On Tue, Dec 14, 2021 at 03:20:47PM +0100, Stephan Gerhold wrote: > Some sound card setups might require extra pin switches to allow > turning off certain audio components. There are two real examples for > this in smartphones/tablets based on MSM8916: > > 1. Analog speaker amplifiers connected to headphone outputs. > > The MSM8916 analog codec does not have a separate "Line Out" port > so some devices have an analog speaker amplifier connected to one > of the headphone outputs. A pin switch is necessary to allow > playback on headphones without also activating the speaker. > > 2. External speaker codec also used as earpiece. > > Some smartphones have two front-facing (stereo) speakers that can > be also configured to act as an earpiece during voice calls. A pin > switch is needed to allow disabling the second speaker during > voice calls. This all makes sense, but how that translates to the DT properties I don't have a clue. > There are existing bindings that allow setting up such pin switches in > simple-card.yaml. Document the same for Qcom sound cards. And that description is equally as bad. > One variant of example 1 above is added to the examples in the DT > schema: There is an analog speaker amplifier connected to the HPH_R > (right headphone channel) output. Adding a "Speaker" pin switch and > widget allows turning off the speaker when audio should be only played > via the connected headphones. > > Cc: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx> > Signed-off-by: Stephan Gerhold <stephan@xxxxxxxxxxx> > --- > .../devicetree/bindings/sound/qcom,sm8250.yaml | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) But nothing new here really, so Acked-by: Rob Herring <robh@xxxxxxxxxx>
