diff options
author | Kumar Gala <galak@kernel.crashing.org> | 2007-02-12 23:57:21 -0600 |
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committer | Kumar Gala <galak@kernel.crashing.org> | 2007-02-12 23:57:21 -0600 |
commit | 54c66f6d781e03dc0b23956234963c4911e6d1c0 (patch) | |
tree | 40619a66ae6d8703a57bf681d087ffeabbffd346 /Documentation/sound/alsa/soc/platform.txt | |
parent | 8ce0a7df6e6117d8814e976d4b7ce6a6b2c9cf93 (diff) | |
parent | 17e0e27020d028a790d97699aff85a43af5be472 (diff) |
Merge branch 'master' into 85xx
Diffstat (limited to 'Documentation/sound/alsa/soc/platform.txt')
-rw-r--r-- | Documentation/sound/alsa/soc/platform.txt | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/Documentation/sound/alsa/soc/platform.txt b/Documentation/sound/alsa/soc/platform.txt new file mode 100644 index 00000000000..e95b16d5a53 --- /dev/null +++ b/Documentation/sound/alsa/soc/platform.txt @@ -0,0 +1,58 @@ +ASoC Platform Driver +==================== + +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. + +Audio DMA +========= + +The platform DMA driver optionally supports the following alsa operations:- + +/* SoC audio ops */ +struct snd_soc_ops { + int (*startup)(struct snd_pcm_substream *); + void (*shutdown)(struct snd_pcm_substream *); + int (*hw_params)(struct snd_pcm_substream *, struct snd_pcm_hw_params *); + int (*hw_free)(struct snd_pcm_substream *); + int (*prepare)(struct snd_pcm_substream *); + int (*trigger)(struct snd_pcm_substream *, int); +}; + +The platform driver exports it's DMA functionailty via struct snd_soc_platform:- + +struct snd_soc_platform { + char *name; + + int (*probe)(struct platform_device *pdev); + int (*remove)(struct platform_device *pdev); + int (*suspend)(struct platform_device *pdev, struct snd_soc_cpu_dai *cpu_dai); + int (*resume)(struct platform_device *pdev, struct snd_soc_cpu_dai *cpu_dai); + + /* pcm creation and destruction */ + int (*pcm_new)(struct snd_card *, struct snd_soc_codec_dai *, struct snd_pcm *); + void (*pcm_free)(struct snd_pcm *); + + /* platform stream ops */ + struct snd_pcm_ops *pcm_ops; +}; + +Please refer to the alsa driver documentation for details of audio DMA. +http://www.alsa-project.org/~iwai/writing-an-alsa-driver/c436.htm + +An example DMA driver is soc/pxa/pxa2xx-pcm.c + + +SoC DAI Drivers +=============== + +Each SoC DAI driver must provide the following features:- + + 1) Digital audio interface (DAI) description + 2) Digital audio interface configuration + 3) PCM's description + 4) Sysclk configuration + 5) Suspend and resume (optional) + +Please see codec.txt for a description of items 1 - 4. |