1 /* mc146818rtc.h - register definitions for the Real-Time-Clock / CMOS RAM
2 * Copyright Torsten Duwe <duwe@informatik.uni-erlangen.de> 1993
3 * derived from Data Sheet, Copyright Motorola 1984 (!).
4 * It was written to be part of the Linux operating system.
5 */
6 /* permission is hereby granted to copy, modify and redistribute this code
7 * in terms of the GNU Library General Public License, Version 2 or later,
8 * at your option.
9 */
10
11 #ifndef _MC146818RTC_H
12 #define _MC146818RTC_H
13 #include <asm/io.h>
14
15 #ifndef RTC_PORT
16 #define RTC_PORT(x) (0x70 + (x))
17 #define RTC_ADDR(x) (0x80 | (x))
18 #define RTC_ALWAYS_BCD 1
19 #endif
20
21 #define CMOS_READ(addr) ({ \
22 outb_p(RTC_ADDR(addr),RTC_PORT(0)); \
23 inb_p(RTC_PORT(1)); \
24 })
25 #define CMOS_WRITE(val, addr) ({ \
26 outb_p(RTC_ADDR(addr),RTC_PORT(0)); \
27 outb_p(val,RTC_PORT(1)); \
28 })
29
30 /**********************************************************************
31 * register summary
32 **********************************************************************/
33 #define RTC_SECONDS 0
34 #define RTC_SECONDS_ALARM 1
35 #define RTC_MINUTES 2
36 #define RTC_MINUTES_ALARM 3
37 #define RTC_HOURS 4
38 #define RTC_HOURS_ALARM 5
39 /* RTC_*_alarm is always true if 2 MSBs are set */
40 # define RTC_ALARM_DONT_CARE 0xC0
41
42 #define RTC_DAY_OF_WEEK 6
43 #define RTC_DAY_OF_MONTH 7
44 #define RTC_MONTH 8
45 #define RTC_YEAR 9
46
47 /* control registers - Moto names
48 */
49 #define RTC_REG_A 10
50 #define RTC_REG_B 11
51 #define RTC_REG_C 12
52 #define RTC_REG_D 13
53
54 /**********************************************************************
55 * register details
56 **********************************************************************/
57 #define RTC_FREQ_SELECT RTC_REG_A
58
59 /* update-in-progress - set to "1" 244 microsecs before RTC goes off the bus,
60 * reset after update (may take 1.984ms @ 32768Hz RefClock) is complete,
61 * totalling to a max high interval of 2.228 ms.
62 */
63 # define RTC_UIP 0x80
64 # define RTC_DIV_CTL 0x70
65 /* divider control: refclock values 4.194 / 1.049 MHz / 32.768 kHz */
66 # define RTC_REF_CLCK_4MHZ 0x00
67 # define RTC_REF_CLCK_1MHZ 0x10
68 # define RTC_REF_CLCK_32KHZ 0x20
69 /* 2 values for divider stage reset, others for "testing purposes only" */
70 # define RTC_DIV_RESET1 0x60
71 # define RTC_DIV_RESET2 0x70
72 /* Periodic intr. / Square wave rate select. 0=none, 1=32.8kHz,... 15=2Hz */
73 # define RTC_RATE_SELECT 0x0F
74
75 /**********************************************************************/
76 #define RTC_CONTROL RTC_REG_B
77 # define RTC_SET 0x80 /* disable updates for clock setting */
78 # define RTC_PIE 0x40 /* periodic interrupt enable */
79 # define RTC_AIE 0x20 /* alarm interrupt enable */
80 # define RTC_UIE 0x10 /* update-finished interrupt enable */
81 # define RTC_SQWE 0x08 /* enable square-wave output */
82 # define RTC_DM_BINARY 0x04 /* all time/date values are BCD if clear */
83 # define RTC_24H 0x02 /* 24 hour mode - else hours bit 7 means pm */
84 # define RTC_DST_EN 0x01 /* auto switch DST - works f. USA only */
85
86 /**********************************************************************/
87 #define RTC_INTR_FLAGS RTC_REG_C
88 /* caution - cleared by read */
89 # define RTC_IRQF 0x80 /* any of the following 3 is active */
90 # define RTC_PF 0x40
91 # define RTC_AF 0x20
92 # define RTC_UF 0x10
93
94 /**********************************************************************/
95 #define RTC_VALID RTC_REG_D
96 # define RTC_VRT 0x80 /* valid RAM and time */
97 /**********************************************************************/
98
99 /* example: !(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY)
100 * determines if the following two #defines are needed
101 */
102 #ifndef BCD_TO_BIN
103 #define BCD_TO_BIN(val) ((val)=((val)&15) + ((val)>>4)*10)
104 #endif
105
106 #ifndef BIN_TO_BCD
107 #define BIN_TO_BCD(val) ((val)=(((val)/10)<<4) + (val)%10)
108 #endif
109
110 #endif /* _MC146818RTC_H */