linux-kernel - Re: [PATCH] drivers: mfd: da9063: Add restart notifier implementation

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Message-ID: <CA+zEjCsf6m8cctHNPBxJczg-J9XC-piAcdtNDO71qmtCtDj9gw@mail.gmail.com>
Date:   Tue, 5 Oct 2021 15:43:23 +0200
From:   Alexandre Ghiti <alexandre.ghiti@...onical.com>
To:     Adam Thomson <Adam.Thomson.Opensource@...semi.com>
Cc:     David Abdurachmanov <david.abdurachmanov@...il.com>,
        Support Opensource <Support.Opensource@...semi.com>,
        Lee Jones <lee.jones@...aro.org>,
        "linux-riscv@...ts.infradead.org" <linux-riscv@...ts.infradead.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] drivers: mfd: da9063: Add restart notifier implementation

On Mon, Oct 4, 2021 at 5:11 PM Adam Thomson
<Adam.Thomson.Opensource@...semi.com> wrote:
>
> On 04 October 2021 13:05, Alexandre Ghiti wrote:
>
> > > > Today I was looking into OpenBSD DA9063 drivers and they might be
> > > > doing what you described for the reset.
> > > >
> > > > dev/fdt/dapmic.c
> > > >
> > > > [..]
> > > > 241 void
> > > > 242 dapmic_reset(void)
> > > > 243 {
> > > > 244     struct dapmic_softc *sc = dapmic_cd.cd_devs[0];
> > > > 245     uint8_t reg;
> > > > 246
> > > > 247     /* Enable tick alarm wakeup with a one second interval. */
> > > > 248     reg = dapmic_reg_read(sc, ALARM_MO);
> > > > 249     reg &= ~ALARM_MO_TICK_TYPE;
> > > > 250     reg |= ALARM_MO_TICK_WAKE;
> > > > 251     dapmic_reg_write(sc, ALARM_MO, reg);
> > > > 252
> > > > 253     /* Enable tick function. */
> > > > 254     reg = dapmic_reg_read(sc, ALARM_Y);
> > > > 255     reg |= ALARM_Y_TICK_ON;
> > > > 256     dapmic_reg_write(sc, ALARM_Y, reg);
> > > > 257
> > > > 258     /* Clear events such that we wake up again. */
> > > > 259     dapmic_reg_write(sc, EVENT_A, dapmic_reg_read(sc, EVENT_A));
> > > > 260     dapmic_reg_write(sc, CONTROL_F, CONTROL_F_SHUTDOWN);
> > > > 261 }
> > > > [..]
> > > >
> > >
> > > Thanks for the pointer! I have just tested this sequence from the
> > > u-boot shell, it resets the board correctly. But then if we try to
> > > power down the board by a long press to the corresponding button on
> > > the board within 16 seconds, it resets the board: so we cannot
> > > shutdown the board in the next 16 seconds that follow this sequence.
> > >
> > > Maybe that can be resolved by using the one-shot alarm as described by
> > > Adam, I'll try to find that in the datasheet.
> >
> > After configuring the one-shot alarm, I still have those intempestive
> > reboots if I try to power down the board by a long press within 16
> > seconds. The only thing I found in the datasheet regarding this timing
> > is in case of power undervoltage, not sure how this is linked to what
> > I see.
> >
> > @Adam Thomson Any ideas?
>
> Nothing immediately springs to mind. Can you confirm this is the nONKEY long
> press that you're attempting here, which is resetting the board rather than
> shutting down?

Yes, this is the nONKEY long press that, if done within ~16sec after
the board is reset using the alarm, resets the board instead of
shutting it down.

>
> Also, would you able to again provide events and fault log when this unwanted
> reset occurs, just in case there's anything there to give a clue. Can then
> discuss internally to see if we can ascertain what might be happening here.

FAULT_LOG = 0x60
EVENT_A = 0x12
EVENT_B to EVENT_D = 0

But I'm unsure of those values since they are the same after the reset
triggered by the one-shot alarm *and* if I clear EVENT_A, the
intempestive reboot does not appear!

Thanks,

Alex