On Thu, 3 Oct 2024, Alexandre Belloni wrote: > 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? > Sure, I will look into it. > 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. > I can't test any patches on SPARC, unless there's some way to do so using QEMU that would satisfy maintainers. (I rely on Daniel to test my patches on an MVME147 system.)
