdef IP_USE_DISABLE
 248                                        /* in theory this is the better way to do it because it still */
 249                                        /* lets through eg the serial irqs, unfortunately it crashes */
 250                                        disable_irq(irq);
 251                                        disabled = 1;
 252#else
 253                                        /*printk("IRQ_INPROGRESS detected for irq %d, disabling - %s disabled\n",
 254                                                irq, disabled ? "already" : "not yet"); */
 255                                        fp->sr = (((fp->sr) & (~0x700))+0x200);
 256                                        disabled = 1;
 257#endif
 258                                        goto iirq;
 259                                }
 260                                q40_state[irq] |= IRQ_INPROGRESS;
 261                                do_IRQ(irq, fp);
 262                                q40_state[irq] &= ~IRQ_INPROGRESS;
 263
 264                                /* naively enable everything, if that fails than    */
 265                                /* this function will be reentered immediately thus */
 266                                /* getting another chance to disable the IRQ        */
 267
 268                                if (disabled) {
 269#ifdef IP_USE_DISABLE
 270                                        if (irq > 4) {
 271                                                disabled = 0;
 272                                                enable_irq(irq);
 273                                        }
 274#else
 275                                        disabled = 0;
 276                                        /*printk("reenabling irq %d\n", irq); */
 277#endif
 278                                }
 279// used to do 'goto repeat;' here, this delayed bh processing too long
 280                                return;
 281                        }
 282                }
 283                if (mer && ccleirq > 0 && !aliased_irq) {
 284                        printk("ISA interrupt from unknown source? EIRQ_REG = %x\n",mer);
 285                        ccleirq--;
 286                }
 287        }
 288 iirq:
 289        mir = master_inb(IIRQ_REG);
 290        /* should test whether keyboard irq is really enabled, doing it in defhand */
 291        if (mir & Q40_IRQ_KEYB_MASK)
 292                do_IRQ(Q40_IRQ_KEYBOARD, fp);
 293
 294        return;
 295}
 296
 297void q40_irq_enable(struct irq_data *data)
 298{
 299        unsigned int irq = data->irq;
 300
 301        if (irq >= 5 && irq <= 15) {
 302                mext_disabled--;
 303                if (mext_disabled > 0)
 304                        printk("q40_irq_enable : nested disable/enable\n");
 305                if (mext_disabled == 0)
 306                        master_outb(1, EXT_ENABLE_REG);
 307        }
 308}
 309
 310
 311void q40_irq_disable(struct irq_data *data)
 312{
 313        unsigned int irq = data->irq;
 314
 315        /* disable ISA iqs : only do something if the driver has been
 316         * verified to be Q40 "compatible" - right now IDE, NE2K
 317         * Any driver should not attempt to sleep across disable_irq !!
 318         */
 319
 320        if (irq >= 5 && irq <= 15) {
 321                master_outb(0, EXT_ENABLE_REG);
 322                mext_disabled++;
 323                if (mext_disabled > 1)
 324                        printk("disable_irq nesting count %d\n",mext_disabled);
 325        }
 326}
 327