xref: /linux/include/linux/mc146818rtc.h (revision 06d07429858317ded2db7986113a9e0129cd599b)
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 <asm/mc146818rtc.h>		/* register access macros */
17 #include <linux/bcd.h>
18 #include <linux/delay.h>
19 #include <linux/pm-trace.h>
20 
21 #ifdef __KERNEL__
22 #include <linux/spinlock.h>		/* spinlock_t */
23 extern spinlock_t rtc_lock;		/* serialize CMOS RAM access */
24 
25 /* Some RTCs extend the mc146818 register set to support alarms of more
26  * than 24 hours in the future; or dates that include a century code.
27  * This platform_data structure can pass this information to the driver.
28  *
29  * Also, some platforms need suspend()/resume() hooks to kick in special
30  * handling of wake alarms, e.g. activating ACPI BIOS hooks or setting up
31  * a separate wakeup alarm used by some almost-clone chips.
32  */
33 struct cmos_rtc_board_info {
34 	void	(*wake_on)(struct device *dev);
35 	void	(*wake_off)(struct device *dev);
36 
37 	u32	flags;
38 #define CMOS_RTC_FLAGS_NOFREQ	(1 << 0)
39 	int	address_space;
40 
41 	u8	rtc_day_alarm;		/* zero, or register index */
42 	u8	rtc_mon_alarm;		/* zero, or register index */
43 	u8	rtc_century;		/* zero, or register index */
44 };
45 #endif
46 
47 /**********************************************************************
48  * register summary
49  **********************************************************************/
50 #define RTC_SECONDS		0
51 #define RTC_SECONDS_ALARM	1
52 #define RTC_MINUTES		2
53 #define RTC_MINUTES_ALARM	3
54 #define RTC_HOURS		4
55 #define RTC_HOURS_ALARM		5
56 /* RTC_*_alarm is always true if 2 MSBs are set */
57 # define RTC_ALARM_DONT_CARE 	0xC0
58 
59 #define RTC_DAY_OF_WEEK		6
60 #define RTC_DAY_OF_MONTH	7
61 #define RTC_MONTH		8
62 #define RTC_YEAR		9
63 
64 /* control registers - Moto names
65  */
66 #define RTC_REG_A		10
67 #define RTC_REG_B		11
68 #define RTC_REG_C		12
69 #define RTC_REG_D		13
70 
71 /**********************************************************************
72  * register details
73  **********************************************************************/
74 #define RTC_FREQ_SELECT	RTC_REG_A
75 
76 /* update-in-progress  - set to "1" 244 microsecs before RTC goes off the bus,
77  * reset after update (may take 1.984ms @ 32768Hz RefClock) is complete,
78  * totalling to a max high interval of 2.228 ms.
79  */
80 # define RTC_UIP		0x80
81 # define RTC_DIV_CTL		0x70
82    /* divider control: refclock values 4.194 / 1.049 MHz / 32.768 kHz */
83 #  define RTC_REF_CLCK_4MHZ	0x00
84 #  define RTC_REF_CLCK_1MHZ	0x10
85 #  define RTC_REF_CLCK_32KHZ	0x20
86    /* 2 values for divider stage reset, others for "testing purposes only" */
87 #  define RTC_DIV_RESET1	0x60
88 #  define RTC_DIV_RESET2	0x70
89    /* In AMD BKDG bit 5 and 6 are reserved, bit 4 is for select dv0 bank */
90 #  define RTC_AMD_BANK_SELECT	0x10
91   /* Periodic intr. / Square wave rate select. 0=none, 1=32.8kHz,... 15=2Hz */
92 # define RTC_RATE_SELECT 	0x0F
93 
94 /**********************************************************************/
95 #define RTC_CONTROL	RTC_REG_B
96 # define RTC_SET 0x80		/* disable updates for clock setting */
97 # define RTC_PIE 0x40		/* periodic interrupt enable */
98 # define RTC_AIE 0x20		/* alarm interrupt enable */
99 # define RTC_UIE 0x10		/* update-finished interrupt enable */
100 # define RTC_SQWE 0x08		/* enable square-wave output */
101 # define RTC_DM_BINARY 0x04	/* all time/date values are BCD if clear */
102 # define RTC_24H 0x02		/* 24 hour mode - else hours bit 7 means pm */
103 # define RTC_DST_EN 0x01	/* auto switch DST - works f. USA only */
104 
105 /**********************************************************************/
106 #define RTC_INTR_FLAGS	RTC_REG_C
107 /* caution - cleared by read */
108 # define RTC_IRQF 0x80		/* any of the following 3 is active */
109 # define RTC_PF 0x40
110 # define RTC_AF 0x20
111 # define RTC_UF 0x10
112 
113 /**********************************************************************/
114 #define RTC_VALID	RTC_REG_D
115 # define RTC_VRT 0x80		/* valid RAM and time */
116 /**********************************************************************/
117 
118 #ifndef ARCH_RTC_LOCATION	/* Override by <asm/mc146818rtc.h>? */
119 
120 #define RTC_IO_EXTENT	0x8
121 #define RTC_IO_EXTENT_USED	0x2
122 #define RTC_IOMAPPED	1	/* Default to I/O mapping. */
123 
124 #else
125 #define RTC_IO_EXTENT_USED      RTC_IO_EXTENT
126 #endif /* ARCH_RTC_LOCATION */
127 
128 bool mc146818_does_rtc_work(void);
129 int mc146818_get_time(struct rtc_time *time, int timeout);
130 int mc146818_set_time(struct rtc_time *time);
131 
132 bool mc146818_avoid_UIP(void (*callback)(unsigned char seconds, void *param),
133 			int timeout,
134 			void *param);
135 
136 #endif /* _MC146818RTC_H */
137