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                pr_warn("%s: ISA IRQ %d not implemented by HW\n", __func__,
  52                        irq);
  53                /* FIXME return -ENXIO; */
  54        }
  55        return 0;
  56}
  57
  58static void q40_irq_shutdown(struct irq_data *data)
  59{
  60}
  61
  62static struct irq_chip q40_irq_chip = {
  63        .name           = "q40",
  64        .irq_startup    = q40_irq_startup,
  65        .irq_shutdown   = q40_irq_shutdown,
  66        .irq_enable     = q40_irq_enable,
  67        .irq_disable    = q40_irq_disable,
  68};
  69
  70/*
  71 * void q40_init_IRQ (void)
  72 *
  73 * Parameters:  None
  74 *
  75 * Returns:     Nothing
  76 *
  77 * This function is called during kernel startup to initialize
  78 * the q40 IRQ handling routines.
  79 */
  80
  81static int disabled;
  82
  83void __init q40_init_IRQ(void)
  84{
  85        m68k_setup_irq_controller(&q40_irq_chip, handle_simple_irq, 1,
  86                                  Q40_IRQ_MAX);
  87
  88        /* setup handler for ISA ints */
  89        m68k_setup_auto_interrupt(q40_irq_handler);
  90
  91        m68k_irq_startup_irq(IRQ_AUTO_2);
  92        m68k_irq_startup_irq(IRQ_AUTO_4);
  93
  94        /* now enable some ints.. */
  95        master_outb(1, EXT_ENABLE_REG);  /* ISA IRQ 5-15 */
  96
  97        /* make sure keyboard IRQ is disabled */
  98        master_outb(0, KEY_IRQ_ENABLE_REG);
  99}
 100
 101
 102/*
 103 * this stuff doesn't really belong here..
 104 */
 105
 106int ql_ticks;              /* 200Hz ticks since last jiffie */
 107static int sound_ticks;
 108
 109#define SVOL 45
 110
 111void q40_mksound(unsigned int hz, unsigned int ticks)
 112{
 113        /* for now ignore hz, except that hz==0 switches off sound */
 114        /* simply alternate the ampl (128-SVOL)-(128+SVOL)-..-.. at 200Hz */
 115        if (hz == 0) {
 116                if (sound_ticks)
 117                        sound_ticks = 1;
 118
 119                *DAC_LEFT = 128;
 120                *DAC_RIGHT = 128;
 121
 122                return;
 123        }
 124        /* sound itself is done in q40_timer_int */
 125        if (sound_ticks == 0)
 126                sound_ticks = 1000; /* pretty long beep */
 127        sound_ticks = ticks << 1;
 128}
 129
 130static irq_handler_t q40_timer_routine;
 131
 132static irqreturn_t q40_timer_int (int irq, void * dev)
 133{
 134        ql_ticks = ql_ticks ? 0 : 1;
 135        if (sound_ticks) {
 136                unsigned char sval=(sound_ticks & 1) ? 128-SVOL : 128+SVOL;
 137                sound_ticks--;
 138                *DAC_LEFT=sval;
 139                *DAC_RIGHT=sval;
 140        }
 141
 142        if (!ql_ticks)
 143                q40_timer_routine(irq, dev);
 144        return IRQ_HANDLED;
 145}
 146
 147void q40_sched_init (irq_handler_t timer_routine)
 148{
 149        int timer_irq;
 150
 151        q40_timer_routine = timer_routine;
 152        timer_irq = Q40_IRQ_FRAME;
 153
 154        if (request_irq(timer_irq, q40_timer_int, 0,
 155                                "timer", q40_timer_int))
 156                panic("Couldn't register timer int");
 157
 158        master_outb(-1, FRAME_CLEAR_REG);
 159        master_outb( 1, FRAME_RATE_REG);
 160}
 161
 162
 163/*
 164 * tables to translate bits into IRQ numbers
 165 * it is a good idea to order the entries by priority
 166 *
 167*/
 168
 169struct IRQ_TABLE{ unsigned mask; int irq ;};
 170#if 0
 171static struct IRQ_TABLE iirqs[]={
 172  {Q40_IRQ_FRAME_MASK,Q40_IRQ_FRAME},
 173  {Q40_IRQ_KEYB_MASK,Q40_IRQ_KEYBOARD},
 174  {0,0}};
 175#endif
 176static struct IRQ_TABLE eirqs[] = {
 177  { .mask = Q40_IRQ3_MASK,      .irq = 3 },     /* ser 1 */
 178  { .mask = Q40_IRQ4_MASK,      .irq = 4 },     /* ser 2 */
 179  { .mask = Q40_IRQ14_MASK,     .irq = 14 },    /* IDE 1 */
 180  { .mask = Q40_IRQ15_MASK,     .irq = 15 },    /* IDE 2 */
 181  { .mask = Q40_IRQ6_MASK,      .irq = 6 },     /* floppy, handled elsewhere */
 182  { .mask = Q40_IRQ7_MASK,      .irq = 7 },     /* par */
 183  { .mask = Q40_IRQ5_MASK,      .irq = 5 },
 184  { .mask = Q40_IRQ10_MASK,     .irq = 10 },
 185  {0,0}
 186};
 187
 188/* complain only this many times about spurious ints : */
 189static int ccleirq=60;    /* ISA dev IRQs*/
 190/*static int cclirq=60;*/     /* internal */
 191
 192/* FIXME: add shared ints,mask,unmask,probing.... */
 193
 194#define IRQ_INPROGRESS 1
 195/*static unsigned short saved_mask;*/
 196//static int do_tint=0;
 197
 198#define DEBUG_Q40INT
 199/*#define IP_USE_DISABLE *//* would be nice, but crashes ???? */
 200
 201static int mext_disabled=0;  /* ext irq disabled by master chip? */
 202static int aliased_irq=0;  /* how many times inside handler ?*/
 203
 204
 205/* got interrupt, dispatch to ISA or keyboard/timer IRQs */
 206static void q40_irq_handler(unsigned int irq, struct pt_regs *fp)
 207{
 208        unsigned mir, mer;
 209        int i;
 210
 211//repeat:
 212        mir = master_inb(IIRQ_REG);
 213#ifdef CONFIG_BLK_DEV_FD
 214        if ((mir & Q40_IRQ_EXT_MASK) &&
 215            (master_inb(EIRQ_REG) & Q40_IRQ6_MASK)) {
 216                floppy_hardint();
 217                return;
 218        }
 219#endif
 220        switch (irq) {
 221        case 4:
 222        case 6:
 223                do_IRQ(Q40_IRQ_SAMPLE, fp);
 224                return;
 225        }
 226        if (mir & Q40_IRQ_FRAME_MASK) {
 227                do_IRQ(Q40_IRQ_FRAME, fp);
 228                master_outb(-1, FRAME_CLEAR_REG);
 229        }
 230        if ((mir & Q40_IRQ_SER_MASK) || (mir & Q40_IRQ_EXT_MASK)) {
 231                mer = master_inb(EIRQ_REG);
 232                for (i = 0; eirqs[i].mask; i++) {
 233                        if (mer & eirqs[i].mask) {
 234                                irq = eirqs[i].irq;
 235/*
 236 * There is a little mess wrt which IRQ really caused this irq request. The
 237 * main problem is that IIRQ_REG and EIRQ_REG reflect the state when they
 238 * are read - which is long after the request came in. In theory IRQs should
 239 * not just go away but they occasionally do
 240 */
 241                                if (irq > 4 && irq <= 15 && mext_disabled) {
 242                                        /*aliased_irq++;*/
 243                                        goto iirq;
 244                                }
 245                                if (q40_state[irq] & IRQ_INPROGRESS) {
 246                                        /* some handlers do local_irq_enable() for irq latency reasons, */
 247                                        /* however reentering an active irq handler is not permitted */
 248#ifdef IP_USE_DISABLE
 249                                        /* in theory this is the better way to do it because it still */
 250                                        /* lets through eg the serial irqs, unfortunately it crashes */
 251                                        disable_irq(irq);
 252                                        disabled = 1;
 253#else
 254                                        /*pr_warn("IRQ_INPROGRESS detected for irq %d, disabling - %s disabled\n",
 255                                                irq, disabled ? "already" : "not yet"); */
 256                                        fp->sr = (((fp->sr) & (~0x700))+0x200);
 257                                        disabled = 1;
 258#endif
 259                                        goto iirq;
 260                                }
 261                                q40_state[irq] |= IRQ_INPROGRESS;
 262                                do_IRQ(irq, fp);
 263                                q40_state[irq] &= ~IRQ_INPROGRESS;
 264
 265                                /* naively enable everything, if that fails than    */
 266                                /* this function will be reentered immediately thus */
 267                                /* getting another chance to disable the IRQ        */
 268
 269                                if (disabled) {
 270#ifdef IP_USE_DISABLE
 271                                        if (irq > 4) {
 272                                                disabled = 0;
 273                                                enable_irq(irq);
 274                                        }
 275#else
 276                                        disabled = 0;
 277                                        /*pr_info("reenabling irq %d\n", irq); */
 278#endif
 279                                }
 280// used to do 'goto repeat;' here, this delayed bh processing too long
 281                                return;
 282                        }
 283                }
 284                if (mer && ccleirq > 0 && !aliased_irq) {
 285                        pr_warn("ISA interrupt from unknown source? EIRQ_REG = %x\n",
 286                                mer);
 287                        ccleirq--;
 288                }
 289        }
 290 iirq:
 291        mir = master_inb(IIRQ_REG);
 292        /* should test whether keyboard irq is really enabled, doing it in defhand */
 293        if (mir & Q40_IRQ_KEYB_MASK)
 294                do_IRQ(Q40_IRQ_KEYBOARD, fp);
 295
 296        return;
 297}
 298
 299void q40_irq_enable(struct irq_data *data)
 300{
 301        unsigned int irq = data->irq;
 302
 303        if (irq >= 5 && irq <= 15) {
 304                mext_disabled--;
 305                if (mext_disabled > 0)
 306                        pr_warn("q40_irq_enable : nested disable/enable\n");
 307                if (mext_disabled == 0)
 308                        master_outb(1, EXT_ENABLE_REG);
 309        }
 310}
 311
 312
 313void q40_irq_disable(struct irq_data *data)
 314{
 315        unsigned int irq = data->irq;
 316
 317        /* disable ISA iqs : only do something if the driver has been
 318         * verified to be Q40 "compatible" - right now IDE, NE2K
 319         * Any driver should not attempt to sleep across disable_irq !!
 320         */
 321
 322        if (irq >= 5 && irq <= 15) {
 323                master_outb(0, EXT_ENABLE_REG);
 324                mext_disabled++;
 325                if (mext_disabled > 1)
 326                        pr_info("disable_irq nesting count %d\n",
 327                                mext_disabled);
 328        }
 329}
 330