hw/mcf_intc.c

   1 /*
   2  * ColdFire Interrupt Controller emulation.
   3  *
   4  * Copyright (c) 2007 CodeSourcery.
   5  *
   6  * This code is licenced under the GPL
   7  */
   8 #include "hw.h"
   9 #include "mcf.h"
  10
  11 typedef struct {
  12     uint64_t ipr;
  13     uint64_t imr;
  14     uint64_t ifr;
  15     uint64_t enabled;
  16     uint8_t icr[64];
  17     CPUState *env;
  18     int active_vector;
  19 } mcf_intc_state;
  20
  21 static void mcf_intc_update(mcf_intc_state *s)
  22 {
  23     uint64_t active;
  24     int i;
  25     int best;
  26     int best_level;
  27
  28     active = (s->ipr | s->ifr) & s->enabled & ~s->imr;
  29     best_level = 0;
  30     best = 64;
  31     if (active) {
  32         for (i = 0; i < 64; i++) {
  33             if ((active & 1) != 0 && s->icr[i] >= best_level) {
  34                 best_level = s->icr[i];
  35                 best = i;
  36             }
  37             active >>= 1;
  38         }
  39     }
  40     s->active_vector = ((best == 64) ? 24 : (best + 64));
  41     m68k_set_irq_level(s->env, best_level, s->active_vector);
  42 }
  43
  44 static uint32_t mcf_intc_read(void *opaque, target_phys_addr_t addr)
  45 {
  46     int offset;
  47     mcf_intc_state *s = (mcf_intc_state *)opaque;
  48     offset = addr & 0xff;
  49     if (offset >= 0x40 && offset < 0x80) {
  50         return s->icr[offset - 0x40];
  51     }
  52     switch (offset) {
  53     case 0x00:
  54         return (uint32_t)(s->ipr >> 32);
  55     case 0x04:
  56         return (uint32_t)s->ipr;
  57     case 0x08:
  58         return (uint32_t)(s->imr >> 32);
  59     case 0x0c:
  60         return (uint32_t)s->imr;
  61     case 0x10:
  62         return (uint32_t)(s->ifr >> 32);
  63     case 0x14:
  64         return (uint32_t)s->ifr;
  65     case 0xe0: /* SWIACK.  */
  66         return s->active_vector;
  67     case 0xe1: case 0xe2: case 0xe3: case 0xe4:
  68     case 0xe5: case 0xe6: case 0xe7:
  69         /* LnIACK */
  70         hw_error("mcf_intc_read: LnIACK not implemented\n");
  71     default:
  72         return 0;
  73     }
  74 }
  75
  76 static void mcf_intc_write(void *opaque, target_phys_addr_t addr, uint32_t val)
  77 {
  78     int offset;
  79     mcf_intc_state *s = (mcf_intc_state *)opaque;
  80     offset = addr & 0xff;
  81     if (offset >= 0x40 && offset < 0x80) {
  82         int n = offset - 0x40;
  83         s->icr[n] = val;
  84         if (val == 0)
  85             s->enabled &= ~(1ull << n);
  86         else
  87             s->enabled |= (1ull << n);
  88         mcf_intc_update(s);
  89         return;
  90     }
  91     switch (offset) {
  92     case 0x00: case 0x04:
  93         /* Ignore IPR writes.  */
  94         return;
  95     case 0x08:
  96         s->imr = (s->imr & 0xffffffff) | ((uint64_t)val << 32);
  97         break;
  98     case 0x0c:
  99         s->imr = (s->imr & 0xffffffff00000000ull) | (uint32_t)val;
 100         break;
 101     default:
 102         hw_error("mcf_intc_write: Bad write offset %d\n", offset);
 103         break;
 104     }
 105     mcf_intc_update(s);
 106 }
 107
 108 static void mcf_intc_set_irq(void *opaque, int irq, int level)
 109 {
 110     mcf_intc_state *s = (mcf_intc_state *)opaque;
 111     if (irq >= 64)
 112         return;
 113     if (level)
 114         s->ipr |= 1ull << irq;
 115     else
 116         s->ipr &= ~(1ull << irq);
 117     mcf_intc_update(s);
 118 }
 119
 120 static void mcf_intc_reset(mcf_intc_state *s)
 121 {
 122     s->imr = ~0ull;
 123     s->ipr = 0;
 124     s->ifr = 0;
 125     s->enabled = 0;
 126     memset(s->icr, 0, 64);
 127     s->active_vector = 24;
 128 }
 129
 130 static CPUReadMemoryFunc * const mcf_intc_readfn[] = {
 131    mcf_intc_read,
 132    mcf_intc_read,
 133    mcf_intc_read
 134 };
 135
 136 static CPUWriteMemoryFunc * const mcf_intc_writefn[] = {
 137    mcf_intc_write,
 138    mcf_intc_write,
 139    mcf_intc_write
 140 };
 141
 142 qemu_irq *mcf_intc_init(target_phys_addr_t base, CPUState *env)
 143 {
 144     mcf_intc_state *s;
 145     int iomemtype;
 146
 147     s = qemu_mallocz(sizeof(mcf_intc_state));
 148     s->env = env;
 149     mcf_intc_reset(s);
 150
 151     iomemtype = cpu_register_io_memory(mcf_intc_readfn,
 152                                        mcf_intc_writefn, s,
 153                                        DEVICE_NATIVE_ENDIAN);
 154     cpu_register_physical_memory(base, 0x100, iomemtype);
 155
 156     return qemu_allocate_irqs(mcf_intc_set_irq, s, 64);
 157 }