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
  37 static void q40_irq_handler(unsigned int, struct pt_regs *fp);
  38 static void q40_enable_irq(unsigned int);
  39 static void q40_disable_irq(unsigned int);
  40
  41 unsigned short q40_ablecount[35];
  42 unsigned short q40_state[35];
  43
  44 static unsigned 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                 /* FIXME return -ENXIO; */
  52         }
  53         return 0;
  54 }
  55
  56 static void q40_irq_shutdown(unsigned int irq)
  57 {
  58 }
  59
  60 static struct irq_chip q40_irq_chip = {
  61         .name           = "q40",
  62         .irq_startup    = q40_irq_startup,
  63         .irq_shutdown   = q40_irq_shutdown,
  64         .irq_enable     = q40_enable_irq,
  65         .irq_disable    = q40_disable_irq,
  66 };
  67
  68 /*
  69  * void q40_init_IRQ (void)
  70  *
  71  * Parameters:  None
  72  *
  73  * Returns:     Nothing
  74  *
  75  * This function is called during kernel startup to initialize
  76  * the q40 IRQ handling routines.
  77  */
  78
  79 static int disabled;
  80
  81 void __init q40_init_IRQ(void)
  82 {
  83         m68k_setup_irq_chip(&q40_irq_chip, 1, Q40_IRQ_MAX);
  84
  85         /* setup handler for ISA ints */
  86         m68k_setup_auto_interrupt(q40_irq_handler);
  87
  88         m68k_irq_startup(IRQ_AUTO_2);
  89         m68k_irq_startup(IRQ_AUTO_4);
  90
  91         /* now enable some ints.. */
  92         master_outb(1, EXT_ENABLE_REG);  /* ISA IRQ 5-15 */
  93
  94         /* make sure keyboard IRQ is disabled */
  95         master_outb(0, KEY_IRQ_ENABLE_REG);
  96 }
  97
  98
  99 /*
 100  * this stuff doesn't really belong here..
 101  */
 102
 103 int ql_ticks;              /* 200Hz ticks since last jiffie */
 104 static int sound_ticks;
 105
 106 #define SVOL 45
 107
 108 void q40_mksound(unsigned int hz, unsigned int ticks)
 109 {
 110         /* for now ignore hz, except that hz==0 switches off sound */
 111         /* simply alternate the ampl (128-SVOL)-(128+SVOL)-..-.. at 200Hz */
 112         if (hz == 0) {
 113                 if (sound_ticks)
 114                         sound_ticks = 1;
 115
 116                 *DAC_LEFT = 128;
 117                 *DAC_RIGHT = 128;
 118
 119                 return;
 120         }
 121         /* sound itself is done in q40_timer_int */
 122         if (sound_ticks == 0)
 123                 sound_ticks = 1000; /* pretty long beep */
 124         sound_ticks = ticks << 1;
 125 }
 126
 127 static irq_handler_t q40_timer_routine;
 128
 129 static irqreturn_t q40_timer_int (int irq, void * dev)
 130 {
 131         ql_ticks = ql_ticks ? 0 : 1;
 132         if (sound_ticks) {
 133                 unsigned char sval=(sound_ticks & 1) ? 128-SVOL : 128+SVOL;
 134                 sound_ticks--;
 135                 *DAC_LEFT=sval;
 136                 *DAC_RIGHT=sval;
 137         }
 138
 139         if (!ql_ticks)
 140                 q40_timer_routine(irq, dev);
 141         return IRQ_HANDLED;
 142 }
 143
 144 void q40_sched_init (irq_handler_t timer_routine)
 145 {
 146         int timer_irq;
 147
 148         q40_timer_routine = timer_routine;
 149         timer_irq = Q40_IRQ_FRAME;
 150
 151         if (request_irq(timer_irq, q40_timer_int, 0,
 152                                 "timer", q40_timer_int))
 153                 panic("Couldn't register timer int");
 154
 155         master_outb(-1, FRAME_CLEAR_REG);
 156         master_outb( 1, FRAME_RATE_REG);
 157 }
 158
 159
 160 /*
 161  * tables to translate bits into IRQ numbers
 162  * it is a good idea to order the entries by priority
 163  *
 164 */
 165
 166 struct IRQ_TABLE{ unsigned mask; int irq ;};
 167 #if 0
 168 static struct IRQ_TABLE iirqs[]={
 169   {Q40_IRQ_FRAME_MASK,Q40_IRQ_FRAME},
 170   {Q40_IRQ_KEYB_MASK,Q40_IRQ_KEYBOARD},
 171   {0,0}};
 172 #endif
 173 static struct IRQ_TABLE eirqs[] = {
 174   { .mask = Q40_IRQ3_MASK,      .irq = 3 },     /* ser 1 */
 175   { .mask = Q40_IRQ4_MASK,      .irq = 4 },     /* ser 2 */
 176   { .mask = Q40_IRQ14_MASK,     .irq = 14 },    /* IDE 1 */
 177   { .mask = Q40_IRQ15_MASK,     .irq = 15 },    /* IDE 2 */
 178   { .mask = Q40_IRQ6_MASK,      .irq = 6 },     /* floppy, handled elsewhere */
 179   { .mask = Q40_IRQ7_MASK,      .irq = 7 },     /* par */
 180   { .mask = Q40_IRQ5_MASK,      .irq = 5 },
 181   { .mask = Q40_IRQ10_MASK,     .irq = 10 },
 182   {0,0}
 183 };
 184
 185 /* complain only this many times about spurious ints : */
 186 static int ccleirq=60;    /* ISA dev IRQs*/
 187 /*static int cclirq=60;*/     /* internal */
 188
 189 /* FIXME: add shared ints,mask,unmask,probing.... */
 190
 191 #define IRQ_INPROGRESS 1
 192 /*static unsigned short saved_mask;*/
 193 //static int do_tint=0;
 194
 195 #define DEBUG_Q40INT
 196 /*#define IP_USE_DISABLE *//* would be nice, but crashes ???? */
 197
 198 static int mext_disabled=0;  /* ext irq disabled by master chip? */
 199 static int aliased_irq=0;  /* how many times inside handler ?*/
 200
 201
 202 /* got interrupt, dispatch to ISA or keyboard/timer IRQs */
 203 static void q40_irq_handler(unsigned int irq, struct pt_regs *fp)
 204 {
 205         unsigned mir, mer;
 206         int i;
 207
 208 //repeat:
 209         mir = master_inb(IIRQ_REG);
 210 #ifdef CONFIG_BLK_DEV_FD
 211         if ((mir & Q40_IRQ_EXT_MASK) &&
 212             (master_inb(EIRQ_REG) & Q40_IRQ6_MASK)) {
 213                 floppy_hardint();
 214                 return;
 215         }
 216 #endif
 217         switch (irq) {
 218         case 4:
 219         case 6:
 220                 __m68k_handle_int(Q40_IRQ_SAMPLE, fp);
 221                 return;
 222         }
 223         if (mir & Q40_IRQ_FRAME_MASK) {
 224                 __m68k_handle_int(Q40_IRQ_FRAME, fp);
 225                 master_outb(-1, FRAME_CLEAR_REG);
 226         }
 227         if ((mir & Q40_IRQ_SER_MASK) || (mir & Q40_IRQ_EXT_MASK)) {
 228                 mer = master_inb(EIRQ_REG);
 229                 for (i = 0; eirqs[i].mask; i++) {
 230                         if (mer & eirqs[i].mask) {
 231                                 irq = eirqs[i].irq;
 232 /*
 233  * There is a little mess wrt which IRQ really caused this irq request. The
 234  * main problem is that IIRQ_REG and EIRQ_REG reflect the state when they
 235  * are read - which is long after the request came in. In theory IRQs should
 236  * not just go away but they occasionally do
 237  */
 238                                 if (irq > 4 && irq <= 15 && mext_disabled) {
 239                                         /*aliased_irq++;*/
 240                                         goto iirq;
 241                                 }
 242                                 if (q40_state[irq] & IRQ_INPROGRESS) {
 243                                         /* some handlers do local_irq_enable() for irq latency reasons, */
 244                                         /* however reentering an active irq handler is not permitted */
 245 #ifdef IP_USE_DISABLE
 246                                         /* in theory this is the better way to do it because it still */
 247                                         /* lets through eg the serial irqs, unfortunately it crashes */
 248                                         disable_irq(irq);
 249                                         disabled = 1;
 250 #else
 251                                         /*printk("IRQ_INPROGRESS detected for irq %d, disabling - %s disabled\n",
 252                                                 irq, disabled ? "already" : "not yet"); */
 253                                         fp->sr = (((fp->sr) & (~0x700))+0x200);
 254                                         disabled = 1;
 255 #endif
 256                                         goto iirq;
 257                                 }
 258                                 q40_state[irq] |= IRQ_INPROGRESS;
 259                                 __m68k_handle_int(irq, fp);
 260                                 q40_state[irq] &= ~IRQ_INPROGRESS;
 261
 262                                 /* naively enable everything, if that fails than    */
 263                                 /* this function will be reentered immediately thus */
 264                                 /* getting another chance to disable the IRQ        */
 265
 266                                 if (disabled) {
 267 #ifdef IP_USE_DISABLE
 268                                         if (irq > 4) {
 269                                                 disabled = 0;
 270                                                 enable_irq(irq);
 271                                         }
 272 #else
 273                                         disabled = 0;
 274                                         /*printk("reenabling irq %d\n", irq); */
 275 #endif
 276                                 }
 277 // used to do 'goto repeat;' here, this delayed bh processing too long
 278                                 return;
 279                         }
 280                 }
 281                 if (mer && ccleirq > 0 && !aliased_irq) {
 282                         printk("ISA interrupt from unknown source? EIRQ_REG = %x\n",mer);
 283                         ccleirq--;
 284                 }
 285         }
 286  iirq:
 287         mir = master_inb(IIRQ_REG);
 288         /* should test whether keyboard irq is really enabled, doing it in defhand */
 289         if (mir & Q40_IRQ_KEYB_MASK)
 290                 __m68k_handle_int(Q40_IRQ_KEYBOARD, fp);
 291
 292         return;
 293 }
 294
 295 void q40_enable_irq(unsigned int irq)
 296 {
 297         if (irq >= 5 && irq <= 15) {
 298                 mext_disabled--;
 299                 if (mext_disabled > 0)
 300                         printk("q40_enable_irq : nested disable/enable\n");
 301                 if (mext_disabled == 0)
 302                         master_outb(1, EXT_ENABLE_REG);
 303         }
 304 }
 305
 306
 307 void q40_disable_irq(unsigned int irq)
 308 {
 309         /* disable ISA iqs : only do something if the driver has been
 310          * verified to be Q40 "compatible" - right now IDE, NE2K
 311          * Any driver should not attempt to sleep across disable_irq !!
 312          */
 313
 314         if (irq >= 5 && irq <= 15) {
 315                 master_outb(0, EXT_ENABLE_REG);
 316                 mext_disabled++;
 317                 if (mext_disabled > 1)
 318                         printk("disable_irq nesting count %d\n",mext_disabled);
 319         }
 320 }
 321
 322 unsigned long q40_probe_irq_on(void)
 323 {
 324         printk("irq probing not working - reconfigure the driver to avoid this\n");
 325         return -1;
 326 }
 327 int q40_probe_irq_off(unsigned long irqs)
 328 {
 329         return -1;
 330 }