linux 音频驱动
linux音频驱动分析 creator sz111@126.com int __init utu2440_uda1341_init(void) { int ret = 0; //printk("ghcstop.........probe\n"); //首先是对L3总线的一些控制操作。 ret = l3_attach_client(&uda1341, "l3-bit-24x0-gpio", "uda1341"); if (ret) { printk("l3_attach_client() failed.\n"); return ret; } l3_open(&uda1341); start_uda1341(); //定义输出和...
linux音频驱动分析 creator sz111@126.com int __init utu2440_uda1341_init(void) { int ret = 0; //printk("ghcstop.........probe\n"); //首先是对L3总线的一些控制操作。 ret = l3_attach_client(&uda1341, "l3-bit-24x0-gpio", "uda1341"); if (ret) { printk("l3_attach_client() failed.\n"); return ret; } l3_open(&uda1341); start_uda1341(); //定义输出和...
这程序可谓是初学者(驱动开发),要学的最为经典的程序之篇! 一大段代码看下来,了解过程!的确要一点时间功夫!! 现在一点就是对,DSP控制那一块有一点迷惑!不知道那些宏是怎么得到来的! 比如:SNDCTL_DSP_SETFMT这个定义是怎么得来的! 在内核里面对此是这样链接的 #define SIOCPARM_MASK 0x1fff /* parameters must be < 8192 bytes */ #define SIOC_OUT 0x20000000 /* copy out parameters */ #define SIOC_IN 0x40000000 /* copy in...
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请高手帮忙看下,是哪里的问题 dm6446开发版 linux2.6.18的内核 外接的音频芯片是tlv320aic23 [email]root@192.168.1.203[/email]:/test# cat /dev/sndstat Sound Driver:3.8.1a-980706 (ALSA v1.0.12rc1 emulation code) Kernel: linux 192.168.1.203 2.6.18_pro500-davinci_evm-arm_v5t_le #1 PREEMPT Fri Nov 21 16:04:04 CST 2014 armv5tejl Config options: 0 Installed drivers: Type 10: ALSA emulation Card config...
为了实现mp3播放，我们最近在sep4020上完成了i2s的驱动，主要经验总结如下： 1. 首先是要在probe函数里进行一系列的初始化，这些初始化对于i2s是很重要的，而且很多 ● 配置操作codec的L3的gpio口线； L3接口相对于一个混音器控制接口，也就是对应在驱动中的mixer结构体，在这里我们需要利用3根gpio口线实现对L3的控制，以下是初始化代码： *(volatile unsigned long*)(GPIO_PORTD_DIR_V) &= ~(0xd //GPB[4:1]=...
ASoC Platform Driver [color="Red"]ASoC平台驱动 ==================== An ASoC platform driver can be divided into audio DMA and SoC DAI configuration and control. The platform drivers only target the SoC CPU and must have no board specific code. [color="Red"]一个ASoC平台驱动可以分为音频DAM和SoC DAI配置和控制。平台驱动只锁定平台处理器为目标，必须不包含任何板级相关代码。 Audio DMA [color="Red"]音频DMA...
ASoC Machine Driver [color="Red"]ASoC机器驱动 =================== The ASoC machine (or board) driver is the code that glues together the platform and codec drivers. [color="Red"]ASoC机器或板级驱动是把平台和解码器驱动粘合在一起的代码。 The machine driver can contain codec and platform specific code. It registers the audio subsystem with the kernel as a platform device and is represented by the foll...
ASoC currently supports the three main Digital Audio Interfaces (DAI) found on SoC controllers and portable audio CODECs today, namely AC97, I2S and PCM. [color="Red"]ASoC现在支持如今的SoC控制器和便携音频解码器上的三个主要数字音频接口，即AC97，I2S，PCM。 AC97 [color="Red"]AC97 ==== AC97 is a five wire interface commonly found on many PC sound cards. It is now also popular in many portable device...
Dynamic Audio Power Management for Portable Devices [color="Red"]便携设备的动态音频电源管理 =================================================== 1. Description [color="Red"]1、概述 ============== Dynamic Audio Power Management (DAPM) is designed to allow portable linux devices to use the minimum amount of power within the audio subsystem at all times. It is independent of other kernel PM and as suc...
