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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* 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
14#include <asm/io.h>
15#include <linux/rtc.h> /* get the user-level API */
16#include <asm/mc146818rtc.h> /* register access macros */
17
18#ifdef __KERNEL__
19#include <linux/spinlock.h> /* spinlock_t */
20extern spinlock_t rtc_lock; /* serialize CMOS RAM access */
21#endif
22
23/**********************************************************************
24 * register summary
25 **********************************************************************/
26#define RTC_SECONDS 0
27#define RTC_SECONDS_ALARM 1
28#define RTC_MINUTES 2
29#define RTC_MINUTES_ALARM 3
30#define RTC_HOURS 4
31#define RTC_HOURS_ALARM 5
32/* RTC_*_alarm is always true if 2 MSBs are set */
33# define RTC_ALARM_DONT_CARE 0xC0
34
35#define RTC_DAY_OF_WEEK 6
36#define RTC_DAY_OF_MONTH 7
37#define RTC_MONTH 8
38#define RTC_YEAR 9
39
40/* control registers - Moto names
41 */
42#define RTC_REG_A 10
43#define RTC_REG_B 11
44#define RTC_REG_C 12
45#define RTC_REG_D 13
46
47/**********************************************************************
48 * register details
49 **********************************************************************/
50#define RTC_FREQ_SELECT RTC_REG_A
51
52/* update-in-progress - set to "1" 244 microsecs before RTC goes off the bus,
53 * reset after update (may take 1.984ms @ 32768Hz RefClock) is complete,
54 * totalling to a max high interval of 2.228 ms.
55 */
56# define RTC_UIP 0x80
57# define RTC_DIV_CTL 0x70
58 /* divider control: refclock values 4.194 / 1.049 MHz / 32.768 kHz */
59# define RTC_REF_CLCK_4MHZ 0x00
60# define RTC_REF_CLCK_1MHZ 0x10
61# define RTC_REF_CLCK_32KHZ 0x20
62 /* 2 values for divider stage reset, others for "testing purposes only" */
63# define RTC_DIV_RESET1 0x60
64# define RTC_DIV_RESET2 0x70
65 /* Periodic intr. / Square wave rate select. 0=none, 1=32.8kHz,... 15=2Hz */
66# define RTC_RATE_SELECT 0x0F
67
68/**********************************************************************/
69#define RTC_CONTROL RTC_REG_B
70# define RTC_SET 0x80 /* disable updates for clock setting */
71# define RTC_PIE 0x40 /* periodic interrupt enable */
72# define RTC_AIE 0x20 /* alarm interrupt enable */
73# define RTC_UIE 0x10 /* update-finished interrupt enable */
74# define RTC_SQWE 0x08 /* enable square-wave output */
75# define RTC_DM_BINARY 0x04 /* all time/date values are BCD if clear */
76# define RTC_24H 0x02 /* 24 hour mode - else hours bit 7 means pm */
77# define RTC_DST_EN 0x01 /* auto switch DST - works f. USA only */
78
79/**********************************************************************/
80#define RTC_INTR_FLAGS RTC_REG_C
81/* caution - cleared by read */
82# define RTC_IRQF 0x80 /* any of the following 3 is active */
83# define RTC_PF 0x40
84# define RTC_AF 0x20
85# define RTC_UF 0x10
86
87/**********************************************************************/
88#define RTC_VALID RTC_REG_D
89# define RTC_VRT 0x80 /* valid RAM and time */
90/**********************************************************************/
91
92#endif /* _MC146818RTC_H */