xref: /openbmc/linux/arch/sh/boards/mach-sh03/rtc.c (revision f8bade6c9a6213c2c5ba6e5bf32415ecab6e41e5)
1  // SPDX-License-Identifier: GPL-2.0
2  /*
3   * linux/arch/sh/boards/sh03/rtc.c -- CTP/PCI-SH03 on-chip RTC support
4   *
5   *  Copyright (C) 2004  Saito.K & Jeanne(ksaito@interface.co.jp)
6   *
7   */
8  
9  #include <linux/init.h>
10  #include <linux/kernel.h>
11  #include <linux/sched.h>
12  #include <linux/time.h>
13  #include <linux/bcd.h>
14  #include <linux/spinlock.h>
15  #include <linux/io.h>
16  #include <linux/rtc.h>
17  #include <linux/platform_device.h>
18  
19  #define RTC_BASE	0xb0000000
20  #define RTC_SEC1	(RTC_BASE + 0)
21  #define RTC_SEC10	(RTC_BASE + 1)
22  #define RTC_MIN1	(RTC_BASE + 2)
23  #define RTC_MIN10	(RTC_BASE + 3)
24  #define RTC_HOU1	(RTC_BASE + 4)
25  #define RTC_HOU10	(RTC_BASE + 5)
26  #define RTC_WEE1	(RTC_BASE + 6)
27  #define RTC_DAY1	(RTC_BASE + 7)
28  #define RTC_DAY10	(RTC_BASE + 8)
29  #define RTC_MON1	(RTC_BASE + 9)
30  #define RTC_MON10	(RTC_BASE + 10)
31  #define RTC_YEA1	(RTC_BASE + 11)
32  #define RTC_YEA10	(RTC_BASE + 12)
33  #define RTC_YEA100	(RTC_BASE + 13)
34  #define RTC_YEA1000	(RTC_BASE + 14)
35  #define RTC_CTL		(RTC_BASE + 15)
36  #define RTC_BUSY	1
37  #define RTC_STOP	2
38  
39  static DEFINE_SPINLOCK(sh03_rtc_lock);
40  
sh03_rtc_gettimeofday(struct device * dev,struct rtc_time * tm)41  static int sh03_rtc_gettimeofday(struct device *dev, struct rtc_time *tm)
42  {
43  	unsigned int year, mon, day, hour, min, sec;
44  
45  	spin_lock(&sh03_rtc_lock);
46   again:
47  	do {
48  		sec  = (__raw_readb(RTC_SEC1) & 0xf) + (__raw_readb(RTC_SEC10) & 0x7) * 10;
49  		min  = (__raw_readb(RTC_MIN1) & 0xf) + (__raw_readb(RTC_MIN10) & 0xf) * 10;
50  		hour = (__raw_readb(RTC_HOU1) & 0xf) + (__raw_readb(RTC_HOU10) & 0xf) * 10;
51  		day  = (__raw_readb(RTC_DAY1) & 0xf) + (__raw_readb(RTC_DAY10) & 0xf) * 10;
52  		mon  = (__raw_readb(RTC_MON1) & 0xf) + (__raw_readb(RTC_MON10) & 0xf) * 10;
53  		year = (__raw_readb(RTC_YEA1) & 0xf) + (__raw_readb(RTC_YEA10) & 0xf) * 10
54  		     + (__raw_readb(RTC_YEA100 ) & 0xf) * 100
55  		     + (__raw_readb(RTC_YEA1000) & 0xf) * 1000;
56  	} while (sec != (__raw_readb(RTC_SEC1) & 0xf) + (__raw_readb(RTC_SEC10) & 0x7) * 10);
57  	if (year == 0 || mon < 1 || mon > 12 || day > 31 || day < 1 ||
58  	    hour > 23 || min > 59 || sec > 59) {
59  		printk(KERN_ERR
60  		       "SH-03 RTC: invalid value, resetting to 1 Jan 2000\n");
61  		printk("year=%d, mon=%d, day=%d, hour=%d, min=%d, sec=%d\n",
62  		       year, mon, day, hour, min, sec);
63  
64  		__raw_writeb(0, RTC_SEC1); __raw_writeb(0, RTC_SEC10);
65  		__raw_writeb(0, RTC_MIN1); __raw_writeb(0, RTC_MIN10);
66  		__raw_writeb(0, RTC_HOU1); __raw_writeb(0, RTC_HOU10);
67  		__raw_writeb(6, RTC_WEE1);
68  		__raw_writeb(1, RTC_DAY1); __raw_writeb(0, RTC_DAY10);
69  		__raw_writeb(1, RTC_MON1); __raw_writeb(0, RTC_MON10);
70  		__raw_writeb(0, RTC_YEA1); __raw_writeb(0, RTC_YEA10);
71  		__raw_writeb(0, RTC_YEA100);
72  		__raw_writeb(2, RTC_YEA1000);
73  		__raw_writeb(0, RTC_CTL);
74  		goto again;
75  	}
76  
77  	spin_unlock(&sh03_rtc_lock);
78  
79  	tm->tm_sec  = sec;
80  	tm->tm_min  = min;
81  	tm->tm_hour = hour;
82  	tm->tm_mday = day;
83  	tm->tm_mon  = mon;
84  	tm->tm_year = year - 1900;
85  
86  	return 0;
87  }
88  
set_rtc_mmss(struct rtc_time * tm)89  static int set_rtc_mmss(struct rtc_time *tm)
90  {
91  	int retval = 0;
92  	int real_seconds, real_minutes, cmos_minutes;
93  	int i;
94  
95  	/* gets recalled with irq locally disabled */
96  	spin_lock(&sh03_rtc_lock);
97  	for (i = 0 ; i < 1000000 ; i++)	/* may take up to 1 second... */
98  		if (!(__raw_readb(RTC_CTL) & RTC_BUSY))
99  			break;
100  	cmos_minutes = (__raw_readb(RTC_MIN1) & 0xf) + (__raw_readb(RTC_MIN10) & 0xf) * 10;
101  	real_seconds = tm->tm_sec;
102  	real_minutes = tm->tm_min;
103  	if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
104  		real_minutes += 30;		/* correct for half hour time zone */
105  	real_minutes %= 60;
106  
107  	if (abs(real_minutes - cmos_minutes) < 30) {
108  		__raw_writeb(real_seconds % 10, RTC_SEC1);
109  		__raw_writeb(real_seconds / 10, RTC_SEC10);
110  		__raw_writeb(real_minutes % 10, RTC_MIN1);
111  		__raw_writeb(real_minutes / 10, RTC_MIN10);
112  	} else {
113  		printk_once(KERN_NOTICE
114  		       "set_rtc_mmss: can't update from %d to %d\n",
115  		       cmos_minutes, real_minutes);
116  		retval = -EINVAL;
117  	}
118  	spin_unlock(&sh03_rtc_lock);
119  
120  	return retval;
121  }
122  
sh03_rtc_settimeofday(struct device * dev,struct rtc_time * tm)123  int sh03_rtc_settimeofday(struct device *dev, struct rtc_time *tm)
124  {
125  	return set_rtc_mmss(tm);
126  }
127  
128  static const struct rtc_class_ops rtc_generic_ops = {
129  	.read_time = sh03_rtc_gettimeofday,
130  	.set_time = sh03_rtc_settimeofday,
131  };
132  
sh03_time_init(void)133  static int __init sh03_time_init(void)
134  {
135  	struct platform_device *pdev;
136  
137  	pdev = platform_device_register_data(NULL, "rtc-generic", -1,
138  					     &rtc_generic_ops,
139  					     sizeof(rtc_generic_ops));
140  
141  	return PTR_ERR_OR_ZERO(pdev);
142  }
143  arch_initcall(sh03_time_init);
144