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
  19#include <asm/ptrace.h>
  20#include <asm/system.h>
  21#include <asm/irq.h>
  22#include <asm/traps.h>
  23
  24#include <asm/q40_master.h>
  25#include <asm/q40ints.h>
  26
  27/*
  28 * Q40 IRQs are defined as follows:
  29 *            3,4,5,6,7,10,11,14,15 : ISA dev IRQs
  30 *            16-31: reserved
  31 *            32   : keyboard int
  32 *            33   : frame int (50/200 Hz periodic timer)
  33 *            34   : sample int (10/20 KHz periodic timer)
  34 *
  35*/
  36
  37static void q40_irq_handler(unsigned int, struct pt_regs *fp);
  38static void q40_enable_irq(unsigned int);
  39static void q40_disable_irq(unsigned int);
  40
  41unsigned short q40_ablecount[35];
  42unsigned short q40_state[35];
  43
  44static int q40_irq_startup(unsigned int irq)
  45{
  46        /* test for ISA ints not implemented by HW */
  47        switch (irq) {
  48        case 1: case 2: case 8: case 9:
  49        case 11: case 12: case 13:
  50                printk("%s: ISA IRQ %d not implemented by HW\n", __func__, irq);
  51                return -ENXIO;
  52        }
  53        return 0;
  54}
  55
  56static void q40_irq_shutdown(unsigned int irq)
  57{
  58}
  59
  60static struct irq_controller q40_irq_controller = {
  61        .name           = "q40",
  62        .lock           = __SPIN_LOCK_UNLOCKED(q40_irq_controller.lock),
  63        .startup        = q40_irq_startup,
  64        .shutdown       = q40_irq_shutdown,
  65        .enable         = q40_enable_irq,
  66        .disable        = q40_disable_irq,
  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_controller, 1, Q40_IRQ_MAX);
  85
  86        /* setup handler for ISA ints */
  87        m68k_setup_auto_interrupt(q40_irq_handler);
  88
  89        m68k_irq_startup(IRQ_AUTO_2);
  90        m68k_irq_startup(IRQ_AUTO_4);
  91
  92        /* now enable some ints.. */
  93        master_outb(1, EXT_ENABLE_REG);  /* ISA IRQ 5-15 */
  94
  95        /* make sure keyboard IRQ is disabled */
  96        master_outb(0, KEY_IRQ_ENABLE_REG);
  97}
  98
  99
 100/*
 101 * this stuff doesn't really belong here..
 102 */
 103
 104int ql_ticks;              /* 200Hz ticks since last jiffie */
 105static int sound_ticks;
 106
 107#define SVOL 45
 108
 109void q40_mksound(unsigned int hz, unsigned int ticks)
 110{
 111        /* for now ignore hz, except that hz==0 switches off sound */
 112        /* simply alternate the ampl (128-SVOL)-(128+SVOL)-..-.. at 200Hz */
 113        if (hz == 0) {
 114                if (sound_ticks)
 115                        sound_ticks = 1;
 116
 117                *DAC_LEFT = 128;
 118                *DAC_RIGHT = 128;
 119
 120                return;
 121        }
 122        /* sound itself is done in q40_timer_int */
 123        if (sound_ticks == 0)
 124                sound_ticks = 1000; /* pretty long beep */
 125        sound_ticks = ticks << 1;
 126}
 127
 128static irq_handler_t q40_timer_routine;
 129
 130static irqreturn_t q40_timer_int (int irq, void * dev)
 131{
 132        ql_ticks = ql_ticks ? 0 : 1;
 133        if (sound_ticks) {
 134                unsigned char sval=(sound_ticks & 1) ? 128-SVOL : 128+SVOL;
 135                sound_ticks--;
 136                *DAC_LEFT=sval;
 137                *DAC_RIGHT=sval;
 138        }
 139
 140        if (!ql_ticks)
 141                q40_timer_routine(irq, dev);
 142        return IRQ_HANDLED;
 143}
 144
 145void q40_sched_init (irq_handler_t timer_routine)
 146{
 147        int timer_irq;
 148
 149        q40_timer_routine = timer_routine;
 150        timer_irq = Q40_IRQ_FRAME;
 151
 152        if (request_irq(timer_irq, q40_timer_int, 0,
 153                                "timer", q40_timer_int))
 154                panic("Couldn't register timer int");
 155
 156        master_outb(-1, FRAME_CLEAR_REG);
 157        master_outb( 1, FRAME_RATE_REG);
 158}
 159
 160
 161/*
 162 * tables to translate bits into IRQ numbers
 163 * it is a good idea to order the entries by priority
 164 *
 165*/
 166
 167struct IRQ_TABLE{ unsigned mask; int irq ;};
 168#if 0
 169static struct IRQ_TABLE iirqs[]={
 170  {Q40_IRQ_FRAME_MASK,Q40_IRQ_FRAME},
 171  {Q40_IRQ_KEYB_MASK,Q40_IRQ_KEYBOARD},
 172  {0,0}};
 173#endif
 174static struct IRQ_TABLE eirqs[] = {
 175  { .mask = Q40_IRQ3_MASK,      .irq = 3 },     /* ser 1 */
 176  { .mask = Q40_IRQ4_MASK,      .irq = 4 },     /* ser 2 */
 177  { .mask = Q40_IRQ14_MASK,     .irq = 14 },    /* IDE 1 */
 178  { .mask = Q40_IRQ15_MASK,     .irq = 15 },    /* IDE 2 */
 179  { .mask = Q40_IRQ6_MASK,      .irq = 6 },     /* floppy, handled elsewhere */
 180  { .mask = Q40_IRQ7_MASK,      .irq = 7 },     /* par */
 181  { .mask = Q40_IRQ5_MASK,      .irq = 5 },
 182  { .mask = Q40_IRQ10_MASK,     .irq = 10 },
 183  {0,0}
 184};
 185
 186/* complain only this many times about spurious ints : */
 187static int ccleirq=60;    /* ISA dev IRQs*/
 188/*static int cclirq=60;*/     /* internal */
 189
 190/* FIXME: add shared ints,mask,unmask,probing.... */
 191
 192#define IRQ_INPROGRESS 1
 193/*static unsigned short saved_mask;*/
 194//static int do_tint=0;
 195
 196#define DEBUG_Q40INT
 197/*#define IP_USE_DISABLE *//* would be nice, but crashes ???? */
 198
 199static int mext_disabled=0;  /* ext irq disabled by master chip? */
 200static int aliased_irq=0;  /* how many times inside handler ?*/
 201
 202
 203/* got interrupt, dispatch to ISA or keyboard/timer IRQs */
 204static void q40_irq_handler(unsigned int irq, struct pt_regs *fp)
 205{
 206        unsigned mir, mer;
 207        int i;
 208
 209//repeat:
 210        mir = master_inb(IIRQ_REG);
 211#ifdef CONFIG_BLK_DEV_FD
 212        if ((mir & Q40_IRQ_EXT_MASK) &&
 213            (master_inb(EIRQ_REG) & Q40_IRQ6_MASK)) {
 214                floppy_hardint();
 215                return;
 216        }
 217#endif
 218        switch (irq) {
 219        case 4:
 220        case 6:
 221                __m68k_handle_int(Q40_IRQ_SAMPLE, fp);
 222                return;
 223        }
 224        if (mir & Q40_IRQ_FRAME_MASK) {
 225                __m68k_handle_int(Q40_IRQ_FRAME, fp);
 226                master_outb(-1, FRAME_CLEAR_REG);
 227        }
 228        if ((mir & Q40_IRQ_SER_MASK) || (mir & Q40_IRQ_EXT_MASK)) {
 229                mer = master_inb(EIRQ_REG);
 230                for (i = 0; eirqs[i].mask; i++) {
 231                        if (mer & eirqs[i].mask) {
 232                                irq = eirqs[i].irq;
 233/*
 234 * There is a little mess wrt which IRQ really caused this irq request. The
 235 * main problem is that IIRQ_REG and EIRQ_REG reflect the state when they
 236 * are read - which is long after the request came in. In theory IRQs should
 237 * not just go away but they occasionally do
 238 */
 239                                if (irq > 4 && irq <= 15 && mext_disabled) {
 240                                        /*aliased_irq++;*/
 241                                        goto iirq;
 242                                }
 243                                if (q40_state[irq] & IRQ_INPROGRESS) {
 244                                        /* some handlers do local_irq_enable() for irq latency reasons, */
 245                                        /* however reentering an active irq handler is not permitted */
 246#ifdef IP_USE_DISABLE
 247                                        /* in theory this is the better way to do it because it still */
 248                                        /* lets through eg the serial irqs, unfortunately it crashes */
 249                                        disable_irq(irq);
 250                                        disabled = 1;
 251#else
 252                                        /*printk("IRQ_INPROGRESS detected for irq %d, disabling - %s disabled\n",
 253                                                irq, disabled ? "already" : "not yet"); */
 254                                        fp->sr = (((fp->sr) & (~0x700))+0x200);
 255                                        disabled = 1;
 256#endif
 257                                        goto iirq;
 258                                }
 259                                q40_state[irq] |= IRQ_INPROGRESS;
 260                                __m68k_handle_int(irq, fp);
 261                                q40_state[irq] &= ~IRQ_INPROGRESS;
 262
 263                                /* naively enable everything, if that fails than    */
 264                                /* this function will be reentered immediately thus */
 265                                /* getting another chance to disable the IRQ        */
 266
 267                                if (disabled) {
 268#ifdef IP_USE_DISABLE
 269                                        if (irq > 4) {
 270                                                disabled = 0;
 271                                                enable_irq(irq);
 272                                        }
 273#else
 274                                        disabled = 0;
 275                                        /*printk("reenabling irq %d\n", irq); */
 276#endif
 277                                }
 278// used to do 'goto repeat;' here, this delayed bh processing too long
 279                                return;
 280                        }
 281                }
 282                if (mer && ccleirq > 0 && !aliased_irq) {
 283                        printk("ISA interrupt from unknown source? EIRQ_REG = %x\n",mer);
 284                        ccleirq--;
 285                }
 286        }
 287 iirq:
 288        mir = master_inb(IIRQ_REG);
 289        /* should test whether keyboard irq is really enabled, doing it in defhand */
 290        if (mir & Q40_IRQ_KEYB_MASK)
 291                __m68k_handle_int(Q40_IRQ_KEYBOARD, fp);
 292
 293        return;
 294}
 295
 296void q40_enable_irq(unsigned int irq)
 297{
 298        if (irq >= 5 && irq <= 15) {
 299                mext_disabled--;
 300                if (mext_disabled > 0)
 301                        printk("q40_enable_irq : nested disable/enable\n");
 302                if (mext_disabled == 0)
 303                        master_outb(1, EXT_ENABLE_REG);
 304        }
 305}
 306
 307
 308void q40_disable_irq(unsigned int irq)
 309{
 310        /* disable ISA iqs : only do something if the driver has been
 311         * verified to be Q40 "compatible" - right now IDE, NE2K
 312         * Any driver should not attempt to sleep across disable_irq !!
 313         */
 314
 315        if (irq >= 5 && irq <= 15) {
 316                master_outb(0, EXT_ENABLE_REG);
 317                mext_disabled++;
 318                if (mext_disabled > 1)
 319                        printk("disable_irq nesting count %d\n",mext_disabled);
 320        }
 321}
 322
 323unsigned long q40_probe_irq_on(void)
 324{
 325        printk("irq probing not working - reconfigure the driver to avoid this\n");
 326        return -1;
 327}
 328int q40_probe_irq_off(unsigned long irqs)
 329{
 330        return -1;
 331}
 332