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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 424 | giacomo | 1 | /* |
| 2 | * include/asm-i386/mach-pc9800/mach_time.h |
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| 3 | * |
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| 4 | * Machine specific set RTC function for PC-9800. |
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| 5 | * Written by Osamu Tomita <tomita@cinet.co.jp> |
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| 6 | */ |
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| 7 | #ifndef _MACH_TIME_H |
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| 8 | #define _MACH_TIME_H |
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| 9 | |||
| 10 | #include <linux/bcd.h> |
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| 11 | #include <linux/upd4990a.h> |
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| 12 | |||
| 13 | /* for check timing call set_rtc_mmss() */ |
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| 14 | /* used in arch/i386/time.c::do_timer_interrupt() */ |
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| 15 | /* |
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| 16 | * Because PC-9800's RTC (NEC uPD4990A) does not allow setting |
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| 17 | * time partially, we always have to read-modify-write the |
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| 18 | * entire time (including year) so that set_rtc_mmss() will |
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| 19 | * take quite much time to execute. You may want to relax |
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| 20 | * RTC resetting interval (currently ~11 minuts)... |
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| 21 | */ |
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| 22 | #define USEC_AFTER 1000000 |
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| 23 | #define USEC_BEFORE 0 |
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| 24 | |||
| 25 | static inline int mach_set_rtc_mmss(unsigned long nowtime) |
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| 26 | { |
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| 27 | int retval = 0; |
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| 28 | int real_seconds, real_minutes, cmos_minutes; |
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| 29 | struct upd4990a_raw_data data; |
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| 30 | |||
| 31 | upd4990a_get_time(&data, 1); |
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| 32 | cmos_minutes = BCD2BIN(data.min); |
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| 33 | |||
| 34 | /* |
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| 35 | * since we're only adjusting minutes and seconds, |
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| 36 | * don't interfere with hour overflow. This avoids |
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| 37 | * messing with unknown time zones but requires your |
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| 38 | * RTC not to be off by more than 15 minutes |
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| 39 | */ |
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| 40 | real_seconds = nowtime % 60; |
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| 41 | real_minutes = nowtime / 60; |
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| 42 | if (((abs(real_minutes - cmos_minutes) + 15) / 30) & 1) |
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| 43 | real_minutes += 30; /* correct for half hour time zone */ |
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| 44 | real_minutes %= 60; |
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| 45 | |||
| 46 | if (abs(real_minutes - cmos_minutes) < 30) { |
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| 47 | u8 temp_seconds = (real_seconds / 10) * 16 + real_seconds % 10; |
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| 48 | u8 temp_minutes = (real_minutes / 10) * 16 + real_minutes % 10; |
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| 49 | |||
| 50 | if (data.sec != temp_seconds || data.min != temp_minutes) { |
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| 51 | data.sec = temp_seconds; |
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| 52 | data.min = temp_minutes; |
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| 53 | upd4990a_set_time(&data, 1); |
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| 54 | } |
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| 55 | } else { |
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| 56 | printk(KERN_WARNING |
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| 57 | "set_rtc_mmss: can't update from %d to %d\n", |
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| 58 | cmos_minutes, real_minutes); |
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| 59 | retval = -1; |
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| 60 | } |
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| 61 | |||
| 62 | /* uPD4990A users' manual says we should issue Register Hold |
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| 63 | * command after reading time, or future Time Read command |
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| 64 | * may not work. When we have set the time, this also starts |
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| 65 | * the clock. |
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| 66 | */ |
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| 67 | upd4990a_serial_command(UPD4990A_REGISTER_HOLD); |
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| 68 | |||
| 69 | return retval; |
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| 70 | } |
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| 71 | |||
| 72 | static inline unsigned long mach_get_cmos_time(void) |
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| 73 | { |
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| 74 | int i; |
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| 75 | u8 prev, cur; |
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| 76 | unsigned int year; |
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| 77 | struct upd4990a_raw_data data; |
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| 78 | |||
| 79 | /* Connect uPD4990A's DATA OUT pin to its 1Hz reference clock. */ |
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| 80 | upd4990a_serial_command(UPD4990A_REGISTER_HOLD); |
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| 81 | |||
| 82 | /* Catch rising edge of reference clock. */ |
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| 83 | prev = ~UPD4990A_READ_DATA(); |
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| 84 | for (i = 0; i < 1800000; i++) { /* may take up to 1 second... */ |
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| 85 | __asm__ ("outb %%al,%0" : : "N" (0x5f)); /* 0.6usec delay */ |
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| 86 | cur = UPD4990A_READ_DATA(); |
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| 87 | if (!(prev & cur & 1)) |
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| 88 | break; |
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| 89 | prev = ~cur; |
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| 90 | } |
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| 91 | |||
| 92 | upd4990a_get_time(&data, 0); |
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| 93 | |||
| 94 | if ((year = BCD2BIN(data.year) + 1900) < 1995) |
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| 95 | year += 100; |
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| 96 | return mktime(year, data.mon, BCD2BIN(data.mday), BCD2BIN(data.hour), |
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| 97 | BCD2BIN(data.min), BCD2BIN(data.sec)); |
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| 98 | } |
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| 99 | |||
| 100 | #endif /* !_MACH_TIME_H */ |