v4.19.13 snapshot.
diff --git a/arch/m68k/atari/time.c b/arch/m68k/atari/time.c
new file mode 100644
index 0000000..9cca642
--- /dev/null
+++ b/arch/m68k/atari/time.c
@@ -0,0 +1,293 @@
+/*
+ * 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/delay.h>
+#include <linux/export.h>
+
+#include <asm/atariints.h>
+
+DEFINE_SPINLOCK(rtc_lock);
+EXPORT_SYMBOL_GPL(rtc_lock);
+
+void __init
+atari_sched_init(irq_handler_t timer_routine)
+{
+    /* 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, timer_routine, 0, "timer", timer_routine))
+	pr_err("Couldn't register timer interrupt\n");
+}
+
+/* ++andreas: gettimeoffset fixed to check for pending interrupt */
+
+#define TICK_SIZE 10000
+
+/* This is always executed with interrupts disabled.  */
+u32 atari_gettimeoffset(void)
+{
+  u32 ticks, offset = 0;
+
+  /* read MFP timer C current value */
+  ticks = st_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 (st_mfp.int_pn_b & (1 << 5))
+      offset = TICK_SIZE;
+
+  ticks = INT_TICKS - ticks;
+  ticks = ticks * 10000L / INT_TICKS;
+
+  return (ticks + offset) * 1000;
+}
+
+
+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 );
+}
+
+/*
+ * Local variables:
+ *  c-indent-level: 4
+ *  tab-width: 8
+ * End:
+ */