From e732d1bcd452a040a18242d555996703465c1ca7 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Thu, 10 Nov 2016 22:17:40 +0100 Subject: [PATCH] ASoC: doc: ReSTize DAI.txt A simple conversion from a plain text file with slight reformatting / corrections. The file name was changed to lower letters to align with others. Acked-by: Mark Brown Signed-off-by: Takashi Iwai --- .../sound/{alsa/soc/DAI.txt => soc/dai.rst} | 28 ++++++++++++------- Documentation/sound/soc/index.rst | 1 + 2 files changed, 19 insertions(+), 10 deletions(-) rename Documentation/sound/{alsa/soc/DAI.txt => soc/dai.rst} (71%) diff --git a/Documentation/sound/alsa/soc/DAI.txt b/Documentation/sound/soc/dai.rst similarity index 71% rename from Documentation/sound/alsa/soc/DAI.txt rename to Documentation/sound/soc/dai.rst index c9679264c559..55820e51708f 100644 --- a/Documentation/sound/alsa/soc/DAI.txt +++ b/Documentation/sound/soc/dai.rst @@ -1,3 +1,7 @@ +================================== +ASoC Digital Audio Interface (DAI) +================================== + ASoC currently supports the three main Digital Audio Interfaces (DAI) found on SoC controllers and portable audio CODECs today, namely AC97, I2S and PCM. @@ -5,21 +9,21 @@ SoC controllers and portable audio CODECs today, namely AC97, I2S and PCM. AC97 ==== - AC97 is a five wire interface commonly found on many PC sound cards. It is +AC97 is a five wire interface commonly found on many PC sound cards. It is now also popular in many portable devices. This DAI has a reset line and time multiplexes its data on its SDATA_OUT (playback) and SDATA_IN (capture) lines. The bit clock (BCLK) is always driven by the CODEC (usually 12.288MHz) and the frame (FRAME) (usually 48kHz) is always driven by the controller. Each AC97 frame is 21uS long and is divided into 13 time slots. -The AC97 specification can be found at :- +The AC97 specification can be found at : http://www.intel.com/p/en_US/business/design I2S === - I2S is a common 4 wire DAI used in HiFi, STB and portable devices. The Tx and +I2S is a common 4 wire DAI used in HiFi, STB and portable devices. The Tx and Rx lines are used for audio transmission, whilst the bit clock (BCLK) and left/right clock (LRC) synchronise the link. I2S is flexible in that either the controller or CODEC can drive (master) the BCLK and LRC clock lines. Bit clock @@ -30,13 +34,15 @@ different sample rates. I2S has several different operating modes:- - o I2S - MSB is transmitted on the falling edge of the first BCLK after LRC - transition. +I2S + MSB is transmitted on the falling edge of the first BCLK after LRC + transition. - o Left Justified - MSB is transmitted on transition of LRC. +Left Justified + MSB is transmitted on transition of LRC. - o Right Justified - MSB is transmitted sample size BCLKs before LRC - transition. +Right Justified + MSB is transmitted sample size BCLKs before LRC transition. PCM === @@ -51,6 +57,8 @@ is sometimes referred to as network mode). Common PCM operating modes:- - o Mode A - MSB is transmitted on falling edge of first BCLK after FRAME/SYNC. +Mode A + MSB is transmitted on falling edge of first BCLK after FRAME/SYNC. - o Mode B - MSB is transmitted on rising edge of FRAME/SYNC. +Mode B + MSB is transmitted on rising edge of FRAME/SYNC. diff --git a/Documentation/sound/soc/index.rst b/Documentation/sound/soc/index.rst index a2e023c91df2..aea7ae7e5aad 100644 --- a/Documentation/sound/soc/index.rst +++ b/Documentation/sound/soc/index.rst @@ -9,3 +9,4 @@ The documentation is spilt into the following sections:- overview codec + dai -- 2.20.1