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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
bbd0abda | 2 | /* |
bbd0abda PM |
3 | * Copyright (C) 1991, 1992, 1995 Linus Torvalds |
4 | * | |
5 | * Adapted for PowerPC (PReP) by Gary Thomas | |
6 | * Modified by Cort Dougan (cort@cs.nmt.edu). | |
7 | * Copied and modified from arch/i386/kernel/time.c | |
8 | * | |
9 | */ | |
10 | #include <linux/errno.h> | |
11 | #include <linux/sched.h> | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/param.h> | |
14 | #include <linux/string.h> | |
15 | #include <linux/mm.h> | |
16 | #include <linux/interrupt.h> | |
17 | #include <linux/time.h> | |
18 | #include <linux/timex.h> | |
19 | #include <linux/kernel_stat.h> | |
20 | #include <linux/mc146818rtc.h> | |
21 | #include <linux/init.h> | |
22 | #include <linux/bcd.h> | |
575e3216 | 23 | #include <linux/ioport.h> |
bbd0abda PM |
24 | |
25 | #include <asm/io.h> | |
26 | #include <asm/nvram.h> | |
27 | #include <asm/prom.h> | |
28 | #include <asm/sections.h> | |
29 | #include <asm/time.h> | |
30 | ||
31 | extern spinlock_t rtc_lock; | |
32 | ||
74d51d02 BH |
33 | #define NVRAM_AS0 0x74 |
34 | #define NVRAM_AS1 0x75 | |
35 | #define NVRAM_DATA 0x77 | |
36 | ||
bbd0abda PM |
37 | static int nvram_as1 = NVRAM_AS1; |
38 | static int nvram_as0 = NVRAM_AS0; | |
39 | static int nvram_data = NVRAM_DATA; | |
40 | ||
41 | long __init chrp_time_init(void) | |
42 | { | |
43 | struct device_node *rtcs; | |
575e3216 | 44 | struct resource r; |
bbd0abda PM |
45 | int base; |
46 | ||
4bf56e17 | 47 | rtcs = of_find_compatible_node(NULL, "rtc", "pnpPNP,b00"); |
bbd0abda | 48 | if (rtcs == NULL) |
4bf56e17 SR |
49 | rtcs = of_find_compatible_node(NULL, "rtc", "ds1385-rtc"); |
50 | if (rtcs == NULL) | |
51 | return 0; | |
52 | if (of_address_to_resource(rtcs, 0, &r)) { | |
53 | of_node_put(rtcs); | |
bbd0abda | 54 | return 0; |
4bf56e17 SR |
55 | } |
56 | of_node_put(rtcs); | |
57 | ||
575e3216 | 58 | base = r.start; |
bbd0abda PM |
59 | nvram_as1 = 0; |
60 | nvram_as0 = base; | |
61 | nvram_data = base + 1; | |
62 | ||
63 | return 0; | |
64 | } | |
65 | ||
66 | int chrp_cmos_clock_read(int addr) | |
67 | { | |
68 | if (nvram_as1 != 0) | |
69 | outb(addr>>8, nvram_as1); | |
70 | outb(addr, nvram_as0); | |
71 | return (inb(nvram_data)); | |
72 | } | |
73 | ||
74 | void chrp_cmos_clock_write(unsigned long val, int addr) | |
75 | { | |
76 | if (nvram_as1 != 0) | |
77 | outb(addr>>8, nvram_as1); | |
78 | outb(addr, nvram_as0); | |
79 | outb(val, nvram_data); | |
80 | return; | |
81 | } | |
82 | ||
83 | /* | |
84 | * Set the hardware clock. -- Cort | |
85 | */ | |
86 | int chrp_set_rtc_time(struct rtc_time *tmarg) | |
87 | { | |
88 | unsigned char save_control, save_freq_select; | |
89 | struct rtc_time tm = *tmarg; | |
90 | ||
91 | spin_lock(&rtc_lock); | |
92 | ||
93 | save_control = chrp_cmos_clock_read(RTC_CONTROL); /* tell the clock it's being set */ | |
94 | ||
95 | chrp_cmos_clock_write((save_control|RTC_SET), RTC_CONTROL); | |
96 | ||
97 | save_freq_select = chrp_cmos_clock_read(RTC_FREQ_SELECT); /* stop and reset prescaler */ | |
98 | ||
99 | chrp_cmos_clock_write((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT); | |
100 | ||
bbd0abda | 101 | if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { |
8f6ba492 AB |
102 | tm.tm_sec = bin2bcd(tm.tm_sec); |
103 | tm.tm_min = bin2bcd(tm.tm_min); | |
104 | tm.tm_hour = bin2bcd(tm.tm_hour); | |
105 | tm.tm_mon = bin2bcd(tm.tm_mon); | |
106 | tm.tm_mday = bin2bcd(tm.tm_mday); | |
107 | tm.tm_year = bin2bcd(tm.tm_year); | |
bbd0abda PM |
108 | } |
109 | chrp_cmos_clock_write(tm.tm_sec,RTC_SECONDS); | |
110 | chrp_cmos_clock_write(tm.tm_min,RTC_MINUTES); | |
111 | chrp_cmos_clock_write(tm.tm_hour,RTC_HOURS); | |
112 | chrp_cmos_clock_write(tm.tm_mon,RTC_MONTH); | |
113 | chrp_cmos_clock_write(tm.tm_mday,RTC_DAY_OF_MONTH); | |
114 | chrp_cmos_clock_write(tm.tm_year,RTC_YEAR); | |
115 | ||
116 | /* The following flags have to be released exactly in this order, | |
117 | * otherwise the DS12887 (popular MC146818A clone with integrated | |
118 | * battery and quartz) will not reset the oscillator and will not | |
119 | * update precisely 500 ms later. You won't find this mentioned in | |
120 | * the Dallas Semiconductor data sheets, but who believes data | |
121 | * sheets anyway ... -- Markus Kuhn | |
122 | */ | |
123 | chrp_cmos_clock_write(save_control, RTC_CONTROL); | |
124 | chrp_cmos_clock_write(save_freq_select, RTC_FREQ_SELECT); | |
125 | ||
126 | spin_unlock(&rtc_lock); | |
127 | return 0; | |
128 | } | |
129 | ||
130 | void chrp_get_rtc_time(struct rtc_time *tm) | |
131 | { | |
132 | unsigned int year, mon, day, hour, min, sec; | |
bbd0abda | 133 | |
4dc12ec7 | 134 | do { |
bbd0abda PM |
135 | sec = chrp_cmos_clock_read(RTC_SECONDS); |
136 | min = chrp_cmos_clock_read(RTC_MINUTES); | |
137 | hour = chrp_cmos_clock_read(RTC_HOURS); | |
138 | day = chrp_cmos_clock_read(RTC_DAY_OF_MONTH); | |
139 | mon = chrp_cmos_clock_read(RTC_MONTH); | |
140 | year = chrp_cmos_clock_read(RTC_YEAR); | |
4dc12ec7 | 141 | } while (sec != chrp_cmos_clock_read(RTC_SECONDS)); |
bbd0abda PM |
142 | |
143 | if (!(chrp_cmos_clock_read(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { | |
8f6ba492 AB |
144 | sec = bcd2bin(sec); |
145 | min = bcd2bin(min); | |
146 | hour = bcd2bin(hour); | |
147 | day = bcd2bin(day); | |
148 | mon = bcd2bin(mon); | |
149 | year = bcd2bin(year); | |
bbd0abda | 150 | } |
49e16b7b | 151 | if (year < 70) |
bbd0abda PM |
152 | year += 100; |
153 | tm->tm_sec = sec; | |
154 | tm->tm_min = min; | |
155 | tm->tm_hour = hour; | |
156 | tm->tm_mday = day; | |
157 | tm->tm_mon = mon; | |
158 | tm->tm_year = year; | |
159 | } |