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建立"controlc%i"音效卡對應的控制節點,
他的fops為snd_ctl_f_ops
snd_pcm_dev_register
snd_register_device_for_dev
建立"pcmc%id%ip"或者"pcmc%id%ic"裝置節點,它的fops為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,這就對應/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 = ;
==> soc_pcm_open
cpu_dai->ops->startup // 無
platform->pcm_ops->open // s3c_dma_open 分配dma空間
codec_dai->ops->startup // uda134x_startup
card_dai_link->ops->startup // s3c24xx_uda134x_startup 獲取clock時鐘源
// cpu_dai單元
struct snd_soc_dai s3c24xx_i2s_dai = ,
.capture = ,
.ops = &s3c24xx_i2s_dai_ops,
};//platform單元
struct snd_soc_platform s3c24xx_soc_platform = ;
static struct snd_pcm_ops s3c_dma_ops = ;
// codec_dai單元
struct snd_soc_dai uda134x_dai = ,
/* capture capabilities */
.capture = ,
/* pcm operations */
.ops = &uda134x_dai_ops,
};//card_dai_link單元
static struct snd_soc_dai_link s3c24xx_uda134x_dai_link = ;
pcm.c
snd_pcm_control_ioctl()
case sndrv_ctl_ioctl_pcm_info:
* s1:get params infofrom userspacearg*
* s2:get info->device
* s3:get info->stream
* s4:get info->subdevice
* s5:getpcmfrom matching special card and device
* s1:get pstrfrom &pcm->streams[stream]
* s2:get substreamfrom pstr->substream
* s3:now! we got struct snd_pcm_substream*substream
* which contents the structsnd_pcm_runtime*runtime;
snd_pcm_runtime裡面有
/* -- hardware description -- */
struct snd_pcm_hardware hw;
structsnd_pcm_hw_constraintshw_constraints;
xx_pcm.c
xx_pcm_hardware
xx_pcm_open()
xx_pcm_ops
xx_soc_platform
snd_soc_register_platform()
xx_soc_platform_init()
module_init
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