一、确认硬件接口
根据硬件原理图设计情况获取对应信息：
| 项目 | vaule |
| 接在哪个I2C | I2C4 |
| 接在哪个I2S | I2S2 |
| I2S2_DOUT, I2S2_DIN | PH11, PE9 |
| I2S2-BCLK，I2S2-LRCK,I2S2-DIN0 | PE6,PE7,PE9 |
二、设备树
1、设备节点
&i2s2_plat {tdm-num = <2>;tx-pin = <0>;rx-pin = <0>;pinctrl-used;pinctrl-names= "default","sleep";pinctrl-0 = <&i2s2_pins_a &i2s2_pins_c >;pinctrl-1 = <&i2s2_pins_b>;tx-hub-en;rx-sync-en;status = "okay";
};&i2s2_mach {soundcard-mach,name = "sndi2s2";soundcard-mach,format = "i2s";soundcard-mach,frame-master = <&i2s2_codec>;soundcard-mach,bitclock-master = <&i2s2_codec>;/* soundcard-mach,frame-inversion; *//* soundcard-mach,bitclock-inversion; */soundcard-mach,slot-num = <2>;soundcard-mach,slot-width = <32>;soundcard-mach,capture-only;status = "okay";i2s2_cpu: soundcard-mach,cpu {sound-dai = <&i2s2_plat>;soundcard-mach,pll-fs = <1>;/* edp mclk: 512fs */^Msoundcard-mach,mclk-fs = <0>;};i2s2_codec: soundcard-mach,codec {sound-dai = <&tef668x>;};
};&twi4 {clock-frequency = <400000>;pinctrl-0 = <&twi4_pins_default>;pinctrl-1 = <&twi4_pins_sleep>;pinctrl-names = "default", "sleep";/* For stability and backwards compatibility, we recommend setting ‘twi_drv_used’ to 1 */twi_drv_used = <1>;twi-supply = <®_dcdc4>;status = "okay";tef668x: tef668x@64 {#sound-dai-cells = <0>;compatible = "tef668x_codec_0";device_type = "tef668x_codec_0";reg = <0x64>; status = "okay";};
};2、pinctr信息
三、驱动移植
1、Kconfig
2、Makefile
3、驱动
bsp/drivers/sound/codecs/tef668x
声卡注册 snd_soc_register_codec
混杂设备注册 tef668x_probe(i2c, i2c_id);
static int tef668x_codec_i2c_probe(struct i2c_client *i2c,const struct i2c_device_id *i2c_id)
{struct tef668x_codec_priv *tef668x_codec;int ret = 0;printk("tef668x_codec_i2c_probe 20241218 17:41\n");tef668x_probe(i2c, i2c_id);tef668x_codec = devm_kzalloc(&i2c->dev, sizeof(struct tef668x_codec_priv), GFP_KERNEL);if (tef668x_codec == NULL) {dev_err(&i2c->dev, "Unable to allocate tef668x_codec private data\n");return -ENOMEM;}gTef668xCodec = tef668x_codec;tef668x_codec->i2c = i2c;dev_set_drvdata(&i2c->dev, tef668x_codec);tef668x_codec->fm_switch_on = false;if (i2c_id->driver_data < TEF668X_CODEC_CHIP_NUMS) {i2c_ctrl[i2c_id->driver_data] = i2c;ret = snd_soc_register_codec(&i2c->dev, &tef668x_codec_soc_codec_driver,tef668x_codec_dai[i2c_id->driver_data], 1);if (ret < 0) {dev_err(&i2c->dev,"Failed to register tef668x_codec codec: %d\n", ret);}} else {pr_err("The wrong i2c_id number :%d\n",(int)(i2c_id->driver_data));}if (ret < 0) {dev_err(&i2c->dev,"Failed to register tef668x_codec codec: %d\n", ret);}return ret;
}混杂设备， 用于 fm 控制调频，搜台
bsp/drivers/sound/codecs/tef668x/misc_drv/tef668x.c
四、FM测试
移植对应APP测试程序后。执行APP，IIC报错
排查后定位，IIC未接上拉电阻，上拉4.7K，到VDD_3V3
上拉后，正常
音频设备：
五、录音播放测试
1、FM 录音
arecord -r 44100 -f S16_LE -D hw:1,0 -c2 /mnt/UDISK/fmrecord.wav
#查看录制状态
cat /proc/asound/sndi2s2/pcm0c/sub0/status
state: RUNNING
owner_pid : 1565
trigger_time: 1434.845529224
tstamp : 0.000000000
delay : 1287
avail : 1287
avail_max : 5513
hw_ptr : 2189948
appl_ptr : 21886612、FM 录制回放
tinymix -D 0 29 1aplay /mnt/UDISK/fmrecord.wav3、问题合集
问题1： 录制数据全0
引脚复用异常
原因： PE9 复用成了 IO Disable
root@Longan:~$ devmem 0x20000C4 320xF0033FFFroot@Longan:~$ devmem 0x20000C0 320x44F00002#设置PE9 I2S
devmem 0x20000C4 32 0xF0033F44解决办法：function 是 i2s2 i2s2_din
i2s2_pins_c: i2s2@2 {pins = "PE9";//I2S2-DIN0function = "i2s2"; //"i2s2_din";drive-strength = <20>;bias-disable;};调试完成！！！！
