Re: [PATCH v3 1/2] regulator: pwm: Add support for a fixed delay after duty cycle changes

From: Rob Herring
Date: Fri Sep 02 2016 - 11:13:21 EST


On Fri, Sep 02, 2016 at 10:11:51AM -0500, Rob Herring wrote:
> On Tue, Aug 30, 2016 at 09:21:15PM -0700, Douglas Anderson wrote:
> > From: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
> >
> > A change of the duty cycle doesn't necessarily cause an immediate switch
> > to the target voltage. On many PWM regulators there is a fixed "settle
> > time" (irrespective of the jump size) that we need to wait after an
> > upward jump. This change introduces the device tree property
> > "settle-time-up-us" which allows us to specify a fixed delay after a
> > voltage increase.
> >
> > We don't add an option of a fixed delay on the way down for now because
> > the way down is probably modelled best with a ramp rate, not a fixed
> > delay.
> >
> > Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
> > Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
> > ---
> > Changes in v3:
> > - Took out fixed delay for falling transitions
> > - Updated description
> >
> > .../devicetree/bindings/regulator/pwm-regulator.txt | 6 ++++++
>
> Acked-by: Rob Herring <robh@xxxxxxxxxx>

I take that back. What Mark said...

>
> > drivers/regulator/pwm-regulator.c | 19 +++++++++++++++----
> > 2 files changed, 21 insertions(+), 4 deletions(-)