Linux 音频驱动
Linux 音频驱动
硬件介绍
WM8960与IMX6ULL之间有两个通信接口：I2C和I2S
其中I2C用于配置WM8960
I2S用于音频数据传输
修改设备树文件
编写I2C子节点设备树
codec: wm8960@1a {
compatible = "wlf,wm8960";
reg = <0x1a>;
clocks = <&clks IMX6UL_CLK_SAI2>;
clock-names = "mclk"; 6 wlf,shared-lrclk;
};
编写I2S子节点设备树
sai2: sai@0202c000 {
compatible = "fsl,imx6ul-sai",
"fsl,imx6sx-sai";
reg = <0x0202c000 0x4000>;
interrupts = <GIC_SPI 98 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&clks IMX6UL_CLK_SAI2_IPG>,
<&clks IMX6UL_CLK_DUMMY>,
<&clks IMX6UL_CLK_SAI2>,
<&clks 0>, <&clks 0>;
clock-names = "bus", "mclk0", "mclk1", "mclk2", "mclk3";
dma-names = "rx", "tx";
dmas = <&sdma 37 24 0>, <&sdma 38 24 0>;
status = "disabled";
};
&sai2 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_sai2
&pinctrl_sai2_hp_det_b>;
assigned-clocks = <&clks IMX6UL_CLK_SAI2_SEL>,
<&clks IMX6UL_CLK_SAI2>;
assigned-clock-parents = <&clks IMX6UL_CLK_PLL4_AUDIO_DIV>;
assigned-clock-rates = <0>, <12288000>;
status = "okay";
};
pinctrl_sai2: sai2grp {
fsl,pins = <
MX6UL_PAD_JTAG_TDI__SAI2_TX_BCLK 0x17088
MX6UL_PAD_JTAG_TDO__SAI2_TX_SYNC 0x17088
MX6UL_PAD_JTAG_TRST_B__SAI2_TX_DATA 0x11088
MX6UL_PAD_JTAG_TCK__SAI2_RX_DATA 0x11088
MX6UL_PAD_JTAG_TMS__SAI2_MCLK 0x17088
>;
};
pinctrl_sai2_hp_det_b: sai2_hp_det_grp {
fsl,pins = <
MX6ULL_PAD_SNVS_TAMPER4__GPIO5_IO04 0x17059
>;
};
sound {
compatible = "fsl,imx6ul-evk-wm8960",
"fsl,imx-audio-wm8960";
model = "wm8960-audio";
cpu-dai = <&sai2>;
audio-codec = <&codec>;
asrc-controller = <&asrc>;
codec-master;
gpr = <&gpr 4 0x100000 0x100000>;
/*
* hp-det = ;
* hp-det-pin: JD1 JD2 or JD3
* hp-det-polarity = 0: hp detect high for headphone
* hp-det-polarity = 1: hp detect high for speaker
*/
hp-det = <3 0>;
/*hp-det-gpios = <&gpio5 4 0>;
mic-det-gpios = <&gpio5 4 0>;*/
audio-routing =
"Headphone Jack", "HP_L",
"Headphone Jack", "HP_R",
"Ext Spk", "SPK_LP",
"Ext Spk", "SPK_LN",
"Ext Spk", "SPK_RP",
"Ext Spk", "SPK_RN",
"LINPUT2", "Mic Jack",
"LINPUT3", "Mic Jack",
"RINPUT1", "Main MIC",
"RINPUT2", "Main MIC",
"Mic Jack", "MICB",
"Main MIC", "MICB",
"CPU-Playback", "ASRC-Playback",
"Playback", "CPU-Playback",
"ASRC-Capture", "CPU-Capture",
"CPU-Capture", "Capture";
};
配置Linux图形化文件
取消ALSA模拟OSS API
-> Device Drivers
-> Sound card support (SOUND [=y])
-> Advanced Linux Sound Architecture (SND [=y])
-> <> OSS Mixer API //不选择
-> <> OSS PCM (digital audio) API //不选择
使能WM8960驱动
-> Device Drivers
-> Sound card support (SOUND [=y])
-> Advanced Linux Sound Architecture (SND [=y])
-> ALSA for SoC audio support (SND_SOC [=y])
-> SoC Audio for Freescale CPUs
-> <*> Asynchronous Sample Rate Converter (ASRC) module support //选中
-> <*> SoC Audio support for i.MX boards with wm8960 //选中
移植alsa-lib和alsa-utils文件
1.获取源文件
alsa-lib-1.2.2.tar.bz2
alsa-utils-1.2.2.tar.bz2
2.解压文件
tar -vxjf alsa-lib-1.2.2.tar.bz2
tar -vxjf alsa-utils-1.2.2.tar.bz2
3.配置文件
//进入 alsa-lib 源码目录
cd alsa-lib-1.2.2/
./configure
--host=arm-linux-gnueabihf
--prefix=/home/zuozhongkai/linux/IMX6ULL/tool/alsa-lib
--with-configdir=/usr/share/arm-alsa
//进入 alsa-utils源码目录
cd alsa-utils-1.2.2/
./configure
--host=arm-linux-gnueabihf
--prefix=/home/zuozhongkai/linux/IMX6ULL/tool/alsa-utils
--with-alsa-inc-prefix=/home/zuozhongkai/linux/IMX6ULL/tool/alsa-lib/include/
--with-alsaprefix=/home/zuozhongkai/linux/IMX6ULL/tool/alsa-lib/lib/
--disable-alsamixer
--disable-xmlto
4.编译文件
make
5.安装文件
sudo make install
6.移植文件
移植alsa-lib文件
cd alsa-lib //进入 alsa-lib
sudo cp lib/* /home/zuozhongkai/linux/nfs/rootfs/lib/ -af
cd /usr/share/arm-alsa //进入 arm-alsa 目录，拷贝配置文件
sudo cp * /home/zuozhongkai/linux/nfs/rootfs/usr/share/arm-alsa/ -raf
移植alsa-utils文件
cd alsa-utils
sudo cp bin/* /home/zuozhongkai/linux/nfs/rootfs/bin/ -rfa
sudo cp sbin/* /home/zuozhongkai/linux/nfs/rootfs/sbin/ -rfa
sudo cp share/* /home/zuozhongkai/linux/nfs/rootfs/usr/share/ -rfa
在开发板根目录/etc/profile添加内容
export ALSA_CONFIG_PATH=/usr/share/arm-alsa/alsa.conf
移植zlib库和mplayer
1.获取源文件
zlib-1.2.11.tar.gz
MPlayer-1.4.tar.gz
2.解压文件
tar -vxzf zlib-1.2.11.tar.gz
tar -vxzf MPlayer-1.4.tar.gz
3.配置文件
cd zlib-1.2.11/ //进去 zlib 源码
CC=arm-linux-gnueabihf-gcc
LD=arm-linux-gnueabihf-ld
AD=arm-linux-gnueabihf-as
./configure
--prefix=/home/zuozhongkai/linux/IMX6ULL/tool/zlib
cd MPlayer-1.4/ //进去 mplayer 源码
./configure
--cc=arm-linux-gnueabihf-gcc
--host-cc=gcc
--target=arm-linux-gnueabihf
--disable-ossaudio
--enable-alsa
--prefix=/home/zuozhongkai/linux/IMX6ULL/tool/mplayer
--extra-cflags=
"-I /home/zuozhongkai/linux/IMX6ULL/tool/zlib/include -I /home/zuozhongkai/linux/IMX6ULL/tool/alsa-lib/include"
--extra-ldflags=
"-L/home/zuozhongkai/linux/IMX6ULL/tool/zlib/lib -Iz -L/home/zuozhongkai/linux/IMX6ULL/tool/alsa-lib/lib -lasound"
--enable-fbdev
--disable-mencoder
4.编译文件
make //编译
5.安装文件
make install
6.移植文件
将可执行文件拷贝到跟文件系统/bin目录下
sudo cp lib/* /home/zuozhongkai/linux/nfs/rootfs/lib/ -rfa