arch/m68k/68000/ints.c

   1 /*
   2  * ints.c - Generic interrupt controller support
   3  *
   4  * This file is subject to the terms and conditions of the GNU General Public
   5  * License.  See the file COPYING in the main directory of this archive
   6  * for more details.
   7  *
   8  * Copyright 1996 Roman Zippel
   9  * Copyright 1999 D. Jeff Dionne <jeff@rt-control.com>
  10  */
  11
  12 #include <linux/types.h>
  13 #include <linux/kernel.h>
  14 #include <linux/init.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/irq.h>
  17 #include <asm/traps.h>
  18 #include <asm/io.h>
  19 #include <asm/machdep.h>
  20
  21 #if defined(CONFIG_M68328)
  22 #include <asm/MC68328.h>
  23 #elif defined(CONFIG_M68EZ328)
  24 #include <asm/MC68EZ328.h>
  25 #elif defined(CONFIG_M68VZ328)
  26 #include <asm/MC68VZ328.h>
  27 #endif
  28
  29 /* assembler routines */
  30 asmlinkage void system_call(void);
  31 asmlinkage void buserr(void);
  32 asmlinkage void trap(void);
  33 asmlinkage void trap3(void);
  34 asmlinkage void trap4(void);
  35 asmlinkage void trap5(void);
  36 asmlinkage void trap6(void);
  37 asmlinkage void trap7(void);
  38 asmlinkage void trap8(void);
  39 asmlinkage void trap9(void);
  40 asmlinkage void trap10(void);
  41 asmlinkage void trap11(void);
  42 asmlinkage void trap12(void);
  43 asmlinkage void trap13(void);
  44 asmlinkage void trap14(void);
  45 asmlinkage void trap15(void);
  46 asmlinkage void trap33(void);
  47 asmlinkage void trap34(void);
  48 asmlinkage void trap35(void);
  49 asmlinkage void trap36(void);
  50 asmlinkage void trap37(void);
  51 asmlinkage void trap38(void);
  52 asmlinkage void trap39(void);
  53 asmlinkage void trap40(void);
  54 asmlinkage void trap41(void);
  55 asmlinkage void trap42(void);
  56 asmlinkage void trap43(void);
  57 asmlinkage void trap44(void);
  58 asmlinkage void trap45(void);
  59 asmlinkage void trap46(void);
  60 asmlinkage void trap47(void);
  61 asmlinkage irqreturn_t bad_interrupt(int, void *);
  62 asmlinkage irqreturn_t inthandler(void);
  63 asmlinkage irqreturn_t inthandler1(void);
  64 asmlinkage irqreturn_t inthandler2(void);
  65 asmlinkage irqreturn_t inthandler3(void);
  66 asmlinkage irqreturn_t inthandler4(void);
  67 asmlinkage irqreturn_t inthandler5(void);
  68 asmlinkage irqreturn_t inthandler6(void);
  69 asmlinkage irqreturn_t inthandler7(void);
  70
  71 /* The 68k family did not have a good way to determine the source
  72  * of interrupts until later in the family.  The EC000 core does
  73  * not provide the vector number on the stack, we vector everything
  74  * into one vector and look in the blasted mask register...
  75  * This code is designed to be fast, almost constant time, not clean!
  76  */
  77 void process_int(int vec, struct pt_regs *fp)
  78 {
  79         int irq;
  80         int mask;
  81
  82         unsigned long pend = ISR;
  83
  84         while (pend) {
  85                 if (pend & 0x0000ffff) {
  86                         if (pend & 0x000000ff) {
  87                                 if (pend & 0x0000000f) {
  88                                         mask = 0x00000001;
  89                                         irq = 0;
  90                                 } else {
  91                                         mask = 0x00000010;
  92                                         irq = 4;
  93                                 }
  94                         } else {
  95                                 if (pend & 0x00000f00) {
  96                                         mask = 0x00000100;
  97                                         irq = 8;
  98                                 } else {
  99                                         mask = 0x00001000;
 100                                         irq = 12;
 101                                 }
 102                         }
 103                 } else {
 104                         if (pend & 0x00ff0000) {
 105                                 if (pend & 0x000f0000) {
 106                                         mask = 0x00010000;
 107                                         irq = 16;
 108                                 } else {
 109                                         mask = 0x00100000;
 110                                         irq = 20;
 111                                 }
 112                         } else {
 113                                 if (pend & 0x0f000000) {
 114                                         mask = 0x01000000;
 115                                         irq = 24;
 116                                 } else {
 117                                         mask = 0x10000000;
 118                                         irq = 28;
 119                                 }
 120                         }
 121                 }
 122
 123                 while (! (mask & pend)) {
 124                         mask <<=1;
 125                         irq++;
 126                 }
 127
 128                 do_IRQ(irq, fp);
 129                 pend &= ~mask;
 130         }
 131 }
 132
 133 static void intc_irq_unmask(struct irq_data *d)
 134 {
 135         IMR &= ~(1 << d->irq);
 136 }
 137
 138 static void intc_irq_mask(struct irq_data *d)
 139 {
 140         IMR |= (1 << d->irq);
 141 }
 142
 143 static struct irq_chip intc_irq_chip = {
 144         .name           = "M68K-INTC",
 145         .irq_mask       = intc_irq_mask,
 146         .irq_unmask     = intc_irq_unmask,
 147 };
 148
 149 /*
 150  * This function should be called during kernel startup to initialize
 151  * the machine vector table.
 152  */
 153 void __init trap_init(void)
 154 {
 155         int i;
 156
 157         /* set up the vectors */
 158         for (i = 72; i < 256; ++i)
 159                 _ramvec[i] = (e_vector) bad_interrupt;
 160
 161         _ramvec[32] = system_call;
 162
 163         _ramvec[65] = (e_vector) inthandler1;
 164         _ramvec[66] = (e_vector) inthandler2;
 165         _ramvec[67] = (e_vector) inthandler3;
 166         _ramvec[68] = (e_vector) inthandler4;
 167         _ramvec[69] = (e_vector) inthandler5;
 168         _ramvec[70] = (e_vector) inthandler6;
 169         _ramvec[71] = (e_vector) inthandler7;
 170 }
 171
 172 void __init init_IRQ(void)
 173 {
 174         int i;
 175
 176         IVR = 0x40; /* Set DragonBall IVR (interrupt base) to 64 */
 177
 178         /* turn off all interrupts */
 179         IMR = ~0;
 180
 181         for (i = 0; (i < NR_IRQS); i++) {
 182                 irq_set_chip(i, &intc_irq_chip);
 183                 irq_set_handler(i, handle_level_irq);
 184         }
 185 }
 186