On Mon, Apr 12, 2021 at 03:27:41PM +0200, Clemens Gruber wrote: > Add the flag and corresponding documentation for PWM_USAGE_POWER. My concern here in the previous round was that PWM_USAGE_POWER isn't a name that intuitively suggests its semantic. Do you disagree? > Cc: Rob Herring <robh+dt@xxxxxxxxxx> > Signed-off-by: Clemens Gruber <clemens.gruber@xxxxxxxxxxxx> > --- > Documentation/devicetree/bindings/pwm/pwm.txt | 3 +++ > include/dt-bindings/pwm/pwm.h | 1 + > 2 files changed, 4 insertions(+) > > diff --git a/Documentation/devicetree/bindings/pwm/pwm.txt b/Documentation/devicetree/bindings/pwm/pwm.txt > index 084886bd721e..fe3a28f887c0 100644 > --- a/Documentation/devicetree/bindings/pwm/pwm.txt > +++ b/Documentation/devicetree/bindings/pwm/pwm.txt > @@ -46,6 +46,9 @@ period in nanoseconds. > Optionally, the pwm-specifier can encode a number of flags (defined in > <dt-bindings/pwm/pwm.h>) in a third cell: > - PWM_POLARITY_INVERTED: invert the PWM signal polarity > +- PWM_USAGE_POWER: Only care about the power output of the signal. This > + allows drivers (if supported) to optimize the signals, for example to > + improve EMI and reduce current spikes. IMHO there are too many open questions about which freedom this gives to the lowlevel driver. If the consumer requests .duty_cycle = 25ns + .period = 100ns, can the driver provide .duty_cycle = 25s + .period = 100s which nominally has the same power output? Let's not introduce more ambiguity than there already is. This is a NAck. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | https://www.pengutronix.de/ |
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