Audio

1. Overview

The audio part of the Omni3576 development board uses the ES8388 driver chip, which is a high-performance, low-power and low-cost audio codec. It includes a 2-channel ADC, a 2-channel DAC, a microphone amplifier, a headphone amplifier, digital sound effects, and analog mixing and gain functions.

2. Sound configuration

1. Check the sound card device

   luckfox@luckfox:~$ arecord -l
   **** List of CAPTURE Hardware Devices ****
   card 0: rockchipes8388 [rockchip-es8388], device 0: dailink-multicodecs ES8323 HiFi-0 [dailink-multicodecs ES8323 HiFi-0]
     Subdevices: 1/1
     Subdevice #0: subdevice #0
     
   luckfox@luckfox:~$ aplay -l
   **** List of PLAYBACK Hardware Devices ****
   card 0: rockchipes8388 [rockchip-es8388], device 0: dailink-multicodecs ES8323 HiFi-0 [dailink-multicodecs ES8323 HiFi-0]
     Subdevices: 1/1
     Subdevice #0: subdevice #0
   card 1: rockchipdp0 [rockchip-dp0], device 0: rockchip-dp0 spdif-hifi-0 [rockchip-dp0 spdif-hifi-0]
     Subdevices: 1/1
     Subdevice #0: subdevice #0

2. Sound card driver directory

   luckfox@luckfox:~$ ls /dev/snd/
   by-path  controlC0  controlC1  pcmC0D0c  pcmC0D0p  pcmC1D0p  seq  timer
   • controlC0 and controlC1: used for sound card control, C0 means sound card 0, C1 means sound card 1, corresponding to the sound output of SOC above
   • pcmC0D0c: pcm device for recording, the last "c" is the abbreviation of capture, indicating the recording device
   • pcmC0D0p and pcmC1D0p: pcm device for playback, the last "p" is the abbreviation of playback, indicating the playback device

   luckfox@luckfox:~$  ls -l /dev/snd/by-path/
   total 0
   lrwxrwxrwx 1 root root 12 Oct 18 10:03 platform-dp0-sound -> ../controlC1
   lrwxrwxrwx 1 root root 12 Oct 18 10:03 platform-es8388-sound -> ../controlC0

3. Test

1. Recording Test

   arecord -Dhw:0,0  -f cd -r 44100 -c 2 -t wav test.wav 

2. Headphone test (plugging in headphones will automatically switch input and output channels)

   设置录音增益：
   tinymix -D 0 set "Left Channel Capture Volume" 8
   tinymix -D 0 set "Right Channel Capture Volume" 8
   设置播放音量：
   tinymix -D 0 set "Output 1 Playback Volume" 33 33
   tinymix -D 0 set "Output 2 Playback Volume" 33 33
   播放：
   aplay -Dhw:0,0 -t wav /userdata/test.wav
   录音：
   arecord -Dhw:0,0  -f cd -r 44100 -c 2 -t wav /userdata/test.wav

3. Playback test

   aplay -Dhw:0,0 -t wav /userdata/test.wav

4. Device tree Overview

1. The Audio DTS source file has been defined in kernel-6.10/arch/arm64/boot/dts/rockchip/luckfox-omni3576-codec.dtsi, and we can call it directly.

   / {
       es8388_sound: es8388-sound {
                   status = "okay";
                   compatible = "rockchip,multicodecs-card";
                   rockchip,card-name = "rockchip-es8388";
                   rockchip,format = "i2s";
                   rockchip,mclk-fs = <256>;
                   rockchip,cpu = <&sai1>;
                   rockchip,codec = <&es8388>;
                   rockchip,audio-routing =
                           "Headphone", "LOUT1",
                           "Headphone", "ROUT1",
                           "Speaker", "LOUT1",
                           "Speaker", "ROUT1",
                           "LINPUT2", "Main Mic",
                           "RINPUT2", "Main Mic",
                           "LINPUT2", "Headset Mic",
                           "RINPUT2", "Headset Mic";
           };
   };
   
   &i2c2 {
           status = "okay";
   
           es8388: es8388@10 {
                   status = "okay";
                   #sound-dai-cells = <0>;
                   compatible = "everest,es8388", "everest,es8323";
                   reg = <0x10>;
                   clocks = <&mclkout_sai1>;
                   clock-names = "mclk";
                   assigned-clocks = <&mclkout_sai1>;
                   assigned-clock-rates = <12288000>;
                   pinctrl-names = "default";
                   pinctrl-0 = <&sai1m0_mclk>;
           };
   };
   
   
   &sai1 {
           status = "okay";
           pinctrl-names = "default";
           pinctrl-0 = <&sai1m0_lrck
                        &sai1m0_sclk
                        &sai1m0_sdi0
                        &sai1m0_sdo0>;
   };