[alsa-devel] [PATCH v2] ALSA: PCM - Add PCM creation API for internal PCMs.

Takashi Iwai tiwai at suse.de
Wed Feb 8 22:35:57 CET 2012

At Wed,  8 Feb 2012 20:33:31 +0000,
Liam Girdwood wrote:
> The new ASoC dynamic PCM core needs to create PCMs and substreams that are
> for use by internal ASoC drivers only and not visible to userspace for
> direct IO. These new PCMs are similar to regular PCMs expect they have no
> device nodes or procfs entries. The ASoC component drivers use them in exactly
> the same way as regular PCMs for PCM and DAI operations.
> The intention is that a dynamic PCM based driver will register both regular
> PCMs and internal PCMs. The regular PCMs will be used for all IO with userspace
> however the internal PCMs will be used by the driver to route digital audio
> through numerous back end DAI links (with potentially a DSP providing different
> hw_params, DAI formats based on the regular front end PCM params) to devices
> like CODECs, MODEMs, Bluetooth, FM, DMICs, etc
> This patch adds a new snd_pcm_new_internal() API call to create the internal PCM
> without device nodes or procfs. It also adds adds a new internal flag to snd_pcm.
> Signed-off-by: Liam Girdwood <lrg at ti.com>
> ---
> Changes since V1
>  - Renamed to Internal PCM instead of Dynamic PCM wrt ALSA.
>  - Removed similar PCM creation code and use flag for procfs/device creation.

The changes look OK to me, but could you fix a few errors/warnings
by checkpatch.pl?



More information about the Alsa-devel mailing list