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1da177e4 LT |
1 | /* |
2 | * Copyright 2001 MontaVista Software Inc. | |
3 | * Author: jsun@mvista.com or jsun@junsun.net | |
4 | * | |
5 | * arch/mips/ddb5xxx/common/rtc_ds1386.c | |
6 | * low-level RTC hookups for s for Dallas 1396 chip. | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify it | |
9 | * under the terms of the GNU General Public License as published by the | |
10 | * Free Software Foundation; either version 2 of the License, or (at your | |
11 | * option) any later version. | |
12 | */ | |
13 | ||
14 | ||
15 | /* | |
16 | * This file exports a function, rtc_ds1386_init(), which expects an | |
17 | * uncached base address as the argument. It will set the two function | |
18 | * pointers expected by the MIPS generic timer code. | |
19 | */ | |
20 | ||
21 | #include <linux/types.h> | |
22 | #include <linux/time.h> | |
23 | #include <linux/bcd.h> | |
24 | ||
25 | #include <asm/time.h> | |
26 | #include <asm/addrspace.h> | |
27 | ||
28 | #include <asm/mc146818rtc.h> | |
29 | #include <asm/debug.h> | |
30 | ||
31 | #define EPOCH 2000 | |
32 | ||
33 | #define READ_RTC(x) *(volatile unsigned char*)(rtc_base+x) | |
34 | #define WRITE_RTC(x, y) *(volatile unsigned char*)(rtc_base+x) = y | |
35 | ||
36 | static unsigned long rtc_base; | |
37 | ||
38 | static unsigned long | |
39 | rtc_ds1386_get_time(void) | |
40 | { | |
41 | u8 byte; | |
42 | u8 temp; | |
43 | unsigned int year, month, day, hour, minute, second; | |
53c2df2f | 44 | unsigned long flags; |
1da177e4 | 45 | |
53c2df2f | 46 | spin_lock_irqsave(&rtc_lock, flags); |
1da177e4 LT |
47 | /* let us freeze external registers */ |
48 | byte = READ_RTC(0xB); | |
49 | byte &= 0x3f; | |
50 | WRITE_RTC(0xB, byte); | |
51 | ||
52 | /* read time data */ | |
53 | year = BCD2BIN(READ_RTC(0xA)) + EPOCH; | |
54 | month = BCD2BIN(READ_RTC(0x9) & 0x1f); | |
55 | day = BCD2BIN(READ_RTC(0x8)); | |
56 | minute = BCD2BIN(READ_RTC(0x2)); | |
57 | second = BCD2BIN(READ_RTC(0x1)); | |
58 | ||
59 | /* hour is special - deal with it later */ | |
60 | temp = READ_RTC(0x4); | |
61 | ||
62 | /* enable time transfer */ | |
63 | byte |= 0x80; | |
64 | WRITE_RTC(0xB, byte); | |
53c2df2f | 65 | spin_unlock_irqrestore(&rtc_lock, flags); |
1da177e4 LT |
66 | |
67 | /* calc hour */ | |
68 | if (temp & 0x40) { | |
69 | /* 12 hour format */ | |
70 | hour = BCD2BIN(temp & 0x1f); | |
71 | if (temp & 0x20) hour += 12; /* PM */ | |
72 | } else { | |
73 | /* 24 hour format */ | |
74 | hour = BCD2BIN(temp & 0x3f); | |
75 | } | |
76 | ||
77 | return mktime(year, month, day, hour, minute, second); | |
78 | } | |
79 | ||
80 | static int | |
81 | rtc_ds1386_set_time(unsigned long t) | |
82 | { | |
83 | struct rtc_time tm; | |
84 | u8 byte; | |
85 | u8 temp; | |
86 | u8 year, month, day, hour, minute, second; | |
53c2df2f | 87 | unsigned long flags; |
1da177e4 | 88 | |
53c2df2f | 89 | spin_lock_irqsave(&rtc_lock, flags); |
1da177e4 LT |
90 | /* let us freeze external registers */ |
91 | byte = READ_RTC(0xB); | |
92 | byte &= 0x3f; | |
93 | WRITE_RTC(0xB, byte); | |
94 | ||
95 | /* convert */ | |
96 | to_tm(t, &tm); | |
97 | ||
98 | ||
99 | /* check each field one by one */ | |
100 | year = BIN2BCD(tm.tm_year - EPOCH); | |
101 | if (year != READ_RTC(0xA)) { | |
102 | WRITE_RTC(0xA, year); | |
103 | } | |
104 | ||
105 | temp = READ_RTC(0x9); | |
106 | month = BIN2BCD(tm.tm_mon+1); /* tm_mon starts from 0 to 11 */ | |
107 | if (month != (temp & 0x1f)) { | |
108 | WRITE_RTC( 0x9, | |
109 | (month & 0x1f) | (temp & ~0x1f) ); | |
110 | } | |
111 | ||
112 | day = BIN2BCD(tm.tm_mday); | |
113 | if (day != READ_RTC(0x8)) { | |
114 | WRITE_RTC(0x8, day); | |
115 | } | |
116 | ||
117 | temp = READ_RTC(0x4); | |
118 | if (temp & 0x40) { | |
119 | /* 12 hour format */ | |
120 | hour = 0x40; | |
121 | if (tm.tm_hour > 12) { | |
122 | hour |= 0x20 | (BIN2BCD(hour-12) & 0x1f); | |
123 | } else { | |
124 | hour |= BIN2BCD(tm.tm_hour); | |
125 | } | |
126 | } else { | |
127 | /* 24 hour format */ | |
128 | hour = BIN2BCD(tm.tm_hour) & 0x3f; | |
129 | } | |
130 | if (hour != temp) WRITE_RTC(0x4, hour); | |
131 | ||
132 | minute = BIN2BCD(tm.tm_min); | |
133 | if (minute != READ_RTC(0x2)) { | |
134 | WRITE_RTC(0x2, minute); | |
135 | } | |
136 | ||
137 | second = BIN2BCD(tm.tm_sec); | |
138 | if (second != READ_RTC(0x1)) { | |
139 | WRITE_RTC(0x1, second); | |
140 | } | |
53c2df2f | 141 | spin_unlock_irqrestore(&rtc_lock, flags); |
1da177e4 LT |
142 | |
143 | return 0; | |
144 | } | |
145 | ||
146 | void | |
147 | rtc_ds1386_init(unsigned long base) | |
148 | { | |
149 | unsigned char byte; | |
150 | ||
151 | /* remember the base */ | |
152 | rtc_base = base; | |
153 | db_assert((rtc_base & 0xe0000000) == KSEG1); | |
154 | ||
155 | /* turn on RTC if it is not on */ | |
156 | byte = READ_RTC(0x9); | |
157 | if (byte & 0x80) { | |
158 | byte &= 0x7f; | |
159 | WRITE_RTC(0x9, byte); | |
160 | } | |
161 | ||
162 | /* enable time transfer */ | |
163 | byte = READ_RTC(0xB); | |
164 | byte |= 0x80; | |
165 | WRITE_RTC(0xB, byte); | |
166 | ||
167 | /* set the function pointers */ | |
d23ee8fe YY |
168 | rtc_mips_get_time = rtc_ds1386_get_time; |
169 | rtc_mips_set_time = rtc_ds1386_set_time; | |
1da177e4 | 170 | } |