xref: /openbmc/linux/arch/sh/boards/mach-sh03/rtc.c (revision 293d5b43)
1 /*
2  * linux/arch/sh/boards/sh03/rtc.c -- CTP/PCI-SH03 on-chip RTC support
3  *
4  *  Copyright (C) 2004  Saito.K & Jeanne(ksaito@interface.co.jp)
5  *
6  */
7 
8 #include <linux/init.h>
9 #include <linux/kernel.h>
10 #include <linux/sched.h>
11 #include <linux/time.h>
12 #include <linux/bcd.h>
13 #include <linux/rtc.h>
14 #include <linux/spinlock.h>
15 #include <asm/io.h>
16 #include <asm/rtc.h>
17 
18 #define RTC_BASE	0xb0000000
19 #define RTC_SEC1	(RTC_BASE + 0)
20 #define RTC_SEC10	(RTC_BASE + 1)
21 #define RTC_MIN1	(RTC_BASE + 2)
22 #define RTC_MIN10	(RTC_BASE + 3)
23 #define RTC_HOU1	(RTC_BASE + 4)
24 #define RTC_HOU10	(RTC_BASE + 5)
25 #define RTC_WEE1	(RTC_BASE + 6)
26 #define RTC_DAY1	(RTC_BASE + 7)
27 #define RTC_DAY10	(RTC_BASE + 8)
28 #define RTC_MON1	(RTC_BASE + 9)
29 #define RTC_MON10	(RTC_BASE + 10)
30 #define RTC_YEA1	(RTC_BASE + 11)
31 #define RTC_YEA10	(RTC_BASE + 12)
32 #define RTC_YEA100	(RTC_BASE + 13)
33 #define RTC_YEA1000	(RTC_BASE + 14)
34 #define RTC_CTL		(RTC_BASE + 15)
35 #define RTC_BUSY	1
36 #define RTC_STOP	2
37 
38 static DEFINE_SPINLOCK(sh03_rtc_lock);
39 
40 unsigned long get_cmos_time(void)
41 {
42 	unsigned int year, mon, day, hour, min, sec;
43 
44 	spin_lock(&sh03_rtc_lock);
45  again:
46 	do {
47 		sec  = (__raw_readb(RTC_SEC1) & 0xf) + (__raw_readb(RTC_SEC10) & 0x7) * 10;
48 		min  = (__raw_readb(RTC_MIN1) & 0xf) + (__raw_readb(RTC_MIN10) & 0xf) * 10;
49 		hour = (__raw_readb(RTC_HOU1) & 0xf) + (__raw_readb(RTC_HOU10) & 0xf) * 10;
50 		day  = (__raw_readb(RTC_DAY1) & 0xf) + (__raw_readb(RTC_DAY10) & 0xf) * 10;
51 		mon  = (__raw_readb(RTC_MON1) & 0xf) + (__raw_readb(RTC_MON10) & 0xf) * 10;
52 		year = (__raw_readb(RTC_YEA1) & 0xf) + (__raw_readb(RTC_YEA10) & 0xf) * 10
53 		     + (__raw_readb(RTC_YEA100 ) & 0xf) * 100
54 		     + (__raw_readb(RTC_YEA1000) & 0xf) * 1000;
55 	} while (sec != (__raw_readb(RTC_SEC1) & 0xf) + (__raw_readb(RTC_SEC10) & 0x7) * 10);
56 	if (year == 0 || mon < 1 || mon > 12 || day > 31 || day < 1 ||
57 	    hour > 23 || min > 59 || sec > 59) {
58 		printk(KERN_ERR
59 		       "SH-03 RTC: invalid value, resetting to 1 Jan 2000\n");
60 		printk("year=%d, mon=%d, day=%d, hour=%d, min=%d, sec=%d\n",
61 		       year, mon, day, hour, min, sec);
62 
63 		__raw_writeb(0, RTC_SEC1); __raw_writeb(0, RTC_SEC10);
64 		__raw_writeb(0, RTC_MIN1); __raw_writeb(0, RTC_MIN10);
65 		__raw_writeb(0, RTC_HOU1); __raw_writeb(0, RTC_HOU10);
66 		__raw_writeb(6, RTC_WEE1);
67 		__raw_writeb(1, RTC_DAY1); __raw_writeb(0, RTC_DAY10);
68 		__raw_writeb(1, RTC_MON1); __raw_writeb(0, RTC_MON10);
69 		__raw_writeb(0, RTC_YEA1); __raw_writeb(0, RTC_YEA10);
70 		__raw_writeb(0, RTC_YEA100);
71 		__raw_writeb(2, RTC_YEA1000);
72 		__raw_writeb(0, RTC_CTL);
73 		goto again;
74 	}
75 
76 	spin_unlock(&sh03_rtc_lock);
77 	return mktime(year, mon, day, hour, min, sec);
78 }
79 
80 void sh03_rtc_gettimeofday(struct timespec *tv)
81 {
82 
83 	tv->tv_sec = get_cmos_time();
84 	tv->tv_nsec = 0;
85 }
86 
87 static int set_rtc_mmss(unsigned long nowtime)
88 {
89 	int retval = 0;
90 	int real_seconds, real_minutes, cmos_minutes;
91 	int i;
92 
93 	/* gets recalled with irq locally disabled */
94 	spin_lock(&sh03_rtc_lock);
95 	for (i = 0 ; i < 1000000 ; i++)	/* may take up to 1 second... */
96 		if (!(__raw_readb(RTC_CTL) & RTC_BUSY))
97 			break;
98 	cmos_minutes = (__raw_readb(RTC_MIN1) & 0xf) + (__raw_readb(RTC_MIN10) & 0xf) * 10;
99 	real_seconds = nowtime % 60;
100 	real_minutes = nowtime / 60;
101 	if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
102 		real_minutes += 30;		/* correct for half hour time zone */
103 	real_minutes %= 60;
104 
105 	if (abs(real_minutes - cmos_minutes) < 30) {
106 		__raw_writeb(real_seconds % 10, RTC_SEC1);
107 		__raw_writeb(real_seconds / 10, RTC_SEC10);
108 		__raw_writeb(real_minutes % 10, RTC_MIN1);
109 		__raw_writeb(real_minutes / 10, RTC_MIN10);
110 	} else {
111 		printk_once(KERN_NOTICE
112 		       "set_rtc_mmss: can't update from %d to %d\n",
113 		       cmos_minutes, real_minutes);
114 		retval = -1;
115 	}
116 	spin_unlock(&sh03_rtc_lock);
117 
118 	return retval;
119 }
120 
121 int sh03_rtc_settimeofday(const time_t secs)
122 {
123 	unsigned long nowtime = secs;
124 
125 	return set_rtc_mmss(nowtime);
126 }
127 
128 void sh03_time_init(void)
129 {
130 	rtc_sh_get_time = sh03_rtc_gettimeofday;
131 	rtc_sh_set_time = sh03_rtc_settimeofday;
132 }
133