hw/lm32_pic.c

   1 /*
   2  *  LatticeMico32 CPU interrupt controller logic.
   3  *
   4  *  Copyright (c) 2010 Michael Walle <michael@walle.cc>
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <assert.h>
  21
  22 #include "hw.h"
  23 #include "pc.h"
  24 #include "monitor.h"
  25 #include "sysbus.h"
  26 #include "trace.h"
  27 #include "lm32_pic.h"
  28
  29 struct LM32PicState {
  30     SysBusDevice busdev;
  31     qemu_irq parent_irq;
  32     uint32_t im;        /* interrupt mask */
  33     uint32_t ip;        /* interrupt pending */
  34     uint32_t irq_state;
  35
  36     /* statistics */
  37     uint32_t stats_irq_count[32];
  38 };
  39 typedef struct LM32PicState LM32PicState;
  40
  41 static LM32PicState *pic;
  42 void pic_info(Monitor *mon)
  43 {
  44     if (pic == NULL) {
  45         return;
  46     }
  47
  48     monitor_printf(mon, "lm32-pic: im=%08x ip=%08x irq_state=%08x\n",
  49             pic->im, pic->ip, pic->irq_state);
  50 }
  51
  52 void irq_info(Monitor *mon)
  53 {
  54     int i;
  55     uint32_t count;
  56
  57     if (pic == NULL) {
  58         return;
  59     }
  60
  61     monitor_printf(mon, "IRQ statistics:\n");
  62     for (i = 0; i < 32; i++) {
  63         count = pic->stats_irq_count[i];
  64         if (count > 0) {
  65             monitor_printf(mon, "%2d: %u\n", i, count);
  66         }
  67     }
  68 }
  69
  70 static void update_irq(LM32PicState *s)
  71 {
  72     s->ip |= s->irq_state;
  73
  74     if (s->ip & s->im) {
  75         trace_lm32_pic_raise_irq();
  76         qemu_irq_raise(s->parent_irq);
  77     } else {
  78         trace_lm32_pic_lower_irq();
  79         qemu_irq_lower(s->parent_irq);
  80     }
  81 }
  82
  83 static void irq_handler(void *opaque, int irq, int level)
  84 {
  85     LM32PicState *s = opaque;
  86
  87     assert(irq < 32);
  88     trace_lm32_pic_interrupt(irq, level);
  89
  90     if (level) {
  91         s->irq_state |= (1 << irq);
  92         s->stats_irq_count[irq]++;
  93     } else {
  94         s->irq_state &= ~(1 << irq);
  95     }
  96
  97     update_irq(s);
  98 }
  99
 100 void lm32_pic_set_im(DeviceState *d, uint32_t im)
 101 {
 102     LM32PicState *s = container_of(d, LM32PicState, busdev.qdev);
 103
 104     trace_lm32_pic_set_im(im);
 105     s->im = im;
 106
 107     update_irq(s);
 108 }
 109
 110 void lm32_pic_set_ip(DeviceState *d, uint32_t ip)
 111 {
 112     LM32PicState *s = container_of(d, LM32PicState, busdev.qdev);
 113
 114     trace_lm32_pic_set_ip(ip);
 115
 116     /* ack interrupt */
 117     s->ip &= ~ip;
 118
 119     update_irq(s);
 120 }
 121
 122 uint32_t lm32_pic_get_im(DeviceState *d)
 123 {
 124     LM32PicState *s = container_of(d, LM32PicState, busdev.qdev);
 125
 126     trace_lm32_pic_get_im(s->im);
 127     return s->im;
 128 }
 129
 130 uint32_t lm32_pic_get_ip(DeviceState *d)
 131 {
 132     LM32PicState *s = container_of(d, LM32PicState, busdev.qdev);
 133
 134     trace_lm32_pic_get_ip(s->ip);
 135     return s->ip;
 136 }
 137
 138 static void pic_reset(DeviceState *d)
 139 {
 140     LM32PicState *s = container_of(d, LM32PicState, busdev.qdev);
 141     int i;
 142
 143     s->im = 0;
 144     s->ip = 0;
 145     s->irq_state = 0;
 146     for (i = 0; i < 32; i++) {
 147         s->stats_irq_count[i] = 0;
 148     }
 149 }
 150
 151 static int lm32_pic_init(SysBusDevice *dev)
 152 {
 153     LM32PicState *s = FROM_SYSBUS(typeof(*s), dev);
 154
 155     qdev_init_gpio_in(&dev->qdev, irq_handler, 32);
 156     sysbus_init_irq(dev, &s->parent_irq);
 157
 158     pic = s;
 159
 160     return 0;
 161 }
 162
 163 static const VMStateDescription vmstate_lm32_pic = {
 164     .name = "lm32-pic",
 165     .version_id = 1,
 166     .minimum_version_id = 1,
 167     .minimum_version_id_old = 1,
 168     .fields      = (VMStateField[]) {
 169         VMSTATE_UINT32(im, LM32PicState),
 170         VMSTATE_UINT32(ip, LM32PicState),
 171         VMSTATE_UINT32(irq_state, LM32PicState),
 172         VMSTATE_UINT32_ARRAY(stats_irq_count, LM32PicState, 32),
 173         VMSTATE_END_OF_LIST()
 174     }
 175 };
 176
 177 static SysBusDeviceInfo lm32_pic_info = {
 178     .init = lm32_pic_init,
 179     .qdev.name  = "lm32-pic",
 180     .qdev.size  = sizeof(LM32PicState),
 181     .qdev.vmsd  = &vmstate_lm32_pic,
 182     .qdev.reset = pic_reset,
 183 };
 184
 185 static void lm32_pic_register(void)
 186 {
 187     sysbus_register_withprop(&lm32_pic_info);
 188 }
 189
 190 device_init(lm32_pic_register)