diff options
Diffstat (limited to 'arch/m68k/atari/time.c')
| -rw-r--r-- | arch/m68k/atari/time.c | 319 |
1 files changed, 319 insertions, 0 deletions
diff --git a/arch/m68k/atari/time.c b/arch/m68k/atari/time.c new file mode 100644 index 000000000..7e44d0e9d --- /dev/null +++ b/arch/m68k/atari/time.c @@ -0,0 +1,319 @@ +/* + * 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 <linux/clocksource.h> +#include <linux/delay.h> +#include <linux/export.h> + +#include <asm/atariints.h> +#include <asm/machdep.h> + +DEFINE_SPINLOCK(rtc_lock); +EXPORT_SYMBOL_GPL(rtc_lock); + +static u64 atari_read_clk(struct clocksource *cs); + +static struct clocksource atari_clk = { + .name = "mfp", + .rating = 100, + .read = atari_read_clk, + .mask = CLOCKSOURCE_MASK(32), + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +static u32 clk_total; +static u8 last_timer_count; + +static irqreturn_t mfp_timer_c_handler(int irq, void *dev_id) +{ + unsigned long flags; + + local_irq_save(flags); + do { + last_timer_count = st_mfp.tim_dt_c; + } while (last_timer_count == 1); + clk_total += INT_TICKS; + legacy_timer_tick(1); + timer_heartbeat(); + local_irq_restore(flags); + + return IRQ_HANDLED; +} + +void __init +atari_sched_init(void) +{ + /* set Timer C data Register */ + st_mfp.tim_dt_c = INT_TICKS; + /* start timer C, div = 1:100 */ + st_mfp.tim_ct_cd = (st_mfp.tim_ct_cd & 15) | 0x60; + /* install interrupt service routine for MFP Timer C */ + if (request_irq(IRQ_MFP_TIMC, mfp_timer_c_handler, IRQF_TIMER, "timer", + NULL)) + pr_err("Couldn't register timer interrupt\n"); + + clocksource_register_hz(&atari_clk, INT_CLK); +} + +/* ++andreas: gettimeoffset fixed to check for pending interrupt */ + +static u64 atari_read_clk(struct clocksource *cs) +{ + unsigned long flags; + u8 count; + u32 ticks; + + local_irq_save(flags); + /* Ensure that the count is monotonically decreasing, even though + * the result may briefly stop changing after counter wrap-around. + */ + count = min(st_mfp.tim_dt_c, last_timer_count); + last_timer_count = count; + + ticks = INT_TICKS - count; + ticks += clk_total; + local_irq_restore(flags); + + return ticks; +} + + +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)) { + sec = bin2bcd(sec); + min = bin2bcd(min); + hour = bin2bcd(hour); + day = bin2bcd(day); + mon = bin2bcd(mon); + year = bin2bcd(year); + if (wday >= 0) + wday = bin2bcd(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 ) { + if (in_atomic() || irqs_disabled()) + mdelay(1); + else + schedule_timeout_interruptible(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)) { + sec = bcd2bin(sec); + min = bcd2bin(min); + hour = bcd2bin(hour); + day = bcd2bin(day); + mon = bcd2bin(mon); + year = bcd2bin(year); + wday = bcd2bin(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 ); +} |