Re: Allwinner RTC

["Jonathan A. Kollasch" <jakllsch%kollasch.net@localhost>]

On Fri, Nov 07, 2014 at 08:48:53AM -0600, Jonathan A. Kollasch wrote:
> On Fri, Nov 07, 2014 at 08:33:49AM -0600, Jonathan A. Kollasch wrote:
> > 
> > Currently whenever I boot NetBSD on my Cubietruck after booting the
> > Android system in NAND the clock is exactly 70 years in the future.
> > 
> > I've looked at the linux-sunxi/drivers/rtc/rtc-sun4i.c code and it
> > appears than all RTCs supported by rtc-sun4i except the sun7i (A20)
> > implement a 63-year RTC based at 1970.  The sun7i uses a 255-year RTC
> > register layout and is based at 1900.
> > 
> > Comparing this to src/sys/arch/arm/allwinner/awin_rtc.c v1.6, I seem to
> > find that we only do as Linux on the A30 chips.
> > 
> > Does anyone have Linux/Android booting on a A10-based system to confirm
> > that it uses the 63-year 1970-based RTC?  I believe you would find that
> > that NetBSD would think it was 70 years earlier than Linux on A10.
> 
> Looking at the A10 User Manual, it seems to indicate it has a 63-year RTC.

Proposed change attached.

	Jonathan Kollasch

Index: sys/arch/arm/allwinner/awin_reg.h
===================================================================
RCS file: /cvsroot/src/sys/arch/arm/allwinner/awin_reg.h,v
retrieving revision 1.42
diff -d -u -a -p -r1.42 awin_reg.h
--- sys/arch/arm/allwinner/awin_reg.h	5 Nov 2014 15:05:20 -0000	1.42
+++ sys/arch/arm/allwinner/awin_reg.h	7 Nov 2014 15:43:24 -0000
@@ -1517,8 +1517,10 @@ struct awin_mmc_idma_descriptor {
 	 AWIN_LOSC_CTRL_RTC_YYMMDD_ACCE)
 
 #define AWIN_RTC_YY_MM_DD_RTC_SIM_CTRL	__BIT(30)
-#define AWIN_RTC_YY_MM_DD_LEAP		__BIT(24)
-#define AWIN_RTC_YY_MM_DD_YEAR		__BITS(23,16)
+#define AWIN_RTC_YY_MM_DD_LEAP		__BIT(22)
+#define AWIN_A20_RTC_YY_MM_DD_LEAP	__BIT(24)
+#define AWIN_RTC_YY_MM_DD_YEAR		__BITS(21,16)
+#define AWIN_A20_RTC_YY_MM_DD_YEAR	__BITS(23,16)
 #define AWIN_RTC_YY_MM_DD_MONTH		__BITS(11,8)
 #define AWIN_RTC_YY_MM_DD_DAY		__BITS(4,0)
 #define AWIN_RTC_HH_MM_SS_WK_NO		__BITS(31,29)
@@ -1907,8 +1909,6 @@ struct awin_mmc_idma_descriptor {
 #define AWIN_A31_RTC_YY_MM_DD_REG		0x0010
 #define AWIN_A31_RTC_HH_MM_SS_REG		0x0014
 
-#define AWIN_A31_RTC_YY_MM_DD_YEAR		__BITS(21,16)
-
 #define AWIN_A31_P2WI_CTRL_REG			0x0000
 #define AWIN_A31_P2WI_CCR_REG			0x0004
 #define AWIN_A31_P2WI_INTE_REG			0x0008
Index: sys/arch/arm/allwinner/awin_rtc.c
===================================================================
RCS file: /cvsroot/src/sys/arch/arm/allwinner/awin_rtc.c,v
retrieving revision 1.6
diff -d -u -a -p -r1.6 awin_rtc.c
--- sys/arch/arm/allwinner/awin_rtc.c	4 Nov 2014 19:22:50 -0000	1.6
+++ sys/arch/arm/allwinner/awin_rtc.c	7 Nov 2014 15:43:24 -0000
@@ -49,6 +49,8 @@ struct awin_rtc_softc {
 	uint32_t sc_loscctrl_reg;
 	uint32_t sc_yymmdd_reg;
 	uint32_t sc_hhmmss_reg;
+	uint32_t sc_year_base;
+	uint32_t sc_year_mask;
 };
 
 #define RTC_READ(sc, reg) \
@@ -99,6 +101,14 @@ awin_rtc_attach(device_t parent, device_
 		sc->sc_hhmmss_reg = AWIN_RTC_HH_MM_SS_REG;
 	}
 
+	if (awin_chip_id() == AWIN_CHIP_ID_A20) {
+		sc->sc_year_base = 1900;
+		sc->sc_year_mask = AWIN_A20_RTC_YY_MM_DD_YEAR;
+	} else {
+		sc->sc_year_base = 1970;
+		sc->sc_year_mask = AWIN_RTC_YY_MM_DD_YEAR;
+	}
+
 	aprint_naive("\n");
 	aprint_normal(": RTC\n");
 
@@ -117,10 +127,7 @@ awin_rtc_gettime(todr_chip_handle_t tch,
 	yymmdd = RTC_READ(sc, sc->sc_yymmdd_reg);
 	hhmmss = RTC_READ(sc, sc->sc_hhmmss_reg);
 
-	dt->dt_year = __SHIFTOUT(yymmdd,
-	    awin_chip_id() == AWIN_CHIP_ID_A31 ?
-	    AWIN_A31_RTC_YY_MM_DD_YEAR : AWIN_RTC_YY_MM_DD_YEAR) +
-	    POSIX_BASE_YEAR;
+	dt->dt_year = __SHIFTOUT(yymmdd, sc->sc_year_mask) + sc->sc_year_base;
 	dt->dt_mon = __SHIFTOUT(yymmdd, AWIN_RTC_YY_MM_DD_MONTH);
 	dt->dt_day = __SHIFTOUT(yymmdd, AWIN_RTC_YY_MM_DD_DAY);
 	dt->dt_wday = __SHIFTOUT(hhmmss, AWIN_RTC_HH_MM_SS_WK_NO);
@@ -149,24 +156,18 @@ awin_rtc_settime(todr_chip_handle_t tch,
 		    "not writing back time\n", dt->dt_year);
 		return EIO;
 	}
-	maxyear = __SHIFTOUT(0xffffffff, 
-	    awin_chip_id() == AWIN_CHIP_ID_A31 ?
-	    AWIN_A31_RTC_YY_MM_DD_YEAR : AWIN_RTC_YY_MM_DD_YEAR)
-	    + POSIX_BASE_YEAR;
+	maxyear = __SHIFTOUT(0xffffffff, sc->sc_year_mask) + sc->sc_year_base;
 	if (dt->dt_year > maxyear) {
 		aprint_normal_dev(sc->sc_dev, "year exceeds available field:"
 		    " %llu, not writing back time\n", dt->dt_year);
 		return EIO;
 	}
 
-	yymmdd = __SHIFTIN(dt->dt_year - POSIX_BASE_YEAR,
-	    awin_chip_id() == AWIN_CHIP_ID_A31 ?
-	    AWIN_A31_RTC_YY_MM_DD_YEAR : AWIN_RTC_YY_MM_DD_YEAR);
+	yymmdd = __SHIFTIN(dt->dt_year - sc->sc_year_base,
+	    sc->sc_year_mask);
 
-	KASSERT(__SHIFTOUT(yymmdd,
-	    awin_chip_id() == AWIN_CHIP_ID_A31 ?
-	    AWIN_A31_RTC_YY_MM_DD_YEAR : AWIN_RTC_YY_MM_DD_YEAR) +
-	    POSIX_BASE_YEAR == dt->dt_year);
+	KASSERT(__SHIFTOUT(yymmdd, sc->sc_year_mask) +
+	    sc->sc_year_base == dt->dt_year);
 
 	yymmdd |= __SHIFTIN(dt->dt_mon, AWIN_RTC_YY_MM_DD_MONTH);
 	yymmdd |= __SHIFTIN(dt->dt_day, AWIN_RTC_YY_MM_DD_DAY);