大家好，第一件事：
我已经搜索过了，但我没有找到任何有用的东西，所以如果这个问题已经解决，我想道歉，在这种情况下，如果你们能指出我正确的帖子，我很乐意关闭这个帖子并标记它解决了。
我们公司正在开发基于 imx8mm SOC 的
开发板（目前我们正在开发 Kontron 开发板）。
我们的目标之一是拥有一个至少有 4 个输入和 4 个输出（32 位样本）的 ALSA 音频设备，所以我正在尝试创建一个设备树并生成所有必要的内核补丁。
与此同时，我们正在使用 Kontron 开发板和 Yocto BSP 来创建操作系统，现在我被正确编译的设备树困住了，但我看不到我的 ALSA 简单声卡。
我们计划使用的 SAI 设备是 SAI3，将 imx8mm 设置为主时钟（我不知道是否是这种情况——我对此表示怀疑——但我们的开发板没有暴露我们制作 TDM 音频所需的 SAI 引脚，所以我可以执行的唯一测试是在 ALSA 下查看 TDM 设备并尝试使用它）。
我们正在尝试使用内核 V5.10，这是自定义设备树文件
/*
* imx8mm custom board device tree file
*/
/dts-v1/;
#include "imx8mm-kontron-n801x-som.dtsi"
#include
/ {
model = "Custom Kontron i.MX8MM board";
compatible = "kontron,imx8mm-n801x-s", "kontron,imx8mm-n801x-som", "kontron,kontron-mx8mm", "fsl,imx8mm";
aliases {
ethernet1 = &usbnet;
};
/* fixed crystal dedicated to mcp2515 */
osc_can: clock-osc-can {
compatible = "fixed-clock";
#clock-cells = <0>;
clock-frequency = <16000000>;
clock-output-names = "osc-can";
};
leds {
compatible = "gpio-leds";
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_gpio_led>;
led1 {
label = "led1";
gpios = <&gpio4 17 GPIO_ACTIVE_LOW>;
linux,default-trigger = "heartbeat";
};
led2 {
label = "led2";
gpios = <&gpio4 19 GPIO_ACTIVE_LOW>;
};
led3 {
label = "led3";
gpios = <&gpio4 18 GPIO_ACTIVE_LOW>;
};
led4 {
label = "led4";
gpios = <&gpio4 8 GPIO_ACTIVE_LOW>;
};
led5 {
label = "led5";
gpios = <&gpio4 9 GPIO_ACTIVE_LOW>;
};
led6 {
label = "led6";
gpios = <&gpio4 7 GPIO_ACTIVE_LOW>;
};
};
reg_rst_eth2: regulator-rst-eth2 {
compatible = "regulator-fixed";
regulator-name = "rst-usb-eth2";
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_usb_eth2>;
gpio = <&gpio3 2 GPIO_ACTIVE_HIGH>;
enable-active-high;
regulator-always-on;
};
reg_vdd_5v: regulator-5v {
compatible = "regulator-fixed";
regulator-name = "vdd-5v";
regulator-min-microvolt = <5000000>;
regulator-max-microvolt = <5000000>;
regulator-always-on;
};
codec_dummy: codec_dummy {
compatible = "linux,snd-soc-dummy";
#sound-dai-cells = <0>;
status = "okay";
};
sound-sai3sound {
compatible = "simple-audio-card";
simple-audio-card,name = "I2S Audio";
simple-audio-card,format = "i2s";
simple-audio-card,bitclock-master = <&snd_cpu>;
simple-audio-card,frame-master = <&snd_cpu>;
status = "okay";
snd_cpu: simple-audio-card,cpu {
sound-dai = <&sai3 0>;
dai-tdm-slot-num = <8>;
dai-tdm-slot-width = <32>;
};
snd_codec: simple-audio-card,codec {
sound-dai = <&codec_dummy>;
};
};
};
&fec1 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_enet>;
phy-connection-type = "rgmii-rxid";
phy-handle = <ðphy>;
status = "okay";
mdio {
#address-cells = <1>;
#size-cells = <0>;
ethphy: ethernet-phy@0 {
compatible = "ethernet-phy-id0007.0570";
reg = <0>;
reset-assert-us = <100>;
reset-deassert-us = <100>;
reset-gpios = <&gpio4 27 GPIO_ACTIVE_LOW>;
vsc8531,led-0-mode = ;
vsc8531,led-1-mode = ;
vsc8531,led-0-combine-disable;
};
};
};
&uart1 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_uart1>;
uart-has-rtscts;
status = "okay";
};
// &uart2 {
// pinctrl-names = "default";
// pinctrl-0 = <&pinctrl_uart2>;
// linux,rs485-enabled-at-boot-time;
// uart-has-rtscts;
// status = "okay";
// };
&usbotg1 {
dr_mode = "otg";
over-current-active-low;
status = "okay";
};
&usbotg2 {
dr_mode = "host";
disable-over-current;
#address-cells = <1>;
#size-cells = <0>;
status = "okay";
usb1@1 {
compatible = "usb424,9514";
reg = <1>;
#address-cells = <1>;
#size-cells = <0>;
usbnet: usbether@1 {
compatible = "usb424,ec00";
reg = <1>;
local-mac-address = [ 00 00 00 00 00 00 ];
};
};
};
&usdhc2 {
pinctrl-names = "default", "state_100mhz", "state_200mhz";
pinctrl-0 = <&pinctrl_usdhc2>;
pinctrl-1 = <&pinctrl_usdhc2_100mhz>;
pinctrl-2 = <&pinctrl_usdhc2_200mhz>;
vmmc-supply = <®_vdd_3v3>;
vqmmc-supply = <®_nvcc_sd>;
cd-gpios = <&gpio2 12 GPIO_ACTIVE_LOW>;
status = "okay";
};
&iomuxc {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_gpio>;
pinctrl_adv7535: adv7535grp {
fsl,pins = <
MX8MM_IOMUXC_SAI1_TXD4_GPIO4_IO16 0x19
>;
};
pinctrl_can: cangrp {
fsl,pins = <
MX8MM_IOMUXC_SAI3_RXFS_GPIO4_IO28 0x19
>;
};
pinctrl_dsi_sel: dsiselgrp {
fsl,pins = <
MX8MM_IOMUXC_SAI1_TXD2_GPIO4_IO14 0x19
>;
};
pinctrl_dsi_oe: dsioegrp {
fsl,pins = <
MX8MM_IOMUXC_SAI1_TXD3_GPIO4_IO15 0x19
>;
};
pinctrl_ecspi2: ecspi2grp {
fsl,pins = <
MX8MM_IOMUXC_ECSPI2_MISO_ECSPI2_MISO 0x82
MX8MM_IOMUXC_ECSPI2_MOSI_ECSPI2_MOSI 0x82
MX8MM_IOMUXC_ECSPI2_SCLK_ECSPI2_SCLK 0x82
MX8MM_IOMUXC_ECSPI2_SS0_GPIO5_IO13 0x19
>;
};
pinctrl_ecspi3: ecspi3grp {
fsl,pins = <
MX8MM_IOMUXC_UART2_RXD_ECSPI3_MISO 0x82
MX8MM_IOMUXC_UART1_TXD_ECSPI3_MOSI 0x82
MX8MM_IOMUXC_UART1_RXD_ECSPI3_SCLK 0x82
MX8MM_IOMUXC_UART2_TXD_GPIO5_IO25 0x19
>;
};
pinctrl_enet: enetgrp {
fsl,pins = <
MX8MM_IOMUXC_ENET_MDC_ENET1_MDC 0x3
MX8MM_IOMUXC_ENET_MDIO_ENET1_MDIO 0x3
MX8MM_IOMUXC_ENET_TD3_ENET1_RGMII_TD3 0x1f
MX8MM_IOMUXC_ENET_TD2_ENET1_RGMII_TD2 0x1f
MX8MM_IOMUXC_ENET_TD1_ENET1_RGMII_TD1 0x1f
MX8MM_IOMUXC_ENET_TD0_ENET1_RGMII_TD0 0x1f
MX8MM_IOMUXC_ENET_RD3_ENET1_RGMII_RD3 0x91
MX8MM_IOMUXC_ENET_RD2_ENET1_RGMII_RD2 0x91
MX8MM_IOMUXC_ENET_RD1_ENET1_RGMII_RD1 0x91
MX8MM_IOMUXC_ENET_RD0_ENET1_RGMII_RD0 0x91
MX8MM_IOMUXC_ENET_TXC_ENET1_RGMII_TXC 0x1f
MX8MM_IOMUXC_ENET_RXC_ENET1_RGMII_RXC 0x91
MX8MM_IOMUXC_ENET_RX_CTL_ENET1_RGMII_RX_CTL 0x91
MX8MM_IOMUXC_ENET_TX_CTL_ENET1_RGMII_TX_CTL 0x1f
MX8MM_IOMUXC_SAI2_MCLK_GPIO4_IO27 0x19 /* PHY RST */
MX8MM_IOMUXC_SAI2_TXC_GPIO4_IO25 0x19 /* ETH IRQ */
>;
};
pinctrl_gpio_led: gpioledgrp {
fsl,pins = <
MX8MM_IOMUXC_NAND_READY_B_GPIO3_IO16 0x19
MX8MM_IOMUXC_SAI1_RXD5_GPIO4_IO7 0x19
MX8MM_IOMUXC_SAI1_RXD6_GPIO4_IO8 0x19
MX8MM_IOMUXC_SAI1_RXD7_GPIO4_IO9 0x19
MX8MM_IOMUXC_SAI1_TXD5_GPIO4_IO17 0x19
MX8MM_IOMUXC_SAI1_TXD6_GPIO4_IO18 0x19
MX8MM_IOMUXC_SAI1_TXD7_GPIO4_IO19 0x19
>;
};
pinctrl_gpio: gpiogrp {
fsl,pins = <
MX8MM_IOMUXC_GPIO1_IO03_GPIO1_IO3 0x19
MX8MM_IOMUXC_GPIO1_IO07_GPIO1_IO7 0x19
MX8MM_IOMUXC_GPIO1_IO09_GPIO1_IO9 0x19
MX8MM_IOMUXC_GPIO1_IO11_GPIO1_IO11 0x19
MX8MM_IOMUXC_GPIO1_IO06_GPIO1_IO6 0x19
MX8MM_IOMUXC_GPIO1_IO08_GPIO1_IO8 0x19
MX8MM_IOMUXC_GPIO1_IO10_GPIO1_IO10 0x19
MX8MM_IOMUXC_SAI3_MCLK_GPIO5_IO2 0x19
>;
};
pinctrl_i2c3: i2c3grp {
fsl,pins = <
MX8MM_IOMUXC_I2C3_SCL_I2C3_SCL 0x400001c3
MX8MM_IOMUXC_I2C3_SDA_I2C3_SDA 0x400001c3
>;
};
pinctrl_i2c4: i2c4grp {
fsl,pins = <
MX8MM_IOMUXC_I2C4_SCL_I2C4_SCL 0x400001c3
MX8MM_IOMUXC_I2C4_SDA_I2C4_SDA 0x400001c3
>;
};
pinctrl_pwm2: pwm2grp {
fsl,pins = <
MX8MM_IOMUXC_SPDIF_RX_PWM2_OUT 0x19
>;
};
pinctrl_sn65dsi84: sn65dsi84grp {
fsl,pins = <
MX8MM_IOMUXC_SAI2_TXD0_GPIO4_IO26 0x19
MX8MM_IOMUXC_SD2_WP_GPIO2_IO20 0x19
>;
};
pinctrl_uart1: uart1grp {
fsl,pins = <
MX8MM_IOMUXC_SAI2_RXC_UART1_DCE_RX 0x140
MX8MM_IOMUXC_SAI2_RXFS_UART1_DCE_TX 0x140
MX8MM_IOMUXC_SAI2_RXD0_UART1_DCE_RTS_B 0x140
MX8MM_IOMUXC_SAI2_TXFS_UART1_DCE_CTS_B 0x140
>;
};
// pinctrl_uart2: uart2grp {
// fsl,pins = <
// MX8MM_IOMUXC_SAI3_TXFS_UART2_DCE_RX 0x140
// MX8MM_IOMUXC_SAI3_TXC_UART2_DCE_TX 0x140
// MX8MM_IOMUXC_SAI3_RXD_UART2_DCE_RTS_B 0x140
// MX8MM_IOMUXC_SAI3_RXC_UART2_DCE_CTS_B 0x140
// >;
// };
pinctrl_usb_eth2: usbeth2grp {
fsl,pins = <
MX8MM_IOMUXC_NAND_CE1_B_GPIO3_IO2 0x19
>;
};
pinctrl_usdhc2: usdhc2grp {
fsl,pins = <
MX8MM_IOMUXC_SD2_CLK_USDHC2_CLK 0x190
MX8MM_IOMUXC_SD2_CMD_USDHC2_CMD 0x1d0
MX8MM_IOMUXC_SD2_DATA0_USDHC2_DATA0 0x1d0
MX8MM_IOMUXC_SD2_DATA1_USDHC2_DATA1 0x1d0
MX8MM_IOMUXC_SD2_DATA2_USDHC2_DATA2 0x1d0
MX8MM_IOMUXC_SD2_DATA3_USDHC2_DATA3 0x1d0
MX8MM_IOMUXC_SD2_CD_B_GPIO2_IO12 0x019
>;
};
pinctrl_usdhc2_100mhz: usdhc2grp100mhz {
fsl,pins = <
MX8MM_IOMUXC_SD2_CLK_USDHC2_CLK 0x194
MX8MM_IOMUXC_SD2_CMD_USDHC2_CMD 0x1d4
MX8MM_IOMUXC_SD2_DATA0_USDHC2_DATA0 0x1d4
MX8MM_IOMUXC_SD2_DATA1_USDHC2_DATA1 0x1d4
MX8MM_IOMUXC_SD2_DATA2_USDHC2_DATA2 0x1d4
MX8MM_IOMUXC_SD2_DATA3_USDHC2_DATA3 0x1d4
MX8MM_IOMUXC_SD2_CD_B_GPIO2_IO12 0x019
>;
};
pinctrl_usdhc2_200mhz: usdhc2grp200mhz {
fsl,pins = <
MX8MM_IOMUXC_SD2_CLK_USDHC2_CLK 0x196
MX8MM_IOMUXC_SD2_CMD_USDHC2_CMD 0x1d6
MX8MM_IOMUXC_SD2_DATA0_USDHC2_DATA0 0x1d6
MX8MM_IOMUXC_SD2_DATA1_USDHC2_DATA1 0x1d6
MX8MM_IOMUXC_SD2_DATA2_USDHC2_DATA2 0x1d6
MX8MM_IOMUXC_SD2_DATA3_USDHC2_DATA3 0x1d6
MX8MM_IOMUXC_SD2_CD_B_GPIO2_IO12 0x019
>;
};
pinctrl_sai3: sai3grp {
fsl,pins = <
MX8MM_IOMUXC_SAI3_TXFS_SAI3_TX_SYNC 0xd6
MX8MM_IOMUXC_SAI3_TXD_SAI3_TX_DATA0 0xd6
MX8MM_IOMUXC_SAI3_TXC_SAI3_TX_BCLK 0xd6
MX8MM_IOMUXC_SAI3_MCLK_SAI3_MCLK 0xd6
>;
};
};
&sai3 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_sai3>;
assigned-clocks = <&clk IMX8MM_CLK_SAI3>;
assigned-clock-parents = <&clk IMX8MM_AUDIO_PLL1_OUT>;
assigned-clock-rates = <24576000>;
fsl,sai-mclk-direction-output;
status = "okay";
};
该设备树文件是在 BSP 和其他有用资源上查阅此论坛/示例后的结果
我还修改了内核配置（使用 bitbake 和 menuconfig），创建了一个片段并附加到 yocto 内核配方
CONFIG_SND_DMAENGINE_PCM=y
CONFIG_SND_SOC_GENERIC_DMAENGINE_PCM=y
CONFIG_SND_SOC_FSL_ESAI=y
CONFIG_SND_SOC=y
CONFIG_SND=y
###########################
#
CONFIG_SND_VERBOSE_PRINTK=y
# CONFIG_SND_PCI is not set
# CONFIG_SND_SPI is not set
# CONFIG_SND_USB is not set
CONFIG_SND_SOC_FSL_AUDMIX=y
#
# SoC Audio support for Freescale i.MX boards:
# CONFIG_NETWORK_FILESYSTEMS is not set
###
CONFIG_SND_DEBUG=y
CONFIG_SND_DEBUG_VERBOSE=y
# CONFIG_SND_PCM_XRUN_DEBUG is not set
# CONFIG_SND_CTL_VALIDATION is not set
CONFIG_SND_SOC_FSL_Asrc=y
CONFIG_SND_SOC_FSL_SAI=y
# CONFIG_SND_SOC_FSL_MQS is not set
CONFIG_SND_SOC_FSL_SSI=y
CONFIG_SND_SOC_FSL_EAsrc=y
CONFIG_SND_SOC_IMX_PCM_DMA=y
CONFIG_SND_SOC_IMX_AUDMUX=y
CONFIG_SND_IMX_SOC=y
# SoC Audio support for Freescale i.MX boards:
#
# CONFIG_SND_SOC_IMX_ES8328 is not set
# CONFIG_SND_SOC_IMX_SGTL5000 is not set
# CONFIG_SND_SOC_IMX_SPDIF is not set
CONFIG_SND_SOC_FSL_ASOC_CARD=y
# CONFIG_SND_SOC_IMX_AUDMIX is not set
CONFIG_SND_SIMPLE_CARD_UTILS=y
CONFIG_SND_SIMPLE_CARD=y
CONFIG_SND_AUDIO_GRAPH_CARD=y
我知道的事情：
- 设备树由 yocto 正确编译并由 linux 内核使用，事实上这是唯一的板载设备树加上如果我在 /proc 下捕获设备树模型这就是结果
root@70820e12a37e:~# cat /proc/device-tree/model
Custom Kontron i.MX8MM board
- 在 /proc/device-tree 下我可以看到我的设备
root@70820e12a37e:/proc/device-tree# ls -alh
total 0
-r--r--r-- 1 root root 4 Jan 4 15:36 #address-cells
-r--r--r-- 1 root root 4 Jan 4 15:36 #size-cells
drwxr-xr-x 27 root root 0 Jan 1 1970 .
drwxr-xr-x 3 root root 0 Jan 1 1970 ..
drwxr-xr-x 2 root root 0 Jan 4 15:36 aliases
drwxr-xr-x 2 root root 0 Jan 4 15:36 chosen
drwxr-xr-x 2 root root 0 Jan 4 15:36 clock-ext1
drwxr-xr-x 2 root root 0 Jan 4 15:36 clock-ext2
drwxr-xr-x 2 root root 0 Jan 4 15:36 clock-ext3
drwxr-xr-x 2 root root 0 Jan 4 15:36 clock-ext4
drwxr-xr-x 2 root root 0 Jan 4 15:36 clock-osc-24m
drwxr-xr-x 2 root root 0 Jan 4 15:36 clock-osc-32k
drwxr-xr-x 2 root root 0 Jan 4 15:36 clock-osc-can
drwxr-xr-x 2 root root 0 Jan 4 15:36 codec_dummy
-r--r--r-- 1 root root 81 Jan 4 15:36 compatible
drwxr-xr-x 8 root root 0 Jan 4 15:36 cpus
-r--r--r-- 1 root root 4 Jan 4 15:36 interrupt-parent
drwxr-xr-x 8 root root 0 Jan 4 15:36 leds
drwxr-xr-x 2 root root 0 Jan 4 15:36 memory@40000000
drwxr-xr-x 2 root root 0 Jan 4 15:36 mipi-video-phy
-r--r--r-- 1 root root 37 Jan 4 15:34 model
-r--r--r-- 1 root root 1 Jan 4 15:36 name
drwxr-xr-x 5 root root 0 Jan 4 15:36 opp-table
drwxr-xr-x 2 root root 0 Jan 4 15:36 pmu
drwxr-xr-x 2 root root 0 Jan 4 15:36 psci
drwxr-xr-x 2 root root 0 Jan 4 15:36 regulator-5v
drwxr-xr-x 2 root root 0 Jan 4 15:36 regulator-rst-eth2
drwxr-xr-x 14 root root 0 Jan 4 15:36 soc@0
drwxr-xr-x 4 root root 0 Jan 4 15:36 sound-sai3sound
drwxr-xr-x 3 root root 0 Jan 4 15:36 thermal-zones
drwxr-xr-x 2 root root 0 Jan 4 15:36 timer
drwxr-xr-x 2 root root 0 Jan 4 15:36 usbphynop1
drwxr-xr-x 2 root root 0 Jan 4 15:36 usbphynop2
ALSA 设备仍然丢失
root@70820e12a37e:/proc/device-tree# aplay -l
aplay: device_list:272: no soundcards found...
此外，内核日志不显示错误，我尝试启用 ALSA 日志调试级别，但在启动期间没有显示任何内容（没有错误，没有声卡，没有警告......只有“找不到声卡......”） .
我真的很难做到这一点，至少在经过大量的试验/错误之后我已经正确地编译了设备树所以我开始思考......我错过了什么吗？是否还有其他一些我需要做的事情，我需要在内核中启用其他一些选项，或者 alsa 设置...感谢每个提示
