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 
14 #include <asm/io.h>
15 #include <linux/rtc.h>			/* get the user-level API */
16 #include <linux/spinlock.h>		/* spinlock_t */
17 #include <asm/mc146818rtc.h>		/* register access macros */
18 
19 extern spinlock_t rtc_lock;		/* serialize CMOS RAM access */
20 
21 /**********************************************************************
22  * register summary
23  **********************************************************************/
24 #define RTC_SECONDS		0
25 #define RTC_SECONDS_ALARM	1
26 #define RTC_MINUTES		2
27 #define RTC_MINUTES_ALARM	3
28 #define RTC_HOURS		4
29 #define RTC_HOURS_ALARM		5
30 /* RTC_*_alarm is always true if 2 MSBs are set */
31 # define RTC_ALARM_DONT_CARE 	0xC0
32 
33 #define RTC_DAY_OF_WEEK		6
34 #define RTC_DAY_OF_MONTH	7
35 #define RTC_MONTH		8
36 #define RTC_YEAR		9
37 
38 /* control registers - Moto names
39  */
40 #define RTC_REG_A		10
41 #define RTC_REG_B		11
42 #define RTC_REG_C		12
43 #define RTC_REG_D		13
44 
45 /**********************************************************************
46  * register details
47  **********************************************************************/
48 #define RTC_FREQ_SELECT	RTC_REG_A
49 
50 /* update-in-progress  - set to "1" 244 microsecs before RTC goes off the bus,
51  * reset after update (may take 1.984ms @ 32768Hz RefClock) is complete,
52  * totalling to a max high interval of 2.228 ms.
53  */
54 # define RTC_UIP		0x80
55 # define RTC_DIV_CTL		0x70
56    /* divider control: refclock values 4.194 / 1.049 MHz / 32.768 kHz */
57 #  define RTC_REF_CLCK_4MHZ	0x00
58 #  define RTC_REF_CLCK_1MHZ	0x10
59 #  define RTC_REF_CLCK_32KHZ	0x20
60    /* 2 values for divider stage reset, others for "testing purposes only" */
61 #  define RTC_DIV_RESET1	0x60
62 #  define RTC_DIV_RESET2	0x70
63   /* Periodic intr. / Square wave rate select. 0=none, 1=32.8kHz,... 15=2Hz */
64 # define RTC_RATE_SELECT 	0x0F
65 
66 /**********************************************************************/
67 #define RTC_CONTROL	RTC_REG_B
68 # define RTC_SET 0x80		/* disable updates for clock setting */
69 # define RTC_PIE 0x40		/* periodic interrupt enable */
70 # define RTC_AIE 0x20		/* alarm interrupt enable */
71 # define RTC_UIE 0x10		/* update-finished interrupt enable */
72 # define RTC_SQWE 0x08		/* enable square-wave output */
73 # define RTC_DM_BINARY 0x04	/* all time/date values are BCD if clear */
74 # define RTC_24H 0x02		/* 24 hour mode - else hours bit 7 means pm */
75 # define RTC_DST_EN 0x01	/* auto switch DST - works f. USA only */
76 
77 /**********************************************************************/
78 #define RTC_INTR_FLAGS	RTC_REG_C
79 /* caution - cleared by read */
80 # define RTC_IRQF 0x80		/* any of the following 3 is active */
81 # define RTC_PF 0x40
82 # define RTC_AF 0x20
83 # define RTC_UF 0x10
84 
85 /**********************************************************************/
86 #define RTC_VALID	RTC_REG_D
87 # define RTC_VRT 0x80		/* valid RAM and time */
88 /**********************************************************************/
89 
90 /* example: !(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY)
91  * determines if the following two #defines are needed
92  */
93 #ifndef BCD_TO_BIN
94 #define BCD_TO_BIN(val) ((val)=((val)&15) + ((val)>>4)*10)
95 #endif
96 
97 #ifndef BIN_TO_BCD
98 #define BIN_TO_BCD(val) ((val)=(((val)/10)<<4) + (val)%10)
99 #endif
100 
101 #ifndef RTC_IO_EXTENT
102 #define RTC_IO_EXTENT	0x10	/* Only really two ports, but...	*/
103 #endif
104 
105 #ifndef RTC_IOMAPPED
106 #define RTC_IOMAPPED	1	/* Default to I/O mapping. */
107 #endif
108 
109 #endif /* _MC146818RTC_H */
110