Messages in this thread Patch in this message | | | Date | Wed, 16 Dec 2020 13:41:33 +0100 | From | Guido Günther <> | Subject | Re: [PATCH 1/1] regulators: bd718x7: Add enable times |
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Hi Matti, On Wed, Dec 16, 2020 at 12:29:20PM +0000, Vaittinen, Matti wrote: > Hello Guido, > > Thanks for looking at this! > > On Wed, 2020-12-16 at 12:05 +0100, Guido Günther wrote: > > Use the typical startup times from the data sheet so boards get a > > reasonable default. Not setting any enable time can lead to board > > hangs > > when e.g. clocks are enabled too soon afterwards. > > > > This fixes gpu power domain resume on the Librem 5. > > > > Signed-off-by: Guido Günther <agx@sigxcpu.org> > > --- > > drivers/regulator/bd718x7-regulator.c | 27 > > +++++++++++++++++++++++++++ > > 1 file changed, 27 insertions(+) > > > > diff --git a/drivers/regulator/bd718x7-regulator.c > > b/drivers/regulator/bd718x7-regulator.c > > index e6d5d98c3cea..d6d34aa4ee2e 100644 > > --- a/drivers/regulator/bd718x7-regulator.c > > +++ b/drivers/regulator/bd718x7-regulator.c > > @@ -613,6 +613,7 @@ static struct bd718xx_regulator_data > > bd71847_regulators[] = { > > .vsel_mask = DVS_BUCK_RUN_MASK, > > .enable_reg = BD718XX_REG_BUCK1_CTRL, > > .enable_mask = BD718XX_BUCK_EN, > > + .enable_time = 144, > > Where are these values obtained from? I have a feeling they might be > board / load specific. If this is the case - can the "regulator-enable- > ramp-delay" from device-tree be used instead to avoid hard-coding board > specific values in the driver? Although, sane defaults would probably > not be a bad idea - if I read code correctly then the constrains from > DT can be used to override these values.
They're the 'typical values' from the data sheet and it's basically all about setting a default for "regulator-enable-ramp-delay" to avoid having every board do the same. If that's not the right thing todo let me know and i add these to each of our boards (which is where i basically started from but then figured that this would be busywork and every board would hit that problem).
> I'd prefer well named defines over raw numeric values though.
So s.th. like
BD71837_BUCK1_STARTUP_TIME 144
(using the terminology from the datasheet)? If that works I'll send a v2.
Cheers, --Guido > > Best Regards > Matti Vaittinen > >
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