Messages in this thread | | | Date | Sun, 4 Jan 2015 17:33:06 -0800 | Subject | Re: [PATCH v4 2/3] pwm: kona: Remove setting default smooth type and polarity for all channels | From | Tim Kryger <> |
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On Sun, Jan 4, 2015 at 5:12 PM, Tim Kryger <tim.kryger@gmail.com> wrote: > On Tue, Dec 30, 2014 at 2:43 PM, Jonathan Richardson > <jonathar@broadcom.com> wrote: >> Setting the default polarity in probe to normal for all channels caused >> the speaker pwm channel to click. The polarity does need to be set to >> normal because the hw default is inversed whereas the pwm framework >> defaults to normal. If a channel is enabled without setting the polarity >> then the signal would be inversed while linux reports normal. A check >> is now done prior to enabling the channel to ensure that the hw polarity >> matches the desired polarity and is changed if there is a discrepency. This >> prevents unnecessary settings being applied to unused channels but still >> ensures the correct polarity to be set. > > A more direct solution that avoids the potentially undesirable > consequences of delaying when polarity changes are written to hardware > would be to update the PWM framework to allow for the registration of > chips with inversed default polarity. > > I will post a patch for your review.
Please see: https://lkml.org/lkml/2015/1/4/199
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