基于ARM平台ALSA音频驱动的设计与实现

发布时间：2018-01-14 02:17

本文关键词：基于ARM平台ALSA音频驱动的设计与实现　出处：《中国地质大学（北京）》2013年硕士论文　论文类型：学位论文

【摘要】：本论文的主要内容是为一款音频编解码芯片编写ALSA音频驱动，实现对其音频流的控制，硬件平台依附于ARM9体系结构的三星2440CPU加上我们的音频编解码芯片。论文中对我们项目中整个的开发流程进行了介绍，首先介绍了一般嵌入式开发的大概流程及相关概念，其中介绍了本论文中所用到的相关硬件平台，主要是ARM体系架构；软件操作系统选用linux2.6.32，并且分析了linux系统的一系列相关内容，并且说明了开发平台、调试环境的搭建。随后就对我所做的ALSA驱动展开论述，从音频相关的概念主要是音频接口规范I2S开始论述，然后是ALSA的架构分析，最后写了ALSA驱动的实现流程，这部分分为三个重点部分：解码器、平台和机器三部分，实现了这部分就把ALSA的大体结构搭建好，然后就是声卡的具体抽象过程，创建CARD及组件，其中涉及到我们所选用音频芯片的很多寄存器的操作，这样我们的ALSA音频驱动就编写完成。随后是将我们驱动编译进内核中并且通过TFTP将UImage放在开发板上，其中的文件系统选用了已经做好的ramdisk，同理应用程序可执行文件也是通过网络传输。最后是关于论文中驱动的测试环节，从应用层调用ALSA驱动操作硬件需要使用中间的ALSALib层，，这就是alsa的作用，提供统一的接口使不同的音频芯片可以在不同的平台使用而不需要从新编写驱动代码。测试驱动接口需要调用ALSAutiles工具，其中编译好后会有aplay、amixer等测试可执行文件，这样我们可以设置不同的参数来完成不同的声卡操作功能及调用驱动的不同接口，这样就可以测试我为音频芯片所编写驱动成功与否或是有什么BUG。测试结果显示声卡驱动接口调用成功，并且功能实现正常，达到为音频芯片提供ALSA的支持。
[Abstract]:The main content of this paper is to compile ALSA audio driver for an audio codec chip, and realize the control of its audio stream. The hardware platform is attached to the Samsung 2440CPU of the ARM9 architecture, plus our audio codec chip.
The entire development process of our project are introduced in this paper, first introduces the general embedded development about process and related concepts, introduced the related hardware platform are used in this thesis, mainly ARM architecture; software use linux2.6.32 operating system, and analyzes a series of related content of the Linux system, and the development platform, debugging environment. Then done on my ALSA drive are discussed from the concept of audio related audio interface specification I2S is mainly discussed, and then analysis the architecture of ALSA, finally write the process to achieve the ALSA driver, this part is divided into three parts: key decoder platform the three part is realized and the machine, this part put the general structure of ALSA structures, and then the abstraction process is sound, and create a CARD component, which relates to what we choose A lot of registers are operated on the audio chip so that our ALSA audio driver is written.
Then we compile our driver into the kernel, and put the UImage on the development board through TFTP. The file system selects the ramdisk that has been completed. Similarly, the application executable is also transmitted through the network.
The last part is about the drive link test, ALSALib need to use the middle layer from the application layer to call the ALSA driver to operate the hardware, this is alsa, to provide a unified interface to different audio chip in platform using different and do not need to write driver code. The test driver interface need to call the ALSAutiles tool. There will be aplay compiled amixer test executable file, so we can set different parameters to achieve different interface function and sound card operation call a different driver, so I can get my test audio chip prepared by driving the success or a sound card driver successfully what BUG. test results show that the and normal function, to provide ALSA support for audio chip.

【学位授予单位】：中国地质大学（北京）
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TN912.3;TP368.1

【参考文献】