linux_dsm_epyc7002/Documentation/devicetree/bindings/sound/dmic.txt
Matthias Kaehlcke 05c9b302ed
ASoC: dmic: Add optional wakeup delay
On some systems a delay is needed after switching on the clocks, to allow
the output to stabilize and avoid a popping noise at the beginning of
the recording. Add the optional device tree property 'wakeup-delay-ms'
and apply the specified delay after enabling the mic. A blocking delay
can't be applied in dmic_daiops_trigger() since the function is called
in atomic context. Instead use a DAPM event handler to set the enable
GPIO and apply the delay in the handler.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-02-19 12:16:41 +00:00

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Device-Tree bindings for Digital microphone (DMIC) codec
This device support generic PDM digital microphone.
Required properties:
- compatible: should be "dmic-codec".
Optional properties:
- dmicen-gpios: GPIO specifier for dmic to control start and stop
- num-channels: Number of microphones on this DAI
- wakeup-delay-ms: Delay (in ms) after enabling the DMIC
Example node:
dmic_codec: dmic@0 {
compatible = "dmic-codec";
dmicen-gpios = <&gpio4 3 GPIO_ACTIVE_HIGH>;
num-channels = <1>;
wakeup-delay-ms <50>;
};