| Message ID | 20170524005255.31223-2-o-takashi@sakamocchi.jp (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
diff --git a/include/sound/pcm.h b/include/sound/pcm.h index c609b891c4c2..6cb8df081787 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -63,6 +63,10 @@ struct snd_pcm_substream; struct snd_pcm_audio_tstamp_config; /* definitions further down */ struct snd_pcm_audio_tstamp_report; +typedef int (*snd_pcm_copy_frames_t)(struct snd_pcm_substream *substream, + unsigned int hwoff, unsigned int long data, + unsigned int off, snd_pcm_uframes_t count); + struct snd_pcm_ops { int (*open)(struct snd_pcm_substream *substream); int (*close)(struct snd_pcm_substream *substream);
Usage of the same function prototype between core and driver implementation dedicates code lucidity. Especially, in a view of device driver developers, if core implementation includes functions with the prototype, it's good examples. In current design of ALSA PCM core, when devices doesn't use DMA between kernel space and device memory or platforms don't have good cache coherent protocol, then drivers need to have own implementation for data transmittion, without existent implementation inner ALSA PCM core. However, for this purpose, ALSA PCM core includes inefficient implementation. Additionally, in a point to which I addressed, it includes complicated codes. This commit introduces 'snd_pcm_copy_frames_t' to produce unified interface for the devices and core implementations. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> --- include/sound/pcm.h | 4 ++++ 1 file changed, 4 insertions(+)