x86: move cpu hotplug from pc to x86
[qemu.git] / hw / rtc / ds1338.c
1 /*
2 * MAXIM DS1338 I2C RTC+NVRAM
3 *
4 * Copyright (c) 2009 CodeSourcery.
5 * Written by Paul Brook
6 *
7 * This code is licensed under the GNU GPL v2.
8 *
9 * Contributions after 2012-01-13 are licensed under the terms of the
10 * GNU GPL, version 2 or (at your option) any later version.
11 */
12
13 #include "qemu/osdep.h"
14 #include "qemu-common.h"
15 #include "hw/i2c/i2c.h"
16 #include "migration/vmstate.h"
17 #include "qemu/bcd.h"
18 #include "qemu/module.h"
19 #include "qom/object.h"
20
21 /* Size of NVRAM including both the user-accessible area and the
22 * secondary register area.
23 */
24 #define NVRAM_SIZE 64
25
26 /* Flags definitions */
27 #define SECONDS_CH 0x80
28 #define HOURS_12 0x40
29 #define HOURS_PM 0x20
30 #define CTRL_OSF 0x20
31
32 #define TYPE_DS1338 "ds1338"
33 typedef struct DS1338State DS1338State;
34 DECLARE_INSTANCE_CHECKER(DS1338State, DS1338,
35 TYPE_DS1338)
36
37 struct DS1338State {
38 I2CSlave parent_obj;
39
40 int64_t offset;
41 uint8_t wday_offset;
42 uint8_t nvram[NVRAM_SIZE];
43 int32_t ptr;
44 bool addr_byte;
45 };
46
47 static const VMStateDescription vmstate_ds1338 = {
48 .name = "ds1338",
49 .version_id = 2,
50 .minimum_version_id = 1,
51 .fields = (VMStateField[]) {
52 VMSTATE_I2C_SLAVE(parent_obj, DS1338State),
53 VMSTATE_INT64(offset, DS1338State),
54 VMSTATE_UINT8_V(wday_offset, DS1338State, 2),
55 VMSTATE_UINT8_ARRAY(nvram, DS1338State, NVRAM_SIZE),
56 VMSTATE_INT32(ptr, DS1338State),
57 VMSTATE_BOOL(addr_byte, DS1338State),
58 VMSTATE_END_OF_LIST()
59 }
60 };
61
62 static void capture_current_time(DS1338State *s)
63 {
64 /* Capture the current time into the secondary registers
65 * which will be actually read by the data transfer operation.
66 */
67 struct tm now;
68 qemu_get_timedate(&now, s->offset);
69 s->nvram[0] = to_bcd(now.tm_sec);
70 s->nvram[1] = to_bcd(now.tm_min);
71 if (s->nvram[2] & HOURS_12) {
72 int tmp = now.tm_hour;
73 if (tmp % 12 == 0) {
74 tmp += 12;
75 }
76 if (tmp <= 12) {
77 s->nvram[2] = HOURS_12 | to_bcd(tmp);
78 } else {
79 s->nvram[2] = HOURS_12 | HOURS_PM | to_bcd(tmp - 12);
80 }
81 } else {
82 s->nvram[2] = to_bcd(now.tm_hour);
83 }
84 s->nvram[3] = (now.tm_wday + s->wday_offset) % 7 + 1;
85 s->nvram[4] = to_bcd(now.tm_mday);
86 s->nvram[5] = to_bcd(now.tm_mon + 1);
87 s->nvram[6] = to_bcd(now.tm_year - 100);
88 }
89
90 static void inc_regptr(DS1338State *s)
91 {
92 /* The register pointer wraps around after 0x3F; wraparound
93 * causes the current time/date to be retransferred into
94 * the secondary registers.
95 */
96 s->ptr = (s->ptr + 1) & (NVRAM_SIZE - 1);
97 if (!s->ptr) {
98 capture_current_time(s);
99 }
100 }
101
102 static int ds1338_event(I2CSlave *i2c, enum i2c_event event)
103 {
104 DS1338State *s = DS1338(i2c);
105
106 switch (event) {
107 case I2C_START_RECV:
108 /* In h/w, capture happens on any START condition, not just a
109 * START_RECV, but there is no need to actually capture on
110 * START_SEND, because the guest can't get at that data
111 * without going through a START_RECV which would overwrite it.
112 */
113 capture_current_time(s);
114 break;
115 case I2C_START_SEND:
116 s->addr_byte = true;
117 break;
118 default:
119 break;
120 }
121
122 return 0;
123 }
124
125 static uint8_t ds1338_recv(I2CSlave *i2c)
126 {
127 DS1338State *s = DS1338(i2c);
128 uint8_t res;
129
130 res = s->nvram[s->ptr];
131 inc_regptr(s);
132 return res;
133 }
134
135 static int ds1338_send(I2CSlave *i2c, uint8_t data)
136 {
137 DS1338State *s = DS1338(i2c);
138
139 if (s->addr_byte) {
140 s->ptr = data & (NVRAM_SIZE - 1);
141 s->addr_byte = false;
142 return 0;
143 }
144 if (s->ptr < 7) {
145 /* Time register. */
146 struct tm now;
147 qemu_get_timedate(&now, s->offset);
148 switch(s->ptr) {
149 case 0:
150 /* TODO: Implement CH (stop) bit. */
151 now.tm_sec = from_bcd(data & 0x7f);
152 break;
153 case 1:
154 now.tm_min = from_bcd(data & 0x7f);
155 break;
156 case 2:
157 if (data & HOURS_12) {
158 int tmp = from_bcd(data & (HOURS_PM - 1));
159 if (data & HOURS_PM) {
160 tmp += 12;
161 }
162 if (tmp % 12 == 0) {
163 tmp -= 12;
164 }
165 now.tm_hour = tmp;
166 } else {
167 now.tm_hour = from_bcd(data & (HOURS_12 - 1));
168 }
169 break;
170 case 3:
171 {
172 /* The day field is supposed to contain a value in
173 the range 1-7. Otherwise behavior is undefined.
174 */
175 int user_wday = (data & 7) - 1;
176 s->wday_offset = (user_wday - now.tm_wday + 7) % 7;
177 }
178 break;
179 case 4:
180 now.tm_mday = from_bcd(data & 0x3f);
181 break;
182 case 5:
183 now.tm_mon = from_bcd(data & 0x1f) - 1;
184 break;
185 case 6:
186 now.tm_year = from_bcd(data) + 100;
187 break;
188 }
189 s->offset = qemu_timedate_diff(&now);
190 } else if (s->ptr == 7) {
191 /* Control register. */
192
193 /* Ensure bits 2, 3 and 6 will read back as zero. */
194 data &= 0xB3;
195
196 /* Attempting to write the OSF flag to logic 1 leaves the
197 value unchanged. */
198 data = (data & ~CTRL_OSF) | (data & s->nvram[s->ptr] & CTRL_OSF);
199
200 s->nvram[s->ptr] = data;
201 } else {
202 s->nvram[s->ptr] = data;
203 }
204 inc_regptr(s);
205 return 0;
206 }
207
208 static void ds1338_reset(DeviceState *dev)
209 {
210 DS1338State *s = DS1338(dev);
211
212 /* The clock is running and synchronized with the host */
213 s->offset = 0;
214 s->wday_offset = 0;
215 memset(s->nvram, 0, NVRAM_SIZE);
216 s->ptr = 0;
217 s->addr_byte = false;
218 }
219
220 static void ds1338_class_init(ObjectClass *klass, void *data)
221 {
222 DeviceClass *dc = DEVICE_CLASS(klass);
223 I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
224
225 k->event = ds1338_event;
226 k->recv = ds1338_recv;
227 k->send = ds1338_send;
228 dc->reset = ds1338_reset;
229 dc->vmsd = &vmstate_ds1338;
230 }
231
232 static const TypeInfo ds1338_info = {
233 .name = TYPE_DS1338,
234 .parent = TYPE_I2C_SLAVE,
235 .instance_size = sizeof(DS1338State),
236 .class_init = ds1338_class_init,
237 };
238
239 static void ds1338_register_types(void)
240 {
241 type_register_static(&ds1338_info);
242 }
243
244 type_init(ds1338_register_types)