Messages in this thread | | | From | Alexandre Ghiti <> | Date | Fri, 24 Sep 2021 18:17:19 +0200 | Subject | Re: [PATCH] drivers: mfd: da9063: Add restart notifier implementation |
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Hi Adam,
On Fri, Sep 24, 2021 at 5:04 PM Adam Thomson <Adam.Thomson.Opensource@diasemi.com> wrote: > > On 21 September 2021 06:34, Alexandre Ghiti wrote: > > > The SiFive Unmatched board uses the da9063 PMIC for reset: add a restart > > notifier that will execute a small i2c sequence allowing to reset the > > board. > > > > The original implementation comes from Marcus Comstedt and Anders > > Montonen > > (https://forums.sifive.com/t/reboot-command/4721/28). > > > > Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com> > > --- > > drivers/mfd/da9063-core.c | 25 +++++++++++++++++++++++++ > > include/linux/mfd/da9063/core.h | 3 +++ > > 2 files changed, 28 insertions(+) > > > > diff --git a/drivers/mfd/da9063-core.c b/drivers/mfd/da9063-core.c > > index df407c3afce3..c87b8d611f20 100644 > > --- a/drivers/mfd/da9063-core.c > > +++ b/drivers/mfd/da9063-core.c > > @@ -20,6 +20,7 @@ > > #include <linux/mutex.h> > > #include <linux/mfd/core.h> > > #include <linux/regmap.h> > > +#include <linux/reboot.h> > > > > #include <linux/mfd/da9063/core.h> > > #include <linux/mfd/da9063/registers.h> > > @@ -158,6 +159,18 @@ static int da9063_clear_fault_log(struct da9063 *da9063) > > return ret; > > } > > > > +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 :)
Thanks,
Alex
> > For board specific sequences, there are machine quirks I believe which can be > used to handle stuff like this, if this really isn't a generic solution to fit > all cases. >
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