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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" |
0d09e41a | 14 | #include "hw/i2c/i2c.h" |
d6454270 | 15 | #include "migration/vmstate.h" |
f348b6d1 | 16 | #include "qemu/bcd.h" |
0b8fa32f | 17 | #include "qemu/module.h" |
db1015e9 | 18 | #include "qom/object.h" |
2f93d8b0 | 19 | #include "sysemu/rtc.h" |
1dfe3943 | 20 | |
ba4906a9 PM |
21 | /* Size of NVRAM including both the user-accessible area and the |
22 | * secondary register area. | |
23 | */ | |
24 | #define NVRAM_SIZE 64 | |
25 | ||
95c93615 AM |
26 | /* Flags definitions */ |
27 | #define SECONDS_CH 0x80 | |
28 | #define HOURS_12 0x40 | |
29 | #define HOURS_PM 0x20 | |
30 | #define CTRL_OSF 0x20 | |
31 | ||
59ab56b9 | 32 | #define TYPE_DS1338 "ds1338" |
8063396b | 33 | OBJECT_DECLARE_SIMPLE_TYPE(DS1338State, DS1338) |
59ab56b9 | 34 | |
db1015e9 | 35 | struct DS1338State { |
59ab56b9 AF |
36 | I2CSlave parent_obj; |
37 | ||
f4741402 | 38 | int64_t offset; |
871edc5f | 39 | uint8_t wday_offset; |
ba4906a9 | 40 | uint8_t nvram[NVRAM_SIZE]; |
f4741402 PM |
41 | int32_t ptr; |
42 | bool addr_byte; | |
db1015e9 | 43 | }; |
1dfe3943 | 44 | |
f4741402 PM |
45 | static const VMStateDescription vmstate_ds1338 = { |
46 | .name = "ds1338", | |
871edc5f | 47 | .version_id = 2, |
f4741402 | 48 | .minimum_version_id = 1, |
f4741402 | 49 | .fields = (VMStateField[]) { |
59ab56b9 | 50 | VMSTATE_I2C_SLAVE(parent_obj, DS1338State), |
f4741402 | 51 | VMSTATE_INT64(offset, DS1338State), |
871edc5f | 52 | VMSTATE_UINT8_V(wday_offset, DS1338State, 2), |
f4741402 PM |
53 | VMSTATE_UINT8_ARRAY(nvram, DS1338State, NVRAM_SIZE), |
54 | VMSTATE_INT32(ptr, DS1338State), | |
55 | VMSTATE_BOOL(addr_byte, DS1338State), | |
56 | VMSTATE_END_OF_LIST() | |
57 | } | |
58 | }; | |
59 | ||
35b87a86 PM |
60 | static void capture_current_time(DS1338State *s) |
61 | { | |
62 | /* Capture the current time into the secondary registers | |
63 | * which will be actually read by the data transfer operation. | |
64 | */ | |
7f7fd0f2 PM |
65 | struct tm now; |
66 | qemu_get_timedate(&now, s->offset); | |
67 | s->nvram[0] = to_bcd(now.tm_sec); | |
68 | s->nvram[1] = to_bcd(now.tm_min); | |
59dda8e0 AM |
69 | if (s->nvram[2] & HOURS_12) { |
70 | int tmp = now.tm_hour; | |
5c78d6a8 AM |
71 | if (tmp % 12 == 0) { |
72 | tmp += 12; | |
59dda8e0 AM |
73 | } |
74 | if (tmp <= 12) { | |
75 | s->nvram[2] = HOURS_12 | to_bcd(tmp); | |
76 | } else { | |
77 | s->nvram[2] = HOURS_12 | HOURS_PM | to_bcd(tmp - 12); | |
35b87a86 PM |
78 | } |
79 | } else { | |
7f7fd0f2 | 80 | s->nvram[2] = to_bcd(now.tm_hour); |
35b87a86 | 81 | } |
871edc5f | 82 | s->nvram[3] = (now.tm_wday + s->wday_offset) % 7 + 1; |
7f7fd0f2 | 83 | s->nvram[4] = to_bcd(now.tm_mday); |
580f5c00 | 84 | s->nvram[5] = to_bcd(now.tm_mon + 1); |
7f7fd0f2 | 85 | s->nvram[6] = to_bcd(now.tm_year - 100); |
35b87a86 PM |
86 | } |
87 | ||
88 | static void inc_regptr(DS1338State *s) | |
89 | { | |
90 | /* The register pointer wraps around after 0x3F; wraparound | |
91 | * causes the current time/date to be retransferred into | |
92 | * the secondary registers. | |
93 | */ | |
94 | s->ptr = (s->ptr + 1) & (NVRAM_SIZE - 1); | |
95 | if (!s->ptr) { | |
96 | capture_current_time(s); | |
97 | } | |
98 | } | |
99 | ||
d307c28c | 100 | static int ds1338_event(I2CSlave *i2c, enum i2c_event event) |
1dfe3943 | 101 | { |
59ab56b9 | 102 | DS1338State *s = DS1338(i2c); |
1dfe3943 PB |
103 | |
104 | switch (event) { | |
105 | case I2C_START_RECV: | |
35b87a86 PM |
106 | /* In h/w, capture happens on any START condition, not just a |
107 | * START_RECV, but there is no need to actually capture on | |
108 | * START_SEND, because the guest can't get at that data | |
109 | * without going through a START_RECV which would overwrite it. | |
110 | */ | |
111 | capture_current_time(s); | |
1dfe3943 PB |
112 | break; |
113 | case I2C_START_SEND: | |
f4741402 | 114 | s->addr_byte = true; |
1dfe3943 PB |
115 | break; |
116 | default: | |
117 | break; | |
118 | } | |
d307c28c CM |
119 | |
120 | return 0; | |
1dfe3943 PB |
121 | } |
122 | ||
2ac4c5f4 | 123 | static uint8_t ds1338_recv(I2CSlave *i2c) |
1dfe3943 | 124 | { |
59ab56b9 | 125 | DS1338State *s = DS1338(i2c); |
1dfe3943 PB |
126 | uint8_t res; |
127 | ||
128 | res = s->nvram[s->ptr]; | |
35b87a86 | 129 | inc_regptr(s); |
1dfe3943 PB |
130 | return res; |
131 | } | |
132 | ||
9e07bdf8 | 133 | static int ds1338_send(I2CSlave *i2c, uint8_t data) |
1dfe3943 | 134 | { |
59ab56b9 AF |
135 | DS1338State *s = DS1338(i2c); |
136 | ||
1dfe3943 | 137 | if (s->addr_byte) { |
ba4906a9 | 138 | s->ptr = data & (NVRAM_SIZE - 1); |
f4741402 | 139 | s->addr_byte = false; |
1dfe3943 PB |
140 | return 0; |
141 | } | |
996e91f0 AM |
142 | if (s->ptr < 7) { |
143 | /* Time register. */ | |
7f7fd0f2 PM |
144 | struct tm now; |
145 | qemu_get_timedate(&now, s->offset); | |
ba4906a9 | 146 | switch(s->ptr) { |
1dfe3943 PB |
147 | case 0: |
148 | /* TODO: Implement CH (stop) bit. */ | |
7f7fd0f2 | 149 | now.tm_sec = from_bcd(data & 0x7f); |
1dfe3943 PB |
150 | break; |
151 | case 1: | |
7f7fd0f2 | 152 | now.tm_min = from_bcd(data & 0x7f); |
1dfe3943 PB |
153 | break; |
154 | case 2: | |
59dda8e0 AM |
155 | if (data & HOURS_12) { |
156 | int tmp = from_bcd(data & (HOURS_PM - 1)); | |
157 | if (data & HOURS_PM) { | |
158 | tmp += 12; | |
159 | } | |
5c78d6a8 AM |
160 | if (tmp % 12 == 0) { |
161 | tmp -= 12; | |
1dfe3943 | 162 | } |
59dda8e0 | 163 | now.tm_hour = tmp; |
1dfe3943 | 164 | } else { |
59dda8e0 | 165 | now.tm_hour = from_bcd(data & (HOURS_12 - 1)); |
1dfe3943 | 166 | } |
1dfe3943 PB |
167 | break; |
168 | case 3: | |
871edc5f AM |
169 | { |
170 | /* The day field is supposed to contain a value in | |
171 | the range 1-7. Otherwise behavior is undefined. | |
172 | */ | |
173 | int user_wday = (data & 7) - 1; | |
174 | s->wday_offset = (user_wday - now.tm_wday + 7) % 7; | |
175 | } | |
1dfe3943 PB |
176 | break; |
177 | case 4: | |
7f7fd0f2 | 178 | now.tm_mday = from_bcd(data & 0x3f); |
1dfe3943 PB |
179 | break; |
180 | case 5: | |
7f7fd0f2 | 181 | now.tm_mon = from_bcd(data & 0x1f) - 1; |
fbac6a7d | 182 | break; |
1dfe3943 | 183 | case 6: |
7f7fd0f2 | 184 | now.tm_year = from_bcd(data) + 100; |
1dfe3943 | 185 | break; |
1dfe3943 | 186 | } |
7f7fd0f2 | 187 | s->offset = qemu_timedate_diff(&now); |
996e91f0 AM |
188 | } else if (s->ptr == 7) { |
189 | /* Control register. */ | |
190 | ||
191 | /* Ensure bits 2, 3 and 6 will read back as zero. */ | |
192 | data &= 0xB3; | |
193 | ||
194 | /* Attempting to write the OSF flag to logic 1 leaves the | |
195 | value unchanged. */ | |
196 | data = (data & ~CTRL_OSF) | (data & s->nvram[s->ptr] & CTRL_OSF); | |
197 | ||
198 | s->nvram[s->ptr] = data; | |
ba4906a9 PM |
199 | } else { |
200 | s->nvram[s->ptr] = data; | |
1dfe3943 | 201 | } |
35b87a86 | 202 | inc_regptr(s); |
1dfe3943 PB |
203 | return 0; |
204 | } | |
205 | ||
ed3d37d2 AM |
206 | static void ds1338_reset(DeviceState *dev) |
207 | { | |
59ab56b9 | 208 | DS1338State *s = DS1338(dev); |
ed3d37d2 AM |
209 | |
210 | /* The clock is running and synchronized with the host */ | |
211 | s->offset = 0; | |
871edc5f | 212 | s->wday_offset = 0; |
ed3d37d2 AM |
213 | memset(s->nvram, 0, NVRAM_SIZE); |
214 | s->ptr = 0; | |
215 | s->addr_byte = false; | |
216 | } | |
217 | ||
b5ea9327 AL |
218 | static void ds1338_class_init(ObjectClass *klass, void *data) |
219 | { | |
f4741402 | 220 | DeviceClass *dc = DEVICE_CLASS(klass); |
b5ea9327 AL |
221 | I2CSlaveClass *k = I2C_SLAVE_CLASS(klass); |
222 | ||
b5ea9327 AL |
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) |