[U-Boot] [PATCH v2 7/9] power: regulator: s2mps11: Add enable delay

Krzysztof Kozlowski krzk at kernel.org
Fri Feb 15 10:11:57 UTC 2019


On Fri, 15 Feb 2019 at 08:04, Lukasz Majewski <lukma at denx.de> wrote:
>
> On Wed, 13 Feb 2019 17:46:46 +0100
> Krzysztof Kozlowski <krzk at kernel.org> wrote:
>
> > According to datasheet, the output on LDO regulators will start
> > appearing after 10-15 us.
> >
> > Signed-off-by: Krzysztof Kozlowski <krzk at kernel.org>
> > ---
> >  drivers/power/regulator/s2mps11_regulator.c | 9 ++++++++-
> >  1 file changed, 8 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/power/regulator/s2mps11_regulator.c
> > b/drivers/power/regulator/s2mps11_regulator.c index
> > 723d27f67c9a..1f1581852ee2 100644 ---
> > a/drivers/power/regulator/s2mps11_regulator.c +++
> > b/drivers/power/regulator/s2mps11_regulator.c @@ -551,7 +551,14 @@
> > static int ldo_get_enable(struct udevice *dev)
> >  static int ldo_set_enable(struct udevice *dev, bool enable)
> >  {
> > -     return s2mps11_ldo_enable(dev, PMIC_OP_SET, &enable);
> > +     int ret;
> > +
> > +     ret = s2mps11_ldo_enable(dev, PMIC_OP_SET, &enable);
> > +
> > +     /* Wait the "enable delay" for voltage to start to rise */
> > +     udelay(15);
>
> Isn't the enable delay provided/read from dts?
> Or is it too early to have dtb parsed?

We could read it from DTB... but I would need to add new property just
for that. I can... just more commits for simple stuff :)

> The udelay(15) seems a bit "magic" value (or is it specified in the
> PMIC manual?).

Yeah, it is magic value mentioned in PMIC manual (actually - 10-15
us). It is the same as ramp delay - PMIC specific value.

Best regards,
Krzysztof


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