hw/intc/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 "qemu/osdep.h"
  26 #include "hw/sysbus.h"
  27 #include "hw/hw.h"
  28 //#include "pc.h"
  29 //#include "etraxfs.h"
  30
  31 #define D(x)
  32
  33 #define R_RW_MASK   0
  34 #define R_R_VECT    1
  35 #define R_R_MASKED_VECT 2
  36 #define R_R_NMI     3
  37 #define R_R_GURU    4
  38 #define R_MAX       5
  39
  40 #define TYPE_ETRAX_FS_PIC "etraxfs,pic"
  41 #define ETRAX_FS_PIC(obj) \
  42     OBJECT_CHECK(struct etrax_pic, (obj), TYPE_ETRAX_FS_PIC)
  43
  44 struct etrax_pic
  45 {
  46     SysBusDevice parent_obj;
  47
  48     MemoryRegion mmio;
  49     void *interrupt_vector;
  50     qemu_irq parent_irq;
  51     qemu_irq parent_nmi;
  52     uint32_t regs[R_MAX];
  53 };
  54
  55 static void pic_update(struct etrax_pic *fs)
  56 {
  57     uint32_t vector = 0;
  58     int i;
  59
  60     fs->regs[R_R_MASKED_VECT] = fs->regs[R_R_VECT] & fs->regs[R_RW_MASK];
  61
  62     /* The ETRAX interrupt controller signals interrupts to the core
  63        through an interrupt request wire and an irq vector bus. If
  64        multiple interrupts are simultaneously active it chooses vector
  65        0x30 and lets the sw choose the priorities.  */
  66     if (fs->regs[R_R_MASKED_VECT]) {
  67         uint32_t mv = fs->regs[R_R_MASKED_VECT];
  68         for (i = 0; i < 31; i++) {
  69             if (mv & 1) {
  70                 vector = 0x31 + i;
  71                 /* Check for multiple interrupts.  */
  72                 if (mv > 1)
  73                     vector = 0x30;
  74                 break;
  75             }
  76             mv >>= 1;
  77         }
  78     }
  79
  80     if (fs->interrupt_vector) {
  81         /* hack alert: ptr property */
  82         *(uint32_t*)(fs->interrupt_vector) = vector;
  83     }
  84     qemu_set_irq(fs->parent_irq, !!vector);
  85 }
  86
  87 static uint64_t
  88 pic_read(void *opaque, hwaddr addr, unsigned int size)
  89 {
  90     struct etrax_pic *fs = opaque;
  91     uint32_t rval;
  92
  93     rval = fs->regs[addr >> 2];
  94     D(printf("%s %x=%x\n", __func__, addr, rval));
  95     return rval;
  96 }
  97
  98 static void pic_write(void *opaque, hwaddr addr,
  99                       uint64_t value, unsigned int size)
 100 {
 101     struct etrax_pic *fs = opaque;
 102     D(printf("%s addr=%x val=%x\n", __func__, addr, value));
 103
 104     if (addr == R_RW_MASK) {
 105         fs->regs[R_RW_MASK] = value;
 106         pic_update(fs);
 107     }
 108 }
 109
 110 static const MemoryRegionOps pic_ops = {
 111     .read = pic_read,
 112     .write = pic_write,
 113     .endianness = DEVICE_NATIVE_ENDIAN,
 114     .valid = {
 115         .min_access_size = 4,
 116         .max_access_size = 4
 117     }
 118 };
 119
 120 static void nmi_handler(void *opaque, int irq, int level)
 121 {
 122     struct etrax_pic *fs = (void *)opaque;
 123     uint32_t mask;
 124
 125     mask = 1 << irq;
 126     if (level)
 127         fs->regs[R_R_NMI] |= mask;
 128     else
 129         fs->regs[R_R_NMI] &= ~mask;
 130
 131     qemu_set_irq(fs->parent_nmi, !!fs->regs[R_R_NMI]);
 132 }
 133
 134 static void irq_handler(void *opaque, int irq, int level)
 135 {
 136     struct etrax_pic *fs = (void *)opaque;
 137
 138     if (irq >= 30) {
 139         nmi_handler(opaque, irq, level);
 140         return;
 141     }
 142
 143     irq -= 1;
 144     fs->regs[R_R_VECT] &= ~(1 << irq);
 145     fs->regs[R_R_VECT] |= (!!level << irq);
 146     pic_update(fs);
 147 }
 148
 149 static void etraxfs_pic_init(Object *obj)
 150 {
 151     DeviceState *dev = DEVICE(obj);
 152     struct etrax_pic *s = ETRAX_FS_PIC(obj);
 153     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
 154
 155     qdev_init_gpio_in(dev, irq_handler, 32);
 156     sysbus_init_irq(sbd, &s->parent_irq);
 157     sysbus_init_irq(sbd, &s->parent_nmi);
 158
 159     memory_region_init_io(&s->mmio, obj, &pic_ops, s,
 160                           "etraxfs-pic", R_MAX * 4);
 161     sysbus_init_mmio(sbd, &s->mmio);
 162 }
 163
 164 static Property etraxfs_pic_properties[] = {
 165     DEFINE_PROP_PTR("interrupt_vector", struct etrax_pic, interrupt_vector),
 166     DEFINE_PROP_END_OF_LIST(),
 167 };
 168
 169 static void etraxfs_pic_class_init(ObjectClass *klass, void *data)
 170 {
 171     DeviceClass *dc = DEVICE_CLASS(klass);
 172
 173     dc->props = etraxfs_pic_properties;
 174     /*
 175      * Note: pointer property "interrupt_vector" may remain null, thus
 176      * no need for dc->cannot_instantiate_with_device_add_yet = true;
 177      */
 178 }
 179
 180 static const TypeInfo etraxfs_pic_info = {
 181     .name          = TYPE_ETRAX_FS_PIC,
 182     .parent        = TYPE_SYS_BUS_DEVICE,
 183     .instance_size = sizeof(struct etrax_pic),
 184     .instance_init = etraxfs_pic_init,
 185     .class_init    = etraxfs_pic_class_init,
 186 };
 187
 188 static void etraxfs_pic_register_types(void)
 189 {
 190     type_register_static(&etraxfs_pic_info);
 191 }
 192
 193 type_init(etraxfs_pic_register_types)