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     MemoryRegion mmio;
  43     void *interrupt_vector;
  44     qemu_irq parent_irq;
  45     qemu_irq parent_nmi;
  46     uint32_t regs[R_MAX];
  47 };
  48
  49 static void pic_update(struct etrax_pic *fs)
  50 {
  51     uint32_t vector = 0;
  52     int i;
  53
  54     fs->regs[R_R_MASKED_VECT] = fs->regs[R_R_VECT] & fs->regs[R_RW_MASK];
  55
  56     /* The ETRAX interrupt controller signals interrupts to the core
  57        through an interrupt request wire and an irq vector bus. If
  58        multiple interrupts are simultaneously active it chooses vector
  59        0x30 and lets the sw choose the priorities.  */
  60     if (fs->regs[R_R_MASKED_VECT]) {
  61         uint32_t mv = fs->regs[R_R_MASKED_VECT];
  62         for (i = 0; i < 31; i++) {
  63             if (mv & 1) {
  64                 vector = 0x31 + i;
  65                 /* Check for multiple interrupts.  */
  66                 if (mv > 1)
  67                     vector = 0x30;
  68                 break;
  69             }
  70             mv >>= 1;
  71         }
  72     }
  73
  74     if (fs->interrupt_vector) {
  75         /* hack alert: ptr property */
  76         *(uint32_t*)(fs->interrupt_vector) = vector;
  77     }
  78     qemu_set_irq(fs->parent_irq, !!vector);
  79 }
  80
  81 static uint64_t
  82 pic_read(void *opaque, target_phys_addr_t addr, unsigned int size)
  83 {
  84     struct etrax_pic *fs = opaque;
  85     uint32_t rval;
  86
  87     rval = fs->regs[addr >> 2];
  88     D(printf("%s %x=%x\n", __func__, addr, rval));
  89     return rval;
  90 }
  91
  92 static void pic_write(void *opaque, target_phys_addr_t addr,
  93                       uint64_t value, unsigned int size)
  94 {
  95     struct etrax_pic *fs = opaque;
  96     D(printf("%s addr=%x val=%x\n", __func__, addr, value));
  97
  98     if (addr == R_RW_MASK) {
  99         fs->regs[R_RW_MASK] = value;
 100         pic_update(fs);
 101     }
 102 }
 103
 104 static const MemoryRegionOps pic_ops = {
 105     .read = pic_read,
 106     .write = pic_write,
 107     .endianness = DEVICE_NATIVE_ENDIAN,
 108     .valid = {
 109         .min_access_size = 4,
 110         .max_access_size = 4
 111     }
 112 };
 113
 114 static void nmi_handler(void *opaque, int irq, int level)
 115 {
 116     struct etrax_pic *fs = (void *)opaque;
 117     uint32_t mask;
 118
 119     mask = 1 << irq;
 120     if (level)
 121         fs->regs[R_R_NMI] |= mask;
 122     else
 123         fs->regs[R_R_NMI] &= ~mask;
 124
 125     qemu_set_irq(fs->parent_nmi, !!fs->regs[R_R_NMI]);
 126 }
 127
 128 static void irq_handler(void *opaque, int irq, int level)
 129 {
 130     struct etrax_pic *fs = (void *)opaque;
 131
 132     if (irq >= 30)
 133         return nmi_handler(opaque, irq, level);
 134
 135     irq -= 1;
 136     fs->regs[R_R_VECT] &= ~(1 << irq);
 137     fs->regs[R_R_VECT] |= (!!level << irq);
 138     pic_update(fs);
 139 }
 140
 141 static int etraxfs_pic_init(SysBusDevice *dev)
 142 {
 143     struct etrax_pic *s = FROM_SYSBUS(typeof (*s), dev);
 144
 145     qdev_init_gpio_in(&dev->qdev, irq_handler, 32);
 146     sysbus_init_irq(dev, &s->parent_irq);
 147     sysbus_init_irq(dev, &s->parent_nmi);
 148
 149     memory_region_init_io(&s->mmio, &pic_ops, s, "etraxfs-pic", R_MAX * 4);
 150     sysbus_init_mmio(dev, &s->mmio);
 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)