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80cabfad FB |
1 | /* |
2 | * QEMU MC146818 RTC emulation | |
3 | * | |
4 | * Copyright (c) 2003-2004 Fabrice Bellard | |
5 | * | |
6 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
7 | * of this software and associated documentation files (the "Software"), to deal | |
8 | * in the Software without restriction, including without limitation the rights | |
9 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
10 | * copies of the Software, and to permit persons to whom the Software is | |
11 | * furnished to do so, subject to the following conditions: | |
12 | * | |
13 | * The above copyright notice and this permission notice shall be included in | |
14 | * all copies or substantial portions of the Software. | |
15 | * | |
16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
17 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
19 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
20 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | |
21 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN | |
22 | * THE SOFTWARE. | |
23 | */ | |
80cabfad FB |
24 | #include "vl.h" |
25 | ||
26 | //#define DEBUG_CMOS | |
27 | ||
28 | #define RTC_SECONDS 0 | |
29 | #define RTC_SECONDS_ALARM 1 | |
30 | #define RTC_MINUTES 2 | |
31 | #define RTC_MINUTES_ALARM 3 | |
32 | #define RTC_HOURS 4 | |
33 | #define RTC_HOURS_ALARM 5 | |
34 | #define RTC_ALARM_DONT_CARE 0xC0 | |
35 | ||
36 | #define RTC_DAY_OF_WEEK 6 | |
37 | #define RTC_DAY_OF_MONTH 7 | |
38 | #define RTC_MONTH 8 | |
39 | #define RTC_YEAR 9 | |
40 | ||
41 | #define RTC_REG_A 10 | |
42 | #define RTC_REG_B 11 | |
43 | #define RTC_REG_C 12 | |
44 | #define RTC_REG_D 13 | |
45 | ||
dff38e7b | 46 | #define REG_A_UIP 0x80 |
80cabfad | 47 | |
dff38e7b FB |
48 | #define REG_B_SET 0x80 |
49 | #define REG_B_PIE 0x40 | |
50 | #define REG_B_AIE 0x20 | |
51 | #define REG_B_UIE 0x10 | |
52 | ||
53 | struct RTCState { | |
54 | uint8_t cmos_data[128]; | |
55 | uint8_t cmos_index; | |
43f493af | 56 | struct tm current_tm; |
dff38e7b | 57 | int irq; |
dff38e7b FB |
58 | /* periodic timer */ |
59 | QEMUTimer *periodic_timer; | |
60 | int64_t next_periodic_time; | |
61 | /* second update */ | |
62 | int64_t next_second_time; | |
63 | QEMUTimer *second_timer; | |
64 | QEMUTimer *second_timer2; | |
65 | }; | |
66 | ||
67 | static void rtc_set_time(RTCState *s); | |
dff38e7b FB |
68 | static void rtc_copy_date(RTCState *s); |
69 | ||
70 | static void rtc_timer_update(RTCState *s, int64_t current_time) | |
71 | { | |
72 | int period_code, period; | |
73 | int64_t cur_clock, next_irq_clock; | |
74 | ||
75 | period_code = s->cmos_data[RTC_REG_A] & 0x0f; | |
76 | if (period_code != 0 && | |
77 | (s->cmos_data[RTC_REG_B] & REG_B_PIE)) { | |
78 | if (period_code <= 2) | |
79 | period_code += 7; | |
80 | /* period in 32 Khz cycles */ | |
81 | period = 1 << (period_code - 1); | |
82 | /* compute 32 khz clock */ | |
83 | cur_clock = muldiv64(current_time, 32768, ticks_per_sec); | |
84 | next_irq_clock = (cur_clock & ~(period - 1)) + period; | |
85 | s->next_periodic_time = muldiv64(next_irq_clock, ticks_per_sec, 32768) + 1; | |
86 | qemu_mod_timer(s->periodic_timer, s->next_periodic_time); | |
87 | } else { | |
88 | qemu_del_timer(s->periodic_timer); | |
89 | } | |
90 | } | |
91 | ||
92 | static void rtc_periodic_timer(void *opaque) | |
93 | { | |
94 | RTCState *s = opaque; | |
95 | ||
96 | rtc_timer_update(s, s->next_periodic_time); | |
97 | s->cmos_data[RTC_REG_C] |= 0xc0; | |
98 | pic_set_irq(s->irq, 1); | |
99 | } | |
80cabfad | 100 | |
b41a2cd1 | 101 | static void cmos_ioport_write(void *opaque, uint32_t addr, uint32_t data) |
80cabfad | 102 | { |
b41a2cd1 | 103 | RTCState *s = opaque; |
80cabfad FB |
104 | |
105 | if ((addr & 1) == 0) { | |
106 | s->cmos_index = data & 0x7f; | |
107 | } else { | |
108 | #ifdef DEBUG_CMOS | |
109 | printf("cmos: write index=0x%02x val=0x%02x\n", | |
110 | s->cmos_index, data); | |
111 | #endif | |
dff38e7b | 112 | switch(s->cmos_index) { |
80cabfad FB |
113 | case RTC_SECONDS_ALARM: |
114 | case RTC_MINUTES_ALARM: | |
115 | case RTC_HOURS_ALARM: | |
116 | /* XXX: not supported */ | |
117 | s->cmos_data[s->cmos_index] = data; | |
118 | break; | |
119 | case RTC_SECONDS: | |
120 | case RTC_MINUTES: | |
121 | case RTC_HOURS: | |
122 | case RTC_DAY_OF_WEEK: | |
123 | case RTC_DAY_OF_MONTH: | |
124 | case RTC_MONTH: | |
125 | case RTC_YEAR: | |
126 | s->cmos_data[s->cmos_index] = data; | |
dff38e7b FB |
127 | /* if in set mode, do not update the time */ |
128 | if (!(s->cmos_data[RTC_REG_B] & REG_B_SET)) { | |
129 | rtc_set_time(s); | |
130 | } | |
80cabfad FB |
131 | break; |
132 | case RTC_REG_A: | |
dff38e7b FB |
133 | /* UIP bit is read only */ |
134 | s->cmos_data[RTC_REG_A] = (data & ~REG_A_UIP) | | |
135 | (s->cmos_data[RTC_REG_A] & REG_A_UIP); | |
136 | rtc_timer_update(s, qemu_get_clock(vm_clock)); | |
137 | break; | |
80cabfad | 138 | case RTC_REG_B: |
dff38e7b FB |
139 | if (data & REG_B_SET) { |
140 | /* set mode: reset UIP mode */ | |
141 | s->cmos_data[RTC_REG_A] &= ~REG_A_UIP; | |
142 | data &= ~REG_B_UIE; | |
143 | } else { | |
144 | /* if disabling set mode, update the time */ | |
145 | if (s->cmos_data[RTC_REG_B] & REG_B_SET) { | |
146 | rtc_set_time(s); | |
147 | } | |
148 | } | |
149 | s->cmos_data[RTC_REG_B] = data; | |
150 | rtc_timer_update(s, qemu_get_clock(vm_clock)); | |
80cabfad FB |
151 | break; |
152 | case RTC_REG_C: | |
153 | case RTC_REG_D: | |
154 | /* cannot write to them */ | |
155 | break; | |
156 | default: | |
157 | s->cmos_data[s->cmos_index] = data; | |
158 | break; | |
159 | } | |
160 | } | |
161 | } | |
162 | ||
dff38e7b | 163 | static inline int to_bcd(RTCState *s, int a) |
80cabfad | 164 | { |
dff38e7b FB |
165 | if (s->cmos_data[RTC_REG_B] & 0x04) { |
166 | return a; | |
167 | } else { | |
168 | return ((a / 10) << 4) | (a % 10); | |
169 | } | |
80cabfad FB |
170 | } |
171 | ||
dff38e7b | 172 | static inline int from_bcd(RTCState *s, int a) |
80cabfad | 173 | { |
dff38e7b FB |
174 | if (s->cmos_data[RTC_REG_B] & 0x04) { |
175 | return a; | |
176 | } else { | |
177 | return ((a >> 4) * 10) + (a & 0x0f); | |
178 | } | |
179 | } | |
180 | ||
181 | static void rtc_set_time(RTCState *s) | |
182 | { | |
43f493af | 183 | struct tm *tm = &s->current_tm; |
dff38e7b FB |
184 | |
185 | tm->tm_sec = from_bcd(s, s->cmos_data[RTC_SECONDS]); | |
186 | tm->tm_min = from_bcd(s, s->cmos_data[RTC_MINUTES]); | |
43f493af FB |
187 | tm->tm_hour = from_bcd(s, s->cmos_data[RTC_HOURS] & 0x7f); |
188 | if (!(s->cmos_data[RTC_REG_B] & 0x02) && | |
189 | (s->cmos_data[RTC_HOURS] & 0x80)) { | |
190 | tm->tm_hour += 12; | |
191 | } | |
dff38e7b FB |
192 | tm->tm_wday = from_bcd(s, s->cmos_data[RTC_DAY_OF_WEEK]); |
193 | tm->tm_mday = from_bcd(s, s->cmos_data[RTC_DAY_OF_MONTH]); | |
194 | tm->tm_mon = from_bcd(s, s->cmos_data[RTC_MONTH]) - 1; | |
195 | tm->tm_year = from_bcd(s, s->cmos_data[RTC_YEAR]) + 100; | |
43f493af FB |
196 | } |
197 | ||
198 | static void rtc_copy_date(RTCState *s) | |
199 | { | |
200 | const struct tm *tm = &s->current_tm; | |
dff38e7b | 201 | |
43f493af FB |
202 | s->cmos_data[RTC_SECONDS] = to_bcd(s, tm->tm_sec); |
203 | s->cmos_data[RTC_MINUTES] = to_bcd(s, tm->tm_min); | |
204 | if (s->cmos_data[RTC_REG_B] & 0x02) { | |
205 | /* 24 hour format */ | |
206 | s->cmos_data[RTC_HOURS] = to_bcd(s, tm->tm_hour); | |
207 | } else { | |
208 | /* 12 hour format */ | |
209 | s->cmos_data[RTC_HOURS] = to_bcd(s, tm->tm_hour % 12); | |
210 | if (tm->tm_hour >= 12) | |
211 | s->cmos_data[RTC_HOURS] |= 0x80; | |
212 | } | |
213 | s->cmos_data[RTC_DAY_OF_WEEK] = to_bcd(s, tm->tm_wday); | |
214 | s->cmos_data[RTC_DAY_OF_MONTH] = to_bcd(s, tm->tm_mday); | |
215 | s->cmos_data[RTC_MONTH] = to_bcd(s, tm->tm_mon + 1); | |
216 | s->cmos_data[RTC_YEAR] = to_bcd(s, tm->tm_year % 100); | |
217 | } | |
218 | ||
219 | /* month is between 0 and 11. */ | |
220 | static int get_days_in_month(int month, int year) | |
221 | { | |
222 | static const int days_tab[12] = { | |
223 | 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 | |
224 | }; | |
225 | int d; | |
226 | if ((unsigned )month >= 12) | |
227 | return 31; | |
228 | d = days_tab[month]; | |
229 | if (month == 1) { | |
230 | if ((year % 4) == 0 && ((year % 100) != 0 || (year % 400) == 0)) | |
231 | d++; | |
232 | } | |
233 | return d; | |
234 | } | |
235 | ||
236 | /* update 'tm' to the next second */ | |
237 | static void rtc_next_second(struct tm *tm) | |
238 | { | |
239 | int days_in_month; | |
240 | ||
241 | tm->tm_sec++; | |
242 | if ((unsigned)tm->tm_sec >= 60) { | |
243 | tm->tm_sec = 0; | |
244 | tm->tm_min++; | |
245 | if ((unsigned)tm->tm_min >= 60) { | |
246 | tm->tm_min = 0; | |
247 | tm->tm_hour++; | |
248 | if ((unsigned)tm->tm_hour >= 24) { | |
249 | tm->tm_hour = 0; | |
250 | /* next day */ | |
251 | tm->tm_wday++; | |
252 | if ((unsigned)tm->tm_wday >= 7) | |
253 | tm->tm_wday = 0; | |
254 | days_in_month = get_days_in_month(tm->tm_mon, | |
255 | tm->tm_year + 1900); | |
256 | tm->tm_mday++; | |
257 | if (tm->tm_mday < 1) { | |
258 | tm->tm_mday = 1; | |
259 | } else if (tm->tm_mday > days_in_month) { | |
260 | tm->tm_mday = 1; | |
261 | tm->tm_mon++; | |
262 | if (tm->tm_mon >= 12) { | |
263 | tm->tm_mon = 0; | |
264 | tm->tm_year++; | |
265 | } | |
266 | } | |
267 | } | |
268 | } | |
269 | } | |
dff38e7b FB |
270 | } |
271 | ||
43f493af | 272 | |
dff38e7b FB |
273 | static void rtc_update_second(void *opaque) |
274 | { | |
275 | RTCState *s = opaque; | |
4721c457 | 276 | int64_t delay; |
dff38e7b FB |
277 | |
278 | /* if the oscillator is not in normal operation, we do not update */ | |
279 | if ((s->cmos_data[RTC_REG_A] & 0x70) != 0x20) { | |
280 | s->next_second_time += ticks_per_sec; | |
281 | qemu_mod_timer(s->second_timer, s->next_second_time); | |
282 | } else { | |
43f493af | 283 | rtc_next_second(&s->current_tm); |
dff38e7b FB |
284 | |
285 | if (!(s->cmos_data[RTC_REG_B] & REG_B_SET)) { | |
286 | /* update in progress bit */ | |
287 | s->cmos_data[RTC_REG_A] |= REG_A_UIP; | |
288 | } | |
4721c457 FB |
289 | /* should be 244 us = 8 / 32768 seconds, but currently the |
290 | timers do not have the necessary resolution. */ | |
291 | delay = (ticks_per_sec * 1) / 100; | |
292 | if (delay < 1) | |
293 | delay = 1; | |
dff38e7b | 294 | qemu_mod_timer(s->second_timer2, |
4721c457 | 295 | s->next_second_time + delay); |
dff38e7b FB |
296 | } |
297 | } | |
298 | ||
299 | static void rtc_update_second2(void *opaque) | |
300 | { | |
301 | RTCState *s = opaque; | |
dff38e7b FB |
302 | |
303 | if (!(s->cmos_data[RTC_REG_B] & REG_B_SET)) { | |
304 | rtc_copy_date(s); | |
305 | } | |
306 | ||
307 | /* check alarm */ | |
308 | if (s->cmos_data[RTC_REG_B] & REG_B_AIE) { | |
309 | if (((s->cmos_data[RTC_SECONDS_ALARM] & 0xc0) == 0xc0 || | |
43f493af | 310 | s->cmos_data[RTC_SECONDS_ALARM] == s->current_tm.tm_sec) && |
dff38e7b | 311 | ((s->cmos_data[RTC_MINUTES_ALARM] & 0xc0) == 0xc0 || |
43f493af | 312 | s->cmos_data[RTC_MINUTES_ALARM] == s->current_tm.tm_mon) && |
dff38e7b | 313 | ((s->cmos_data[RTC_HOURS_ALARM] & 0xc0) == 0xc0 || |
43f493af | 314 | s->cmos_data[RTC_HOURS_ALARM] == s->current_tm.tm_hour)) { |
dff38e7b FB |
315 | |
316 | s->cmos_data[RTC_REG_C] |= 0xa0; | |
317 | pic_set_irq(s->irq, 1); | |
318 | } | |
319 | } | |
320 | ||
321 | /* update ended interrupt */ | |
322 | if (s->cmos_data[RTC_REG_B] & REG_B_UIE) { | |
323 | s->cmos_data[RTC_REG_C] |= 0x90; | |
324 | pic_set_irq(s->irq, 1); | |
325 | } | |
326 | ||
327 | /* clear update in progress bit */ | |
328 | s->cmos_data[RTC_REG_A] &= ~REG_A_UIP; | |
329 | ||
330 | s->next_second_time += ticks_per_sec; | |
331 | qemu_mod_timer(s->second_timer, s->next_second_time); | |
80cabfad FB |
332 | } |
333 | ||
b41a2cd1 | 334 | static uint32_t cmos_ioport_read(void *opaque, uint32_t addr) |
80cabfad | 335 | { |
b41a2cd1 | 336 | RTCState *s = opaque; |
80cabfad FB |
337 | int ret; |
338 | if ((addr & 1) == 0) { | |
339 | return 0xff; | |
340 | } else { | |
341 | switch(s->cmos_index) { | |
342 | case RTC_SECONDS: | |
343 | case RTC_MINUTES: | |
344 | case RTC_HOURS: | |
345 | case RTC_DAY_OF_WEEK: | |
346 | case RTC_DAY_OF_MONTH: | |
347 | case RTC_MONTH: | |
348 | case RTC_YEAR: | |
80cabfad FB |
349 | ret = s->cmos_data[s->cmos_index]; |
350 | break; | |
351 | case RTC_REG_A: | |
352 | ret = s->cmos_data[s->cmos_index]; | |
80cabfad FB |
353 | break; |
354 | case RTC_REG_C: | |
355 | ret = s->cmos_data[s->cmos_index]; | |
356 | pic_set_irq(s->irq, 0); | |
357 | s->cmos_data[RTC_REG_C] = 0x00; | |
358 | break; | |
359 | default: | |
360 | ret = s->cmos_data[s->cmos_index]; | |
361 | break; | |
362 | } | |
363 | #ifdef DEBUG_CMOS | |
364 | printf("cmos: read index=0x%02x val=0x%02x\n", | |
365 | s->cmos_index, ret); | |
366 | #endif | |
367 | return ret; | |
368 | } | |
369 | } | |
370 | ||
dff38e7b FB |
371 | void rtc_set_memory(RTCState *s, int addr, int val) |
372 | { | |
373 | if (addr >= 0 && addr <= 127) | |
374 | s->cmos_data[addr] = val; | |
375 | } | |
376 | ||
377 | void rtc_set_date(RTCState *s, const struct tm *tm) | |
378 | { | |
43f493af | 379 | s->current_tm = *tm; |
dff38e7b FB |
380 | rtc_copy_date(s); |
381 | } | |
382 | ||
383 | static void rtc_save(QEMUFile *f, void *opaque) | |
384 | { | |
385 | RTCState *s = opaque; | |
386 | ||
387 | qemu_put_buffer(f, s->cmos_data, 128); | |
388 | qemu_put_8s(f, &s->cmos_index); | |
43f493af FB |
389 | |
390 | qemu_put_be32s(f, &s->current_tm.tm_sec); | |
391 | qemu_put_be32s(f, &s->current_tm.tm_min); | |
392 | qemu_put_be32s(f, &s->current_tm.tm_hour); | |
393 | qemu_put_be32s(f, &s->current_tm.tm_wday); | |
394 | qemu_put_be32s(f, &s->current_tm.tm_mday); | |
395 | qemu_put_be32s(f, &s->current_tm.tm_mon); | |
396 | qemu_put_be32s(f, &s->current_tm.tm_year); | |
dff38e7b FB |
397 | |
398 | qemu_put_timer(f, s->periodic_timer); | |
399 | qemu_put_be64s(f, &s->next_periodic_time); | |
400 | ||
401 | qemu_put_be64s(f, &s->next_second_time); | |
402 | qemu_put_timer(f, s->second_timer); | |
403 | qemu_put_timer(f, s->second_timer2); | |
80cabfad FB |
404 | } |
405 | ||
dff38e7b | 406 | static int rtc_load(QEMUFile *f, void *opaque, int version_id) |
80cabfad | 407 | { |
dff38e7b FB |
408 | RTCState *s = opaque; |
409 | ||
410 | if (version_id != 1) | |
411 | return -EINVAL; | |
80cabfad | 412 | |
dff38e7b FB |
413 | qemu_get_buffer(f, s->cmos_data, 128); |
414 | qemu_get_8s(f, &s->cmos_index); | |
43f493af FB |
415 | |
416 | qemu_get_be32s(f, &s->current_tm.tm_sec); | |
417 | qemu_get_be32s(f, &s->current_tm.tm_min); | |
418 | qemu_get_be32s(f, &s->current_tm.tm_hour); | |
419 | qemu_get_be32s(f, &s->current_tm.tm_wday); | |
420 | qemu_get_be32s(f, &s->current_tm.tm_mday); | |
421 | qemu_get_be32s(f, &s->current_tm.tm_mon); | |
422 | qemu_get_be32s(f, &s->current_tm.tm_year); | |
dff38e7b FB |
423 | |
424 | qemu_get_timer(f, s->periodic_timer); | |
425 | qemu_get_be64s(f, &s->next_periodic_time); | |
426 | ||
427 | qemu_get_be64s(f, &s->next_second_time); | |
428 | qemu_get_timer(f, s->second_timer); | |
429 | qemu_get_timer(f, s->second_timer2); | |
430 | return 0; | |
431 | } | |
432 | ||
433 | RTCState *rtc_init(int base, int irq) | |
434 | { | |
435 | RTCState *s; | |
436 | ||
437 | s = qemu_mallocz(sizeof(RTCState)); | |
438 | if (!s) | |
439 | return NULL; | |
80cabfad FB |
440 | |
441 | s->irq = irq; | |
442 | s->cmos_data[RTC_REG_A] = 0x26; | |
443 | s->cmos_data[RTC_REG_B] = 0x02; | |
444 | s->cmos_data[RTC_REG_C] = 0x00; | |
445 | s->cmos_data[RTC_REG_D] = 0x80; | |
446 | ||
dff38e7b FB |
447 | s->periodic_timer = qemu_new_timer(vm_clock, |
448 | rtc_periodic_timer, s); | |
449 | s->second_timer = qemu_new_timer(vm_clock, | |
450 | rtc_update_second, s); | |
451 | s->second_timer2 = qemu_new_timer(vm_clock, | |
452 | rtc_update_second2, s); | |
453 | ||
454 | s->next_second_time = qemu_get_clock(vm_clock) + (ticks_per_sec * 99) / 100; | |
455 | qemu_mod_timer(s->second_timer2, s->next_second_time); | |
456 | ||
b41a2cd1 FB |
457 | register_ioport_write(base, 2, 1, cmos_ioport_write, s); |
458 | register_ioport_read(base, 2, 1, cmos_ioport_read, s); | |
dff38e7b FB |
459 | |
460 | register_savevm("mc146818rtc", base, 1, rtc_save, rtc_load, s); | |
461 | return s; | |
80cabfad FB |
462 | } |
463 |