Hello, On 03/10/2024 13:23:22+1000, Finn Thain wrote: > The m48t59 driver is needed by both SPARC and MVME systems. Linux on > MVME uses 1970 as "year zero" rather than 1968 that's used on SPARC. > Add support for the MVME convention. Otherwise, the RTC on non-SPARC > systems can only read and write dates between 1900 and 1999. > > Tested-by: Daniel Palmer <daniel@xxxxxxxx> > Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxx> > --- > drivers/rtc/rtc-m48t59.c | 31 +++++++++++++++---------------- > 1 file changed, 15 insertions(+), 16 deletions(-) > > diff --git a/drivers/rtc/rtc-m48t59.c b/drivers/rtc/rtc-m48t59.c > index f0f6b9b6daec..e2d882ea5c2f 100644 > --- a/drivers/rtc/rtc-m48t59.c > +++ b/drivers/rtc/rtc-m48t59.c > @@ -57,6 +57,17 @@ m48t59_mem_readb(struct device *dev, u32 ofs) > return readb(m48t59->ioaddr+ofs); > } > > +/* > + * Sun SPARC machines count years since 1968. MVME machines running Linux > + * count years since 1970. > + */ > + > +#ifdef CONFIG_SPARC > +#define YEAR0 68 > +#else > +#define YEAR0 70 > +#endif > + > /* > * NOTE: M48T59 only uses BCD mode > */ > @@ -82,10 +93,7 @@ static int m48t59_rtc_read_time(struct device *dev, struct rtc_time *tm) > dev_dbg(dev, "Century bit is enabled\n"); > tm->tm_year += 100; /* one century */ > } > -#ifdef CONFIG_SPARC > - /* Sun SPARC machines count years since 1968 */ > - tm->tm_year += 68; > -#endif > + tm->tm_year += YEAR0; > I'm super happy to see someone working on this, while you are it, can you use m48t59->rtc->start_secs and m48t59->rtc->set_start_time in probe instead of offsetting tm_year in read_time/set_time so we can later use device tree or any other mechanism to extend the range? It is super funny because I was telling Geert that I wanted to get rid of this #ifdef CONFIG_SPARC two weeks ago at LPC. That could indeed then come from platform data. > tm->tm_wday = bcd2bin(val & 0x07); > tm->tm_hour = bcd2bin(M48T59_READ(M48T59_HOUR) & 0x3F); > @@ -108,10 +116,7 @@ static int m48t59_rtc_set_time(struct device *dev, struct rtc_time *tm) > u8 val = 0; > int year = tm->tm_year; > > -#ifdef CONFIG_SPARC > - /* Sun SPARC machines count years since 1968 */ > - year -= 68; > -#endif > + year -= YEAR0; > > dev_dbg(dev, "RTC set time %04d-%02d-%02d %02d/%02d/%02d\n", > year + 1900, tm->tm_mon, tm->tm_mday, > @@ -163,10 +168,7 @@ static int m48t59_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm) > M48T59_SET_BITS(M48T59_CNTL_READ, M48T59_CNTL); > > tm->tm_year = bcd2bin(M48T59_READ(M48T59_YEAR)); > -#ifdef CONFIG_SPARC > - /* Sun SPARC machines count years since 1968 */ > - tm->tm_year += 68; > -#endif > + tm->tm_year += YEAR0; > /* tm_mon is 0-11 */ > tm->tm_mon = bcd2bin(M48T59_READ(M48T59_MONTH)) - 1; > > @@ -199,10 +201,7 @@ static int m48t59_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) > unsigned long flags; > int year = tm->tm_year; > > -#ifdef CONFIG_SPARC > - /* Sun SPARC machines count years since 1968 */ > - year -= 68; > -#endif > + year -= YEAR0; > > /* If no irq, we don't support ALARM */ > if (m48t59->irq == NO_IRQ) > -- > 2.39.5 > -- Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
