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 "qemu-common.h"
11#include "hw/timer/aspeed_rtc.h"
12#include "migration/vmstate.h"
13#include "qemu/log.h"
14#include "qemu/timer.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
27static 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
47static 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
68static 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
97static 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
123static 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
131static const MemoryRegionOps aspeed_rtc_ops = {
132 .read = aspeed_rtc_read,
133 .write = aspeed_rtc_write,
134 .endianness = DEVICE_NATIVE_ENDIAN,
135};
136
137static const VMStateDescription vmstate_aspeed_rtc = {
138 .name = TYPE_ASPEED_RTC,
139 .version_id = 1,
140 .fields = (VMStateField[]) {
141 VMSTATE_UINT32_ARRAY(reg, AspeedRtcState, 0x18),
142 VMSTATE_INT32(offset, AspeedRtcState),
143 VMSTATE_INT32(offset, AspeedRtcState),
144 VMSTATE_END_OF_LIST()
145 }
146};
147
148static void aspeed_rtc_realize(DeviceState *dev, Error **errp)
149{
150 SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
151 AspeedRtcState *s = ASPEED_RTC(dev);
152
153 sysbus_init_irq(sbd, &s->irq);
154
155 memory_region_init_io(&s->iomem, OBJECT(s), &aspeed_rtc_ops, s,
156 "aspeed-rtc", 0x18ULL);
157 sysbus_init_mmio(sbd, &s->iomem);
158}
159
160static void aspeed_rtc_class_init(ObjectClass *klass, void *data)
161{
162 DeviceClass *dc = DEVICE_CLASS(klass);
163
164 dc->realize = aspeed_rtc_realize;
165 dc->vmsd = &vmstate_aspeed_rtc;
166 dc->reset = aspeed_rtc_reset;
167}
168
169static const TypeInfo aspeed_rtc_info = {
170 .name = TYPE_ASPEED_RTC,
171 .parent = TYPE_SYS_BUS_DEVICE,
172 .instance_size = sizeof(AspeedRtcState),
173 .class_init = aspeed_rtc_class_init,
174};
175
176static void aspeed_rtc_register_types(void)
177{
178 type_register_static(&aspeed_rtc_info);
179}
180
181type_init(aspeed_rtc_register_types)
182