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:
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.
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@linaro.org Signed-off-by: Stephan Gerhold stephan@gerhold.net
.../devicetree/bindings/sound/qcom,sm8250.yaml | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)
But nothing new here really, so
Acked-by: Rob Herring robh@kernel.org