❗❗❗ 本文档使能PDM接口，目的为了使用MEMS麦克风--使用纯PDM数字麦，不外接任何声卡设备

✔️ 软件系统： Linux 4.19.206

1. 源码修改

使能PDM接口很简单，只需要在设备树文件中做修改，具体的修改内容如下：

PDM接口功能一共有M0、M1和M2三组，本文档使用的是M2引脚。

diff --git a/arch/arm64/boot/dts/rockchip/OK3568-C-common.dtsi b/arch/arm64/boot/dts/rockchip/OK3568-C-common.dtsi

index 31ffd6024..4124346d2 100644

--- a/arch/arm64/boot/dts/rockchip/OK3568-C-common.dtsi

+++ b/arch/arm64/boot/dts/rockchip/OK3568-C-common.dtsi

@@ -174,13 +174,13 @@

  };

  pdmics: dummy-codec {

- status = "disabled";

+ status = "okay";

  compatible = "rockchip,dummy-codec";

  #sound-dai-cells = <0>;

  };

  pdm_mic_array: pdm-mic-array {

- status = "disabled";

+ status = "okay";

  compatible = "**-audio-card";

  **-audio-card,name = "rockchip,pdm-mic-array";

  **-audio-card,cpu {

@@ -1382,7 +1382,7 @@

 };

 &pwm14 {

- status = "okay";

+ status = "disabled";

 };

 &rk_rga {

@@ -1792,7 +1792,7 @@

 };

 &uart3 {

- status = "okay";

+ status = "disabled";

  pinctrl-names = "default";

  pinctrl-0 = <&uart3m1_xfer>;

 };

@@ -1840,3 +1840,14 @@

  spi-max-frequency = <50000000>;

  };

 };

+

+&pdm {

+ status = "okay";

+   pinctrl-names = "default";

+ pinctrl-0 = <

+ &pdmm2_clk1

+ &pdmm2_sdi0

+ &pdmm2_sdi1

+ &pdmm2_sdi2

+ &pdmm2_sdi3>;

+};

\ No newline at end of file

2.PDM接口测试