stm32mp157wm8960音频驱动调试笔记
stm32mp157wm8960⾳频驱动调试笔记这次调试wm8960⾳频驱动遇到了好多的坑，研究好⼏天终于调试好了。
驱动调试步骤
驱动能不能成功加载是调试的第⼀⼤步骤，也是最关键的步骤之⼀。
1.查看硬件原理图:
2.打开对应的设备树（stm32mp157a-xxx.dtsi）:
因为wm8960是挂载到I2C4上，所以在设备树I2C4节点上添加wm8960设备节点。
wm8960: wm8960@1a {
compatible ="wlf,wm8960";
reg =<0x1a>;
#sound-dai-cells =<0>;
status ="okay";
wlf,shared-lrclk;
clocks =<&sai2a>;
clock-names ="mclk";
port {
#address-cells =<1>;
#size-cells =<0>;
wm8960_tx_endpoint: endpoint@0{
reg =<0x0>;
remote-endpoint =<&sai2b_endpoint>;
frame-master;
bitclock-master;
};
wm8960_rx_endpoint: endpoint@1{
reg =<0x1>;心理咨询师证怎么考需要什么条件
remote-endpoint =<&sai2a_endpoint>;
frame-master;
bitclock-master;
};
};
};
其中节点的clocks =< sai2a >是需要看原理图使⽤的是SAI2A 还是SAI2B作为主时钟。
3.SAI2配置：
&sai2 {
clocks =<&rcc SAI2>,<&rcc PLL3_Q>,<&rcc PLL3_R>;
clock-names ="pclk","x8k","x11k";
pinctrl-names ="default","sleep";
pinctrl-0=<&sai2a_pins_a>,<&sai2b_pins_b>;
pinctrl-1=<&sai2a_sleep_pins_a>,<&sai2b_sleep_pins_b>;
status ="okay";
sai2a: audio-controller@4400b004 {
dma-names ="rx";
#clock-cells =<0>;
clocks =<&rcc SAI2_K>;
clock-names ="sai_ck";
status ="okay";
sai2a_port: port {
sai2a_endpoint: endpoint {
remote-endpoint =<&wm8960_rx_endpoint>;
format ="i2s";
mclk-fs =<256>;
dai-tdm-slot-num =<2>;
dai-tdm-slot-width =<16>;
};
};
};
sai2b: audio-controller@4400b024 {
dma-names ="tx";
st,sync =<&sai2a 2>;
clocks =<&rcc SAI2_K>,<&sai2a>;
clock-names ="sai_ck","MCLK";
status ="okay";
sai2b_port: port {
sai2b_endpoint: endpoint {
remote-endpoint =<&wm8960_tx_endpoint>;
format ="i2s";
mclk-fs =<256>;
dai-tdm-slot-num =<2>;
dai-tdm-slot-width =<16>;
};
};
};
};
其中⽐较重要的是sai2a，sai2b的输⼊输出问题，上述原理图描述的是sai2a作为ADC(capture),sai2b作为DAC(playback)，所以，此时sai2a节点中的dma-names = ‘tx’，sai2b则是dma-names = ‘rx’，另外还有st,sync = <&sai2a 2>;
上市公司回购细则这⾥可以参考内核源码路径:Documentation/devicetree/bindings/sound/⽂档
4.sound节点配置
compatible ="audio-graph-card";
label ="wm8960-audio";
mclk-fs =<256>;
dai-format ="i2s";
widgets =
"Microphone","Mic Jack",
"Line","Line In",
"Line","Line Out",
关于立夏的谚语
"Speaker","Speaker",
"Headphone","Headphone Jack";
routing =
"Headphone Jack","HP_L",
"Headphone Jack","HP_R",
"Speaker","SPK_LP",
"Speaker","SPK_LN",
"Speaker","SPK_RP",
"Speaker","SPK_RN",
"LINPUT1","MICB",
英语四级分数
"LINPUT3","MICB";
dais =<&sai2a_port &sai2b_port>;
status ="okay";
};
5.配置引脚(stm32mp15-pinctrl.dtsi)：
sai2a_pins_a: sai2a-0{
pins {
pinmux =<STM32_PINMUX('I',6, AF10)>;/* SAI2_SD_A */
bias-disable;
drive-push-pull;
slew-rate =<0>;乔迁之喜的祝福语怎么说
};
};
sai2a_sleep_pins_a: sai2a-1{
pins {
pinmux =<STM32_PINMUX('I',6, ANALOG)>;/* SAI2_SD_A */
关联词语练习
};
};
sai2b_pins_b: sai2b-2{
pins {
pinmux =<STM32_PINMUX('E',11, AF10)>,/* SAI2_SD_B */ <STM32_PINMUX('I',5, AF10)>,/* SAI2_SCK_A */
<STM32_PINMUX('I',7, AF10)>,/* SAI2_FS_A */
<STM32_PINMUX('E',0, AF10)>;/* SAI2_MCLK_A */
bias-disable;
drive-push-pull;
slew-rate =<0>;
};
};
sai2b_sleep_pins_b: sai2b-3{
pins {
pinmux =<STM32_PINMUX('E',11, ANALOG)>,/* SAI2_SD_B */ <STM32_PINMUX('I',5, ANALOG)>,/* SAI2_SCK_A */
<STM32_PINMUX('I',7, ANALOG)>,/* SAI2_FS_A */
<STM32_PINMUX('E',0, ANALOG)>;/* SAI2_MCLK_A */
};
};
如果出现上述的启动打印信息，证明wm8960驱动加载成功了。接下来看看有⽆有出现声卡节点。
[root@stm32mp157]:~# ls /dev/snd/
by-path/  controlC0  pcmC0D0c  pcmC0D1p  timer
pcmC0D0c 是录⾳设备
pcmC0D1p 是播放设备
[root@stm32mp157]:~# aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: wm8960audio [wm8960-audio], device 1:4400b024.audio-controller-wm8960-hifi wm8960-hifi-1[4400b024.audio-controller-wm8960-hifi wm8960-hifi-1]
Subdevices:1/1
Subdevice #0: subdevice #0
[root@stm32mp157]:~# arecord -l
**** List of CAPTURE Hardware Devices ****
card 0: wm8960audio [wm8960-audio], device 0:4400b004.audio-controller-wm8960-hifi wm8960-hifi-0[4400b004.audio-controller-wm8960-hifi wm8960-hifi-0]
Subdevices:1/1
Subdevice #0: subdevice #0
声卡0，设备0 -->是录⾳设备
声卡0，设备1 -->是播放设备
7.故障问题
如果使⽤命令:aplay xxx.wav,⼀直卡在命令⾏不结束，没有任何的报错信息，你需要查看原理图，是否对应设备树的配置问题。
如果aplay xxx.wav ，出现以下报错信息:
[root@-stm32mp157]:~# aplay -Dhw:0.0 /usr/share/sounds/alsa/Rear_Right.wav
ALSA lib …/…/…/alsa-lib-1.2.1.2/src/pcm/pcm_hw.c:1829:(_snd_pcm_hw_open) Invalid value for ca
rd
aplay: main:828: audio open error: No such device
需要使⽤aplay -l 查看播放的设备号，查看/f配置的是否正确。可以使⽤命令 aplay -Dhw:0.1 xxx.wav 来指定设备播放。
曾经驱动加载也成功了，就是没有声⾳，查了硬件和驱动都没有什么问题，alsamixer也设置了声⾳的⾼低，还是不⾏，发现f 也会有⼀定的影响。
pcm.dmix_44100{
type dmix
ipc_key 5678293
ipc_key_add_uid yes
slave{
pcm "hw:0,0"
period_time 40000
buffer_time 360000
format S16_LE
rate 44100
}
}
pcm.!dsnoop_44100{
type dsnoop
ipc_key 5778293
ipc_key_add_uid yes
slave{
pcm "hw:0,1"
period_time 40000
buffer_time 360000
format S16_LE
rate 44100
}
}
pcm.asymed{
type asym
playback.pcm "dmix_44100"
capture.pcm "dsnoop_44100"
}
pcm.dsp0{
type plug
slave.pcm "asymed"
}
pcm.!default{
type plug
route_policy "average"
slave.pcm "asymed"
}
ctl.!default{
type hw
card 0
}
ctl.mixer0{
type hw
card 0
}
⼼得体会
当遇到问题的时候，不要急，驱动打印信息会帮你到失败的原因，还是不⾏的话，可以参考别⼈成功的案例，在硬件电路改成⼀样的，看是否是硬件或者芯⽚的问题。
附上wm8960驱动⽂件和f的配置⽂件链接:

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