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b65769fc01
This fixes a bug in read_persistent_clock() which causes the system clock to lag the Real Time Clock by one month. The problem was noticed on a Mac, but theoretically it must also affect Atari, BVME6000 and Q40. The tm_mon value in the struct rtc_time passed to mach_hwclk() is zero-based, and atari_mste_hwclk(), atari_tt_hwclk(), bvme6000_hwclk(), mac_hwclk() and q40_hwclk() all make this adjustment. Unfortunately, dn_dummy_hwclk(), mvme147_hwclk(), mvme16x_hwclk(), sun3_hwclk() and sun3x_hwclk() fail to decrement tm_mon. Also m68328_hwclk() assumes a one-based tm_mon. Bring these platforms into line and fix read_persistent_clock() so it works correctly on all m68k platforms. The datasheets for the RTC devices found on the affected platforms all confirm that the year is stored as a value in the range 0-99 and the month is stored as a value in the range 1-12. Please refer to the datasheets for MC146818 (Apollo), DS1643 (MVME), ICM7170 (Sun 3) and M48T02 (Sun 3x). Reported-by: Stan Johnson <userm57@yahoo.com> Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
77 lines
1.7 KiB
C
77 lines
1.7 KiB
C
/*
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* arch/m68k/sun3/intersil.c
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*
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* basic routines for accessing the intersil clock within the sun3 machines
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*
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* started 11/12/1999 Sam Creasey
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file COPYING in the main directory of this archive
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* for more details.
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*/
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#include <linux/kernel.h>
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#include <linux/rtc.h>
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#include <asm/errno.h>
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#include <asm/intersil.h>
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#include <asm/machdep.h>
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/* bits to set for start/run of the intersil */
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#define STOP_VAL (INTERSIL_STOP | INTERSIL_INT_ENABLE | INTERSIL_24H_MODE)
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#define START_VAL (INTERSIL_RUN | INTERSIL_INT_ENABLE | INTERSIL_24H_MODE)
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/* does this need to be implemented? */
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u32 sun3_gettimeoffset(void)
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{
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return 1000;
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}
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/* get/set hwclock */
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int sun3_hwclk(int set, struct rtc_time *t)
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{
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volatile struct intersil_dt *todintersil;
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unsigned long flags;
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todintersil = (struct intersil_dt *) &intersil_clock->counter;
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local_irq_save(flags);
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intersil_clock->cmd_reg = STOP_VAL;
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/* set or read the clock */
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if(set) {
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todintersil->csec = 0;
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todintersil->hour = t->tm_hour;
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todintersil->minute = t->tm_min;
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todintersil->second = t->tm_sec;
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todintersil->month = t->tm_mon + 1;
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todintersil->day = t->tm_mday;
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todintersil->year = (t->tm_year - 68) % 100;
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todintersil->weekday = t->tm_wday;
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} else {
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/* read clock */
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t->tm_sec = todintersil->csec;
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t->tm_hour = todintersil->hour;
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t->tm_min = todintersil->minute;
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t->tm_sec = todintersil->second;
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t->tm_mon = todintersil->month - 1;
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t->tm_mday = todintersil->day;
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t->tm_year = todintersil->year + 68;
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t->tm_wday = todintersil->weekday;
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if (t->tm_year < 70)
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t->tm_year += 100;
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}
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intersil_clock->cmd_reg = START_VAL;
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local_irq_restore(flags);
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return 0;
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}
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