readme.txt

根据芯片WM8782在LINUX环境下实现的音频驱动

					WM8782子板使用说明
1、硬件说明：
	①WM8782子板。在该子板上j1(Line-in),j2(Mic-in),j3(Headerphone out)
	
2、软件说明：
	①所需文件：
		mxc_i2s.c/mx27-wm8782-pcm.c mxc-pcm.h/wm8782.c wm8782.h/wm8782-mixer.c 		wm8782-mixer.h
		
		把文件mxc_i2s.c放到目录drivers\mxc\ssi
		把文件mx27-wm8782-pcm.c mxc-pcm.h/wm8782.c wm8782.h/wm8782-mixer.c 				wm8782-mixer.h 放到目录sound\arm\
	②修改Makefile,Kconfig
		drivers\mxc\ssi\Makefile添加如下代码：
			obj-$(CONFIG_MX27_SSI_I2S)+= mxc-ssi-i2s.o
     			mxc-ssi-i2s-objs := mxc_i2s.o
		drivers\mxc\ssi\Kconfig添加如下代码：
		config MX27_SSI_I2S
			tristate "mxc i2s slave mode"
			depends on MXC_SSI  
			---help---
			Say Y to support mx27 ssi for i2s slave mode.

		sound\arm\Makefile添加如下代码：
			CFLAGS_mx27-wm8782-pcm.o  = -I$(TOPDIR)/drivers/mxc
			obj-$(CONFIG_SND_MX27_WM8782_PCM) += snd-mx27-wm8782-pcm.o
			snd-mx27-wm8782-pcm-objs := mx27-wm8782-pcm.o

			obj-$(CONFIG_SND_WM8782_MIXER) += snd-mx27-wm8782-mixer.o
			snd-mx27-wm8782-mixer-objs := wm8782-mixer.o

			obj-$(CONFIG_SND_WM8782) += snd-mx27-wm8782.o
			snd-mx27-wm8782-objs := wm8782.o


		sound\arm\Kconfig添加如下代码：
		config SND_WM8782	
			tristate "WM8782 codec support" 
			depends on SND && ARCH_MXC  
			help
			Say Y here to include support for wm8782 codec.

		config SND_WM8782_MIXER
			tristate "WM8782 mixer support"
			depends on SND && ARCH_MXC 
			help
			Say Y here to include support for wm8782 codec alsa mixer.

		config SND_MX27_WM8782_PCM
			tristate "WM8782 pcm support"
			depends on SND && ARCH_MXC && MXC_DAM && MXC_SSI
			select SND_PCM
			help
			Say Y here to include support for wm8782 codec pcm		  

③内核配置选项：
	device drivers-->mxc support drivers-->mxc ssi support-->mxc i2s slave mode,Y\M

	device drivers-->sound-->advanced linux sound architecture-->alsa arm devices--			>wm8782 codec support,Y\M

	device drivers-->sound-->advanced linux sound architecture-->alsa arm devices--			>wm8782 mixer support ,Y\M

	device drivers-->sound-->advanced linux sound architecture-->alsa arm devices--			>wm8782 pcm support,Y\M

④配置mixer:
	执行alsamixer进行相应的配置。默认情况下可以播放，和mic录音。
	

⑤加载模块：
	insmod mxc-ssi-i2s.ko
	insmod snd-mx27-wm8782-mixer.ko
	insmod snd-mx27-wm8782-pcm.ko
	insmod snd-mx27-wm8782.ko

⑥测试：
	录音：
		8k,stereo录音:arecord -f S16_LE -r 8000 -c 2 -t wav -d 10 /tmp/rec
	
	注：支持8k录音