diff options
Diffstat (limited to 'arch/m68k/atari/time.c')
| -rw-r--r-- | arch/m68k/atari/time.c | 348 |
1 files changed, 348 insertions, 0 deletions
diff --git a/arch/m68k/atari/time.c b/arch/m68k/atari/time.c new file mode 100644 index 000000000000..6df7fb60dfea --- /dev/null +++ b/arch/m68k/atari/time.c @@ -0,0 +1,348 @@ +/* + * linux/arch/m68k/atari/time.c + * + * Atari time and real time clock stuff + * + * Assembled of parts of former atari/config.c 97-12-18 by Roman Hodek + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of this archive + * for more details. + */ + +#include <linux/types.h> +#include <linux/mc146818rtc.h> +#include <linux/interrupt.h> +#include <linux/init.h> +#include <linux/rtc.h> +#include <linux/bcd.h> + +#include <asm/atariints.h> + +void __init +atari_sched_init(irqreturn_t (*timer_routine)(int, void *, struct pt_regs *)) +{ + /* set Timer C data Register */ + mfp.tim_dt_c = INT_TICKS; + /* start timer C, div = 1:100 */ + mfp.tim_ct_cd = (mfp.tim_ct_cd & 15) | 0x60; + /* install interrupt service routine for MFP Timer C */ + request_irq(IRQ_MFP_TIMC, timer_routine, IRQ_TYPE_SLOW, + "timer", timer_routine); +} + +/* ++andreas: gettimeoffset fixed to check for pending interrupt */ + +#define TICK_SIZE 10000 + +/* This is always executed with interrupts disabled. */ +unsigned long atari_gettimeoffset (void) +{ + unsigned long ticks, offset = 0; + + /* read MFP timer C current value */ + ticks = mfp.tim_dt_c; + /* The probability of underflow is less than 2% */ + if (ticks > INT_TICKS - INT_TICKS / 50) + /* Check for pending timer interrupt */ + if (mfp.int_pn_b & (1 << 5)) + offset = TICK_SIZE; + + ticks = INT_TICKS - ticks; + ticks = ticks * 10000L / INT_TICKS; + + return ticks + offset; +} + + +static void mste_read(struct MSTE_RTC *val) +{ +#define COPY(v) val->v=(mste_rtc.v & 0xf) + do { + COPY(sec_ones) ; COPY(sec_tens) ; COPY(min_ones) ; + COPY(min_tens) ; COPY(hr_ones) ; COPY(hr_tens) ; + COPY(weekday) ; COPY(day_ones) ; COPY(day_tens) ; + COPY(mon_ones) ; COPY(mon_tens) ; COPY(year_ones) ; + COPY(year_tens) ; + /* prevent from reading the clock while it changed */ + } while (val->sec_ones != (mste_rtc.sec_ones & 0xf)); +#undef COPY +} + +static void mste_write(struct MSTE_RTC *val) +{ +#define COPY(v) mste_rtc.v=val->v + do { + COPY(sec_ones) ; COPY(sec_tens) ; COPY(min_ones) ; + COPY(min_tens) ; COPY(hr_ones) ; COPY(hr_tens) ; + COPY(weekday) ; COPY(day_ones) ; COPY(day_tens) ; + COPY(mon_ones) ; COPY(mon_tens) ; COPY(year_ones) ; + COPY(year_tens) ; + /* prevent from writing the clock while it changed */ + } while (val->sec_ones != (mste_rtc.sec_ones & 0xf)); +#undef COPY +} + +#define RTC_READ(reg) \ + ({ unsigned char __val; \ + (void) atari_writeb(reg,&tt_rtc.regsel); \ + __val = tt_rtc.data; \ + __val; \ + }) + +#define RTC_WRITE(reg,val) \ + do { \ + atari_writeb(reg,&tt_rtc.regsel); \ + tt_rtc.data = (val); \ + } while(0) + + +#define HWCLK_POLL_INTERVAL 5 + +int atari_mste_hwclk( int op, struct rtc_time *t ) +{ + int hour, year; + int hr24=0; + struct MSTE_RTC val; + + mste_rtc.mode=(mste_rtc.mode | 1); + hr24=mste_rtc.mon_tens & 1; + mste_rtc.mode=(mste_rtc.mode & ~1); + + if (op) { + /* write: prepare values */ + + val.sec_ones = t->tm_sec % 10; + val.sec_tens = t->tm_sec / 10; + val.min_ones = t->tm_min % 10; + val.min_tens = t->tm_min / 10; + hour = t->tm_hour; + if (!hr24) { + if (hour > 11) + hour += 20 - 12; + if (hour == 0 || hour == 20) + hour += 12; + } + val.hr_ones = hour % 10; + val.hr_tens = hour / 10; + val.day_ones = t->tm_mday % 10; + val.day_tens = t->tm_mday / 10; + val.mon_ones = (t->tm_mon+1) % 10; + val.mon_tens = (t->tm_mon+1) / 10; + year = t->tm_year - 80; + val.year_ones = year % 10; + val.year_tens = year / 10; + val.weekday = t->tm_wday; + mste_write(&val); + mste_rtc.mode=(mste_rtc.mode | 1); + val.year_ones = (year % 4); /* leap year register */ + mste_rtc.mode=(mste_rtc.mode & ~1); + } + else { + mste_read(&val); + t->tm_sec = val.sec_ones + val.sec_tens * 10; + t->tm_min = val.min_ones + val.min_tens * 10; + hour = val.hr_ones + val.hr_tens * 10; + if (!hr24) { + if (hour == 12 || hour == 12 + 20) + hour -= 12; + if (hour >= 20) + hour += 12 - 20; + } + t->tm_hour = hour; + t->tm_mday = val.day_ones + val.day_tens * 10; + t->tm_mon = val.mon_ones + val.mon_tens * 10 - 1; + t->tm_year = val.year_ones + val.year_tens * 10 + 80; + t->tm_wday = val.weekday; + } + return 0; +} + +int atari_tt_hwclk( int op, struct rtc_time *t ) +{ + int sec=0, min=0, hour=0, day=0, mon=0, year=0, wday=0; + unsigned long flags; + unsigned char ctrl; + int pm = 0; + + ctrl = RTC_READ(RTC_CONTROL); /* control registers are + * independent from the UIP */ + + if (op) { + /* write: prepare values */ + + sec = t->tm_sec; + min = t->tm_min; + hour = t->tm_hour; + day = t->tm_mday; + mon = t->tm_mon + 1; + year = t->tm_year - atari_rtc_year_offset; + wday = t->tm_wday + (t->tm_wday >= 0); + + if (!(ctrl & RTC_24H)) { + if (hour > 11) { + pm = 0x80; + if (hour != 12) + hour -= 12; + } + else if (hour == 0) + hour = 12; + } + + if (!(ctrl & RTC_DM_BINARY)) { + BIN_TO_BCD(sec); + BIN_TO_BCD(min); + BIN_TO_BCD(hour); + BIN_TO_BCD(day); + BIN_TO_BCD(mon); + BIN_TO_BCD(year); + if (wday >= 0) BIN_TO_BCD(wday); + } + } + + /* Reading/writing the clock registers is a bit critical due to + * the regular update cycle of the RTC. While an update is in + * progress, registers 0..9 shouldn't be touched. + * The problem is solved like that: If an update is currently in + * progress (the UIP bit is set), the process sleeps for a while + * (50ms). This really should be enough, since the update cycle + * normally needs 2 ms. + * If the UIP bit reads as 0, we have at least 244 usecs until the + * update starts. This should be enough... But to be sure, + * additionally the RTC_SET bit is set to prevent an update cycle. + */ + + while( RTC_READ(RTC_FREQ_SELECT) & RTC_UIP ) { + current->state = TASK_INTERRUPTIBLE; + schedule_timeout(HWCLK_POLL_INTERVAL); + } + + local_irq_save(flags); + RTC_WRITE( RTC_CONTROL, ctrl | RTC_SET ); + if (!op) { + sec = RTC_READ( RTC_SECONDS ); + min = RTC_READ( RTC_MINUTES ); + hour = RTC_READ( RTC_HOURS ); + day = RTC_READ( RTC_DAY_OF_MONTH ); + mon = RTC_READ( RTC_MONTH ); + year = RTC_READ( RTC_YEAR ); + wday = RTC_READ( RTC_DAY_OF_WEEK ); + } + else { + RTC_WRITE( RTC_SECONDS, sec ); + RTC_WRITE( RTC_MINUTES, min ); + RTC_WRITE( RTC_HOURS, hour + pm); + RTC_WRITE( RTC_DAY_OF_MONTH, day ); + RTC_WRITE( RTC_MONTH, mon ); + RTC_WRITE( RTC_YEAR, year ); + if (wday >= 0) RTC_WRITE( RTC_DAY_OF_WEEK, wday ); + } + RTC_WRITE( RTC_CONTROL, ctrl & ~RTC_SET ); + local_irq_restore(flags); + + if (!op) { + /* read: adjust values */ + + if (hour & 0x80) { + hour &= ~0x80; + pm = 1; + } + + if (!(ctrl & RTC_DM_BINARY)) { + BCD_TO_BIN(sec); + BCD_TO_BIN(min); + BCD_TO_BIN(hour); + BCD_TO_BIN(day); + BCD_TO_BIN(mon); + BCD_TO_BIN(year); + BCD_TO_BIN(wday); + } + + if (!(ctrl & RTC_24H)) { + if (!pm && hour == 12) + hour = 0; + else if (pm && hour != 12) + hour += 12; + } + + t->tm_sec = sec; + t->tm_min = min; + t->tm_hour = hour; + t->tm_mday = day; + t->tm_mon = mon - 1; + t->tm_year = year + atari_rtc_year_offset; + t->tm_wday = wday - 1; + } + + return( 0 ); +} + + +int atari_mste_set_clock_mmss (unsigned long nowtime) +{ + short real_seconds = nowtime % 60, real_minutes = (nowtime / 60) % 60; + struct MSTE_RTC val; + unsigned char rtc_minutes; + + mste_read(&val); + rtc_minutes= val.min_ones + val.min_tens * 10; + if ((rtc_minutes < real_minutes + ? real_minutes - rtc_minutes + : rtc_minutes - real_minutes) < 30) + { + val.sec_ones = real_seconds % 10; + val.sec_tens = real_seconds / 10; + val.min_ones = real_minutes % 10; + val.min_tens = real_minutes / 10; + mste_write(&val); + } + else + return -1; + return 0; +} + +int atari_tt_set_clock_mmss (unsigned long nowtime) +{ + int retval = 0; + short real_seconds = nowtime % 60, real_minutes = (nowtime / 60) % 60; + unsigned char save_control, save_freq_select, rtc_minutes; + + save_control = RTC_READ (RTC_CONTROL); /* tell the clock it's being set */ + RTC_WRITE (RTC_CONTROL, save_control | RTC_SET); + + save_freq_select = RTC_READ (RTC_FREQ_SELECT); /* stop and reset prescaler */ + RTC_WRITE (RTC_FREQ_SELECT, save_freq_select | RTC_DIV_RESET2); + + rtc_minutes = RTC_READ (RTC_MINUTES); + if (!(save_control & RTC_DM_BINARY)) + BCD_TO_BIN (rtc_minutes); + + /* Since we're only adjusting minutes and seconds, don't interfere + with hour overflow. This avoids messing with unknown time zones + but requires your RTC not to be off by more than 30 minutes. */ + if ((rtc_minutes < real_minutes + ? real_minutes - rtc_minutes + : rtc_minutes - real_minutes) < 30) + { + if (!(save_control & RTC_DM_BINARY)) + { + BIN_TO_BCD (real_seconds); + BIN_TO_BCD (real_minutes); + } + RTC_WRITE (RTC_SECONDS, real_seconds); + RTC_WRITE (RTC_MINUTES, real_minutes); + } + else + retval = -1; + + RTC_WRITE (RTC_FREQ_SELECT, save_freq_select); + RTC_WRITE (RTC_CONTROL, save_control); + return retval; +} + +/* + * Local variables: + * c-indent-level: 4 + * tab-width: 8 + * End: + */ |