rtc.c revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac 
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 <asm/io.h>
13#include <linux/rtc.h>
14#include <linux/spinlock.h>
15
16#define RTC_BASE	0xb0000000
17#define RTC_SEC1	(RTC_BASE + 0)
18#define RTC_SEC10	(RTC_BASE + 1)
19#define RTC_MIN1	(RTC_BASE + 2)
20#define RTC_MIN10	(RTC_BASE + 3)
21#define RTC_HOU1	(RTC_BASE + 4)
22#define RTC_HOU10	(RTC_BASE + 5)
23#define RTC_WEE1	(RTC_BASE + 6)
24#define RTC_DAY1	(RTC_BASE + 7)
25#define RTC_DAY10	(RTC_BASE + 8)
26#define RTC_MON1	(RTC_BASE + 9)
27#define RTC_MON10	(RTC_BASE + 10)
28#define RTC_YEA1	(RTC_BASE + 11)
29#define RTC_YEA10	(RTC_BASE + 12)
30#define RTC_YEA100	(RTC_BASE + 13)
31#define RTC_YEA1000	(RTC_BASE + 14)
32#define RTC_CTL		(RTC_BASE + 15)
33#define RTC_BUSY	1
34#define RTC_STOP	2
35
36#ifndef BCD_TO_BIN
37#define BCD_TO_BIN(val) ((val)=((val)&15) + ((val)>>4)*10)
38#endif
39
40#ifndef BIN_TO_BCD
41#define BIN_TO_BCD(val)	((val)=(((val)/10)<<4) + (val)%10)
42#endif
43
44extern void (*rtc_get_time)(struct timespec *);
45extern int (*rtc_set_time)(const time_t);
46extern spinlock_t rtc_lock;
47
48unsigned long get_cmos_time(void)
49{
50	unsigned int year, mon, day, hour, min, sec;
51	int i;
52
53	spin_lock(&rtc_lock);
54 again:
55	for (i = 0 ; i < 1000000 ; i++)	/* may take up to 1 second... */
56		if (!(ctrl_inb(RTC_CTL) & RTC_BUSY))
57			break;
58	do {
59		sec  = (ctrl_inb(RTC_SEC1) & 0xf) + (ctrl_inb(RTC_SEC10) & 0x7) * 10;
60		min  = (ctrl_inb(RTC_MIN1) & 0xf) + (ctrl_inb(RTC_MIN10) & 0xf) * 10;
61		hour = (ctrl_inb(RTC_HOU1) & 0xf) + (ctrl_inb(RTC_HOU10) & 0xf) * 10;
62		day  = (ctrl_inb(RTC_DAY1) & 0xf) + (ctrl_inb(RTC_DAY10) & 0xf) * 10;
63		mon  = (ctrl_inb(RTC_MON1) & 0xf) + (ctrl_inb(RTC_MON10) & 0xf) * 10;
64		year = (ctrl_inb(RTC_YEA1) & 0xf) + (ctrl_inb(RTC_YEA10) & 0xf) * 10
65		     + (ctrl_inb(RTC_YEA100 ) & 0xf) * 100
66		     + (ctrl_inb(RTC_YEA1000) & 0xf) * 1000;
67	} while (sec != (ctrl_inb(RTC_SEC1) & 0xf) + (ctrl_inb(RTC_SEC10) & 0x7) * 10);
68	if (year == 0 || mon < 1 || mon > 12 || day > 31 || day < 1 ||
69	    hour > 23 || min > 59 || sec > 59) {
70		printk(KERN_ERR
71		       "SH-03 RTC: invalid value, resetting to 1 Jan 2000\n");
72		printk("year=%d, mon=%d, day=%d, hour=%d, min=%d, sec=%d\n",
73		       year, mon, day, hour, min, sec);
74
75		ctrl_outb(0, RTC_SEC1); ctrl_outb(0, RTC_SEC10);
76		ctrl_outb(0, RTC_MIN1); ctrl_outb(0, RTC_MIN10);
77		ctrl_outb(0, RTC_HOU1); ctrl_outb(0, RTC_HOU10);
78		ctrl_outb(6, RTC_WEE1);
79		ctrl_outb(1, RTC_DAY1); ctrl_outb(0, RTC_DAY10);
80		ctrl_outb(1, RTC_MON1); ctrl_outb(0, RTC_MON10);
81		ctrl_outb(0, RTC_YEA1); ctrl_outb(0, RTC_YEA10);
82		ctrl_outb(0, RTC_YEA100);
83		ctrl_outb(2, RTC_YEA1000);
84		ctrl_outb(0, RTC_CTL);
85		goto again;
86	}
87
88	spin_unlock(&rtc_lock);
89	return mktime(year, mon, day, hour, min, sec);
90}
91
92void sh03_rtc_gettimeofday(struct timespec *tv)
93{
94
95	tv->tv_sec = get_cmos_time();
96	tv->tv_nsec = 0;
97}
98
99static int set_rtc_mmss(unsigned long nowtime)
100{
101	int retval = 0;
102	int real_seconds, real_minutes, cmos_minutes;
103	int i;
104
105	/* gets recalled with irq locally disabled */
106	spin_lock(&rtc_lock);
107	for (i = 0 ; i < 1000000 ; i++)	/* may take up to 1 second... */
108		if (!(ctrl_inb(RTC_CTL) & RTC_BUSY))
109			break;
110	cmos_minutes = (ctrl_inb(RTC_MIN1) & 0xf) + (ctrl_inb(RTC_MIN10) & 0xf) * 10;
111	real_seconds = nowtime % 60;
112	real_minutes = nowtime / 60;
113	if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
114		real_minutes += 30;		/* correct for half hour time zone */
115	real_minutes %= 60;
116
117	if (abs(real_minutes - cmos_minutes) < 30) {
118		ctrl_outb(real_seconds % 10, RTC_SEC1);
119		ctrl_outb(real_seconds / 10, RTC_SEC10);
120		ctrl_outb(real_minutes % 10, RTC_MIN1);
121		ctrl_outb(real_minutes / 10, RTC_MIN10);
122	} else {
123		printk(KERN_WARNING
124		       "set_rtc_mmss: can't update from %d to %d\n",
125		       cmos_minutes, real_minutes);
126		retval = -1;
127	}
128	spin_unlock(&rtc_lock);
129
130	return retval;
131}
132
133int sh03_rtc_settimeofday(const time_t secs)
134{
135	unsigned long nowtime = secs;
136
137	return set_rtc_mmss(nowtime);
138}
139
140void sh03_time_init(void)
141{
142	rtc_get_time = sh03_rtc_gettimeofday;
143	rtc_set_time = sh03_rtc_settimeofday;
144}
145