我正在移植wm8904芯片，codec的内容使用i.mx6库中自带的wm8904.c，imx的内容修改了imx-wm8962为imx-wm8904.c
启动信息为：
<3>imx ssi imx_ssi_probe
<3>ssi clk -1063799288
<3>imx-wm8904 sysclk: 24000000
<3>imx ssi imx_ssi_dai_probe
<3>Device is a WM8904, ID is 8904
<6>wm8904 0-001a: revision A
<3>wm8904 finish
<3>wm8904 0-001a: Failed to add route DMIC->DMICDAT
<3>imx ssi imx_pcm_new
<3>imx ssi imx_pcm_preallocate_dma_buffer
<3>imx ssi imx_pcm_preallocate_dma_buffer
<6>asoc: wm8904-hifi <-> imx-ssi.1 mapping ok
<6>input: wm8904-audio DMIC as /devices/platform/soc-audio.6/sound/card0/input4
<6>input: wm8904-audio Headphone Jack as /devices/platform/soc-audio.6/sound/card0/input5
<6>imx_3stack asoc driver
<6>asoc: mxc-hdmi-soc <-> imx-hdmi-soc-dai.0 mapping ok
<6>ALSA device list:
<6> #0: wm8904-audio
<6> #1: imx-hdmi-soc
测试方法：
./tinyplay audio8k16S.wav
程序可以正确执行，有wm8904发来的BCLK和FS波形，但是没有i.mx6 ssi的tx引脚没有波形。
1. 对比了wm8962产生的BCLK波形和FS波形，确定wm8904输出波形没有问题。
2. 看了dmesg，没有任何错误信息
3. 在dma的pointer位置打了log， dma是正常输出的
<3>audio_dma_irq
<3>snd_imx_pcm_pointer: 0 0
<3>snd_imx_pcm_pointer: 0 0
<3>audio_dma_irq
<3>snd_imx_pcm_pointer: 4096 1024
<3>snd_imx_pcm_pointer: 4096 1024
<3>audio_dma_irq
<3>snd_imx_pcm_pointer: 8192 2048
<3>snd_imx_pcm_pointer: 8192 2048
<3>audio_dma_irq
<3>snd_imx_pcm_pointer: 12288 3072
<3>snd_imx_pcm_pointer: 12288 3072
<3>audio_dma_irq
<3>snd_imx_pcm_pointer: 0 0
<3>snd_imx_pcm_pointer: 0 0
<3>audio_dma_irq
<3>snd_imx_pcm_pointer: 4096 1024
<3>snd_imx_pcm_pointer: 4096 1024
<3>audio_dma_irq
<3>snd_imx_pcm_pointer: 8192 2048
<3>snd_imx_pcm_pointer: 8192 2048
<3>audio_dma_irq
<3>snd_imx_pcm_pointer: 12288 3072
<3>snd_imx_pcm_pointer: 12288 3072
<3>audio_dma_irq
<3>snd_imx_pcm_pointer: 0 0
<3>snd_imx_pcm_pointer: 0 0
<3>audio_dma_irq
<3>snd_imx_pcm_pointer: 4096 1024
<3>snd_imx_pcm_pointer: 4096 1024
<3>audio_dma_irq
<3>snd_imx_pcm_pointer: 8192 2048
<3>snd_imx_pcm_pointer: 8192 2048
<3>audio_dma_irq
<3>snd_imx_pcm_pointer: 12288 3072
<3>snd_imx_pcm_pointer: 12288 3072
<3>audio_dma_irq
<3>snd_imx_pcm_pointer: 0 0
<3>snd_imx_pcm_pointer: 0 0
<3>audio_dma_irq
<3>snd_imx_pcm_pointer: 4096 1024
<3>snd_imx_pcm_pointer: 4096 1024
<3>audio_dma_irq
<3>snd_imx_pcm_pointer: 8192 2048
<3>snd_imx_pcm_pointer: 8192 2048
<3>audio_dma_irq
<3>snd_imx_pcm_pointer: 12288 3072
<3>snd_imx_pcm_pointer: 12288 3072
<3>audio_dma_irq
<3>snd_imx_pcm_pointer: 0 0
<3>snd_imx_pcm_pointer: 0 0
<3>audio_dma_irq
<3>snd_imx_pcm_pointer: 4096 1024
<3>snd_imx_pcm_pointer: 4096 1024
<3>audio_dma_irq
<3>snd_imx_pcm_pointer: 8192 2048
<3>snd_imx_pcm_pointer: 8192 2048
<3>audio_dma_irq
<3>snd_imx_pcm_pointer: 12288 3072
<3>snd_imx_pcm_pointer: 12288 3072
<3>audio_dma_irq
4. 对比了wm8962播放声音时和wm8904的ssi寄存器内容是相同的
<3>trigger start
<3>playback
<3>ssi enable
<3>ssi: scr 15b
<3>ssi: sisr 3323
<3>ssi: sier 80001
<3>ssi: stcr 38d
<3>ssi: stccr 4e100
<3>ssi: sfcsr 460046
<3>ssi: str 1113
<3>trigger stop
<3>ssi unenable
<3>ssi: scr 158
<3>ssi: sisr 3003
<3>ssi: sier 0
<3>ssi: stcr 38d
<3>ssi: stccr 4e100
<3>ssi: sfcsr 460046
<3>ssi: str 110a
