Commit | Line | Data |
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1da177e4 | 1 | /* |
a09e64fb | 2 | * arch/arm/mach-footbridge/include/mach/time.h |
1da177e4 LT |
3 | * |
4 | * Copyright (C) 1998 Russell King. | |
5 | * Copyright (C) 1998 Phil Blundell | |
6 | * | |
7 | * CATS has a real-time clock, though the evaluation board doesn't. | |
8 | * | |
9 | * Changelog: | |
10 | * 21-Mar-1998 RMK Created | |
11 | * 27-Aug-1998 PJB CATS support | |
12 | * 28-Dec-1998 APH Made leds optional | |
13 | * 20-Jan-1999 RMK Started merge of EBSA285, CATS and NetWinder | |
14 | * 16-Mar-1999 RMK More support for EBSA285-like machines with RTCs in | |
15 | */ | |
16 | ||
17 | #define RTC_PORT(x) (rtc_base+(x)) | |
18 | #define RTC_ALWAYS_BCD 0 | |
19 | ||
20 | #include <linux/timex.h> | |
21 | #include <linux/init.h> | |
22 | #include <linux/sched.h> | |
23 | #include <linux/mc146818rtc.h> | |
24 | #include <linux/bcd.h> | |
25 | ||
a09e64fb | 26 | #include <mach/hardware.h> |
1da177e4 LT |
27 | #include <asm/io.h> |
28 | ||
29 | #include <asm/mach/time.h> | |
30 | #include "common.h" | |
31 | ||
32 | static int rtc_base; | |
33 | ||
34 | static unsigned long __init get_isa_cmos_time(void) | |
35 | { | |
36 | unsigned int year, mon, day, hour, min, sec; | |
1da177e4 LT |
37 | |
38 | // check to see if the RTC makes sense..... | |
39 | if ((CMOS_READ(RTC_VALID) & RTC_VRT) == 0) | |
40 | return mktime(1970, 1, 1, 0, 0, 0); | |
41 | ||
4af6ec46 | 42 | do { |
1da177e4 LT |
43 | sec = CMOS_READ(RTC_SECONDS); |
44 | min = CMOS_READ(RTC_MINUTES); | |
45 | hour = CMOS_READ(RTC_HOURS); | |
46 | day = CMOS_READ(RTC_DAY_OF_MONTH); | |
47 | mon = CMOS_READ(RTC_MONTH); | |
48 | year = CMOS_READ(RTC_YEAR); | |
49 | } while (sec != CMOS_READ(RTC_SECONDS)); | |
50 | ||
51 | if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { | |
52 | BCD_TO_BIN(sec); | |
53 | BCD_TO_BIN(min); | |
54 | BCD_TO_BIN(hour); | |
55 | BCD_TO_BIN(day); | |
56 | BCD_TO_BIN(mon); | |
57 | BCD_TO_BIN(year); | |
58 | } | |
59 | if ((year += 1900) < 1970) | |
60 | year += 100; | |
61 | return mktime(year, mon, day, hour, min, sec); | |
62 | } | |
63 | ||
64 | static int set_isa_cmos_time(void) | |
65 | { | |
66 | int retval = 0; | |
67 | int real_seconds, real_minutes, cmos_minutes; | |
68 | unsigned char save_control, save_freq_select; | |
69 | unsigned long nowtime = xtime.tv_sec; | |
70 | ||
71 | save_control = CMOS_READ(RTC_CONTROL); /* tell the clock it's being set */ | |
72 | CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL); | |
73 | ||
74 | save_freq_select = CMOS_READ(RTC_FREQ_SELECT); /* stop and reset prescaler */ | |
75 | CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT); | |
76 | ||
77 | cmos_minutes = CMOS_READ(RTC_MINUTES); | |
78 | if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) | |
79 | BCD_TO_BIN(cmos_minutes); | |
80 | ||
81 | /* | |
82 | * since we're only adjusting minutes and seconds, | |
83 | * don't interfere with hour overflow. This avoids | |
84 | * messing with unknown time zones but requires your | |
85 | * RTC not to be off by more than 15 minutes | |
86 | */ | |
87 | real_seconds = nowtime % 60; | |
88 | real_minutes = nowtime / 60; | |
89 | if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1) | |
90 | real_minutes += 30; /* correct for half hour time zone */ | |
91 | real_minutes %= 60; | |
92 | ||
93 | if (abs(real_minutes - cmos_minutes) < 30) { | |
94 | if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { | |
95 | BIN_TO_BCD(real_seconds); | |
96 | BIN_TO_BCD(real_minutes); | |
97 | } | |
98 | CMOS_WRITE(real_seconds,RTC_SECONDS); | |
99 | CMOS_WRITE(real_minutes,RTC_MINUTES); | |
100 | } else | |
101 | retval = -1; | |
102 | ||
103 | /* The following flags have to be released exactly in this order, | |
104 | * otherwise the DS12887 (popular MC146818A clone with integrated | |
105 | * battery and quartz) will not reset the oscillator and will not | |
106 | * update precisely 500 ms later. You won't find this mentioned in | |
107 | * the Dallas Semiconductor data sheets, but who believes data | |
108 | * sheets anyway ... -- Markus Kuhn | |
109 | */ | |
110 | CMOS_WRITE(save_control, RTC_CONTROL); | |
111 | CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT); | |
112 | ||
113 | return retval; | |
114 | } | |
115 | ||
116 | void __init isa_rtc_init(void) | |
117 | { | |
e055d5bf | 118 | if (machine_is_personal_server()) |
1da177e4 LT |
119 | /* |
120 | * Add-in 21285s shouldn't access the RTC | |
121 | */ | |
122 | rtc_base = 0; | |
123 | else | |
124 | rtc_base = 0x70; | |
125 | ||
126 | if (rtc_base) { | |
127 | int reg_d, reg_b; | |
128 | ||
129 | /* | |
130 | * Probe for the RTC. | |
131 | */ | |
132 | reg_d = CMOS_READ(RTC_REG_D); | |
133 | ||
134 | /* | |
135 | * make sure the divider is set | |
136 | */ | |
137 | CMOS_WRITE(RTC_REF_CLCK_32KHZ, RTC_REG_A); | |
138 | ||
139 | /* | |
140 | * Set control reg B | |
141 | * (24 hour mode, update enabled) | |
142 | */ | |
143 | reg_b = CMOS_READ(RTC_REG_B) & 0x7f; | |
144 | reg_b |= 2; | |
145 | CMOS_WRITE(reg_b, RTC_REG_B); | |
146 | ||
147 | if ((CMOS_READ(RTC_REG_A) & 0x7f) == RTC_REF_CLCK_32KHZ && | |
148 | CMOS_READ(RTC_REG_B) == reg_b) { | |
149 | struct timespec tv; | |
150 | ||
151 | /* | |
152 | * We have a RTC. Check the battery | |
153 | */ | |
154 | if ((reg_d & 0x80) == 0) | |
155 | printk(KERN_WARNING "RTC: *** warning: CMOS battery bad\n"); | |
156 | ||
157 | tv.tv_nsec = 0; | |
158 | tv.tv_sec = get_isa_cmos_time(); | |
159 | do_settimeofday(&tv); | |
160 | set_rtc = set_isa_cmos_time; | |
161 | } else | |
162 | rtc_base = 0; | |
163 | } | |
164 | } |