树莓派-MIC篇

1 DMIC驱动

arch\arm\boot\dts\overlays\example-sound-overlay.dts

// Definitions for example audio add on soundcard

/dts-v1/;

/plugin/;

 

/ {

compatible = "brcm,bcm2835";

 

fragment@0 {

target = <&i2s>;

__overlay__ {

status = "okay";

};

};

 

fragment@1 {

target = <&sound>;

__overlay__ {

compatible = "ai,example-soundcard";

i2s-controller = <&i2s>;

status = "okay";

};

};

};

 

linux\arch\arm\boot\dts\overlays\Makefile

dtbo-$(RPI_DT_OVERLAYS) += example-sound.dtbo

 

sound\soc\bcm\example-soundcard.c

#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/kmod.h>

#include <linux/platform_device.h>

#include <sound/simple_card.h>

#include <linux/delay.h>

 

void device_release_callback(struct device *dev) { /*  do nothing */ };

static struct asoc_simple_card_info snd_rpi_simple_card_info = {

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