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13#include "qemu/osdep.h"
14#include "qemu-common.h"
15#include "hw/i2c/i2c.h"
16#include "qemu/bcd.h"
17
18
19
20
21#define NVRAM_SIZE 64
22
23
24#define SECONDS_CH 0x80
25#define HOURS_12 0x40
26#define HOURS_PM 0x20
27#define CTRL_OSF 0x20
28
29#define TYPE_DS1338 "ds1338"
30#define DS1338(obj) OBJECT_CHECK(DS1338State, (obj), TYPE_DS1338)
31
32typedef struct DS1338State {
33 I2CSlave parent_obj;
34
35 int64_t offset;
36 uint8_t wday_offset;
37 uint8_t nvram[NVRAM_SIZE];
38 int32_t ptr;
39 bool addr_byte;
40} DS1338State;
41
42static const VMStateDescription vmstate_ds1338 = {
43 .name = "ds1338",
44 .version_id = 2,
45 .minimum_version_id = 1,
46 .fields = (VMStateField[]) {
47 VMSTATE_I2C_SLAVE(parent_obj, DS1338State),
48 VMSTATE_INT64(offset, DS1338State),
49 VMSTATE_UINT8_V(wday_offset, DS1338State, 2),
50 VMSTATE_UINT8_ARRAY(nvram, DS1338State, NVRAM_SIZE),
51 VMSTATE_INT32(ptr, DS1338State),
52 VMSTATE_BOOL(addr_byte, DS1338State),
53 VMSTATE_END_OF_LIST()
54 }
55};
56
57static void capture_current_time(DS1338State *s)
58{
59
60
61
62 struct tm now;
63 qemu_get_timedate(&now, s->offset);
64 s->nvram[0] = to_bcd(now.tm_sec);
65 s->nvram[1] = to_bcd(now.tm_min);
66 if (s->nvram[2] & HOURS_12) {
67 int tmp = now.tm_hour;
68 if (tmp % 12 == 0) {
69 tmp += 12;
70 }
71 if (tmp <= 12) {
72 s->nvram[2] = HOURS_12 | to_bcd(tmp);
73 } else {
74 s->nvram[2] = HOURS_12 | HOURS_PM | to_bcd(tmp - 12);
75 }
76 } else {
77 s->nvram[2] = to_bcd(now.tm_hour);
78 }
79 s->nvram[3] = (now.tm_wday + s->wday_offset) % 7 + 1;
80 s->nvram[4] = to_bcd(now.tm_mday);
81 s->nvram[5] = to_bcd(now.tm_mon + 1);
82 s->nvram[6] = to_bcd(now.tm_year - 100);
83}
84
85static void inc_regptr(DS1338State *s)
86{
87
88
89
90
91 s->ptr = (s->ptr + 1) & (NVRAM_SIZE - 1);
92 if (!s->ptr) {
93 capture_current_time(s);
94 }
95}
96
97static int ds1338_event(I2CSlave *i2c, enum i2c_event event)
98{
99 DS1338State *s = DS1338(i2c);
100
101 switch (event) {
102 case I2C_START_RECV:
103
104
105
106
107
108 capture_current_time(s);
109 break;
110 case I2C_START_SEND:
111 s->addr_byte = true;
112 break;
113 default:
114 break;
115 }
116
117 return 0;
118}
119
120static int ds1338_recv(I2CSlave *i2c)
121{
122 DS1338State *s = DS1338(i2c);
123 uint8_t res;
124
125 res = s->nvram[s->ptr];
126 inc_regptr(s);
127 return res;
128}
129
130static int ds1338_send(I2CSlave *i2c, uint8_t data)
131{
132 DS1338State *s = DS1338(i2c);
133
134 if (s->addr_byte) {
135 s->ptr = data & (NVRAM_SIZE - 1);
136 s->addr_byte = false;
137 return 0;
138 }
139 if (s->ptr < 7) {
140
141 struct tm now;
142 qemu_get_timedate(&now, s->offset);
143 switch(s->ptr) {
144 case 0:
145
146 now.tm_sec = from_bcd(data & 0x7f);
147 break;
148 case 1:
149 now.tm_min = from_bcd(data & 0x7f);
150 break;
151 case 2:
152 if (data & HOURS_12) {
153 int tmp = from_bcd(data & (HOURS_PM - 1));
154 if (data & HOURS_PM) {
155 tmp += 12;
156 }
157 if (tmp % 12 == 0) {
158 tmp -= 12;
159 }
160 now.tm_hour = tmp;
161 } else {
162 now.tm_hour = from_bcd(data & (HOURS_12 - 1));
163 }
164 break;
165 case 3:
166 {
167
168
169
170 int user_wday = (data & 7) - 1;
171 s->wday_offset = (user_wday - now.tm_wday + 7) % 7;
172 }
173 break;
174 case 4:
175 now.tm_mday = from_bcd(data & 0x3f);
176 break;
177 case 5:
178 now.tm_mon = from_bcd(data & 0x1f) - 1;
179 break;
180 case 6:
181 now.tm_year = from_bcd(data) + 100;
182 break;
183 }
184 s->offset = qemu_timedate_diff(&now);
185 } else if (s->ptr == 7) {
186
187
188
189 data &= 0xB3;
190
191
192
193 data = (data & ~CTRL_OSF) | (data & s->nvram[s->ptr] & CTRL_OSF);
194
195 s->nvram[s->ptr] = data;
196 } else {
197 s->nvram[s->ptr] = data;
198 }
199 inc_regptr(s);
200 return 0;
201}
202
203static void ds1338_reset(DeviceState *dev)
204{
205 DS1338State *s = DS1338(dev);
206
207
208 s->offset = 0;
209 s->wday_offset = 0;
210 memset(s->nvram, 0, NVRAM_SIZE);
211 s->ptr = 0;
212 s->addr_byte = false;
213}
214
215static void ds1338_class_init(ObjectClass *klass, void *data)
216{
217 DeviceClass *dc = DEVICE_CLASS(klass);
218 I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
219
220 k->event = ds1338_event;
221 k->recv = ds1338_recv;
222 k->send = ds1338_send;
223 dc->reset = ds1338_reset;
224 dc->vmsd = &vmstate_ds1338;
225}
226
227static const TypeInfo ds1338_info = {
228 .name = TYPE_DS1338,
229 .parent = TYPE_I2C_SLAVE,
230 .instance_size = sizeof(DS1338State),
231 .class_init = ds1338_class_init,
232};
233
234static void ds1338_register_types(void)
235{
236 type_register_static(&ds1338_info);
237}
238
239type_init(ds1338_register_types)
240