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 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
  56 static void q40_irq_shutdown(unsigned int irq)
  57 {
  58 }
  59
  60 static 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
  80 static int disabled;
  81
  82 void __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
 104 int ql_ticks;              /* 200Hz ticks since last jiffie */
 105 static int sound_ticks;
 106
 107 #define SVOL 45
 108
 109 void 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
 128 static irq_handler_t q40_timer_routine;
 129
 130 static 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
 145 void 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
 167 struct IRQ_TABLE{ unsigned mask; int irq ;};
 168 #if 0
 169 static 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
 174 static 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 : */
 187 static 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
 199 static int mext_disabled=0;  /* ext irq disabled by master chip? */
 200 static int aliased_irq=0;  /* how many times inside handler ?*/
 201
 202
 203 /* got interrupt, dispatch to ISA or keyboard/timer IRQs */
 204 static 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
 296 void 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
 308 void 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
 323 unsigned long q40_probe_irq_on(void)
 324 {
 325         printk("irq probing not working - reconfigure the driver to avoid this\n");
 326         return -1;
 327 }
 328 int q40_probe_irq_off(unsigned long irqs)
 329 {
 330         return -1;
 331 }