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
32static int nvram_as1 = NVRAM_AS1;
33static int nvram_as0 = NVRAM_AS0;
34static int nvram_data = NVRAM_DATA;
35
36long __init chrp_time_init(void)
37{
38	struct device_node *rtcs;
39	struct resource r;
40	int base;
41
42	rtcs = of_find_compatible_node(NULL, "rtc", "pnpPNP,b00");
43	if (rtcs == NULL)
44		rtcs = of_find_compatible_node(NULL, "rtc", "ds1385-rtc");
45	if (rtcs == NULL)
46		return 0;
47	if (of_address_to_resource(rtcs, 0, &r)) {
48		of_node_put(rtcs);
49		return 0;
50	}
51	of_node_put(rtcs);
52
53	base = r.start;
54	nvram_as1 = 0;
55	nvram_as0 = base;
56	nvram_data = base + 1;
57
58	return 0;
59}
60
61int chrp_cmos_clock_read(int addr)
62{
63	if (nvram_as1 != 0)
64		outb(addr>>8, nvram_as1);
65	outb(addr, nvram_as0);
66	return (inb(nvram_data));
67}
68
69void chrp_cmos_clock_write(unsigned long val, int addr)
70{
71	if (nvram_as1 != 0)
72		outb(addr>>8, nvram_as1);
73	outb(addr, nvram_as0);
74	outb(val, nvram_data);
75	return;
76}
77
78/*
79 * Set the hardware clock. -- Cort
80 */
81int chrp_set_rtc_time(struct rtc_time *tmarg)
82{
83	unsigned char save_control, save_freq_select;
84	struct rtc_time tm = *tmarg;
85
86	spin_lock(&rtc_lock);
87
88	save_control = chrp_cmos_clock_read(RTC_CONTROL); /* tell the clock it's being set */
89
90	chrp_cmos_clock_write((save_control|RTC_SET), RTC_CONTROL);
91
92	save_freq_select = chrp_cmos_clock_read(RTC_FREQ_SELECT); /* stop and reset prescaler */
93
94	chrp_cmos_clock_write((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
95
96	if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
97		BIN_TO_BCD(tm.tm_sec);
98		BIN_TO_BCD(tm.tm_min);
99		BIN_TO_BCD(tm.tm_hour);
100		BIN_TO_BCD(tm.tm_mon);
101		BIN_TO_BCD(tm.tm_mday);
102		BIN_TO_BCD(tm.tm_year);
103	}
104	chrp_cmos_clock_write(tm.tm_sec,RTC_SECONDS);
105	chrp_cmos_clock_write(tm.tm_min,RTC_MINUTES);
106	chrp_cmos_clock_write(tm.tm_hour,RTC_HOURS);
107	chrp_cmos_clock_write(tm.tm_mon,RTC_MONTH);
108	chrp_cmos_clock_write(tm.tm_mday,RTC_DAY_OF_MONTH);
109	chrp_cmos_clock_write(tm.tm_year,RTC_YEAR);
110
111	/* The following flags have to be released exactly in this order,
112	 * otherwise the DS12887 (popular MC146818A clone with integrated
113	 * battery and quartz) will not reset the oscillator and will not
114	 * update precisely 500 ms later. You won't find this mentioned in
115	 * the Dallas Semiconductor data sheets, but who believes data
116	 * sheets anyway ...                           -- Markus Kuhn
117	 */
118	chrp_cmos_clock_write(save_control, RTC_CONTROL);
119	chrp_cmos_clock_write(save_freq_select, RTC_FREQ_SELECT);
120
121	spin_unlock(&rtc_lock);
122	return 0;
123}
124
125void chrp_get_rtc_time(struct rtc_time *tm)
126{
127	unsigned int year, mon, day, hour, min, sec;
128
129	do {
130		sec = chrp_cmos_clock_read(RTC_SECONDS);
131		min = chrp_cmos_clock_read(RTC_MINUTES);
132		hour = chrp_cmos_clock_read(RTC_HOURS);
133		day = chrp_cmos_clock_read(RTC_DAY_OF_MONTH);
134		mon = chrp_cmos_clock_read(RTC_MONTH);
135		year = chrp_cmos_clock_read(RTC_YEAR);
136	} while (sec != chrp_cmos_clock_read(RTC_SECONDS));
137
138	if (!(chrp_cmos_clock_read(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
139		BCD_TO_BIN(sec);
140		BCD_TO_BIN(min);
141		BCD_TO_BIN(hour);
142		BCD_TO_BIN(day);
143		BCD_TO_BIN(mon);
144		BCD_TO_BIN(year);
145	}
146	if (year < 70)
147		year += 100;
148	tm->tm_sec = sec;
149	tm->tm_min = min;
150	tm->tm_hour = hour;
151	tm->tm_mday = day;
152	tm->tm_mon = mon;
153	tm->tm_year = year;
154}
155