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.
There are existing bindings that allow setting up such pin switches in simple-card.yaml. Document the same for Qcom sound cards.
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(+)
diff --git a/Documentation/devicetree/bindings/sound/qcom,sm8250.yaml b/Documentation/devicetree/bindings/sound/qcom,sm8250.yaml index e50964c54bb9..4bfda04b4608 100644 --- a/Documentation/devicetree/bindings/sound/qcom,sm8250.yaml +++ b/Documentation/devicetree/bindings/sound/qcom,sm8250.yaml @@ -39,6 +39,14 @@ properties: $ref: /schemas/types.yaml#/definitions/string description: User visible long sound card name
+ pin-switches: + description: List of widget names for which pin switches should be created. + $ref: /schemas/types.yaml#/definitions/string-array + + widgets: + description: User specified audio sound widgets. + $ref: /schemas/types.yaml#/definitions/non-unique-string-array + # Only valid for some compatibles (see allOf if below) reg: true reg-names: true @@ -251,7 +259,15 @@ examples: reg-names = "mic-iomux", "spkr-iomux";
model = "msm8916"; + widgets = + "Speaker", "Speaker", + "Headphone", "Headphones"; + pin-switches = "Speaker"; audio-routing = + "Speaker", "Speaker Amp OUT", + "Speaker Amp IN", "HPH_R", + "Headphones", "HPH_L", + "Headphones", "HPH_R", "AMIC1", "MIC BIAS Internal1", "AMIC2", "MIC BIAS Internal2", "AMIC3", "MIC BIAS Internal3";