hw/syborg_timer.c

   1 /*
   2  * Syborg Interval Timer.
   3  *
   4  * Copyright (c) 2008 CodeSourcery
   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 "qemu-timer.h"
  27 #include "syborg.h"
  28
  29 //#define DEBUG_SYBORG_TIMER
  30
  31 #ifdef DEBUG_SYBORG_TIMER
  32 #define DPRINTF(fmt, ...) \
  33 do { printf("syborg_timer: " fmt , ##args); } while (0)
  34 #define BADF(fmt, ...) \
  35 do { fprintf(stderr, "syborg_timer: error: " fmt , ## __VA_ARGS__); \
  36     exit(1);} while (0)
  37 #else
  38 #define DPRINTF(fmt, ...) do {} while(0)
  39 #define BADF(fmt, ...) \
  40 do { fprintf(stderr, "syborg_timer: error: " fmt , ## __VA_ARGS__);} while (0)
  41 #endif
  42
  43 enum {
  44     TIMER_ID          = 0,
  45     TIMER_RUNNING     = 1,
  46     TIMER_ONESHOT     = 2,
  47     TIMER_LIMIT       = 3,
  48     TIMER_VALUE       = 4,
  49     TIMER_INT_ENABLE  = 5,
  50     TIMER_INT_STATUS  = 6,
  51     TIMER_FREQ        = 7
  52 };
  53
  54 typedef struct {
  55     SysBusDevice busdev;
  56     ptimer_state *timer;
  57     int running;
  58     int oneshot;
  59     uint32_t limit;
  60     uint32_t freq;
  61     uint32_t int_level;
  62     uint32_t int_enabled;
  63     qemu_irq irq;
  64 } SyborgTimerState;
  65
  66 static void syborg_timer_update(SyborgTimerState *s)
  67 {
  68     /* Update interrupt.  */
  69     if (s->int_level && s->int_enabled) {
  70         qemu_irq_raise(s->irq);
  71     } else {
  72         qemu_irq_lower(s->irq);
  73     }
  74 }
  75
  76 static void syborg_timer_tick(void *opaque)
  77 {
  78     SyborgTimerState *s = (SyborgTimerState *)opaque;
  79     //DPRINTF("Timer Tick\n");
  80     s->int_level = 1;
  81     if (s->oneshot)
  82         s->running = 0;
  83     syborg_timer_update(s);
  84 }
  85
  86 static uint32_t syborg_timer_read(void *opaque, target_phys_addr_t offset)
  87 {
  88     SyborgTimerState *s = (SyborgTimerState *)opaque;
  89
  90     DPRINTF("Reg read %d\n", (int)offset);
  91     offset &= 0xfff;
  92     switch (offset >> 2) {
  93     case TIMER_ID:
  94         return SYBORG_ID_TIMER;
  95     case TIMER_RUNNING:
  96         return s->running;
  97     case TIMER_ONESHOT:
  98         return s->oneshot;
  99     case TIMER_LIMIT:
 100         return s->limit;
 101     case TIMER_VALUE:
 102         return ptimer_get_count(s->timer);
 103     case TIMER_INT_ENABLE:
 104         return s->int_enabled;
 105     case TIMER_INT_STATUS:
 106         return s->int_level;
 107     case TIMER_FREQ:
 108         return s->freq;
 109     default:
 110         cpu_abort(cpu_single_env, "syborg_timer_read: Bad offset %x\n",
 111                   (int)offset);
 112         return 0;
 113     }
 114 }
 115
 116 static void syborg_timer_write(void *opaque, target_phys_addr_t offset,
 117                                uint32_t value)
 118 {
 119     SyborgTimerState *s = (SyborgTimerState *)opaque;
 120
 121     DPRINTF("Reg write %d\n", (int)offset);
 122     offset &= 0xfff;
 123     switch (offset >> 2) {
 124     case TIMER_RUNNING:
 125         if (value == s->running)
 126             break;
 127         s->running = value;
 128         if (value) {
 129             ptimer_run(s->timer, s->oneshot);
 130         } else {
 131             ptimer_stop(s->timer);
 132         }
 133         break;
 134     case TIMER_ONESHOT:
 135         if (s->running) {
 136             ptimer_stop(s->timer);
 137         }
 138         s->oneshot = value;
 139         if (s->running) {
 140             ptimer_run(s->timer, s->oneshot);
 141         }
 142         break;
 143     case TIMER_LIMIT:
 144         s->limit = value;
 145         ptimer_set_limit(s->timer, value, 1);
 146         break;
 147     case TIMER_VALUE:
 148         ptimer_set_count(s->timer, value);
 149         break;
 150     case TIMER_INT_ENABLE:
 151         s->int_enabled = value;
 152         syborg_timer_update(s);
 153         break;
 154     case TIMER_INT_STATUS:
 155         s->int_level &= ~value;
 156         syborg_timer_update(s);
 157         break;
 158     default:
 159         cpu_abort(cpu_single_env, "syborg_timer_write: Bad offset %x\n",
 160                   (int)offset);
 161         break;
 162     }
 163 }
 164
 165 static CPUReadMemoryFunc *syborg_timer_readfn[] = {
 166     syborg_timer_read,
 167     syborg_timer_read,
 168     syborg_timer_read
 169 };
 170
 171 static CPUWriteMemoryFunc *syborg_timer_writefn[] = {
 172     syborg_timer_write,
 173     syborg_timer_write,
 174     syborg_timer_write
 175 };
 176
 177 static void syborg_timer_save(QEMUFile *f, void *opaque)
 178 {
 179     SyborgTimerState *s = opaque;
 180
 181     qemu_put_be32(f, s->running);
 182     qemu_put_be32(f, s->oneshot);
 183     qemu_put_be32(f, s->limit);
 184     qemu_put_be32(f, s->int_level);
 185     qemu_put_be32(f, s->int_enabled);
 186     qemu_put_ptimer(f, s->timer);
 187 }
 188
 189 static int syborg_timer_load(QEMUFile *f, void *opaque, int version_id)
 190 {
 191     SyborgTimerState *s = opaque;
 192
 193     if (version_id != 1)
 194         return -EINVAL;
 195
 196     s->running = qemu_get_be32(f);
 197     s->oneshot = qemu_get_be32(f);
 198     s->limit = qemu_get_be32(f);
 199     s->int_level = qemu_get_be32(f);
 200     s->int_enabled = qemu_get_be32(f);
 201     qemu_get_ptimer(f, s->timer);
 202
 203     return 0;
 204 }
 205
 206 static void syborg_timer_init(SysBusDevice *dev)
 207 {
 208     SyborgTimerState *s = FROM_SYSBUS(SyborgTimerState, dev);
 209     QEMUBH *bh;
 210     int iomemtype;
 211
 212     s->freq = qdev_get_prop_int(&dev->qdev, "frequency", 0);
 213     if (s->freq == 0) {
 214         fprintf(stderr, "syborg_timer: Zero/unset frequency\n");
 215         exit(1);
 216     }
 217     sysbus_init_irq(dev, &s->irq);
 218     iomemtype = cpu_register_io_memory(0, syborg_timer_readfn,
 219                                        syborg_timer_writefn, s);
 220     sysbus_init_mmio(dev, 0x1000, iomemtype);
 221
 222     bh = qemu_bh_new(syborg_timer_tick, s);
 223     s->timer = ptimer_init(bh);
 224     ptimer_set_freq(s->timer, s->freq);
 225     register_savevm("syborg_timer", -1, 1,
 226                     syborg_timer_save, syborg_timer_load, s);
 227 }
 228
 229 static void syborg_timer_register_devices(void)
 230 {
 231     sysbus_register_dev("syborg,timer", sizeof(SyborgTimerState),
 232                         syborg_timer_init);
 233 }
 234
 235 device_init(syborg_timer_register_devices)