summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/platforms/maple/time.c
blob: eac569dee27cc0d576069ddbd933520121ff681d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
/*
 *  (c) Copyright 2004 Benjamin Herrenschmidt (benh@kernel.crashing.org),
 *                     IBM Corp. 
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version
 *  2 of the License, or (at your option) any later version.
 *
 */

#undef DEBUG

#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/time.h>
#include <linux/adb.h>
#include <linux/pmu.h>
#include <linux/interrupt.h>
#include <linux/mc146818rtc.h>
#include <linux/bcd.h>

#include <asm/sections.h>
#include <asm/prom.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/machdep.h>
#include <asm/time.h>

#include "maple.h"

#ifdef DEBUG
#define DBG(x...) printk(x)
#else
#define DBG(x...)
#endif

static int maple_rtc_addr;

static int maple_clock_read(int addr)
{
	outb_p(addr, maple_rtc_addr);
	return inb_p(maple_rtc_addr+1);
}

static void maple_clock_write(unsigned long val, int addr)
{
	outb_p(addr, maple_rtc_addr);
	outb_p(val, maple_rtc_addr+1);
}

void maple_get_rtc_time(struct rtc_time *tm)
{
	do {
		tm->tm_sec = maple_clock_read(RTC_SECONDS);
		tm->tm_min = maple_clock_read(RTC_MINUTES);
		tm->tm_hour = maple_clock_read(RTC_HOURS);
		tm->tm_mday = maple_clock_read(RTC_DAY_OF_MONTH);
		tm->tm_mon = maple_clock_read(RTC_MONTH);
		tm->tm_year = maple_clock_read(RTC_YEAR);
	} while (tm->tm_sec != maple_clock_read(RTC_SECONDS));

	if (!(maple_clock_read(RTC_CONTROL) & RTC_DM_BINARY)
	    || RTC_ALWAYS_BCD) {
		tm->tm_sec = bcd2bin(tm->tm_sec);
		tm->tm_min = bcd2bin(tm->tm_min);
		tm->tm_hour = bcd2bin(tm->tm_hour);
		tm->tm_mday = bcd2bin(tm->tm_mday);
		tm->tm_mon = bcd2bin(tm->tm_mon);
		tm->tm_year = bcd2bin(tm->tm_year);
	  }
	if ((tm->tm_year + 1900) < 1970)
		tm->tm_year += 100;

	GregorianDay(tm);
}

int maple_set_rtc_time(struct rtc_time *tm)
{
	unsigned char save_control, save_freq_select;
	int sec, min, hour, mon, mday, year;

	spin_lock(&rtc_lock);

	save_control = maple_clock_read(RTC_CONTROL); /* tell the clock it's being set */

	maple_clock_write((save_control|RTC_SET), RTC_CONTROL);

	save_freq_select = maple_clock_read(RTC_FREQ_SELECT); /* stop and reset prescaler */

	maple_clock_write((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);

	sec = tm->tm_sec;
	min = tm->tm_min;
	hour = tm->tm_hour;
	mon = tm->tm_mon;
	mday = tm->tm_mday;
	year = tm->tm_year;

	if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
		sec = bin2bcd(sec);
		min = bin2bcd(min);
		hour = bin2bcd(hour);
		mon = bin2bcd(mon);
		mday = bin2bcd(mday);
		year = bin2bcd(year);
	}
	maple_clock_write(sec, RTC_SECONDS);
	maple_clock_write(min, RTC_MINUTES);
	maple_clock_write(hour, RTC_HOURS);
	maple_clock_write(mon, RTC_MONTH);
	maple_clock_write(mday, RTC_DAY_OF_MONTH);
	maple_clock_write(year, RTC_YEAR);

	/* The following flags have to be released exactly in this order,
	 * otherwise the DS12887 (popular MC146818A clone with integrated
	 * battery and quartz) will not reset the oscillator and will not
	 * update precisely 500 ms later. You won't find this mentioned in
	 * the Dallas Semiconductor data sheets, but who believes data
	 * sheets anyway ...                           -- Markus Kuhn
	 */
	maple_clock_write(save_control, RTC_CONTROL);
	maple_clock_write(save_freq_select, RTC_FREQ_SELECT);

	spin_unlock(&rtc_lock);

	return 0;
}

static struct resource rtc_iores = {
	.name = "rtc",
	.flags = IORESOURCE_BUSY,
};

unsigned long __init maple_get_boot_time(void)
{
	struct rtc_time tm;
	struct device_node *rtcs;

	rtcs = of_find_compatible_node(NULL, "rtc", "pnpPNP,b00");
	if (rtcs) {
		struct resource r;
		if (of_address_to_resource(rtcs, 0, &r)) {
			printk(KERN_EMERG "Maple: Unable to translate RTC"
			       " address\n");
			goto bail;
		}
		if (!(r.flags & IORESOURCE_IO)) {
			printk(KERN_EMERG "Maple: RTC address isn't PIO!\n");
			goto bail;
		}
		maple_rtc_addr = r.start;
		printk(KERN_INFO "Maple: Found RTC at IO 0x%x\n",
		       maple_rtc_addr);
	}
 bail:
	if (maple_rtc_addr == 0) {
		maple_rtc_addr = RTC_PORT(0); /* legacy address */
		printk(KERN_INFO "Maple: No device node for RTC, assuming "
		       "legacy address (0x%x)\n", maple_rtc_addr);
	}

	rtc_iores.start = maple_rtc_addr;
	rtc_iores.end = maple_rtc_addr + 7;
	request_resource(&ioport_resource, &rtc_iores);

	maple_get_rtc_time(&tm);
	return mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday,
		      tm.tm_hour, tm.tm_min, tm.tm_sec);
}

OpenPOWER on IntegriCloud