hw/timer/puv3_ost.c

   1 /*
   2  * OSTimer device simulation in PKUnity SoC
   3  *
   4  * Copyright (C) 2010-2012 Guan Xuetao
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation, or any later version.
   9  * See the COPYING file in the top-level directory.
  10  */
  11 #include "qemu/osdep.h"
  12 #include "hw/sysbus.h"
  13 #include "hw/ptimer.h"
  14 #include "qemu/main-loop.h"
  15
  16 #undef DEBUG_PUV3
  17 #include "hw/unicore32/puv3.h"
  18
  19 #define TYPE_PUV3_OST "puv3_ost"
  20 #define PUV3_OST(obj) OBJECT_CHECK(PUV3OSTState, (obj), TYPE_PUV3_OST)
  21
  22 /* puv3 ostimer implementation. */
  23 typedef struct PUV3OSTState {
  24     SysBusDevice parent_obj;
  25
  26     MemoryRegion iomem;
  27     QEMUBH *bh;
  28     qemu_irq irq;
  29     ptimer_state *ptimer;
  30
  31     uint32_t reg_OSMR0;
  32     uint32_t reg_OSCR;
  33     uint32_t reg_OSSR;
  34     uint32_t reg_OIER;
  35 } PUV3OSTState;
  36
  37 static uint64_t puv3_ost_read(void *opaque, hwaddr offset,
  38         unsigned size)
  39 {
  40     PUV3OSTState *s = opaque;
  41     uint32_t ret = 0;
  42
  43     switch (offset) {
  44     case 0x10: /* Counter Register */
  45         ret = s->reg_OSMR0 - (uint32_t)ptimer_get_count(s->ptimer);
  46         break;
  47     case 0x14: /* Status Register */
  48         ret = s->reg_OSSR;
  49         break;
  50     case 0x1c: /* Interrupt Enable Register */
  51         ret = s->reg_OIER;
  52         break;
  53     default:
  54         DPRINTF("Bad offset %x\n", (int)offset);
  55     }
  56     DPRINTF("offset 0x%x, value 0x%x\n", offset, ret);
  57     return ret;
  58 }
  59
  60 static void puv3_ost_write(void *opaque, hwaddr offset,
  61         uint64_t value, unsigned size)
  62 {
  63     PUV3OSTState *s = opaque;
  64
  65     DPRINTF("offset 0x%x, value 0x%x\n", offset, value);
  66     switch (offset) {
  67     case 0x00: /* Match Register 0 */
  68         s->reg_OSMR0 = value;
  69         if (s->reg_OSMR0 > s->reg_OSCR) {
  70             ptimer_set_count(s->ptimer, s->reg_OSMR0 - s->reg_OSCR);
  71         } else {
  72             ptimer_set_count(s->ptimer, s->reg_OSMR0 +
  73                     (0xffffffff - s->reg_OSCR));
  74         }
  75         ptimer_run(s->ptimer, 2);
  76         break;
  77     case 0x14: /* Status Register */
  78         assert(value == 0);
  79         if (s->reg_OSSR) {
  80             s->reg_OSSR = value;
  81             qemu_irq_lower(s->irq);
  82         }
  83         break;
  84     case 0x1c: /* Interrupt Enable Register */
  85         s->reg_OIER = value;
  86         break;
  87     default:
  88         DPRINTF("Bad offset %x\n", (int)offset);
  89     }
  90 }
  91
  92 static const MemoryRegionOps puv3_ost_ops = {
  93     .read = puv3_ost_read,
  94     .write = puv3_ost_write,
  95     .impl = {
  96         .min_access_size = 4,
  97         .max_access_size = 4,
  98     },
  99     .endianness = DEVICE_NATIVE_ENDIAN,
 100 };
 101
 102 static void puv3_ost_tick(void *opaque)
 103 {
 104     PUV3OSTState *s = opaque;
 105
 106     DPRINTF("ost hit when ptimer counter from 0x%x to 0x%x!\n",
 107             s->reg_OSCR, s->reg_OSMR0);
 108
 109     s->reg_OSCR = s->reg_OSMR0;
 110     if (s->reg_OIER) {
 111         s->reg_OSSR = 1;
 112         qemu_irq_raise(s->irq);
 113     }
 114 }
 115
 116 static int puv3_ost_init(SysBusDevice *dev)
 117 {
 118     PUV3OSTState *s = PUV3_OST(dev);
 119
 120     s->reg_OIER = 0;
 121     s->reg_OSSR = 0;
 122     s->reg_OSMR0 = 0;
 123     s->reg_OSCR = 0;
 124
 125     sysbus_init_irq(dev, &s->irq);
 126
 127     s->bh = qemu_bh_new(puv3_ost_tick, s);
 128     s->ptimer = ptimer_init(s->bh, PTIMER_POLICY_DEFAULT);
 129     ptimer_set_freq(s->ptimer, 50 * 1000 * 1000);
 130
 131     memory_region_init_io(&s->iomem, OBJECT(s), &puv3_ost_ops, s, "puv3_ost",
 132             PUV3_REGS_OFFSET);
 133     sysbus_init_mmio(dev, &s->iomem);
 134
 135     return 0;
 136 }
 137
 138 static void puv3_ost_class_init(ObjectClass *klass, void *data)
 139 {
 140     SysBusDeviceClass *sdc = SYS_BUS_DEVICE_CLASS(klass);
 141
 142     sdc->init = puv3_ost_init;
 143 }
 144
 145 static const TypeInfo puv3_ost_info = {
 146     .name = TYPE_PUV3_OST,
 147     .parent = TYPE_SYS_BUS_DEVICE,
 148     .instance_size = sizeof(PUV3OSTState),
 149     .class_init = puv3_ost_class_init,
 150 };
 151
 152 static void puv3_ost_register_type(void)
 153 {
 154     type_register_static(&puv3_ost_info);
 155 }
 156
 157 type_init(puv3_ost_register_type)