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 */
24
25 #ifndef HW_RTC_MC146818RTC_REGS_H
26 #define HW_RTC_MC146818RTC_REGS_H
27
28 #include "qemu/timer.h"
29 #include "qemu/host-utils.h"
30
31 #define RTC_SECONDS 0
32 #define RTC_SECONDS_ALARM 1
33 #define RTC_MINUTES 2
34 #define RTC_MINUTES_ALARM 3
35 #define RTC_HOURS 4
36 #define RTC_HOURS_ALARM 5
37 #define RTC_ALARM_DONT_CARE 0xC0
38
39 #define RTC_DAY_OF_WEEK 6
40 #define RTC_DAY_OF_MONTH 7
41 #define RTC_MONTH 8
42 #define RTC_YEAR 9
43
44 #define RTC_REG_A 10
45 #define RTC_REG_B 11
46 #define RTC_REG_C 12
47 #define RTC_REG_D 13
48
49 /* PC cmos mappings */
50 #define RTC_CENTURY 0x32
51 #define RTC_IBM_PS2_CENTURY_BYTE 0x37
52
53 #define REG_A_UIP 0x80
54
55 #define REG_B_SET 0x80
56 #define REG_B_PIE 0x40
57 #define REG_B_AIE 0x20
58 #define REG_B_UIE 0x10
59 #define REG_B_SQWE 0x08
60 #define REG_B_DM 0x04
61 #define REG_B_24H 0x02
62
63 #define REG_C_UF 0x10
64 #define REG_C_IRQF 0x80
65 #define REG_C_PF 0x40
66 #define REG_C_AF 0x20
67 #define REG_C_MASK 0x70
68
periodic_period_to_clock(int period_code)69 static inline uint32_t periodic_period_to_clock(int period_code)
70 {
71 if (!period_code) {
72 return 0;
73 }
74
75 if (period_code <= 2) {
76 period_code += 7;
77 }
78 /* period in 32 Khz cycles */
79 return 1 << (period_code - 1);
80 }
81
82 #define RTC_CLOCK_RATE 32768
83
periodic_clock_to_ns(int64_t clocks)84 static inline int64_t periodic_clock_to_ns(int64_t clocks)
85 {
86 return muldiv64(clocks, NANOSECONDS_PER_SECOND, RTC_CLOCK_RATE);
87 }
88
89 #endif
90