Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Russell King | a09e64f | 2008-08-05 16:14:15 +0100 | [diff] [blame] | 2 | * arch/arm/mach-footbridge/include/mach/time.h |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Russell King | fced80c | 2008-09-06 12:10:45 +0100 | [diff] [blame] | 25 | #include <linux/io.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | |
Russell King | a09e64f | 2008-08-05 16:14:15 +0100 | [diff] [blame] | 27 | #include <mach/hardware.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Matt Mackall | 4af6ec4 | 2006-03-28 01:56:05 -0800 | [diff] [blame] | 42 | do { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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) { |
Adrian Bunk | f1bcf7e | 2008-08-08 19:34:35 +0300 | [diff] [blame] | 52 | sec = bcd2bin(sec); |
| 53 | min = bcd2bin(min); |
| 54 | hour = bcd2bin(hour); |
| 55 | day = bcd2bin(day); |
| 56 | mon = bcd2bin(mon); |
| 57 | year = bcd2bin(year); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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) |
Adrian Bunk | f1bcf7e | 2008-08-08 19:34:35 +0300 | [diff] [blame] | 79 | cmos_minutes = bcd2bin(cmos_minutes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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) { |
Adrian Bunk | f1bcf7e | 2008-08-08 19:34:35 +0300 | [diff] [blame] | 95 | real_seconds = bin2bcd(real_seconds); |
| 96 | real_minutes = bin2bcd(real_minutes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | { |
Adrian Bunk | e055d5bf | 2008-04-22 01:43:27 +0100 | [diff] [blame] | 118 | if (machine_is_personal_server()) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | } |