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authorLiam Girdwood <liam.r.girdwood@linux.intel.com>2013-09-20 17:19:05 (GMT)
committerMark Brown <broonie@linaro.org>2013-09-23 11:06:24 (GMT)
commitda5feefeda496f003a2e909762e72843cb9837a6 (patch)
tree290c09b744d0f7d759235799e0be2f3c9609a4da /Documentation/sound
parent272b98c6455f00884f0350f775c5342358ebb73f (diff)
ASoC: Docs: Update codec documentation
Update the codec class driver documentation and bring it up to date with the current code base. This includes API changes, regmap and multi component. Signed-off-by: Liam Girdwood <liam.r.girdwood@linux.intel.com> Signed-off-by: Mark Brown <broonie@linaro.org>
Diffstat (limited to 'Documentation/sound')
-rw-r--r--Documentation/sound/alsa/soc/codec.txt46
1 files changed, 15 insertions, 31 deletions
diff --git a/Documentation/sound/alsa/soc/codec.txt b/Documentation/sound/alsa/soc/codec.txt
index bce23a4..db5f9c9 100644
--- a/Documentation/sound/alsa/soc/codec.txt
+++ b/Documentation/sound/alsa/soc/codec.txt
@@ -1,22 +1,23 @@
-ASoC Codec Driver
-=================
+ASoC Codec Class Driver
+=======================
-The codec driver is generic and hardware independent code that configures the
-codec to provide audio capture and playback. It should contain no code that is
-specific to the target platform or machine. All platform and machine specific
-code should be added to the platform and machine drivers respectively.
+The codec class driver is generic and hardware independent code that configures
+the codec, FM, MODEM, BT or external DSP to provide audio capture and playback.
+It should contain no code that is specific to the target platform or machine.
+All platform and machine specific code should be added to the platform and
+machine drivers respectively.
-Each codec driver *must* provide the following features:-
+Each codec class driver *must* provide the following features:-
1) Codec DAI and PCM configuration
- 2) Codec control IO - using I2C, 3 Wire(SPI) or both APIs
+ 2) Codec control IO - using RegMap API
3) Mixers and audio controls
4) Codec audio operations
+ 5) DAPM description.
+ 6) DAPM event handler.
Optionally, codec drivers can also provide:-
- 5) DAPM description.
- 6) DAPM event handler.
7) DAC Digital mute control.
Its probably best to use this guide in conjunction with the existing codec
@@ -64,26 +65,9 @@ struct snd_soc_dai_driver wm8731_dai = {
2 - Codec control IO
--------------------
The codec can usually be controlled via an I2C or SPI style interface
-(AC97 combines control with data in the DAI). The codec drivers provide
-functions to read and write the codec registers along with supplying a
-register cache:-
-
- /* IO control data and register cache */
- void *control_data; /* codec control (i2c/3wire) data */
- void *reg_cache;
-
-Codec read/write should do any data formatting and call the hardware
-read write below to perform the IO. These functions are called by the
-core and ALSA when performing DAPM or changing the mixer:-
-
- unsigned int (*read)(struct snd_soc_codec *, unsigned int);
- int (*write)(struct snd_soc_codec *, unsigned int, unsigned int);
-
-Codec hardware IO functions - usually points to either the I2C, SPI or AC97
-read/write:-
-
- hw_write_t hw_write;
- hw_read_t hw_read;
+(AC97 combines control with data in the DAI). The codec driver should use the
+Regmap API for all codec IO. Please see include/linux/regmap.h and existing
+codec drivers for example regmap usage.
3 - Mixers and audio controls
@@ -127,7 +111,7 @@ Defines a stereo enumerated control
4 - Codec Audio Operations
--------------------------
-The codec driver also supports the following ALSA operations:-
+The codec driver also supports the following ALSA PCM operations:-
/* SoC audio ops */
struct snd_soc_ops {

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