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

Lukasz Majewski
2019-02-15T10:55:58Z

Hi Krzysztof,

> On Fri, 15 Feb 2019 at 08:04, Lukasz Majewski <lukma@denx.de> wrote:
> >
> > On Wed, 13 Feb 2019 17:46:46 +0100
> > Krzysztof Kozlowski <krzk@kernel.org> wrote:
> >
> > > According to datasheet, the output on LDO regulators will start
> > > appearing after 10-15 us.
> > >
> > > Signed-off-by: Krzysztof Kozlowski <krzk@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 :)

No, lets keep simple things simple :-). No need for extra DTB property.

>
> > 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.

Ok, If it is in the manual then we shall stick to it (and vendor just
stated - delay for 15ms).

>
> Best regards,
> Krzysztof

Best regards,

Lukasz Majewski

--

DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma at denx.de
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 488 bytes
Desc: OpenPGP digital signature
URL: <http://lists.denx.de/pipermail/u-boot/attachments/20190215/dbe847a0/attachment.sig>