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Paul Mackerrasbbd0abda2005-10-26 21:45:56 +10001/*
Paul Mackerrasbbd0abda2005-10-26 21:45:56 +10002 * 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>
David Woodhouse575e3212006-01-14 00:13:49 +000022#include <linux/ioport.h>
Paul Mackerrasbbd0abda2005-10-26 21:45:56 +100023
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;
David Woodhouse575e3212006-01-14 00:13:49 +000039 struct resource r;
Paul Mackerrasbbd0abda2005-10-26 21:45:56 +100040 int base;
41
Stephen Rothwell4bf56e12007-04-24 13:48:41 +100042 rtcs = of_find_compatible_node(NULL, "rtc", "pnpPNP,b00");
Paul Mackerrasbbd0abda2005-10-26 21:45:56 +100043 if (rtcs == NULL)
Stephen Rothwell4bf56e12007-04-24 13:48:41 +100044 rtcs = of_find_compatible_node(NULL, "rtc", "ds1385-rtc");
45 if (rtcs == NULL)
Paul Mackerrasbbd0abda2005-10-26 21:45:56 +100046 return 0;
Stephen Rothwell4bf56e12007-04-24 13:48:41 +100047 if (of_address_to_resource(rtcs, 0, &r)) {
48 of_node_put(rtcs);
49 return 0;
50 }
51 of_node_put(rtcs);
52
David Woodhouse575e3212006-01-14 00:13:49 +000053 base = r.start;
Paul Mackerrasbbd0abda2005-10-26 21:45:56 +100054 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
Paul Mackerrasbbd0abda2005-10-26 21:45:56 +100096 if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
Adrian Bunk8f6ba492008-08-09 02:34:53 +100097 tm.tm_sec = bin2bcd(tm.tm_sec);
98 tm.tm_min = bin2bcd(tm.tm_min);
99 tm.tm_hour = bin2bcd(tm.tm_hour);
100 tm.tm_mon = bin2bcd(tm.tm_mon);
101 tm.tm_mday = bin2bcd(tm.tm_mday);
102 tm.tm_year = bin2bcd(tm.tm_year);
Paul Mackerrasbbd0abda2005-10-26 21:45:56 +1000103 }
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;
Paul Mackerrasbbd0abda2005-10-26 21:45:56 +1000128
Matt Mackall4dc12ec2006-03-28 01:56:03 -0800129 do {
Paul Mackerrasbbd0abda2005-10-26 21:45:56 +1000130 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);
Matt Mackall4dc12ec2006-03-28 01:56:03 -0800136 } while (sec != chrp_cmos_clock_read(RTC_SECONDS));
Paul Mackerrasbbd0abda2005-10-26 21:45:56 +1000137
138 if (!(chrp_cmos_clock_read(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
Adrian Bunk8f6ba492008-08-09 02:34:53 +1000139 sec = bcd2bin(sec);
140 min = bcd2bin(min);
141 hour = bcd2bin(hour);
142 day = bcd2bin(day);
143 mon = bcd2bin(mon);
144 year = bcd2bin(year);
Paul Mackerrasbbd0abda2005-10-26 21:45:56 +1000145 }
Paul Mackerras49e16b72005-11-18 15:52:38 +1100146 if (year < 70)
Paul Mackerrasbbd0abda2005-10-26 21:45:56 +1000147 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}