hw/arm/syborg_rtc.c

   1 /*
   2  * Syborg RTC
   3  *
   4  * Copyright (c) 2008 CodeSourcery
   5  * Copyright (c) 2010, 2013 Stefan Weil
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a copy
   8  * of this software and associated documentation files (the "Software"), to deal
   9  * in the Software without restriction, including without limitation the rights
  10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11  * copies of the Software, and to permit persons to whom the Software is
  12  * furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included in
  15  * all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  23  * THE SOFTWARE.
  24  */
  25
  26 #include "hw/sysbus.h"
  27 #include "qemu/timer.h"
  28 #include "syborg.h"
  29
  30 enum {
  31     RTC_ID        = 0,
  32     RTC_LATCH     = 1,
  33     RTC_DATA_LOW  = 2,
  34     RTC_DATA_HIGH = 3
  35 };
  36
  37 typedef struct {
  38     SysBusDevice busdev;
  39     MemoryRegion iomem;
  40     int64_t offset;
  41     int64_t data;
  42     qemu_irq irq;
  43 } SyborgRTCState;
  44
  45 static uint64_t syborg_rtc_read(void *opaque, hwaddr offset,
  46                                 unsigned size)
  47 {
  48     SyborgRTCState *s = (SyborgRTCState *)opaque;
  49     offset &= 0xfff;
  50     switch (offset >> 2) {
  51     case RTC_ID:
  52         return SYBORG_ID_RTC;
  53     case RTC_DATA_LOW:
  54         return (uint32_t)s->data;
  55     case RTC_DATA_HIGH:
  56         return (uint32_t)(s->data >> 32);
  57     default:
  58         cpu_abort(cpu_single_env, "syborg_rtc_read: Bad offset %x\n",
  59                   (int)offset);
  60         return 0;
  61     }
  62 }
  63
  64 static void syborg_rtc_write(void *opaque, hwaddr offset,
  65                              uint64_t value, unsigned size)
  66 {
  67     SyborgRTCState *s = (SyborgRTCState *)opaque;
  68     uint64_t now;
  69
  70     offset &= 0xfff;
  71     switch (offset >> 2) {
  72     case RTC_LATCH:
  73         now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
  74         if (value >= 4) {
  75             s->offset = s->data - now;
  76         } else {
  77             s->data = now + s->offset;
  78             while (value) {
  79                 s->data /= 1000;
  80                 value--;
  81             }
  82         }
  83         break;
  84     case RTC_DATA_LOW:
  85         s->data = (s->data & ~(uint64_t)0xffffffffu) | value;
  86         break;
  87     case RTC_DATA_HIGH:
  88         s->data = (s->data & 0xffffffffu) | ((uint64_t)value << 32);
  89         break;
  90     default:
  91         cpu_abort(cpu_single_env, "syborg_rtc_write: Bad offset %x\n",
  92                   (int)offset);
  93         break;
  94     }
  95 }
  96
  97 static const MemoryRegionOps syborg_rtc_ops = {
  98     .read = syborg_rtc_read,
  99     .write = syborg_rtc_write,
 100     .endianness = DEVICE_NATIVE_ENDIAN,
 101 };
 102
 103 static const VMStateDescription vmstate_syborg_rtc = {
 104     .name = "syborg_keyboard",
 105     .version_id = 1,
 106     .minimum_version_id = 1,
 107     .minimum_version_id_old = 1,
 108     .fields      = (VMStateField[]) {
 109         VMSTATE_INT64(offset, SyborgRTCState),
 110         VMSTATE_INT64(data, SyborgRTCState),
 111         VMSTATE_END_OF_LIST()
 112     }
 113 };
 114
 115 static int syborg_rtc_init(SysBusDevice *sbd)
 116 {
 117     DeviceState *dev = DEVICE(sbd);
 118     SyborgRTCState *s = SYBORG_RTC(dev);
 119     struct tm tm;
 120
 121     memory_region_init_io(&s->iomem, &syborg_rtc_ops, s, "rtc", 0x1000);
 122     sysbus_init_mmio(sbd, &s->iomem);
 123
 124     qemu_get_timedate(&tm, 0);
 125     s->offset = (uint64_t)mktime(&tm) * 1000000000;
 126
 127     vmstate_register(&dev->qdev, -1, &vmstate_syborg_rtc, s);
 128     return 0;
 129 }
 130
 131 static void syborg_rtc_class_init(ObjectClass *klass, void *data)
 132 {
 133     DeviceClass *dc = DEVICE_CLASS(klass);
 134     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
 135     dc->desc = "syborg rtc";
 136     //~ dc->reset = syborg_rtc_reset;
 137     //~ dc->vmsd = &syborg_rtc_vmsd;
 138     k->init = syborg_rtc_init;
 139 }
 140
 141 static const TypeInfo syborg_rtc_info = {
 142     .name = "syborg,rtc",
 143     .parent = TYPE_SYS_BUS_DEVICE,
 144     .instance_size = sizeof(SyborgRTCState),
 145     .class_init = syborg_rtc_class_init
 146 };
 147
 148 static void syborg_rtc_register_types(void)
 149 {
 150     type_register_static(&syborg_rtc_info);
 151 }
 152
 153 type_init(syborg_rtc_register_types)