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 "sysbus.h"
  26 #include "hw.h"
  27 //#include "pc.h"
  28 //#include "etraxfs.h"
  29
  30 #define D(x)
  31
  32 #define R_RW_MASK   0
  33 #define R_R_VECT    1
  34 #define R_R_MASKED_VECT 2
  35 #define R_R_NMI     3
  36 #define R_R_GURU    4
  37 #define R_MAX       5
  38
  39 struct etrax_pic
  40 {
  41     SysBusDevice busdev;
  42     uint32_t *interrupt_vector;
  43     qemu_irq parent_irq;
  44     qemu_irq parent_nmi;
  45     uint32_t regs[R_MAX];
  46 };
  47
  48 static void pic_update(struct etrax_pic *fs)
  49 {
  50     uint32_t vector = 0;
  51     int i;
  52
  53     fs->regs[R_R_MASKED_VECT] = fs->regs[R_R_VECT] & fs->regs[R_RW_MASK];
  54
  55     /* The ETRAX interrupt controller signals interrupts to teh core
  56        through an interrupt request wire and an irq vector bus. If
  57        multiple interrupts are simultaneously active it chooses vector
  58        0x30 and lets the sw choose the priorities.  */
  59     if (fs->regs[R_R_MASKED_VECT]) {
  60         uint32_t mv = fs->regs[R_R_MASKED_VECT];
  61         for (i = 0; i < 31; i++) {
  62             if (mv & 1) {
  63                 vector = 0x31 + i;
  64                 /* Check for multiple interrupts.  */
  65                 if (mv > 1)
  66                     vector = 0x30;
  67                 break;
  68             }
  69             mv >>= 1;
  70         }
  71     }
  72
  73     if (fs->interrupt_vector) {
  74         *fs->interrupt_vector = vector;
  75     }
  76     qemu_set_irq(fs->parent_irq, !!vector);
  77 }
  78
  79 static uint32_t pic_readl (void *opaque, target_phys_addr_t addr)
  80 {
  81     struct etrax_pic *fs = opaque;
  82     uint32_t rval;
  83
  84     rval = fs->regs[addr >> 2];
  85     D(printf("%s %x=%x\n", __func__, addr, rval));
  86     return rval;
  87 }
  88
  89 static void
  90 pic_writel (void *opaque, target_phys_addr_t addr, uint32_t value)
  91 {
  92     struct etrax_pic *fs = opaque;
  93     D(printf("%s addr=%x val=%x\n", __func__, addr, value));
  94
  95     if (addr == R_RW_MASK) {
  96         fs->regs[R_RW_MASK] = value;
  97         pic_update(fs);
  98     }
  99 }
 100
 101 static CPUReadMemoryFunc *pic_read[] = {
 102     NULL, NULL,
 103     &pic_readl,
 104 };
 105
 106 static CPUWriteMemoryFunc *pic_write[] = {
 107     NULL, NULL,
 108     &pic_writel,
 109 };
 110
 111 static void nmi_handler(void *opaque, int irq, int level)
 112 {
 113     struct etrax_pic *fs = (void *)opaque;
 114     uint32_t mask;
 115
 116     mask = 1 << irq;
 117     if (level)
 118         fs->regs[R_R_NMI] |= mask;
 119     else
 120         fs->regs[R_R_NMI] &= ~mask;
 121
 122     qemu_set_irq(fs->parent_nmi, !!fs->regs[R_R_NMI]);
 123 }
 124
 125 static void irq_handler(void *opaque, int irq, int level)
 126 {
 127     struct etrax_pic *fs = (void *)opaque;
 128
 129     if (irq >= 30)
 130         return nmi_handler(opaque, irq, level);
 131
 132     irq -= 1;
 133     fs->regs[R_R_VECT] &= ~(1 << irq);
 134     fs->regs[R_R_VECT] |= (!!level << irq);
 135     pic_update(fs);
 136 }
 137
 138 static void etraxfs_pic_init(SysBusDevice *dev)
 139 {
 140     struct etrax_pic *s = FROM_SYSBUS(typeof (*s), dev);
 141     int intr_vect_regs;
 142
 143     s->interrupt_vector = qdev_get_prop_ptr(&dev->qdev, "interrupt_vector");
 144     qdev_init_gpio_in(&dev->qdev, irq_handler, 32);
 145     sysbus_init_irq(dev, &s->parent_irq);
 146     sysbus_init_irq(dev, &s->parent_nmi);
 147
 148     intr_vect_regs = cpu_register_io_memory(0, pic_read, pic_write, s);
 149     sysbus_init_mmio(dev, R_MAX * 4, intr_vect_regs);
 150 }
 151
 152 static void etraxfs_pic_register(void)
 153 {
 154     sysbus_register_dev("etraxfs,pic", sizeof (struct etrax_pic),
 155                         etraxfs_pic_init);
 156 }
 157
 158 device_init(etraxfs_pic_register)