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
30 extern spinlock_t rtc_lock;
31
32 #define NVRAM_AS0 0x74
33 #define NVRAM_AS1 0x75
34 #define NVRAM_DATA 0x77
35
36 static int nvram_as1 = NVRAM_AS1;
37 static int nvram_as0 = NVRAM_AS0;
38 static int nvram_data = NVRAM_DATA;
39
chrp_time_init(void)40 long __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
chrp_cmos_clock_read(int addr)65 int 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
chrp_cmos_clock_write(unsigned long val,int addr)73 void 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 */
chrp_set_rtc_time(struct rtc_time * tmarg)85 int 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
chrp_get_rtc_time(struct rtc_time * tm)129 void 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