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     void *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         /* hack alert: ptr property */
  75         *(uint32_t*)(fs->interrupt_vector) = vector;
  76     }
  77     qemu_set_irq(fs->parent_irq, !!vector);
  78 }
  79
  80 static uint32_t pic_readl (void *opaque, target_phys_addr_t addr)
  81 {
  82     struct etrax_pic *fs = opaque;
  83     uint32_t rval;
  84
  85     rval = fs->regs[addr >> 2];
  86     D(printf("%s %x=%x\n", __func__, addr, rval));
  87     return rval;
  88 }
  89
  90 static void
  91 pic_writel (void *opaque, target_phys_addr_t addr, uint32_t value)
  92 {
  93     struct etrax_pic *fs = opaque;
  94     D(printf("%s addr=%x val=%x\n", __func__, addr, value));
  95
  96     if (addr == R_RW_MASK) {
  97         fs->regs[R_RW_MASK] = value;
  98         pic_update(fs);
  99     }
 100 }
 101
 102 static CPUReadMemoryFunc * const pic_read[] = {
 103     NULL, NULL,
 104     &pic_readl,
 105 };
 106
 107 static CPUWriteMemoryFunc * const pic_write[] = {
 108     NULL, NULL,
 109     &pic_writel,
 110 };
 111
 112 static void nmi_handler(void *opaque, int irq, int level)
 113 {
 114     struct etrax_pic *fs = (void *)opaque;
 115     uint32_t mask;
 116
 117     mask = 1 << irq;
 118     if (level)
 119         fs->regs[R_R_NMI] |= mask;
 120     else
 121         fs->regs[R_R_NMI] &= ~mask;
 122
 123     qemu_set_irq(fs->parent_nmi, !!fs->regs[R_R_NMI]);
 124 }
 125
 126 static void irq_handler(void *opaque, int irq, int level)
 127 {
 128     struct etrax_pic *fs = (void *)opaque;
 129
 130     if (irq >= 30)
 131         return nmi_handler(opaque, irq, level);
 132
 133     irq -= 1;
 134     fs->regs[R_R_VECT] &= ~(1 << irq);
 135     fs->regs[R_R_VECT] |= (!!level << irq);
 136     pic_update(fs);
 137 }
 138
 139 static int etraxfs_pic_init(SysBusDevice *dev)
 140 {
 141     struct etrax_pic *s = FROM_SYSBUS(typeof (*s), dev);
 142     int intr_vect_regs;
 143
 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(pic_read, pic_write, s,
 149                                             DEVICE_NATIVE_ENDIAN);
 150     sysbus_init_mmio(dev, R_MAX * 4, intr_vect_regs);
 151     return 0;
 152 }
 153
 154 static SysBusDeviceInfo etraxfs_pic_info = {
 155     .init = etraxfs_pic_init,
 156     .qdev.name  = "etraxfs,pic",
 157     .qdev.size  = sizeof(struct etrax_pic),
 158     .qdev.props = (Property[]) {
 159         DEFINE_PROP_PTR("interrupt_vector", struct etrax_pic, interrupt_vector),
 160         DEFINE_PROP_END_OF_LIST(),
 161     }
 162 };
 163
 164 static void etraxfs_pic_register(void)
 165 {
 166     sysbus_register_withprop(&etraxfs_pic_info);
 167 }
 168
 169 device_init(etraxfs_pic_register)