1/*
2 *  Copyright (C) 1991, 1992, 1995  Linus Torvalds
3 *
4 * Adapted for PowerPC (PReP) by Gary Thomas
5 * Modified by Cort Dougan (cort@cs.nmt.edu).
6 * Copied and modified from arch/i386/kernel/time.c
7 *
8 */
9#include <linux/errno.h>
10#include <linux/sched.h>
11#include <linux/kernel.h>
12#include <linux/param.h>
13#include <linux/string.h>
14#include <linux/mm.h>
15#include <linux/interrupt.h>
16#include <linux/time.h>
17#include <linux/timex.h>
18#include <linux/kernel_stat.h>
19#include <linux/mc146818rtc.h>
20#include <linux/init.h>
21#include <linux/bcd.h>
22#include <linux/ioport.h>
23
24#include <asm/io.h>
25#include <asm/nvram.h>
26#include <asm/prom.h>
27#include <asm/sections.h>
28#include <asm/time.h>
29
30extern spinlock_t rtc_lock;
31
32#define NVRAM_AS0  0x74
33#define NVRAM_AS1  0x75
34#define NVRAM_DATA 0x77
35
36static int nvram_as1 = NVRAM_AS1;
37static int nvram_as0 = NVRAM_AS0;
38static int nvram_data = NVRAM_DATA;
39
40long __init chrp_time_init(void)
41{
42	struct device_node *rtcs;
43	struct resource r;
44	int base;
45
46	rtcs = of_find_compatible_node(NULL, "rtc", "pnpPNP,b00");
47	if (rtcs == NULL)
48		rtcs = of_find_compatible_node(NULL, "rtc", "ds1385-rtc");
49	if (rtcs == NULL)
50		return 0;
51	if (of_address_to_resource(rtcs, 0, &r)) {
52		of_node_put(rtcs);
53		return 0;
54	}
55	of_node_put(rtcs);
56
57	base = r.start;
58	nvram_as1 = 0;
59	nvram_as0 = base;
60	nvram_data = base + 1;
61
62	return 0;
63}
64
65int chrp_cmos_clock_read(int addr)
66{
67	if (nvram_as1 != 0)
68		outb(addr>>8, nvram_as1);
69	outb(addr, nvram_as0);
70	return (inb(nvram_data));
71}
72
73void chrp_cmos_clock_write(unsigned long val, int addr)
74{
75	if (nvram_as1 != 0)
76		outb(addr>>8, nvram_as1);
77	outb(addr, nvram_as0);
78	outb(val, nvram_data);
79	return;
80}
81
82/*
83 * Set the hardware clock. -- Cort
84 */
85int chrp_set_rtc_time(struct rtc_time *tmarg)
86{
87	unsigned char save_control, save_freq_select;
88	struct rtc_time tm = *tmarg;
89
90	spin_lock(&rtc_lock);
91
92	save_control = chrp_cmos_clock_read(RTC_CONTROL); /* tell the clock it's being set */
93
94	chrp_cmos_clock_write((save_control|RTC_SET), RTC_CONTROL);
95
96	save_freq_select = chrp_cmos_clock_read(RTC_FREQ_SELECT); /* stop and reset prescaler */
97
98	chrp_cmos_clock_write((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
99
100	if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
101		tm.tm_sec = bin2bcd(tm.tm_sec);
102		tm.tm_min = bin2bcd(tm.tm_min);
103		tm.tm_hour = bin2bcd(tm.tm_hour);
104		tm.tm_mon = bin2bcd(tm.tm_mon);
105		tm.tm_mday = bin2bcd(tm.tm_mday);
106		tm.tm_year = bin2bcd(tm.tm_year);
107	}
108	chrp_cmos_clock_write(tm.tm_sec,RTC_SECONDS);
109	chrp_cmos_clock_write(tm.tm_min,RTC_MINUTES);
110	chrp_cmos_clock_write(tm.tm_hour,RTC_HOURS);
111	chrp_cmos_clock_write(tm.tm_mon,RTC_MONTH);
112	chrp_cmos_clock_write(tm.tm_mday,RTC_DAY_OF_MONTH);
113	chrp_cmos_clock_write(tm.tm_year,RTC_YEAR);
114
115	/* The following flags have to be released exactly in this order,
116	 * otherwise the DS12887 (popular MC146818A clone with integrated
117	 * battery and quartz) will not reset the oscillator and will not
118	 * update precisely 500 ms later. You won't find this mentioned in
119	 * the Dallas Semiconductor data sheets, but who believes data
120	 * sheets anyway ...                           -- Markus Kuhn
121	 */
122	chrp_cmos_clock_write(save_control, RTC_CONTROL);
123	chrp_cmos_clock_write(save_freq_select, RTC_FREQ_SELECT);
124
125	spin_unlock(&rtc_lock);
126	return 0;
127}
128
129void chrp_get_rtc_time(struct rtc_time *tm)
130{
131	unsigned int year, mon, day, hour, min, sec;
132
133	do {
134		sec = chrp_cmos_clock_read(RTC_SECONDS);
135		min = chrp_cmos_clock_read(RTC_MINUTES);
136		hour = chrp_cmos_clock_read(RTC_HOURS);
137		day = chrp_cmos_clock_read(RTC_DAY_OF_MONTH);
138		mon = chrp_cmos_clock_read(RTC_MONTH);
139		year = chrp_cmos_clock_read(RTC_YEAR);
140	} while (sec != chrp_cmos_clock_read(RTC_SECONDS));
141
142	if (!(chrp_cmos_clock_read(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
143		sec = bcd2bin(sec);
144		min = bcd2bin(min);
145		hour = bcd2bin(hour);
146		day = bcd2bin(day);
147		mon = bcd2bin(mon);
148		year = bcd2bin(year);
149	}
150	if (year < 70)
151		year += 100;
152	tm->tm_sec = sec;
153	tm->tm_min = min;
154	tm->tm_hour = hour;
155	tm->tm_mday = day;
156	tm->tm_mon = mon;
157	tm->tm_year = year;
158}
159