原文地址：嵌入式Linux之我行——Linux-2.6.30.4在2440上的移植之UDA1341声卡驱动 作者：hbhuanggang
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：
