Files
luban-lite-t3e-pro/doc/topics/sdk/i2s/i2s_arch.html
2025-01-23 16:37:00 +08:00

186 lines
13 KiB
HTML
Raw Blame History

This file contains ambiguous Unicode characters
This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
<!DOCTYPE html><html xmlns="http://www.w3.org/1999/xhtml" xml:lang="zh-cn" lang="zh-cn" data-whc_version="26.0">
<head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/><meta name="viewport" content="width=device-width, initial-scale=1.0"/><meta http-equiv="X-UA-Compatible" content="IE=edge"/><meta name="description" content="内核中音频采用 ALSA 驱动框架该框架管理所有与音频相关的软件与硬件I2S 的驱动设计需要遵循该框架的基本要求。ALSA 音频框架将底层的硬件驱动分为三个部分machine、pltform 与 codec。三者的关系如下图所示 ALSA 框架将底层划分为三部分后,使得 platform 和 codec 的驱动实现变得更加简单,二者只专注于实现自己的功能代码,由 machine 驱动来实现 ..."/><meta name="DC.rights.owner" content="(C) 版权 2025"/><meta name="copyright" content="(C) 版权 2025"/><meta name="generator" content="DITA-OT"/><meta name="DC.type" content="concept"/><meta name="DC.creator" content="yan.wang"/><meta name="DC.date.created" content="2024-01-18"/><meta name="DC.date.modified" content="2024-12-02"/><meta name="DC.format" content="HTML5"/><meta name="DC.identifier" content="i2s_architecture"/><meta name="DC.language" content="zh-CN"/><title>I2S 架构设计</title><!-- Build number 2023110923. --><meta name="wh-path2root" content="../../../"/><meta name="wh-toc-id" content=""/><meta name="wh-source-relpath" content="topics/sdk/i2s/i2s_arch.dita"/><meta name="wh-out-relpath" content="topics/sdk/i2s/i2s_arch.html"/>
<link rel="stylesheet" type="text/css" href="../../../webhelp/app/commons.css?buildId=2023110923"/>
<link rel="stylesheet" type="text/css" href="../../../webhelp/app/topic.css?buildId=2023110923"/>
<script src="../../../webhelp/app/options/properties.js?buildId=20250121171154"></script>
<script src="../../../webhelp/app/localization/strings.js?buildId=2023110923"></script>
<script src="../../../webhelp/app/search/index/keywords.js?buildId=20250121171154"></script>
<script defer="defer" src="../../../webhelp/app/commons.js?buildId=2023110923"></script>
<script defer="defer" src="../../../webhelp/app/topic.js?buildId=2023110923"></script>
<link rel="stylesheet" type="text/css" href="../../../webhelp/template/aic-styles-web.css?buildId=2023110923"/><link rel="stylesheet" type="text/css" href="../../../webhelp/template/notes.css?buildId=2023110923"/><link rel="stylesheet" type="text/css" href="../../../webhelp/template/aic-common.css?buildId=2023110923"/><link rel="stylesheet" type="text/css" href="../../../webhelp/template/aic-images.css?buildId=2023110923"/><link rel="stylesheet" type="text/css" href="../../../webhelp/template/footnote.css?buildId=2023110923"/><link rel="stylesheet" type="text/css" href="../../../webhelp/template/aic-web-watermark.css?buildId=2023110923"/><link rel="stylesheet" type="text/css" href="../../../webhelp/template/topic-body-list.css?buildId=2023110923"/></head>
<body id="i2s_architecture" class="wh_topic_page frmBody">
<a href="#wh_topic_body" class="sr-only sr-only-focusable">
跳转到主要内容
</a>
<header class="navbar navbar-default wh_header">
<div class="container-fluid">
<div class="wh_header_flex_container navbar-nav navbar-expand-md navbar-dark">
<div class="wh_logo_and_publication_title_container">
<div class="wh_logo_and_publication_title">
<a href="http://www.artinchip.com" class=" wh_logo d-none d-sm-block "><img src="../../../company-logo-white.png" alt="RTOS SDK 使用指南SDK 指南文件"/></a>
<div class=" wh_publication_title "><a href="../../../index.html"><span class="booktitle"><span class="ph mainbooktitle">RTOS SDK 使用指南</span><span class="ph booktitlealt">SDK 指南文件</span></span></a></div>
</div>
</div>
<div class="wh_top_menu_and_indexterms_link collapse navbar-collapse" id="wh_top_menu_and_indexterms_link">
</div>
</div>
</div>
</header>
<div class=" wh_search_input navbar-form wh_topic_page_search search " role="form">
<form id="searchForm" method="get" role="search" action="../../../search.html"><div><input type="search" placeholder="搜索 " class="wh_search_textfield" id="textToSearch" name="searchQuery" aria-label="搜索查询" required="required"/><button type="submit" class="wh_search_button" aria-label="搜索"><span class="search_input_text">搜索</span></button></div></form>
</div>
<div class="container-fluid" id="wh_topic_container">
<div class="row">
<nav class="wh_tools d-print-none navbar-expand-md" aria-label="Tools">
<div data-tooltip-position="bottom" class=" wh_breadcrumb "></div>
<div class="wh_right_tools">
<button class="wh_hide_highlight" aria-label="切换搜索突出显示" title="切换搜索突出显示"></button>
<button class="webhelp_expand_collapse_sections" data-next-state="collapsed" aria-label="折叠截面" title="折叠截面"></button>
<div class=" wh_print_link print d-none d-md-inline-block "><button onClick="window.print()" title="打印此页" aria-label="打印此页"></button></div>
</div>
</nav>
</div>
<div class="wh_content_area">
<div class="row">
<div class="col-lg-10 col-md-10 col-sm-10 col-xs-12" id="wh_topic_body">
<button id="wh_close_topic_toc_button" class="close-toc-button d-none" aria-label="Toggle topic table of content" aria-controls="wh_topic_toc" aria-expanded="true">
<span class="close-toc-icon-container">
<span class="close-toc-icon"></span>
</span>
</button>
<div class=" wh_topic_content body "><main role="main"><article class="- topic/topic concept/concept topic concept" role="article" aria-labelledby="ariaid-title1"><span class="edit-link" style="font-size:12px; opacity:0.6; text-align:right; vertical-align:middle"><a target="_blank" href="http://172.16.35.88/tasks/jdssno1uvvbf2mltu9kb9v3if05d5gopuakboe8hlud18rma/edit/F:/aicdita/aicdita-cn/topics/sdk/i2s/i2s_arch.dita">Edit online</a></span><h1 class="- topic/title title topictitle1" id="ariaid-title1">I2S 架构设计</h1><div class="date inPage">2 Dec 2024</div><div style="color: gray;">
Read time: 1 minute(s)
</div><div class="- topic/body concept/conbody body conbody"><p class="- topic/p p" data-ofbid="d46280e23__20250121171517">内核中音频采用 ALSA 驱动框架该框架管理所有与音频相关的软件与硬件I2S 的驱动设计需要遵循该框架的基本要求。ALSA 音频框架将底层的硬件驱动分为三个部分machine、pltform 与 codec。三者的关系如下图所示</p><div class="- topic/p p" data-ofbid="d46280e25__20250121171517"><br/><div class="imagecenter"><img class="- topic/image image imagecenter" id="i2s_architecture__image_kk1_sg3_d1c" src="../../../images/i2s/i2s_alsa_design.png" width="384" alt="design_12"/></div><br/></div><p class="- topic/p p" data-ofbid="d46280e29__20250121171517">ALSA 框架将底层划分为三部分后,使得 platform 和 codec 的驱动实现变得更加简单,二者只专注于实现自己的功能代码,由 machine 驱动来实现 platform 和 codec 的耦合,二者依靠 dai 和 codec_dai 进行数据传输。platform 驱动的主要作用是完成音频数据的管理,最终通过 SOC 的数字音频接口(cpu_dai)把音频数据传送给 codec 进行播放或将 codec 采集的音频数据存储到内存中。</p><p class="- topic/p p" data-ofbid="d46280e31__20250121171517">在具体的实现上ALSA 将 platform 驱动platform 可以简单理解为 SOC 端的驱动)分为两部分:实现音频数据传输和管理的 DMA 驱动和 CPU
DAI 的驱动。且 ALSA 框架中已实现了 DMA 对音频数据管理部分的驱动 代码,所以 S 的驱动只需要实现 CPU
DAI 部分的驱动,音频数据管理部分只需要指定数据传输的起始地址或目的地址,以及传输位宽即可。</p><section class="- topic/section section" id="i2s_architecture__section_lc4_sg3_d1c" data-ofbid="i2s_architecture__section_lc4_sg3_d1c"><h2 class="- topic/title title sectiontitle">CPU DAI 驱动</h2>
<p class="- topic/p p" data-ofbid="d46280e38__20250121171517">在驱动实现上,无论是 codec 还是 platformALSA 将它们统一划分为 component 和 dai所以就要相应的实现 driver 和 driver。
然后调用 component 进行统一注册。snd_soc_component_driver 主要是注册与 dapm 相关的音频控件等信息snd_soc_dai_driver 主要是注册数字音频接口 S 或 PCM 等的信息及底层操作函数。</p>
<p class="- topic/p p" data-ofbid="d46280e41__20250121171517">由于在 platform 端,主要是 S 接口和 DMA 的传输配置,不存在音频控件,所以 DAI 的驱动主要是实现 driver。包括指定 S 接口支持的通道数、采样率、支持的数据格式,以及对 S 配置和控制的回调函数集合 snd_soc_dai_ops 的实现</p>
</section><section class="- topic/section section" id="i2s_architecture__section_mc4_sg3_d1c" data-ofbid="i2s_architecture__section_mc4_sg3_d1c"><h2 class="- topic/title title sectiontitle">音频 DMA 驱动</h2>
<p class="- topic/p p" data-ofbid="d46280e49__20250121171517">ALSA 架构中,对 DMA 的一些配置和传输的函数已经由 ALSA 框架实现,所以这部分驱动实现只需要指定 playback 和 capture 中 DMA 传输的地址以及传输的位宽,然后调用 register
进行注册即可。</p>
</section></div></article></main></div>
</div>
<nav role="navigation" id="wh_topic_toc" aria-label="On this page" class="col-lg-2 d-none d-lg-block navbar d-print-none">
<div id="wh_topic_toc_content">
<div class=" wh_topic_toc "><div class="wh_topic_label">在本页上</div><ul><li class="section-item"><div class="section-title"><a href="#i2s_architecture__section_lc4_sg3_d1c" data-tocid="i2s_architecture__section_lc4_sg3_d1c">CPU DAI 驱动</a></div></li><li class="section-item"><div class="section-title"><a href="#i2s_architecture__section_mc4_sg3_d1c" data-tocid="i2s_architecture__section_mc4_sg3_d1c">音频 DMA 驱动</a></div></li></ul></div>
</div>
</nav>
</div>
</div>
</div>
<footer class="navbar navbar-default wh_footer">
<div class=" footer-container mx-auto ">
<title>footer def</title>
<style><!--
.p1 {
font-family: FangZhengShuSong, Times, serif;
}
.p2 {
font-family: Arial, Helvetica, sans-serif;
}
.p3 {
font-family: "Lucida Console", "Courier New", monospace;
}
--></style>
<div class="webhelp.fragment.footer">
<p class="p1">Copyright © 2019-2024 广东匠芯创科技有限公司. All rights reserved.</p>
</div><div>
<div class="generation_time">
Update Time: 2025-01-21
</div>
</div>
</div>
</footer>
<div id="go2top" class="d-print-none">
<span class="oxy-icon oxy-icon-up"></span>
</div>
<div id="modal_img_large" class="modal">
<span class="close oxy-icon oxy-icon-remove"></span>
<div id="modal_img_container"></div>
<div id="caption"></div>
</div>
<script src="${pd}/publishing/publishing-styles-AIC-template/js/custom.js" defer="defer"></script>
</body>
</html>