hw/rtc/aspeed_rtc.c

   1 /*
   2  * ASPEED Real Time Clock
   3  * Joel Stanley <joel@jms.id.au>
   4  *
   5  * Copyright 2019 IBM Corp
   6  * SPDX-License-Identifier: GPL-2.0-or-later
   7  */
   8
   9 #include "qemu/osdep.h"
  10 #include "hw/rtc/aspeed_rtc.h"
  11 #include "migration/vmstate.h"
  12 #include "qemu/log.h"
  13 #include "qemu/timer.h"
  14 #include "sysemu/rtc.h"
  15
  16 #include "trace.h"
  17
  18 #define COUNTER1        (0x00 / 4)
  19 #define COUNTER2        (0x04 / 4)
  20 #define ALARM           (0x08 / 4)
  21 #define CONTROL         (0x10 / 4)
  22 #define ALARM_STATUS    (0x14 / 4)
  23
  24 #define RTC_UNLOCKED    BIT(1)
  25 #define RTC_ENABLED     BIT(0)
  26
  27 static void aspeed_rtc_calc_offset(AspeedRtcState *rtc)
  28 {
  29     struct tm tm;
  30     uint32_t year, cent;
  31     uint32_t reg1 = rtc->reg[COUNTER1];
  32     uint32_t reg2 = rtc->reg[COUNTER2];
  33
  34     tm.tm_mday = (reg1 >> 24) & 0x1f;
  35     tm.tm_hour = (reg1 >> 16) & 0x1f;
  36     tm.tm_min = (reg1 >> 8) & 0x3f;
  37     tm.tm_sec = (reg1 >> 0) & 0x3f;
  38
  39     cent = (reg2 >> 16) & 0x1f;
  40     year = (reg2 >> 8) & 0x7f;
  41     tm.tm_mon = ((reg2 >>  0) & 0x0f) - 1;
  42     tm.tm_year = year + (cent * 100) - 1900;
  43
  44     rtc->offset = qemu_timedate_diff(&tm);
  45 }
  46
  47 static uint32_t aspeed_rtc_get_counter(AspeedRtcState *rtc, int r)
  48 {
  49     uint32_t year, cent;
  50     struct tm now;
  51
  52     qemu_get_timedate(&now, rtc->offset);
  53
  54     switch (r) {
  55     case COUNTER1:
  56         return (now.tm_mday << 24) | (now.tm_hour << 16) |
  57             (now.tm_min << 8) | now.tm_sec;
  58     case COUNTER2:
  59         cent = (now.tm_year + 1900) / 100;
  60         year = now.tm_year % 100;
  61         return ((cent & 0x1f) << 16) | ((year & 0x7f) << 8) |
  62             ((now.tm_mon + 1) & 0xf);
  63     default:
  64         g_assert_not_reached();
  65     }
  66 }
  67
  68 static uint64_t aspeed_rtc_read(void *opaque, hwaddr addr,
  69                                 unsigned size)
  70 {
  71     AspeedRtcState *rtc = opaque;
  72     uint64_t val;
  73     uint32_t r = addr >> 2;
  74
  75     switch (r) {
  76     case COUNTER1:
  77     case COUNTER2:
  78         if (rtc->reg[CONTROL] & RTC_ENABLED) {
  79             rtc->reg[r] = aspeed_rtc_get_counter(rtc, r);
  80         }
  81         /* fall through */
  82     case CONTROL:
  83         val = rtc->reg[r];
  84         break;
  85     case ALARM:
  86     case ALARM_STATUS:
  87     default:
  88         qemu_log_mask(LOG_UNIMP, "%s: 0x%" HWADDR_PRIx "\n", __func__, addr);
  89         return 0;
  90     }
  91
  92     trace_aspeed_rtc_read(addr, val);
  93
  94     return val;
  95 }
  96
  97 static void aspeed_rtc_write(void *opaque, hwaddr addr,
  98                              uint64_t val, unsigned size)
  99 {
 100     AspeedRtcState *rtc = opaque;
 101     uint32_t r = addr >> 2;
 102
 103     switch (r) {
 104     case COUNTER1:
 105     case COUNTER2:
 106         if (!(rtc->reg[CONTROL] & RTC_UNLOCKED)) {
 107             break;
 108         }
 109         /* fall through */
 110     case CONTROL:
 111         rtc->reg[r] = val;
 112         aspeed_rtc_calc_offset(rtc);
 113         break;
 114     case ALARM:
 115     case ALARM_STATUS:
 116     default:
 117         qemu_log_mask(LOG_UNIMP, "%s: 0x%" HWADDR_PRIx "\n", __func__, addr);
 118         break;
 119     }
 120     trace_aspeed_rtc_write(addr, val);
 121 }
 122
 123 static void aspeed_rtc_reset(DeviceState *d)
 124 {
 125     AspeedRtcState *rtc = ASPEED_RTC(d);
 126
 127     rtc->offset = 0;
 128     memset(rtc->reg, 0, sizeof(rtc->reg));
 129 }
 130
 131 static const MemoryRegionOps aspeed_rtc_ops = {
 132     .read = aspeed_rtc_read,
 133     .write = aspeed_rtc_write,
 134     .endianness = DEVICE_NATIVE_ENDIAN,
 135 };
 136
 137 static const VMStateDescription vmstate_aspeed_rtc = {
 138     .name = TYPE_ASPEED_RTC,
 139     .version_id = 2,
 140     .fields = (const VMStateField[]) {
 141         VMSTATE_UINT32_ARRAY(reg, AspeedRtcState, 0x18),
 142         VMSTATE_INT64(offset, AspeedRtcState),
 143         VMSTATE_END_OF_LIST()
 144     }
 145 };
 146
 147 static void aspeed_rtc_realize(DeviceState *dev, Error **errp)
 148 {
 149     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
 150     AspeedRtcState *s = ASPEED_RTC(dev);
 151
 152     sysbus_init_irq(sbd, &s->irq);
 153
 154     memory_region_init_io(&s->iomem, OBJECT(s), &aspeed_rtc_ops, s,
 155                           "aspeed-rtc", 0x18ULL);
 156     sysbus_init_mmio(sbd, &s->iomem);
 157 }
 158
 159 static void aspeed_rtc_class_init(ObjectClass *klass, void *data)
 160 {
 161     DeviceClass *dc = DEVICE_CLASS(klass);
 162
 163     dc->realize = aspeed_rtc_realize;
 164     dc->vmsd = &vmstate_aspeed_rtc;
 165     dc->reset = aspeed_rtc_reset;
 166 }
 167
 168 static const TypeInfo aspeed_rtc_info = {
 169     .name          = TYPE_ASPEED_RTC,
 170     .parent        = TYPE_SYS_BUS_DEVICE,
 171     .instance_size = sizeof(AspeedRtcState),
 172     .class_init    = aspeed_rtc_class_init,
 173 };
 174
 175 static void aspeed_rtc_register_types(void)
 176 {
 177     type_register_static(&aspeed_rtc_info);
 178 }
 179
 180 type_init(aspeed_rtc_register_types)