Messages in this thread | | | From | Alexandre Ghiti <> | Date | Thu, 30 Sep 2021 11:55:16 +0200 | Subject | Re: [PATCH] drivers: mfd: da9063: Add restart notifier implementation |
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Hi Adam,
Thank you for your answer.
On Wed, Sep 29, 2021 at 3:33 PM Adam Thomson <Adam.Thomson.Opensource@diasemi.com> wrote: > > On 24 September 2021 17:17, Alexandre Ghiti wrote: > > > > > +static int da9063_restart_notify(struct notifier_block *this, > > > > + unsigned long mode, void *cmd) > > > > +{ > > > > + struct da9063 *da9063 = container_of(this, struct da9063, > > > > restart_handler); > > > > + > > > > + regmap_write(da9063->regmap, DA9063_REG_PAGE_CON, 0x00); > > > > + regmap_write(da9063->regmap, DA9063_REG_CONTROL_F, 0x04); > > > > + regmap_write(da9063->regmap, DA9063_REG_CONTROL_A, 0x68); > > > > + > > > > + return NOTIFY_DONE; > > > > +} > > > > > > I will talk with our HW team to clarify, but this sequence looks to be very > > > specific to the needs of the platform in question which doesn't feel right to > > > me. As was mentioned on another thread as well, the watchdog driver already > > has > > > a restart function to reset the device (and thus the system), so I don't believe > > > we should have multiple of these. > > > > From the discussion that happened here > > https://www.dialog-semiconductor.com/products/pmics?post_id=10052#tab- > > support_tab_content, > > it does not seem possible to use the watchdog on a chip whose OTP does > > not set AUTOBOOT. But anyway, I'm looking forward to hearing from the > > HW team :) > > So I've discussed this internally and so far it's not completely clear how the > sequence you provided actually performs the reset as you suggest. It certainly > doesn't look like it should, so maybe this relates to an external pin somehow > triggering the restart in this particular scenario? I'd be interested to > understand which event bits are set when the board does restart to understand > what did actually trigger the boot-up.
After clearing all those registers and a reset as done in this patch, I get the following values:
FAULT_LOG: 0x00 EVENT_A: 0x10 => As per the datasheet, "Sequencer reached final position caused event" ? EVENT_B: 0x00 EVENT_C: 0x00 EVENT_D: 0x00
Do you need any other info?
> > Regardless of this though, the consensus right now would be to use the RTC as a > wake event to restart the platform. An alarm can be set for a couple of seconds > into the future (or longer if required) and that would provide the event > required to come up from powerdown/shutdown, in the absence of AUTOBOOT being > set in OTP. I believe this would be the safest route to take in this case. You > can then just use the SHUTDOWN bit on CONTROL_F to take down the board. > > To reiterate, I believe this should be made a board specific quirk, rather than > as part of the generic MFD core of DA9063, as the timings may vary for other > platforms.
Alex
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