分类：
soc_probe ==> snd_soc_register_card或者snd_soc_register_dai或者snd_soc_register_platform或者snd_soc_register_codec ==> snd_soc_instantiate_cards ==> snd_soc_instantiate_card ==> codec_dev->probe ==> uda134x_soc_probe ==> snd_soc_new_pcms ==> soc_new_pcm ==> snd_pcm_new snd_soc_new_pcms snd_card_create snd_ctl_create snd_ctl_dev_register创建"controlC%i"声卡对应的控制节点, 他的fops为snd_ctl_f_ops snd_pcm_dev_register snd_register_device_for_dev 创建"pcmC%iD%ip"或者"pcmC%iD%ic"设备节点,它的fops为snd_pcm_f_ops[2] snd_pcm_f_ops[2] ==> snd_pcm_playback_open或者snd_pcm_capture_open ==> snd_pcm_open或者oss的snd_pcm_oss_f_reg.snd_pcm_oss_open,这就对应/dev/dsp了 ==> snd_pcm_open_file或者oss的snd_pcm_oss_open_file ==> snd_pcm_open_substream ==> soc_pcm_open /* ASoC PCM operations */ static struct snd_pcm_ops soc_pcm_ops = { .open = soc_pcm_open, .close = soc_codec_close, .hw_params = soc_pcm_hw_params, .hw_free = soc_pcm_hw_free, .prepare = soc_pcm_prepare, .trigger = soc_pcm_trigger, }; ==> soc_pcm_open cpu_dai->ops->startup // 无 platform->pcm_ops->open // s3c_dma_open 分配DMA空间 codec_dai->ops->startup // uda134x_startup card_dai_link->ops->startup // s3c24xx_uda134x_startup 获取clock时钟源 // cpu_dai单元 struct snd_soc_dai s3c24xx_i2s_dai = { .name = "s3c24xx-i2s", .id = 0, .probe = s3c24xx_i2s_probe, .suspend = s3c24xx_i2s_suspend, .resume = s3c24xx_i2s_resume, .playback = { .channels_min = 2, .channels_max = 2, .rates = S3C24XX_I2S_RATES, .formats = SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_LE,}, .capture = { .channels_min = 2, .channels_max = 2, .rates = S3C24XX_I2S_RATES, .formats = SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_LE,}, .ops = &s3c24xx_i2s_dai_ops, }; //platform单元 struct snd_soc_platform s3c24xx_soc_platform = { .name = "s3c24xx-audio", .pcm_ops = &s3c_dma_ops, .pcm_new = s3c_dma_new, .pcm_free = s3c_dma_free_dma_buffers, }; static struct snd_pcm_ops s3c_dma_ops = { .open = s3c_dma_open, .close = s3c_dma_close, .ioctl = snd_pcm_lib_ioctl, .hw_params = s3c_dma_hw_params, .hw_free = s3c_dma_hw_free, .prepare = s3c_dma_prepare, .trigger = s3c_dma_trigger, .pointer = s3c_dma_pointer, .mmap = s3c_dma_mmap, }; // codec_dai单元 struct snd_soc_dai uda134x_dai = { .name = "UDA134X", /* playback capabilities */ .playback = { .stream_name = "Playback", .channels_min = 1, .channels_max = 2, .rates = UDA134X_RATES, .formats = UDA134X_FORMATS, }, /* capture capabilities */ .capture = { .stream_name = "Capture", .channels_min = 1, .channels_max = 2, .rates = UDA134X_RATES, .formats = UDA134X_FORMATS, }, /* pcm operations */ .ops = &uda134x_dai_ops, }; //card_dai_link单元 static struct snd_soc_dai_link s3c24xx_uda134x_dai_link = { .name = "UDA134X", .stream_name = "UDA134X", .codec_dai = &uda134x_dai, .cpu_dai = &s3c24xx_i2s_dai, .ops = &s3c24xx_uda134x_ops, };