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Diffstat (limited to 'Documentation/sound/alsa/soc/overview.txt')
| -rw-r--r-- | Documentation/sound/alsa/soc/overview.txt | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/Documentation/sound/alsa/soc/overview.txt b/Documentation/sound/alsa/soc/overview.txt index 753c5cc5984..c47ce953067 100644 --- a/Documentation/sound/alsa/soc/overview.txt +++ b/Documentation/sound/alsa/soc/overview.txt @@ -2,18 +2,19 @@ ALSA SoC Layer ============== The overall project goal of the ALSA System on Chip (ASoC) layer is to provide -better ALSA support for embedded system on chip procesors (e.g. pxa2xx, au1x00, +better ALSA support for embedded system-on-chip processors (e.g. pxa2xx, au1x00, iMX, etc) and portable audio codecs. Currently there is some support in the kernel for SoC audio, however it has some limitations:- * Currently, codec drivers are often tightly coupled to the underlying SoC - cpu. This is not ideal and leads to code duplication i.e. Linux now has 4 + CPU. This is not ideal and leads to code duplication i.e. Linux now has 4 different wm8731 drivers for 4 different SoC platforms. - * There is no standard method to signal user initiated audio events. - e.g. Headphone/Mic insertion, Headphone/Mic detection after an insertion - event. These are quite common events on portable devices and ofter require - machine specific code to re route audio, enable amps etc after such an event. + * There is no standard method to signal user initiated audio events (e.g. + Headphone/Mic insertion, Headphone/Mic detection after an insertion + event). These are quite common events on portable devices and often require + machine specific code to re-route audio, enable amps, etc., after such an + event. * Current drivers tend to power up the entire codec when playing (or recording) audio. This is fine for a PC, but tends to waste a lot of @@ -44,7 +45,7 @@ features :- signals the codec when to change power states. * Machine specific controls: Allow machines to add controls to the sound card - e.g. volume control for speaker amp. + (e.g. volume control for speaker amp). To achieve all this, ASoC basically splits an embedded audio system into 3 components :- @@ -57,7 +58,7 @@ components :- interface drivers (e.g. I2S, AC97, PCM) for that platform. * Machine driver: The machine driver handles any machine specific controls and - audio events. i.e. turing on an amp at start of playback. + audio events (e.g. turning on an amp at start of playback). Documentation |