Use the same inittodr()/resettodr() implementation as on

amd64/arm64/armv7/sparc64 and move it to the end of machdep.c.  Rework the
actual implementation for the MC14818 compatible RTC into something that can
be used as a todr_handle just like on amd64.

ok sthen@

3 files changed, 146 insertions, 88 deletions

diff --git a/sys/arch/i386/i386/machdep.c b/sys/arch/i386/i386/machdep.c
index 765d8dd57ab..7600f40c446 100644
--- a/sys/arch/i386/i386/machdep.c
+++ b/sys/arch/i386/i386/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.631 2019/06/14 18:13:55 kettenis Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.632 2020/04/29 08:53:45 kettenis Exp $	*/
 /*	$NetBSD: machdep.c,v 1.214 1996/11/10 03:16:17 thorpej Exp $	*/
 
 /*-
@@ -378,6 +378,7 @@ cpu_startup(void)
 
 	printf("%s", version);
 	startclocks();
+	rtcinit();
 
 	printf("real mem  = %llu (%lluMB)\n",
 	    (unsigned long long)ptoa((psize_t)physmem),
@@ -4037,3 +4038,91 @@ intr_barrier(void *ih)
 	sched_barrier(NULL);
 }
 
+#include <sys/timetc.h>
+#include <dev/clock_subr.h>
+
+todr_chip_handle_t todr_handle;
+
+#define MINYEAR		((OpenBSD / 100) - 1)	/* minimum plausible year */
+
+/*
+ * inittodr:
+ *
+ *      Initialize time from the time-of-day register.
+ */
+void
+inittodr(time_t base)
+{
+	time_t deltat;
+	struct timeval rtctime;
+	struct timespec ts;
+	int badbase;
+
+	if (base < (MINYEAR - 1970) * SECYR) {
+		printf("WARNING: preposterous time in file system\n");
+		/* read the system clock anyway */
+		base = (MINYEAR - 1970) * SECYR;
+		badbase = 1;
+	} else
+		badbase = 0;
+
+	if (todr_handle == NULL ||
+	    todr_gettime(todr_handle, &rtctime) != 0 ||
+	    rtctime.tv_sec < (MINYEAR - 1970) * SECYR) {
+		/*
+		 * Believe the time in the file system for lack of
+		 * anything better, resetting the TODR.
+		 */
+		rtctime.tv_sec = base;
+		rtctime.tv_usec = 0;
+		if (todr_handle != NULL && !badbase)
+			printf("WARNING: bad clock chip time\n");
+		ts.tv_sec = rtctime.tv_sec;
+		ts.tv_nsec = rtctime.tv_usec * 1000;
+		tc_setclock(&ts);
+		goto bad;
+	} else {
+		ts.tv_sec = rtctime.tv_sec;
+		ts.tv_nsec = rtctime.tv_usec * 1000;
+		tc_setclock(&ts);
+	}
+
+	if (!badbase) {
+		/*
+		 * See if we gained/lost two or more days; if
+		 * so, assume something is amiss.
+		 */
+		deltat = rtctime.tv_sec - base;
+		if (deltat < 0)
+			deltat = -deltat;
+		if (deltat < 2 * SECDAY)
+			return;         /* all is well */
+#ifndef SMALL_KERNEL
+		printf("WARNING: clock %s %lld days\n",
+		    rtctime.tv_sec < base ? "lost" : "gained",
+		    (long long)(deltat / SECDAY));
+#endif
+	}
+ bad:
+	printf("WARNING: CHECK AND RESET THE DATE!\n");
+}
+
+/*
+ * resettodr:
+ *
+ *      Reset the time-of-day register with the current time.
+ */
+void
+resettodr(void)
+{
+	struct timeval rtctime;
+
+	if (time_second == 1)
+		return;
+
+	microtime(&rtctime);
+
+	if (todr_handle != NULL &&
+	    todr_settime(todr_handle, &rtctime) != 0)
+		printf("WARNING: can't update clock chip time\n");
+}
diff --git a/sys/arch/i386/include/cpu.h b/sys/arch/i386/include/cpu.h
index 8f8d0535687..63e5e840e96 100644
--- a/sys/arch/i386/include/cpu.h
+++ b/sys/arch/i386/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.168 2019/12/20 07:55:30 jsg Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.169 2020/04/29 08:53:45 kettenis Exp $	*/
 /*	$NetBSD: cpu.h,v 1.35 1996/05/05 19:29:26 christos Exp $	*/
 
 /*-
@@ -421,7 +421,7 @@ void	proc_trampoline(void);
 /* clock.c */
 extern void (*initclock_func)(void);
 void	startclocks(void);
-void	rtcdrain(void *);
+void	rtcinit(void);
 void	rtcstart(void);
 void	rtcstop(void);
 void	i8254_delay(int);
diff --git a/sys/arch/i386/isa/clock.c b/sys/arch/i386/isa/clock.c
index 2b3fe2e626f..836ac088662 100644
--- a/sys/arch/i386/isa/clock.c
+++ b/sys/arch/i386/isa/clock.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: clock.c,v 1.56 2019/08/22 01:11:19 deraadt Exp $	*/
+/*	$OpenBSD: clock.c,v 1.57 2020/04/29 08:53:45 kettenis Exp $	*/
 /*	$NetBSD: clock.c,v 1.39 1996/05/12 23:11:54 mycroft Exp $	*/
 
 /*-
@@ -99,6 +99,7 @@ WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 #include <machine/pio.h>
 #include <machine/cpufunc.h>
 
+#include <dev/clock_subr.h>
 #include <dev/isa/isareg.h>
 #include <dev/isa/isavar.h>
 #include <dev/ic/mc146818reg.h>
@@ -110,8 +111,6 @@ int	clockintr(void *);
 int	gettick(void);
 int	rtcget(mc_todregs *);
 void	rtcput(mc_todregs *);
-int	hexdectodec(int);
-int	dectohexdec(int);
 int	rtcintr(void *);
 void	rtcdrain(void *);
 int	calibrate_cyclecounter_ctr(void);
@@ -481,21 +480,17 @@ rtcput(mc_todregs *regs)
 }
 
 int
-hexdectodec(int n)
+bcdtobin(int n)
 {
-
 	return (((n >> 4) & 0x0f) * 10 + (n & 0x0f));
 }
 
 int
-dectohexdec(int n)
+bintobcd(int n)
 {
-
 	return ((u_char)(((n / 10) << 4) & 0xf0) | ((n % 10) & 0x0f));
 }
 
-static int timeset;
-
 /*
  * check whether the CMOS layout is "standard"-like (ie, not PS/2-like),
  * to be called at splclock()
@@ -551,7 +546,7 @@ clock_expandyear(int clockyear)
 #endif
 		return (clockyear);
 	}
-	cmoscentury = hexdectodec(cmoscentury);
+	cmoscentury = bcdtobin(cmoscentury);
 
 	if (cmoscentury != clockcentury) {
 		/* XXX note: saying "century is 20" might confuse the naive. */
@@ -566,7 +561,7 @@ clock_expandyear(int clockyear)
 			       clockcentury);
 			s = splclock();
 			mc146818_write(NULL, NVRAM_CENTURY,
-				       dectohexdec(clockcentury));
+				       bintobcd(clockcentury));
 			splx(s);
 		}
 	} else if (cmoscentury == 19 && rtc_update_century == 0)
@@ -575,110 +570,84 @@ clock_expandyear(int clockyear)
 	return (clockyear);
 }
 
-/*
- * Initialize the time of day register, based on the time base which is, e.g.
- * from a filesystem.
- */
-void
-inittodr(time_t base)
+int
+rtcgettime(struct todr_chip_handle *handle, struct timeval *tv)
 {
-	struct timespec ts;
 	mc_todregs rtclk;
 	struct clock_ymdhms dt;
 	int s;
-
-
-	ts.tv_nsec = 0;
-
-	/*
-	 * We mostly ignore the suggested time and go for the RTC clock time
-	 * stored in the CMOS RAM.  If the time can't be obtained from the
-	 * CMOS, or if the time obtained from the CMOS is 5 or more years
-	 * less than the suggested time, we used the suggested time.  (In
-	 * the latter case, it's likely that the CMOS battery has died.)
-	 */
-
-	if (base < 15*SECYR) {	/* if before 1985, something's odd... */
-		printf("WARNING: preposterous time in file system\n");
-		/* read the system clock anyway */
-		base = 17*SECYR + 186*SECDAY + SECDAY/2;
-	}
-
+	
 	s = splclock();
 	if (rtcget(&rtclk)) {
 		splx(s);
-		printf("WARNING: invalid time in clock chip\n");
-		goto fstime;
+		return EINVAL;
 	}
 	splx(s);
 
-	dt.dt_sec = hexdectodec(rtclk[MC_SEC]);
-	dt.dt_min = hexdectodec(rtclk[MC_MIN]);
-	dt.dt_hour = hexdectodec(rtclk[MC_HOUR]);
-	dt.dt_day = hexdectodec(rtclk[MC_DOM]);
-	dt.dt_mon = hexdectodec(rtclk[MC_MONTH]);
-	dt.dt_year = clock_expandyear(hexdectodec(rtclk[MC_YEAR]));
-
-	ts.tv_sec = clock_ymdhms_to_secs(&dt) - utc_offset;
-
-	if (base < ts.tv_sec - 5*SECYR)
-		printf("WARNING: file system time much less than clock time\n");
-	else if (base > ts.tv_sec + 5*SECYR) {
-		printf("WARNING: clock time much less than file system time\n");
-		printf("WARNING: using file system time\n");
-		goto fstime;
-	}
+#ifdef CLOCK_DEBUG
+	printf("readclock: %x/%x/%x %x:%x:%x\n", rtclk[MC_YEAR],
+	    rtclk[MC_MONTH], rtclk[MC_DOM], rtclk[MC_HOUR], rtclk[MC_MIN],
+	    rtclk[MC_SEC]);
+#endif
 
-	tc_setclock(&ts);
-	timeset = 1;
-	return;
+	dt.dt_sec = bcdtobin(rtclk[MC_SEC]);
+	dt.dt_min = bcdtobin(rtclk[MC_MIN]);
+	dt.dt_hour = bcdtobin(rtclk[MC_HOUR]);
+	dt.dt_day = bcdtobin(rtclk[MC_DOM]);
+	dt.dt_mon = bcdtobin(rtclk[MC_MONTH]);
+	dt.dt_year = clock_expandyear(bcdtobin(rtclk[MC_YEAR]));
 
-fstime:
-	ts.tv_sec = base;
-	tc_setclock(&ts);
-	timeset = 1;
-	printf("WARNING: CHECK AND RESET THE DATE!\n");
+	tv->tv_sec = clock_ymdhms_to_secs(&dt) - utc_offset;
+	tv->tv_usec = 0;
+	return 0;
 }
 
-/*
- * Reset the clock.
- */
-void
-resettodr(void)
+int
+rtcsettime(struct todr_chip_handle *handle, struct timeval *tv)
 {
 	mc_todregs rtclk;
 	struct clock_ymdhms dt;
-	int century;
-	int s;
-
-	/*
-	 * We might have been called by boot() due to a crash early
-	 * on.  Don't reset the clock chip in this case.
-	 */
-	if (!timeset)
-		return;
+	int century, s;
 
 	s = splclock();
 	if (rtcget(&rtclk))
-		bzero(&rtclk, sizeof(rtclk));
+		memset(&rtclk, 0, sizeof(rtclk));
 	splx(s);
 
 	clock_secs_to_ymdhms(time_second + utc_offset, &dt);
 
-	rtclk[MC_SEC] = dectohexdec(dt.dt_sec);
-	rtclk[MC_MIN] = dectohexdec(dt.dt_min);
-	rtclk[MC_HOUR] = dectohexdec(dt.dt_hour);
-	rtclk[MC_DOW] = dt.dt_wday;
-	rtclk[MC_YEAR] = dectohexdec(dt.dt_year % 100);
-	rtclk[MC_MONTH] = dectohexdec(dt.dt_mon);
-	rtclk[MC_DOM] = dectohexdec(dt.dt_day);
+	rtclk[MC_SEC] = bintobcd(dt.dt_sec);
+	rtclk[MC_MIN] = bintobcd(dt.dt_min);
+	rtclk[MC_HOUR] = bintobcd(dt.dt_hour);
+	rtclk[MC_DOW] = dt.dt_wday + 1;
+	rtclk[MC_YEAR] = bintobcd(dt.dt_year % 100);
+	rtclk[MC_MONTH] = bintobcd(dt.dt_mon);
+	rtclk[MC_DOM] = bintobcd(dt.dt_day);
+
+#ifdef CLOCK_DEBUG
+	printf("setclock: %x/%x/%x %x:%x:%x\n", rtclk[MC_YEAR], rtclk[MC_MONTH],
+	   rtclk[MC_DOM], rtclk[MC_HOUR], rtclk[MC_MIN], rtclk[MC_SEC]);
+#endif
+
 	s = splclock();
 	rtcput(&rtclk);
 	if (rtc_update_century > 0) {
-		century = dectohexdec(dt.dt_year / 100);
+		century = bintobcd(dt.dt_year / 100);
 		mc146818_write(NULL, NVRAM_CENTURY, century); /* XXX softc */
 	}
 	splx(s);
+	return 0;
+}
+
+extern todr_chip_handle_t todr_handle;
+struct todr_chip_handle rtc_todr;
+
+void
+rtcinit(void)
+{
+	rtc_todr.todr_gettime = rtcgettime;
+	rtc_todr.todr_settime = rtcsettime;
+	todr_handle = &rtc_todr;
 }
 
 void