hw/etraxfs_pic.c

   1 /*
   2  * QEMU ETRAX Interrupt Controller.
   3  *
   4  * Copyright (c) 2008 Edgar E. Iglesias, Axis Communications AB.
   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
  25 #include <stdio.h>
  26 #include "hw.h"
  27
  28 #define D(x)
  29
  30 struct fs_pic_state_t
  31 {
  32         CPUState *env;
  33         target_phys_addr_t base;
  34
  35         uint32_t rw_mask;
  36         /* Active interrupt lines.  */
  37         uint32_t r_vect;
  38         /* Active lines, gated through the mask.  */
  39         uint32_t r_masked_vect;
  40         uint32_t r_nmi;
  41         uint32_t r_guru;
  42 };
  43
  44 static uint32_t pic_readb (void *opaque, target_phys_addr_t addr)
  45 {
  46         return 0;
  47 }
  48 static uint32_t pic_readw (void *opaque, target_phys_addr_t addr)
  49 {
  50         return 0;
  51 }
  52
  53 static uint32_t pic_readl (void *opaque, target_phys_addr_t addr)
  54 {
  55         struct fs_pic_state_t *fs = opaque;
  56         uint32_t rval;
  57
  58         /* Transform this to a relative addr.  */
  59         addr -= fs->base;
  60         switch (addr)
  61         {
  62                 case 0x0:
  63                         rval = fs->rw_mask;
  64                         break;
  65                 case 0x4:
  66                         rval = fs->r_vect;
  67                         break;
  68                 case 0x8:
  69                         rval = fs->r_masked_vect;
  70                         break;
  71                 case 0xc:
  72                         rval = fs->r_nmi;
  73                         break;
  74                 case 0x10:
  75                         rval = fs->r_guru;
  76                         break;
  77                 default:
  78                         cpu_abort(fs->env, "invalid PIC register.\n");
  79                         break;
  80
  81         }
  82         D(printf("%s %x=%x\n", __func__, addr, rval));
  83         return rval;
  84 }
  85
  86 static void
  87 pic_writeb (void *opaque, target_phys_addr_t addr, uint32_t value)
  88 {
  89 }
  90
  91 static void
  92 pic_writew (void *opaque, target_phys_addr_t addr, uint32_t value)
  93 {
  94 }
  95
  96 static void
  97 pic_writel (void *opaque, target_phys_addr_t addr, uint32_t value)
  98 {
  99         struct fs_pic_state_t *fs = opaque;
 100         D(printf("%s addr=%x val=%x\n", __func__, addr, value));
 101         /* Transform this to a relative addr.  */
 102         addr -= fs->base;
 103         switch (addr)
 104         {
 105                 case 0x0:
 106                         fs->rw_mask = value;
 107                         break;
 108                 case 0x4:
 109                         fs->r_vect = value;
 110                         break;
 111                 case 0x8:
 112                         fs->r_masked_vect = value;
 113                         break;
 114                 case 0xc:
 115                         fs->r_nmi = value;
 116                         break;
 117                 case 0x10:
 118                         fs->r_guru = value;
 119                         break;
 120                 default:
 121                         cpu_abort(fs->env, "invalid PIC register.\n");
 122                         break;
 123         }
 124 }
 125
 126 static CPUReadMemoryFunc *pic_read[] = {
 127         &pic_readb,
 128         &pic_readw,
 129         &pic_readl,
 130 };
 131
 132 static CPUWriteMemoryFunc *pic_write[] = {
 133         &pic_writeb,
 134         &pic_writew,
 135         &pic_writel,
 136 };
 137
 138 void pic_info(void)
 139 {
 140 }
 141
 142 void irq_info(void)
 143 {
 144 }
 145
 146 static void etraxfs_pic_handler(void *opaque, int irq, int level)
 147 {
 148         struct fs_pic_state_t *fs = (void *)opaque;
 149         CPUState *env = fs->env;
 150         int i;
 151         uint32_t vector = 0;
 152
 153         D(printf("%s irq=%d level=%d mask=%x v=%x mv=%x\n",
 154                  __func__, irq, level,
 155                  fs->rw_mask, fs->r_vect, fs->r_masked_vect));
 156
 157         fs->r_vect &= ~(1 << irq);
 158         fs->r_vect |= (!!level << irq);
 159         fs->r_masked_vect = fs->r_vect & fs->rw_mask;
 160
 161         /* The ETRAX interrupt controller signals interrupts to teh core
 162            through an interrupt request wire and an irq vector bus. If
 163            multiple interrupts are simultaneously active it chooses vector
 164            0x30 and lets the sw choose the priorities.  */
 165         if (fs->r_masked_vect) {
 166                 uint32_t mv = fs->r_masked_vect;
 167                 for (i = 0; i < 31; i++) {
 168                         if (mv & 1) {
 169                                 vector = 0x31 + i;
 170                                 /* Check for multiple interrupts.  */
 171                                 if (mv > 1)
 172                                         vector = 0x30;
 173                                 break;
 174                         }
 175                         mv >>= 1;
 176                 }
 177                 if (vector) {
 178                         env->interrupt_vector = vector;
 179                         D(printf("%s vector=%x\n", __func__, vector));
 180                         cpu_interrupt(env, CPU_INTERRUPT_HARD);
 181                 }
 182         } else {
 183                 env->interrupt_vector = 0;
 184                 cpu_reset_interrupt(env, CPU_INTERRUPT_HARD);
 185                 D(printf("%s reset irqs\n", __func__));
 186         }
 187 }
 188
 189 qemu_irq *etraxfs_pic_init(CPUState *env, target_phys_addr_t base)
 190 {
 191         struct fs_pic_state_t *fs;
 192         qemu_irq *pic;
 193         int intr_vect_regs;
 194
 195         fs = qemu_mallocz(sizeof *fs);
 196         if (!fs)
 197                 return NULL;
 198         fs->env = env;
 199
 200         pic = qemu_allocate_irqs(etraxfs_pic_handler, fs, 30);
 201
 202         intr_vect_regs = cpu_register_io_memory(0, pic_read, pic_write, fs);
 203         cpu_register_physical_memory(base, 0x14, intr_vect_regs);
 204         fs->base = base;
 205
 206         return pic;
 207 }