hw/heathrow_pic.c

   1 /*
   2  * Heathrow PIC support (standard PowerMac PIC)
   3  *
   4  * Copyright (c) 2005 Fabrice Bellard
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24 #include "vl.h"
  25
  26 //#define DEBUG
  27
  28 typedef struct HeathrowPIC {
  29     uint32_t events;
  30     uint32_t mask;
  31     uint32_t levels;
  32     uint32_t level_triggered;
  33 } HeathrowPIC;
  34
  35 struct HeathrowPICS {
  36     HeathrowPIC pics[2];
  37 };
  38
  39 static inline int check_irq(HeathrowPIC *pic)
  40 {
  41     return (pic->events | (pic->levels & pic->level_triggered)) & pic->mask;
  42 }
  43
  44 /* update the CPU irq state */
  45 static void heathrow_pic_update(HeathrowPICS *s)
  46 {
  47     if (check_irq(&s->pics[0]) || check_irq(&s->pics[1])) {
  48         cpu_interrupt(first_cpu, CPU_INTERRUPT_HARD);
  49     } else {
  50         cpu_reset_interrupt(first_cpu, CPU_INTERRUPT_HARD);
  51     }
  52 }
  53
  54 static void pic_writel (void *opaque, target_phys_addr_t addr, uint32_t value)
  55 {
  56     HeathrowPICS *s = opaque;
  57     HeathrowPIC *pic;
  58     unsigned int n;
  59
  60     value = bswap32(value);
  61 #ifdef DEBUG
  62     printf("pic_writel: %08x: %08x\n",
  63            addr, value);
  64 #endif
  65     n = ((addr & 0xfff) - 0x10) >> 4;
  66     if (n >= 2)
  67         return;
  68     pic = &s->pics[n];
  69     switch(addr & 0xf) {
  70     case 0x04:
  71         pic->mask = value;
  72         heathrow_pic_update(s);
  73         break;
  74     case 0x08:
  75         /* do not reset level triggered IRQs */
  76         value &= ~pic->level_triggered;
  77         pic->events &= ~value;
  78         heathrow_pic_update(s);
  79         break;
  80     default:
  81         break;
  82     }
  83 }
  84
  85 static uint32_t pic_readl (void *opaque, target_phys_addr_t addr)
  86 {
  87     HeathrowPICS *s = opaque;
  88     HeathrowPIC *pic;
  89     unsigned int n;
  90     uint32_t value;
  91
  92     n = ((addr & 0xfff) - 0x10) >> 4;
  93     if (n >= 2) {
  94         value = 0;
  95     } else {
  96         pic = &s->pics[n];
  97         switch(addr & 0xf) {
  98         case 0x0:
  99             value = pic->events;
 100             break;
 101         case 0x4:
 102             value = pic->mask;
 103             break;
 104         case 0xc:
 105             value = pic->levels;
 106             break;
 107         default:
 108             value = 0;
 109             break;
 110         }
 111     }
 112 #ifdef DEBUG
 113     printf("pic_readl: %08x: %08x\n",
 114            addr, value);
 115 #endif
 116     value = bswap32(value);
 117     return value;
 118 }
 119
 120 static CPUWriteMemoryFunc *pic_write[] = {
 121     &pic_writel,
 122     &pic_writel,
 123     &pic_writel,
 124 };
 125
 126 static CPUReadMemoryFunc *pic_read[] = {
 127     &pic_readl,
 128     &pic_readl,
 129     &pic_readl,
 130 };
 131
 132
 133 void heathrow_pic_set_irq(void *opaque, int num, int level)
 134 {
 135     HeathrowPICS *s = opaque;
 136     HeathrowPIC *pic;
 137     unsigned int irq_bit;
 138
 139 #if defined(DEBUG)
 140     {
 141         static int last_level[64];
 142         if (last_level[num] != level) {
 143             printf("set_irq: num=0x%02x level=%d\n", num, level);
 144             last_level[num] = level;
 145         }
 146     }
 147 #endif
 148     pic = &s->pics[1 - (num >> 5)];
 149     irq_bit = 1 << (num & 0x1f);
 150     if (level) {
 151         pic->events |= irq_bit & ~pic->level_triggered;
 152         pic->levels |= irq_bit;
 153     } else {
 154         pic->levels &= ~irq_bit;
 155     }
 156     heathrow_pic_update(s);
 157 }
 158
 159 HeathrowPICS *heathrow_pic_init(int *pmem_index)
 160 {
 161     HeathrowPICS *s;
 162
 163     s = qemu_mallocz(sizeof(HeathrowPICS));
 164     s->pics[0].level_triggered = 0;
 165     s->pics[1].level_triggered = 0x1ff00000;
 166     *pmem_index = cpu_register_io_memory(0, pic_read, pic_write, s);
 167     return s;
 168 }