On Thu, 17 Mar 2022 18:16:17 +0100 Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx> wrote: > Hi, > > On 17/03/2022 11:28:20-0400, Hugo Villeneuve wrote: > > On Thu, 10 Mar 2022 21:58:49 +0100 > > Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx> wrote: > > > > > On 10/03/2022 11:09:18-0500, Hugo Villeneuve wrote: > > > > On Wed, 9 Mar 2022 17:22:42 +0100 > > > > Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx> wrote: > > > > > > > > > The PCF2127 doesn't support UIE because setting an alarm to fire every > > > > > second confuses the chip and the fastest we can go is an alarm every 2 > > > > > seconds. > > > > > > > > Hi Alexandre, > > > > can you describe what "confuses the chip" means? > > > > > > > > In my experimental PCF2131 driver, I activated UIE and it seems to be working fine at 1s intervals, but since it is similar to PCF2127, maybe there is still a problem and I just didn't see it. > > > > > > > > > > Did you remove uie_unsupported? Else, you may have been using uie > > > emulation. In my tests last year, the pcf2127 was failing to reassert > > > the interrupt if an alarm was set every second. The same happens on > > > other NXP based RTCs (i.e. including microcrystal ones). > > > > > > I'm going to test again soon (and also reply to your series). > > > > Hi, > > I have now access to a board with a PCF2129T. > > > > I actually did the test again this afternoon with a pcf2127... > > > I have been able to test with it by sending ioctl RTC_UIE_ON and > > confirm that it exhibits the problem you reported. Basically, the > > first alarm triggers the IRQ after 1s, as expected, but the next > > configured alarm 1s into the future never triggers the IRQ again. But > > the time/date registers seem to be updating (incrementin) correctly > > after that. > > > > ...and so we agree on what we observe. My guess is that the alarm > comparator has a latch that triggers only every second update and so you > need 2 seconds between each alarms. > > [...] > > > I even did some tests where, in pcf2127_rtc_set_alarm(), I disabled > > all the alarm registers (set to 0x80), except for the SECONDS alarm > > register. In this case, I observed that the IRQ is triggered after > > 61s. This seems to indicate that the alarm detection circuitry is > > still somewhat operating (AF flag / INT pin), but there is probably a > > bug in the IC when the configured alarm is close to current time after > > AF is set once... > > > > I also have done other tests by disabling then re-enabling AIE, > > stopping and restarting the oscillator (STOP bit), etc, but to no > > avail. > > > > However, in pcf2127_rtc_set_alarm(), if I set the alarm 2s past the > > current time, instead of 1s, then the IRQ is always triggered after > > 2s. > > > > I have opened a support case with NXP to investigate this strange > > behavior. > > Let me know if you ever get a reply. Hi Alexandre, after two months and a lot of emails with NXP awful technical support, I was never able to have a valid answer to the problem, apart from "Use a new device as the PCF2127 is not recommended for new designs" :( On the other hand, have you had time to look at my patch series for the PCF2131 driver? Thank you, Hugo. > > > > > Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx> > > > > > --- > > > > > drivers/rtc/rtc-pcf2127.c | 1 + > > > > > 1 file changed, 1 insertion(+) > > > > > > > > > > diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c > > > > > index f8469b134411..63b275b014bd 100644 > > > > > --- a/drivers/rtc/rtc-pcf2127.c > > > > > +++ b/drivers/rtc/rtc-pcf2127.c > > > > > @@ -656,6 +656,7 @@ static int pcf2127_probe(struct device *dev, struct regmap *regmap, > > > > > pcf2127->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; > > > > > pcf2127->rtc->range_max = RTC_TIMESTAMP_END_2099; > > > > > pcf2127->rtc->set_start_time = true; /* Sets actual start to 1970 */ > > > > > + set_bit(RTC_FEATURE_ALARM_RES_2S, pcf2127->rtc->features); > > > > > clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, pcf2127->rtc->features); > > > > > clear_bit(RTC_FEATURE_ALARM, pcf2127->rtc->features); > > > > > > > > > > -- > > > > > 2.35.1 > > > > > > > > > > > > > > > > > -- > > > > Hugo Villeneuve <hugo@xxxxxxxxxxx> > > > > > > -- > > > Alexandre Belloni, co-owner and COO, Bootlin > > > Embedded Linux and Kernel engineering > > > https://bootlin.com > > > > > > > > > -- > > Hugo Villeneuve <hugo@xxxxxxxxxxx> > > -- > Alexandre Belloni, co-owner and COO, Bootlin > Embedded Linux and Kernel engineering > https://bootlin.com > -- Hugo Villeneuve <hugo@xxxxxxxxxxx>
