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
  36 static void q40_irq_handler(unsigned int, struct pt_regs *fp);
  37 static void q40_irq_enable(struct irq_data *data);
  38 static void q40_irq_disable(struct irq_data *data);
  39
  40 unsigned short q40_ablecount[35];
  41 unsigned short q40_state[35];
  42
  43 static 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
  57 static void q40_irq_shutdown(struct irq_data *data)
  58 {
  59 }
  60
  61 static 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
  80 static int disabled;
  81
  82 void __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
 105 int ql_ticks;              /* 200Hz ticks since last jiffie */
 106 static int sound_ticks;
 107
 108 #define SVOL 45
 109
 110 void 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
 129 static irq_handler_t q40_timer_routine;
 130
 131 static 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
 146 void 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
 168 struct IRQ_TABLE{ unsigned mask; int irq ;};
 169 #if 0
 170 static 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
 175 static 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 : */
 188 static 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
 200 static int mext_disabled=0;  /* ext irq disabled by master chip? */
 201 static int aliased_irq=0;  /* how many times inside handler ?*/
 202
 203
 204 /* got interrupt, dispatch to ISA or keyboard/timer IRQs */
 205 static 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
 297 void 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
 311 void 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 }