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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-12 21:58:13 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-12 21:58:13 -0800 |
commit | e7aa8c2eb11ba69b1b69099c3c7bd6be3087b0ba (patch) | |
tree | f63906f41699c8e38af9d12b063e2ceab0286ef2 /Documentation/sound/soc/platform.rst | |
parent | e34bac726d27056081d0250c0e173e4b155aa340 (diff) | |
parent | 868c97a846a73e937d835b09b8c885a69df50ec8 (diff) | |
download | op-kernel-dev-e7aa8c2eb11ba69b1b69099c3c7bd6be3087b0ba.zip op-kernel-dev-e7aa8c2eb11ba69b1b69099c3c7bd6be3087b0ba.tar.gz |
Merge tag 'docs-4.10' of git://git.lwn.net/linux
Pull documentation update from Jonathan Corbet:
"These are the documentation changes for 4.10.
It's another busy cycle for the docs tree, as the sphinx conversion
continues. Highlights include:
- Further work on PDF output, which remains a bit of a pain but
should be more solid now.
- Five more DocBook template files converted to Sphinx. Only 27 to
go... Lots of plain-text files have also been converted and
integrated.
- Images in binary formats have been replaced with more
source-friendly versions.
- Various bits of organizational work, including the renaming of
various files discussed at the kernel summit.
- New documentation for the device_link mechanism.
... and, of course, lots of typo fixes and small updates"
* tag 'docs-4.10' of git://git.lwn.net/linux: (193 commits)
dma-buf: Extract dma-buf.rst
Update Documentation/00-INDEX
docs: 00-INDEX: document directories/files with no docs
docs: 00-INDEX: remove non-existing entries
docs: 00-INDEX: add missing entries for documentation files/dirs
docs: 00-INDEX: consolidate process/ and admin-guide/ description
scripts: add a script to check if Documentation/00-INDEX is sane
Docs: change sh -> awk in REPORTING-BUGS
Documentation/core-api/device_link: Add initial documentation
core-api: remove an unexpected unident
ppc/idle: Add documentation for powersave=off
Doc: Correct typo, "Introdution" => "Introduction"
Documentation/atomic_ops.txt: convert to ReST markup
Documentation/local_ops.txt: convert to ReST markup
Documentation/assoc_array.txt: convert to ReST markup
docs-rst: parse-headers.pl: cleanup the documentation
docs-rst: fix media cleandocs target
docs-rst: media/Makefile: reorganize the rules
docs-rst: media: build SVG from graphviz files
docs-rst: replace bayer.png by a SVG image
...
Diffstat (limited to 'Documentation/sound/soc/platform.rst')
-rw-r--r-- | Documentation/sound/soc/platform.rst | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/Documentation/sound/soc/platform.rst b/Documentation/sound/soc/platform.rst new file mode 100644 index 0000000..d557490 --- /dev/null +++ b/Documentation/sound/soc/platform.rst @@ -0,0 +1,82 @@ +==================== +ASoC Platform Driver +==================== + +An ASoC platform driver class can be divided into audio DMA drivers, SoC DAI +drivers and DSP drivers. 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 its DMA functionality via struct +snd_soc_platform_driver:- +:: + + struct snd_soc_platform_driver { + 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 *); + + /* + * For platform caused delay reporting. + * Optional. + */ + snd_pcm_sframes_t (*delay)(struct snd_pcm_substream *, + struct snd_soc_dai *); + + /* 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/ + +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. + + +SoC DSP Drivers +=============== + +Each SoC DSP driver usually supplies the following features :- + +1. DAPM graph +2. Mixer controls +3. DMA IO to/from DSP buffers (if applicable) +4. Definition of DSP front end (FE) PCM devices. + +Please see DPCM.txt for a description of item 4. |