1/*
2 *  (c) Copyright 2004 Benjamin Herrenschmidt (benh@kernel.crashing.org),
3 *                     IBM Corp.
4 *
5 *  This program is free software; you can redistribute it and/or
6 *  modify it under the terms of the GNU General Public License
7 *  as published by the Free Software Foundation; either version
8 *  2 of the License, or (at your option) any later version.
9 *
10 */
11
12#undef DEBUG
13
14#include <linux/errno.h>
15#include <linux/sched.h>
16#include <linux/kernel.h>
17#include <linux/param.h>
18#include <linux/string.h>
19#include <linux/mm.h>
20#include <linux/init.h>
21#include <linux/time.h>
22#include <linux/adb.h>
23#include <linux/pmu.h>
24#include <linux/interrupt.h>
25#include <linux/mc146818rtc.h>
26#include <linux/bcd.h>
27
28#include <asm/sections.h>
29#include <asm/prom.h>
30#include <asm/io.h>
31#include <asm/pgtable.h>
32#include <asm/machdep.h>
33#include <asm/time.h>
34
35#include "maple.h"
36
37#ifdef DEBUG
38#define DBG(x...) printk(x)
39#else
40#define DBG(x...)
41#endif
42
43static int maple_rtc_addr;
44
45static int maple_clock_read(int addr)
46{
47	outb_p(addr, maple_rtc_addr);
48	return inb_p(maple_rtc_addr+1);
49}
50
51static void maple_clock_write(unsigned long val, int addr)
52{
53	outb_p(addr, maple_rtc_addr);
54	outb_p(val, maple_rtc_addr+1);
55}
56
57void maple_get_rtc_time(struct rtc_time *tm)
58{
59	do {
60		tm->tm_sec = maple_clock_read(RTC_SECONDS);
61		tm->tm_min = maple_clock_read(RTC_MINUTES);
62		tm->tm_hour = maple_clock_read(RTC_HOURS);
63		tm->tm_mday = maple_clock_read(RTC_DAY_OF_MONTH);
64		tm->tm_mon = maple_clock_read(RTC_MONTH);
65		tm->tm_year = maple_clock_read(RTC_YEAR);
66	} while (tm->tm_sec != maple_clock_read(RTC_SECONDS));
67
68	if (!(maple_clock_read(RTC_CONTROL) & RTC_DM_BINARY)
69	    || RTC_ALWAYS_BCD) {
70		tm->tm_sec = bcd2bin(tm->tm_sec);
71		tm->tm_min = bcd2bin(tm->tm_min);
72		tm->tm_hour = bcd2bin(tm->tm_hour);
73		tm->tm_mday = bcd2bin(tm->tm_mday);
74		tm->tm_mon = bcd2bin(tm->tm_mon);
75		tm->tm_year = bcd2bin(tm->tm_year);
76	  }
77	if ((tm->tm_year + 1900) < 1970)
78		tm->tm_year += 100;
79
80	GregorianDay(tm);
81}
82
83int maple_set_rtc_time(struct rtc_time *tm)
84{
85	unsigned char save_control, save_freq_select;
86	int sec, min, hour, mon, mday, year;
87
88	spin_lock(&rtc_lock);
89
90	save_control = maple_clock_read(RTC_CONTROL); /* tell the clock it's being set */
91
92	maple_clock_write((save_control|RTC_SET), RTC_CONTROL);
93
94	save_freq_select = maple_clock_read(RTC_FREQ_SELECT); /* stop and reset prescaler */
95
96	maple_clock_write((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
97
98	sec = tm->tm_sec;
99	min = tm->tm_min;
100	hour = tm->tm_hour;
101	mon = tm->tm_mon;
102	mday = tm->tm_mday;
103	year = tm->tm_year;
104
105	if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
106		sec = bin2bcd(sec);
107		min = bin2bcd(min);
108		hour = bin2bcd(hour);
109		mon = bin2bcd(mon);
110		mday = bin2bcd(mday);
111		year = bin2bcd(year);
112	}
113	maple_clock_write(sec, RTC_SECONDS);
114	maple_clock_write(min, RTC_MINUTES);
115	maple_clock_write(hour, RTC_HOURS);
116	maple_clock_write(mon, RTC_MONTH);
117	maple_clock_write(mday, RTC_DAY_OF_MONTH);
118	maple_clock_write(year, RTC_YEAR);
119
120	/* The following flags have to be released exactly in this order,
121	 * otherwise the DS12887 (popular MC146818A clone with integrated
122	 * battery and quartz) will not reset the oscillator and will not
123	 * update precisely 500 ms later. You won't find this mentioned in
124	 * the Dallas Semiconductor data sheets, but who believes data
125	 * sheets anyway ...                           -- Markus Kuhn
126	 */
127	maple_clock_write(save_control, RTC_CONTROL);
128	maple_clock_write(save_freq_select, RTC_FREQ_SELECT);
129
130	spin_unlock(&rtc_lock);
131
132	return 0;
133}
134
135static struct resource rtc_iores = {
136	.name = "rtc",
137	.flags = IORESOURCE_BUSY,
138};
139
140unsigned long __init maple_get_boot_time(void)
141{
142	struct rtc_time tm;
143	struct device_node *rtcs;
144
145	rtcs = of_find_compatible_node(NULL, "rtc", "pnpPNP,b00");
146	if (rtcs) {
147		struct resource r;
148		if (of_address_to_resource(rtcs, 0, &r)) {
149			printk(KERN_EMERG "Maple: Unable to translate RTC"
150			       " address\n");
151			goto bail;
152		}
153		if (!(r.flags & IORESOURCE_IO)) {
154			printk(KERN_EMERG "Maple: RTC address isn't PIO!\n");
155			goto bail;
156		}
157		maple_rtc_addr = r.start;
158		printk(KERN_INFO "Maple: Found RTC at IO 0x%x\n",
159		       maple_rtc_addr);
160	}
161 bail:
162	if (maple_rtc_addr == 0) {
163		maple_rtc_addr = RTC_PORT(0); /* legacy address */
164		printk(KERN_INFO "Maple: No device node for RTC, assuming "
165		       "legacy address (0x%x)\n", maple_rtc_addr);
166	}
167
168	rtc_iores.start = maple_rtc_addr;
169	rtc_iores.end = maple_rtc_addr + 7;
170	request_resource(&ioport_resource, &rtc_iores);
171
172	maple_get_rtc_time(&tm);
173	return mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday,
174		      tm.tm_hour, tm.tm_min, tm.tm_sec);
175}
176
177