| Message ID | 20190320113010.8955-3-alexandre.belloni@bootlin.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/3] rtc: sh: stop resetting time to epoch | expand |
On Wed, Mar 20, 2019 at 12:30 PM Alexandre Belloni <alexandre.belloni@bootlin.com> wrote: > The SH RTC is a BCD RTC with some version having 4 digits for the year. > > The range for the RTCs with only 2 digits for the year was unfortunately > shifted to handle 1999 to 2098. > > Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> > --- a/include/linux/rtc.h > +++ b/include/linux/rtc.h > @@ -165,6 +165,7 @@ struct rtc_device { > #define RTC_TIMESTAMP_BEGIN_1900 -2208989361LL /* 1900-01-01 00:00:00 */ mktime64(1900, 1, 1, 0, 0, 0) = -2208988800 ?? Is this due to leap seconds, and mktime64() is valid for 1970 and later only? Gr{oetje,eeting}s, Geert
On 21/03/2019 11:22:26+0100, Geert Uytterhoeven wrote: > On Wed, Mar 20, 2019 at 12:30 PM Alexandre Belloni > <alexandre.belloni@bootlin.com> wrote: > > The SH RTC is a BCD RTC with some version having 4 digits for the year. > > > > The range for the RTCs with only 2 digits for the year was unfortunately > > shifted to handle 1999 to 2098. > > > > Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> > > Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> > > > --- a/include/linux/rtc.h > > +++ b/include/linux/rtc.h > > @@ -165,6 +165,7 @@ struct rtc_device { > > #define RTC_TIMESTAMP_BEGIN_1900 -2208989361LL /* 1900-01-01 00:00:00 */ > > mktime64(1900, 1, 1, 0, 0, 0) = -2208988800 ?? > > Is this due to leap seconds, and mktime64() is valid for 1970 and later only? > That's a bug, it seems I didn't use the correct timezone when doing the calculation. Thanks for spotting that, you can send a patch to correct it or I can do it.
Hi Alexander, On Fri, Mar 22, 2019 at 7:12 AM Alexandre Belloni <alexandre.belloni@bootlin.com> wrote: > On 21/03/2019 11:22:26+0100, Geert Uytterhoeven wrote: > > On Wed, Mar 20, 2019 at 12:30 PM Alexandre Belloni > > <alexandre.belloni@bootlin.com> wrote: > > > The SH RTC is a BCD RTC with some version having 4 digits for the year. > > > > > > The range for the RTCs with only 2 digits for the year was unfortunately > > > shifted to handle 1999 to 2098. > > > > > > Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> > > > > Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> > > > > > --- a/include/linux/rtc.h > > > +++ b/include/linux/rtc.h > > > @@ -165,6 +165,7 @@ struct rtc_device { > > > #define RTC_TIMESTAMP_BEGIN_1900 -2208989361LL /* 1900-01-01 00:00:00 */ > > > > mktime64(1900, 1, 1, 0, 0, 0) = -2208988800 ?? > > > > Is this due to leap seconds, and mktime64() is valid for 1970 and later only? > > > > That's a bug, it seems I didn't use the correct timezone when doing the > calculation. Thanks for spotting that, you can send a patch to correct > it or I can do it. Thanks for confirming, done. Gr{oetje,eeting}s, Geert
diff --git a/drivers/rtc/rtc-sh.c b/drivers/rtc/rtc-sh.c index b582af10ddb5..37964a867de7 100644 --- a/drivers/rtc/rtc-sh.c +++ b/drivers/rtc/rtc-sh.c @@ -601,6 +601,14 @@ static int __init sh_rtc_probe(struct platform_device *pdev) rtc->rtc_dev->ops = &sh_rtc_ops; rtc->rtc_dev->max_user_freq = 256; + if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) { + rtc->rtc_dev->range_min = RTC_TIMESTAMP_BEGIN_1900; + rtc->rtc_dev->range_max = RTC_TIMESTAMP_END_9999; + } else { + rtc->rtc_dev->range_min = mktime64(1999, 1, 1, 0, 0, 0); + rtc->rtc_dev->range_max = mktime64(2098, 12, 31, 23, 59, 59); + } + ret = rtc_register_device(rtc->rtc_dev); if (ret) goto err_unmap; diff --git a/include/linux/rtc.h b/include/linux/rtc.h index f89bfbb54902..588120ba372c 100644 --- a/include/linux/rtc.h +++ b/include/linux/rtc.h @@ -165,6 +165,7 @@ struct rtc_device { #define RTC_TIMESTAMP_BEGIN_1900 -2208989361LL /* 1900-01-01 00:00:00 */ #define RTC_TIMESTAMP_BEGIN_2000 946684800LL /* 2000-01-01 00:00:00 */ #define RTC_TIMESTAMP_END_2099 4102444799LL /* 2099-12-31 23:59:59 */ +#define RTC_TIMESTAMP_END_9999 253402300799LL /* 9999-12-31 23:59:59 */ extern struct rtc_device *devm_rtc_device_register(struct device *dev, const char *name,
The SH RTC is a BCD RTC with some version having 4 digits for the year. The range for the RTCs with only 2 digits for the year was unfortunately shifted to handle 1999 to 2098. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> --- drivers/rtc/rtc-sh.c | 8 ++++++++ include/linux/rtc.h | 1 + 2 files changed, 9 insertions(+)