嵌入式Linux之我行——Linux-2.6.30.4在2440上的移植之UDA1341声卡驱动

嵌入式Linux之我行，主要讲述和总结了本人在学习嵌入式linux中的每个步骤。一为总结经验，二希望能给想入门嵌入式Linux的朋友提供方便。如有错误之处，谢请指正。

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一、移植环境

• 主  机：VMWare--Fedora 9
• 开发板：Mini2440--64MB Nand
• 编译器：arm-linux-gcc-4.3.2

二、移植步骤

1. 替换声卡驱动源码。因linux-2.6.30.4中版本为1.0.20的声卡驱动有bug，在播放音视频时会出现断断续续的现象，所以我们先用早期版本1.0.18a替换之(可在linux-2.6.29.xxx的内核中提取)，具体操作如下：

#cp -rf /linux-2.6.29.xxx/sound /linux-2.6.30.4/sound    //替换sound目录

#cp -rf /linux-2.6.29.xxx/include/sound /linux-2.6.30.4/include/sound    //替换include/sound目录

#cp -rf /linux-2.6.29.xxx/include/asm-arm /linux-2.6.30.4/include    //复制include/asm-arm目录

#cp -f /linux-2.6.29.xxx/arch/arm/mach-s3c2410/include/mach/audio.h /linux-2.6.30.4/arch/arm/mach-s3c2410/include/mach    //复制audio.h到相应目录

#gedit /linux-2.6.30.4/include/linux/proc_fs.h    //修改proc_fs.h文件，在第70行添加如下内容

struct module *owner;    //因为在sound/core/info.c第159和982行中用到

2. 定义并添加声卡设备到系统设备初始化列表中

 

#gedit arch/arm/plat-s3c24xx/devs.c    //定义，添加如下内容

#include <mach/regs-gpio.h>
#include <sound/s3c24xx_uda134x.h>

/* UDA1341 */
static struct s3c24xx_uda134x_platform_data s3c24xx_uda134x_data = {
 .l3_clk = S3C2410_GPB4,
 .l3_data = S3C2410_GPB3,
 .l3_mode = S3C2410_GPB2,
 .model = UDA134X_UDA1341,
};

struct platform_device s3c_device_uda134x = {
 .name = "s3c24xx_uda134x",
 .dev = {
  .platform_data = &s3c24xx_uda134x_data,
 }
};

EXPORT_SYMBOL(s3c_device_uda134x);


#gedit arch/arm/plat-s3c/include/plat/devs.h    //声明，添加如下内容

extern struct platform_device s3c_device_uda134x;

#gedit arch/arm/mach-s3c2440/mach-smdk2440.c    //添加到设备列表，红色部分

static struct platform_device *smdk2440_devices[] __initdata = {
    &s3c_device_usb,
    &s3c_device_sdi,
    &s3c_device_lcd,
    &s3c_device_wdt,
    &s3c_device_i2c0,
    &s3c_device_iis,
    &s3c_device_rtc,
    &s3c_device_dm9000,
    &s3c_device_uda134x,
};

3. 配置内核选项

Device Drivers --->
    <*> Sound card support --->
        --- Sound card support
        <*> Advanced Linux Sound Architecture --->
            --- Advanced Linux Sound Architecture
            < > Sequencer support
            <*> OSS Mixer API
            <*> OSS PCM (digital audio) API
            [*] OSS PCM (digital audio) API - Include plugin system
            [ ] Dynamic device file minor numbers
            [*] Support old ALSA API
            [*] Verbose procfs contents
            [*] Verbose printk
            [ ] Debug
            [ ] Generic sound devices --->
            [ ] ARM sound devices --->
            [ ] SPI sound devices --->
            [*] USB sound devices --->
            <*> ALSA for SoC audio support --->
                --- ALSA for SoC audio support
                <*> SoC Audio for the Samsung S3C24XX chips
                < > SoC AC97 Audio support for LN2440SBC - ALC650
                <*> SoC I2S Audio support UDA134X wired to a S3C24XX
                < > Build all ASoC CODEC drivers
        < > Open Sound System (DEPRECATED) --->

4. 编译内核并下载到开发板上。可以看到启动信息中声卡设备成功加载

5. 测试声卡设备。先建立设备节点，声卡的主设备号为14。然后使用cat /dev/sound/dsp > /tmp/test.wav进行录音测试，再用cat /tmp/test.wav > /dev/sound/dsp播放录音，操作如图：