1 files changed, 22 insertions, 20 deletions
diff --git a/Documentation/sound/alsa/soc/overview.txt b/Documentation/sound/alsa/soc/overview.txt
index c47ce9530677..1e4c6d3655f2 100644
--- a/Documentation/sound/alsa/soc/overview.txt
+++ b/Documentation/sound/alsa/soc/overview.txt
@@ -1,25 +1,26 @@
 ALSA SoC Layer
 ==============
-The overall project goal of the ALSA System on Chip (ASoC) layer is to provide
+The overall project goal of the ALSA System on Chip (ASoC) layer is to
-better ALSA support for embedded system-on-chip processors (e.g. pxa2xx, au1x00,
+provide better ALSA support for embedded system-on-chip processors (e.g.
-iMX, etc) and portable audio codecs. Currently there is some support in the
+pxa2xx, au1x00, iMX, etc) and portable audio codecs.  Prior to the ASoC
-kernel for SoC audio, however it has some limitations:-
+subsystem there was some support in the kernel for SoC audio, however it
+had some limitations:-
-  * Currently, codec drivers are often tightly coupled to the underlying SoC
+  * Codec drivers were 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 - for example,
-    different wm8731 drivers for 4 different SoC platforms.
+    Linux had different wm8731 drivers for 4 different SoC platforms.
-  * There is no standard method to signal user initiated audio events (e.g.
+  * There was 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
+  * Drivers tended to power up the entire codec when playing (or
-    (or recording) audio. This is fine for a PC, but tends to waste a lot of
+    recording) audio. This is fine for a PC, but tends to waste a lot of
-    power on portable devices. There is also no support for saving power via
+    power on portable devices. There was also no support for saving
-    changing codec oversampling rates, bias currents, etc.
+    power via changing codec oversampling rates, bias currents, etc.
 ASoC Design
@@ -31,12 +32,13 @@ features :-
  * Codec independence. Allows reuse of codec drivers on other platforms
    and machines.
-  * Easy I2S/PCM audio interface setup between codec and SoC. Each SoC interface
+  * Easy I2S/PCM audio interface setup between codec and SoC. Each SoC
-    and codec registers it's audio interface capabilities with the core and are
+    interface and codec registers it's audio interface capabilities with the
-    subsequently matched and configured when the application hw params are known.
+    core and are subsequently matched and configured when the application
+    hardware parameters are known.
  * Dynamic Audio Power Management (DAPM). DAPM automatically sets the codec to
-    it's minimum power state at all times. This includes powering up/down
+    its minimum power state at all times. This includes powering up/down
    internal power blocks depending on the internal codec audio routing and any
    active streams.
@@ -45,16 +47,16 @@ 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 amplifier).
 To achieve all this, ASoC basically splits an embedded audio system into 3
 components :-
  * Codec driver: The codec driver is platform independent and contains audio
-    controls, audio interface capabilities, codec dapm definition and codec IO
+    controls, audio interface capabilities, codec DAPM definition and codec IO
    functions.
-  * Platform driver: The platform driver contains the audio dma engine and audio
+  * Platform driver: The platform driver contains the audio DMA engine and audio
    interface drivers (e.g. I2S, AC97, PCM) for that platform.
  * Machine driver: The machine driver handles any machine specific controls and
@@ -81,4 +83,4 @@ machine.txt: Machine driver internals.
 pop_clicks.txt: How to minimise audio artifacts.
-clocking.txt: ASoC clocking for best power performance.
-\ No newline at end of file
+clocking.txt: ASoC clocking for best power performance.

diff --git a/Documentation/sound/alsa/soc/overview.txt b/Documentation/sound/alsa/soc/overview.txt index c47ce9530677..1e4c6d3655f2 100644 --- a/Documentation/sound/alsa/soc/overview.txt +++ b/Documentation/sound/alsa/soc/overview.txt
@@ -1,25 +1,26 @@
1	ALSA SoC Layer	1	ALSA SoC Layer
2	==============	2	==============
3		3
4	The overall project goal of the ALSA System on Chip (ASoC) layer is to provide	4	The overall project goal of the ALSA System on Chip (ASoC) layer is to
5	better ALSA support for embedded system-on-chip processors (e.g. pxa2xx, au1x00,	5	provide better ALSA support for embedded system-on-chip processors (e.g.
6	iMX, etc) and portable audio codecs. Currently there is some support in the	6	pxa2xx, au1x00, iMX, etc) and portable audio codecs. Prior to the ASoC
7	kernel for SoC audio, however it has some limitations:-	7	subsystem there was some support in the kernel for SoC audio, however it
		8	had some limitations:-
8		9
9	* Currently, codec drivers are often tightly coupled to the underlying SoC	10	* Codec drivers were often tightly coupled to the underlying SoC
10	CPU. This is not ideal and leads to code duplication i.e. Linux now has 4	11	CPU. This is not ideal and leads to code duplication - for example,
11	different wm8731 drivers for 4 different SoC platforms.	12	Linux had different wm8731 drivers for 4 different SoC platforms.
12		13
13	* There is no standard method to signal user initiated audio events (e.g.	14	* There was no standard method to signal user initiated audio events (e.g.
14	Headphone/Mic insertion, Headphone/Mic detection after an insertion	15	Headphone/Mic insertion, Headphone/Mic detection after an insertion
15	event). These are quite common events on portable devices and often require	16	event). These are quite common events on portable devices and often require
16	machine specific code to re-route audio, enable amps, etc., after such an	17	machine specific code to re-route audio, enable amps, etc., after such an
17	event.	18	event.
18		19
19	* Current drivers tend to power up the entire codec when playing	20	* Drivers tended to power up the entire codec when playing (or
20	(or recording) audio. This is fine for a PC, but tends to waste a lot of	21	recording) audio. This is fine for a PC, but tends to waste a lot of
21	power on portable devices. There is also no support for saving power via	22	power on portable devices. There was also no support for saving
22	changing codec oversampling rates, bias currents, etc.	23	power via changing codec oversampling rates, bias currents, etc.
23		24
24		25
25	ASoC Design	26	ASoC Design
@@ -31,12 +32,13 @@ features :-
31	* Codec independence. Allows reuse of codec drivers on other platforms	32	* Codec independence. Allows reuse of codec drivers on other platforms
32	and machines.	33	and machines.
33		34
34	* Easy I2S/PCM audio interface setup between codec and SoC. Each SoC interface	35	* Easy I2S/PCM audio interface setup between codec and SoC. Each SoC
35	and codec registers it's audio interface capabilities with the core and are	36	interface and codec registers it's audio interface capabilities with the
36	subsequently matched and configured when the application hw params are known.	37	core and are subsequently matched and configured when the application
		38	hardware parameters are known.
37		39
38	* Dynamic Audio Power Management (DAPM). DAPM automatically sets the codec to	40	* Dynamic Audio Power Management (DAPM). DAPM automatically sets the codec to
39	it's minimum power state at all times. This includes powering up/down	41	its minimum power state at all times. This includes powering up/down
40	internal power blocks depending on the internal codec audio routing and any	42	internal power blocks depending on the internal codec audio routing and any
41	active streams.	43	active streams.
42		44
@@ -45,16 +47,16 @@ features :-
45	signals the codec when to change power states.	47	signals the codec when to change power states.
46		48
47	* Machine specific controls: Allow machines to add controls to the sound card	49	* Machine specific controls: Allow machines to add controls to the sound card
48	(e.g. volume control for speaker amp).	50	(e.g. volume control for speaker amplifier).
49		51
50	To achieve all this, ASoC basically splits an embedded audio system into 3	52	To achieve all this, ASoC basically splits an embedded audio system into 3
51	components :-	53	components :-
52		54
53	* Codec driver: The codec driver is platform independent and contains audio	55	* Codec driver: The codec driver is platform independent and contains audio
54	controls, audio interface capabilities, codec dapm definition and codec IO	56	controls, audio interface capabilities, codec DAPM definition and codec IO
55	functions.	57	functions.
56		58
57	* Platform driver: The platform driver contains the audio dma engine and audio	59	* Platform driver: The platform driver contains the audio DMA engine and audio
58	interface drivers (e.g. I2S, AC97, PCM) for that platform.	60	interface drivers (e.g. I2S, AC97, PCM) for that platform.
59		61
60	* Machine driver: The machine driver handles any machine specific controls and	62	* Machine driver: The machine driver handles any machine specific controls and
@@ -81,4 +83,4 @@ machine.txt: Machine driver internals.
81		83
82	pop_clicks.txt: How to minimise audio artifacts.	84	pop_clicks.txt: How to minimise audio artifacts.
83		85
84	clocking.txt: ASoC clocking for best power performance. \ No newline at end of file	86	clocking.txt: ASoC clocking for best power performance.