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1dfe3943 PB |
1 | /* |
2 | * MAXIM DS1338 I2C RTC+NVRAM | |
3 | * | |
4 | * Copyright (c) 2009 CodeSourcery. | |
5 | * Written by Paul Brook | |
6 | * | |
8e31bf38 | 7 | * This code is licensed under the GNU GPL v2. |
6b620ca3 PB |
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. | |
1dfe3943 PB |
11 | */ |
12 | ||
282bc81e | 13 | #include "qemu/osdep.h" |
4771d756 | 14 | #include "qemu-common.h" |
0d09e41a | 15 | #include "hw/i2c/i2c.h" |
1dfe3943 | 16 | |
ba4906a9 PM |
17 | /* Size of NVRAM including both the user-accessible area and the |
18 | * secondary register area. | |
19 | */ | |
20 | #define NVRAM_SIZE 64 | |
21 | ||
95c93615 AM |
22 | /* Flags definitions */ |
23 | #define SECONDS_CH 0x80 | |
24 | #define HOURS_12 0x40 | |
25 | #define HOURS_PM 0x20 | |
26 | #define CTRL_OSF 0x20 | |
27 | ||
59ab56b9 AF |
28 | #define TYPE_DS1338 "ds1338" |
29 | #define DS1338(obj) OBJECT_CHECK(DS1338State, (obj), TYPE_DS1338) | |
30 | ||
31 | typedef struct DS1338State { | |
32 | I2CSlave parent_obj; | |
33 | ||
f4741402 | 34 | int64_t offset; |
871edc5f | 35 | uint8_t wday_offset; |
ba4906a9 | 36 | uint8_t nvram[NVRAM_SIZE]; |
f4741402 PM |
37 | int32_t ptr; |
38 | bool addr_byte; | |
1dfe3943 PB |
39 | } DS1338State; |
40 | ||
f4741402 PM |
41 | static const VMStateDescription vmstate_ds1338 = { |
42 | .name = "ds1338", | |
871edc5f | 43 | .version_id = 2, |
f4741402 | 44 | .minimum_version_id = 1, |
f4741402 | 45 | .fields = (VMStateField[]) { |
59ab56b9 | 46 | VMSTATE_I2C_SLAVE(parent_obj, DS1338State), |
f4741402 | 47 | VMSTATE_INT64(offset, DS1338State), |
871edc5f | 48 | VMSTATE_UINT8_V(wday_offset, DS1338State, 2), |
f4741402 PM |
49 | VMSTATE_UINT8_ARRAY(nvram, DS1338State, NVRAM_SIZE), |
50 | VMSTATE_INT32(ptr, DS1338State), | |
51 | VMSTATE_BOOL(addr_byte, DS1338State), | |
52 | VMSTATE_END_OF_LIST() | |
53 | } | |
54 | }; | |
55 | ||
35b87a86 PM |
56 | static void capture_current_time(DS1338State *s) |
57 | { | |
58 | /* Capture the current time into the secondary registers | |
59 | * which will be actually read by the data transfer operation. | |
60 | */ | |
7f7fd0f2 PM |
61 | struct tm now; |
62 | qemu_get_timedate(&now, s->offset); | |
63 | s->nvram[0] = to_bcd(now.tm_sec); | |
64 | s->nvram[1] = to_bcd(now.tm_min); | |
59dda8e0 AM |
65 | if (s->nvram[2] & HOURS_12) { |
66 | int tmp = now.tm_hour; | |
5c78d6a8 AM |
67 | if (tmp % 12 == 0) { |
68 | tmp += 12; | |
59dda8e0 AM |
69 | } |
70 | if (tmp <= 12) { | |
71 | s->nvram[2] = HOURS_12 | to_bcd(tmp); | |
72 | } else { | |
73 | s->nvram[2] = HOURS_12 | HOURS_PM | to_bcd(tmp - 12); | |
35b87a86 PM |
74 | } |
75 | } else { | |
7f7fd0f2 | 76 | s->nvram[2] = to_bcd(now.tm_hour); |
35b87a86 | 77 | } |
871edc5f | 78 | s->nvram[3] = (now.tm_wday + s->wday_offset) % 7 + 1; |
7f7fd0f2 | 79 | s->nvram[4] = to_bcd(now.tm_mday); |
580f5c00 | 80 | s->nvram[5] = to_bcd(now.tm_mon + 1); |
7f7fd0f2 | 81 | s->nvram[6] = to_bcd(now.tm_year - 100); |
35b87a86 PM |
82 | } |
83 | ||
84 | static void inc_regptr(DS1338State *s) | |
85 | { | |
86 | /* The register pointer wraps around after 0x3F; wraparound | |
87 | * causes the current time/date to be retransferred into | |
88 | * the secondary registers. | |
89 | */ | |
90 | s->ptr = (s->ptr + 1) & (NVRAM_SIZE - 1); | |
91 | if (!s->ptr) { | |
92 | capture_current_time(s); | |
93 | } | |
94 | } | |
95 | ||
9e07bdf8 | 96 | static void ds1338_event(I2CSlave *i2c, enum i2c_event event) |
1dfe3943 | 97 | { |
59ab56b9 | 98 | DS1338State *s = DS1338(i2c); |
1dfe3943 PB |
99 | |
100 | switch (event) { | |
101 | case I2C_START_RECV: | |
35b87a86 PM |
102 | /* In h/w, capture happens on any START condition, not just a |
103 | * START_RECV, but there is no need to actually capture on | |
104 | * START_SEND, because the guest can't get at that data | |
105 | * without going through a START_RECV which would overwrite it. | |
106 | */ | |
107 | capture_current_time(s); | |
1dfe3943 PB |
108 | break; |
109 | case I2C_START_SEND: | |
f4741402 | 110 | s->addr_byte = true; |
1dfe3943 PB |
111 | break; |
112 | default: | |
113 | break; | |
114 | } | |
115 | } | |
116 | ||
9e07bdf8 | 117 | static int ds1338_recv(I2CSlave *i2c) |
1dfe3943 | 118 | { |
59ab56b9 | 119 | DS1338State *s = DS1338(i2c); |
1dfe3943 PB |
120 | uint8_t res; |
121 | ||
122 | res = s->nvram[s->ptr]; | |
35b87a86 | 123 | inc_regptr(s); |
1dfe3943 PB |
124 | return res; |
125 | } | |
126 | ||
9e07bdf8 | 127 | static int ds1338_send(I2CSlave *i2c, uint8_t data) |
1dfe3943 | 128 | { |
59ab56b9 AF |
129 | DS1338State *s = DS1338(i2c); |
130 | ||
1dfe3943 | 131 | if (s->addr_byte) { |
ba4906a9 | 132 | s->ptr = data & (NVRAM_SIZE - 1); |
f4741402 | 133 | s->addr_byte = false; |
1dfe3943 PB |
134 | return 0; |
135 | } | |
996e91f0 AM |
136 | if (s->ptr < 7) { |
137 | /* Time register. */ | |
7f7fd0f2 PM |
138 | struct tm now; |
139 | qemu_get_timedate(&now, s->offset); | |
ba4906a9 | 140 | switch(s->ptr) { |
1dfe3943 PB |
141 | case 0: |
142 | /* TODO: Implement CH (stop) bit. */ | |
7f7fd0f2 | 143 | now.tm_sec = from_bcd(data & 0x7f); |
1dfe3943 PB |
144 | break; |
145 | case 1: | |
7f7fd0f2 | 146 | now.tm_min = from_bcd(data & 0x7f); |
1dfe3943 PB |
147 | break; |
148 | case 2: | |
59dda8e0 AM |
149 | if (data & HOURS_12) { |
150 | int tmp = from_bcd(data & (HOURS_PM - 1)); | |
151 | if (data & HOURS_PM) { | |
152 | tmp += 12; | |
153 | } | |
5c78d6a8 AM |
154 | if (tmp % 12 == 0) { |
155 | tmp -= 12; | |
1dfe3943 | 156 | } |
59dda8e0 | 157 | now.tm_hour = tmp; |
1dfe3943 | 158 | } else { |
59dda8e0 | 159 | now.tm_hour = from_bcd(data & (HOURS_12 - 1)); |
1dfe3943 | 160 | } |
1dfe3943 PB |
161 | break; |
162 | case 3: | |
871edc5f AM |
163 | { |
164 | /* The day field is supposed to contain a value in | |
165 | the range 1-7. Otherwise behavior is undefined. | |
166 | */ | |
167 | int user_wday = (data & 7) - 1; | |
168 | s->wday_offset = (user_wday - now.tm_wday + 7) % 7; | |
169 | } | |
1dfe3943 PB |
170 | break; |
171 | case 4: | |
7f7fd0f2 | 172 | now.tm_mday = from_bcd(data & 0x3f); |
1dfe3943 PB |
173 | break; |
174 | case 5: | |
7f7fd0f2 | 175 | now.tm_mon = from_bcd(data & 0x1f) - 1; |
fbac6a7d | 176 | break; |
1dfe3943 | 177 | case 6: |
7f7fd0f2 | 178 | now.tm_year = from_bcd(data) + 100; |
1dfe3943 | 179 | break; |
1dfe3943 | 180 | } |
7f7fd0f2 | 181 | s->offset = qemu_timedate_diff(&now); |
996e91f0 AM |
182 | } else if (s->ptr == 7) { |
183 | /* Control register. */ | |
184 | ||
185 | /* Ensure bits 2, 3 and 6 will read back as zero. */ | |
186 | data &= 0xB3; | |
187 | ||
188 | /* Attempting to write the OSF flag to logic 1 leaves the | |
189 | value unchanged. */ | |
190 | data = (data & ~CTRL_OSF) | (data & s->nvram[s->ptr] & CTRL_OSF); | |
191 | ||
192 | s->nvram[s->ptr] = data; | |
ba4906a9 PM |
193 | } else { |
194 | s->nvram[s->ptr] = data; | |
1dfe3943 | 195 | } |
35b87a86 | 196 | inc_regptr(s); |
1dfe3943 PB |
197 | return 0; |
198 | } | |
199 | ||
9e07bdf8 | 200 | static int ds1338_init(I2CSlave *i2c) |
1dfe3943 PB |
201 | { |
202 | return 0; | |
203 | } | |
204 | ||
ed3d37d2 AM |
205 | static void ds1338_reset(DeviceState *dev) |
206 | { | |
59ab56b9 | 207 | DS1338State *s = DS1338(dev); |
ed3d37d2 AM |
208 | |
209 | /* The clock is running and synchronized with the host */ | |
210 | s->offset = 0; | |
871edc5f | 211 | s->wday_offset = 0; |
ed3d37d2 AM |
212 | memset(s->nvram, 0, NVRAM_SIZE); |
213 | s->ptr = 0; | |
214 | s->addr_byte = false; | |
215 | } | |
216 | ||
b5ea9327 AL |
217 | static void ds1338_class_init(ObjectClass *klass, void *data) |
218 | { | |
f4741402 | 219 | DeviceClass *dc = DEVICE_CLASS(klass); |
b5ea9327 AL |
220 | I2CSlaveClass *k = I2C_SLAVE_CLASS(klass); |
221 | ||
222 | k->init = ds1338_init; | |
223 | k->event = ds1338_event; | |
224 | k->recv = ds1338_recv; | |
225 | k->send = ds1338_send; | |
ed3d37d2 | 226 | dc->reset = ds1338_reset; |
f4741402 | 227 | dc->vmsd = &vmstate_ds1338; |
b5ea9327 AL |
228 | } |
229 | ||
8c43a6f0 | 230 | static const TypeInfo ds1338_info = { |
59ab56b9 | 231 | .name = TYPE_DS1338, |
39bffca2 AL |
232 | .parent = TYPE_I2C_SLAVE, |
233 | .instance_size = sizeof(DS1338State), | |
234 | .class_init = ds1338_class_init, | |
1dfe3943 PB |
235 | }; |
236 | ||
83f7d43a | 237 | static void ds1338_register_types(void) |
1dfe3943 | 238 | { |
39bffca2 | 239 | type_register_static(&ds1338_info); |
1dfe3943 PB |
240 | } |
241 | ||
83f7d43a | 242 | type_init(ds1338_register_types) |