rtc.c revision cd1408f22d2fd8f0d09c082b07cf0b9bcfb6eac9 
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
38static DEFINE_SPINLOCK(sh03_rtc_lock);
39
40unsigned 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  = (ctrl_inb(RTC_SEC1) & 0xf) + (ctrl_inb(RTC_SEC10) & 0x7) * 10;
48		min  = (ctrl_inb(RTC_MIN1) & 0xf) + (ctrl_inb(RTC_MIN10) & 0xf) * 10;
49		hour = (ctrl_inb(RTC_HOU1) & 0xf) + (ctrl_inb(RTC_HOU10) & 0xf) * 10;
50		day  = (ctrl_inb(RTC_DAY1) & 0xf) + (ctrl_inb(RTC_DAY10) & 0xf) * 10;
51		mon  = (ctrl_inb(RTC_MON1) & 0xf) + (ctrl_inb(RTC_MON10) & 0xf) * 10;
52		year = (ctrl_inb(RTC_YEA1) & 0xf) + (ctrl_inb(RTC_YEA10) & 0xf) * 10
53		     + (ctrl_inb(RTC_YEA100 ) & 0xf) * 100
54		     + (ctrl_inb(RTC_YEA1000) & 0xf) * 1000;
55	} while (sec != (ctrl_inb(RTC_SEC1) & 0xf) + (ctrl_inb(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		ctrl_outb(0, RTC_SEC1); ctrl_outb(0, RTC_SEC10);
64		ctrl_outb(0, RTC_MIN1); ctrl_outb(0, RTC_MIN10);
65		ctrl_outb(0, RTC_HOU1); ctrl_outb(0, RTC_HOU10);
66		ctrl_outb(6, RTC_WEE1);
67		ctrl_outb(1, RTC_DAY1); ctrl_outb(0, RTC_DAY10);
68		ctrl_outb(1, RTC_MON1); ctrl_outb(0, RTC_MON10);
69		ctrl_outb(0, RTC_YEA1); ctrl_outb(0, RTC_YEA10);
70		ctrl_outb(0, RTC_YEA100);
71		ctrl_outb(2, RTC_YEA1000);
72		ctrl_outb(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
80void sh03_rtc_gettimeofday(struct timespec *tv)
81{
82
83	tv->tv_sec = get_cmos_time();
84	tv->tv_nsec = 0;
85}
86
87static 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 (!(ctrl_inb(RTC_CTL) & RTC_BUSY))
97			break;
98	cmos_minutes = (ctrl_inb(RTC_MIN1) & 0xf) + (ctrl_inb(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		ctrl_outb(real_seconds % 10, RTC_SEC1);
107		ctrl_outb(real_seconds / 10, RTC_SEC10);
108		ctrl_outb(real_minutes % 10, RTC_MIN1);
109		ctrl_outb(real_minutes / 10, RTC_MIN10);
110	} else {
111		printk(KERN_WARNING
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
121int sh03_rtc_settimeofday(const time_t secs)
122{
123	unsigned long nowtime = secs;
124
125	return set_rtc_mmss(nowtime);
126}
127
128void sh03_time_init(void)
129{
130	rtc_sh_get_time = sh03_rtc_gettimeofday;
131	rtc_sh_set_time = sh03_rtc_settimeofday;
132}
133