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diff --git a/Documentation/sound/alsa/soc/DAI.txt b/Documentation/sound/alsa/soc/DAI.txt new file mode 100644 index 0000000..919de76 --- /dev/null +++ b/Documentation/sound/alsa/soc/DAI.txt @@ -0,0 +1,380 @@ +ASoC currently supports the three main Digital Audio Interfaces (DAI) found on +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 +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 http://intel.com/ + + +I2S +=== + + I2S is a common 4 wire DAI used in HiFi, STB and portable devices. The Tx and +Rx lines are used for audio transmision, 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 +usually varies depending on the sample rate and the master system clock +(SYSCLK). LRCLK is the same as the sample rate. A few devices support separate +ADC and DAC LRCLK's, this allows for similtanious capture and playback at +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. + + o Left Justified - MSB is transmitted on transition of LRC. + + o Right Justified - MSB is transmitted sample size BCLK's before LRC + transition. + +PCM +=== + +PCM is another 4 wire interface, very similar to I2S, that can support a more +flexible protocol. It has bit clock (BCLK) and sync (SYNC) lines that are used +to synchronise the link whilst the Tx and Rx lines are used to transmit and +receive the audio data. Bit clock usually varies depending on sample rate +whilst sync runs at the sample rate. PCM also supports Time Division +Multiplexing (TDM) in that several devices can use the bus similtaniuosly (This +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. + + o Mode B - MSB is transmitted on rising edge of FRAME/SYNC. + + +ASoC DAI Configuration +====================== + +Every CODEC DAI and SoC DAI must have their capabilities defined in order to +be configured together at runtime when the audio and clocking parameters are +known. This is achieved by creating an array of struct snd_soc_hw_mode in the +the CODEC and SoC interface drivers. Each element in the array describes a DAI +mode and each mode is usually based upon the DAI system clock to sample rate +ratio (FS). + +i.e. 48k sample rate @ 256 FS = sytem clock of 12.288 MHz + 48000 * 256 = 12288000 + +The CPU and Codec DAI modes are then ANDed together at runtime to determine the +rutime DAI configuration for both the Codec and CPU. + +When creating a new codec or SoC DAI it's probably best to start of with a few +sample rates first and then test your interface. + +struct snd_soc_dai_mode is defined (in soc.h) as:- + +/* SoC DAI mode */ +struct snd_soc_hw_mode { + unsigned int fmt:16; /* SND_SOC_DAIFMT_* */ + unsigned int tdm:16; /* SND_SOC_DAITDM_* */ + unsigned int pcmfmt:6; /* SNDRV_PCM_FORMAT_* */ + unsigned int pcmrate:16; /* SND_SOC_DAIRATE_* */ + unsigned int pcmdir:2; /* SND_SOC_DAIDIR_* */ + unsigned int flags:8; /* hw flags */ + unsigned int fs:32; /* mclk to rate dividers */ + unsigned int bfs:16; /* mclk to bclk dividers */ + unsigned long priv; /* private mode data */ +}; + +fmt: +---- +This field defines the DAI mode hardware format (e.g. I2S settings) and +supports the following settings:- + + 1) hardware DAI formats + +#define SND_SOC_DAIFMT_I2S (1 << 0) /* I2S mode */ +#define SND_SOC_DAIFMT_RIGHT_J (1 << 1) /* Right justified mode */ +#define SND_SOC_DAIFMT_LEFT_J (1 << 2) /* Left Justified mode */ +#define SND_SOC_DAIFMT_DSP_A (1 << 3) /* L data msb after FRM */ +#define SND_SOC_DAIFMT_DSP_B (1 << 4) /* L data msb during FRM */ +#define SND_SOC_DAIFMT_AC97 (1 << 5) /* AC97 */ + + 2) hw DAI signal inversions + +#define SND_SOC_DAIFMT_NB_NF (1 << 8) /* normal bit clock + frame */ +#define SND_SOC_DAIFMT_NB_IF (1 << 9) /* normal bclk + inv frm */ +#define SND_SOC_DAIFMT_IB_NF (1 << 10) /* invert bclk + nor frm */ +#define SND_SOC_DAIFMT_IB_IF (1 << 11) /* invert bclk + frm */ + + 3) hw clock masters + This is wrt the codec, the inverse is true for the interface + i.e. if the codec is clk and frm master then the interface is + clk and frame slave. + +#define SND_SOC_DAIFMT_CBM_CFM (1 << 12) /* codec clk & frm master */ +#define SND_SOC_DAIFMT_CBS_CFM (1 << 13) /* codec clk slave & frm master */ +#define SND_SOC_DAIFMT_CBM_CFS (1 << 14) /* codec clk master & frame slave */ +#define SND_SOC_DAIFMT_CBS_CFS (1 << 15) /* codec clk & frm slave */ + +At least one option from each section must be selected. Multiple selections are +also supported e.g. + + .fmt = SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_LEFT_J | SND_SOC_DAIFMT_RIGHT_J | \ + SND_SOC_DAIFMT_NB_NF | SND_SOC_DAIFMT_NB_IF | SND_SOC_DAIFMT_IB_NF | \ + SND_SOC_DAIFMT_IB_IF + + +tdm: +------ +This field defines the Time Division Multiplexing left and right word +positions for the DAI mode if applicable. Set to SND_SOC_DAITDM_LRDW(0,0) for +no TDM. + + +pcmfmt: +--------- +The hardware PCM format. This describes the PCM formats supported by the DAI +mode e.g. + + .hwpcmfmt = SNDRV_PCM_FORMAT_S16_LE | SNDRV_PCM_FORMAT_S20_3LE | \ + SNDRV_PCM_FORMAT_S24_3LE + +pcmrate: +---------- +The PCM sample rates supported by the DAI mode. e.g. + + .hwpcmrate = SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_11025 | SNDRV_PCM_RATE_16000 | \ + SNDRV_PCM_RATE_22050 | SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 | \ + SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_88200 | SNDRV_PCM_RATE_96000 + + +pcmdir: +--------- +The stream directions supported by this mode. e.g. playback and capture + + +flags: +-------- +The DAI hardware flags supported by the mode. + +SND_SOC_DAI_BFS_DIV +This flag states that bit clock is generated by dividing MCLK in this mode, if +this flag is absent the bitclock generated by mulitiplying sample rate. + +NOTE: Bitclock division and mulitiplication modes can be safely matched by the +core logic. + + +fs: +----- +The FS supported by this DAI mode FS is the ratio between the system clock and +the sample rate. See above + +bfs: +------ +BFS is the ratio of BCLK to MCLK or the ratio of BCLK to sample rate (this +depends on the codec or CPU DAI). + +The BFS supported by the DAI mode. This can either be the ratio between the +bitclock (BCLK) and the sample rate OR the ratio between the system clock and +the sample rate. Depends on the SND_SOC_DAI_BFS_DIV flag above. + +priv: +----- +private codec mode data. + + + +Examples +======== + +Note that Codec DAI and CPU DAI examples are interchangeable in these examples +as long as the bus master is reversed. i.e. + + SND_SOC_DAIFMT_CBM_CFM would become SND_SOC_DAIFMT_CBS_CFS + and vice versa. + +This applies to all SND_SOC_DAIFMT_CB*_CF*. + +Example 1 +--------- + +Simple codec that only runs at 8k & 48k @ 256FS in master mode, can generate a +BCLK of either MCLK/2 or MCLK/4. + + /* codec master */ + {SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_CBM_CFM, SND_SOC_DAITDM_LRDW(0,0), + SNDRV_PCM_FORMAT_S16_LE, SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_48000, + SND_SOC_DAIDIR_PLAYBACK | SND_SOC_DAIDIR_CAPTURE, SND_SOC_DAI_BFS_DIV, + 256, SND_SOC_FSBD(2) | SND_SOC_FSBD(4)}, + + +Example 2 +--------- +Simple codec that only runs at 8k & 48k @ 256FS in master mode, can generate a +BCLK of either Rate * 32 or Rate * 64. + + /* codec master */ + {SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_CBM_CFM, SND_SOC_DAITDM_LRDW(0,0), + SNDRV_PCM_FORMAT_S16_LE, SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_48000, + SND_SOC_DAIDIR_PLAYBACK | SND_SOC_DAIDIR_CAPTURE, 0, + 256, SND_SOC_FSB(32) | SND_SOC_FSB(64)}, + + +Example 3 +--------- +Codec that only runs at 8k & 48k @ 256FS in master mode, can generate a +BCLK of either Rate * 32 or Rate * 64. Codec can also run in slave mode as long +as BCLK is rate * 32 or rate * 64. + + /* codec master */ + {SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_CBM_CFM, SND_SOC_DAITDM_LRDW(0,0), + SNDRV_PCM_FORMAT_S16_LE, SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_48000, + SND_SOC_DAIDIR_PLAYBACK | SND_SOC_DAIDIR_CAPTURE, 0, + 256, SND_SOC_FSB(32) | SND_SOC_FSB(64)}, + + /* codec slave */ + {SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_CBS_CFS, SND_SOC_DAITDM_LRDW(0,0), + SNDRV_PCM_FORMAT_S16_LE, SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_48000, + SND_SOC_DAIDIR_PLAYBACK | SND_SOC_DAIDIR_CAPTURE, 0, + SND_SOC_FS_ALL, SND_SOC_FSB(32) | SND_SOC_FSB(64)}, + + +Example 4 +--------- +Codec that only runs at 8k, 16k, 32k, 48k, 96k @ 128FS, 192FS & 256FS in master +mode and can generate a BCLK of MCLK / (1,2,4,8,16). Codec can also run in slave +mode as and does not care about FS or BCLK (as long as there is enough bandwidth). + + #define CODEC_FSB \ + (SND_SOC_FSBD(1) | SND_SOC_FSBD(2) | SND_SOC_FSBD(4) | \ + SND_SOC_FSBD(8) | SND_SOC_FSBD(16)) + + #define CODEC_RATES \ + (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_16000 | SNDRV_PCM_RATE_32000 |\ + SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_96000) + + /* codec master @ 128, 192 & 256 FS */ + {SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_CBM_CFM, SND_SOC_DAITDM_LRDW(0,0), + SNDRV_PCM_FORMAT_S16_LE, CODEC_RATES, + SND_SOC_DAIDIR_PLAYBACK | SND_SOC_DAIDIR_CAPTURE, SND_SOC_DAI_BFS_DIV, + 128, CODEC_FSB}, + + {SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_CBM_CFM, SND_SOC_DAITDM_LRDW(0,0), + SNDRV_PCM_FORMAT_S16_LE, CODEC_RATES, + SND_SOC_DAIDIR_PLAYBACK | SND_SOC_DAIDIR_CAPTURE, SND_SOC_DAI_BFS_DIV, + 192, CODEC_FSB}, + + {SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_CBM_CFM, SND_SOC_DAITDM_LRDW(0,0), + SNDRV_PCM_FORMAT_S16_LE, CODEC_RATES, + SND_SOC_DAIDIR_PLAYBACK | SND_SOC_DAIDIR_CAPTURE, SND_SOC_DAI_BFS_DIV, + 256, CODEC_FSB}, + + /* codec slave */ + {SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_CBS_CFS, SND_SOC_DAITDM_LRDW(0,0), + SNDRV_PCM_FORMAT_S16_LE, CODEC_RATES, + SND_SOC_DAIDIR_PLAYBACK | SND_SOC_DAIDIR_CAPTURE, 0, + SND_SOC_FS_ALL, SND_SOC_FSB_ALL}, + + +Example 5 +--------- +Codec that only runs at 8k, 44.1k, 48k @ different FS in master mode (for use +with a fixed MCLK) and can generate a BCLK of MCLK / (1,2,4,8,16). +Codec can also run in slave mode as and does not care about FS or BCLK (as long +as there is enough bandwidth). Codec can support 16, 24 and 32 bit PCM sample +sizes. + + #define CODEC_FSB \ + (SND_SOC_FSBD(1) | SND_SOC_FSBD(2) | SND_SOC_FSBD(4) | \ + SND_SOC_FSBD(8) | SND_SOC_FSBD(16)) + + #define CODEC_PCM_FORMATS \ + (SNDRV_PCM_FORMAT_S16_LE | SNDRV_PCM_FORMAT_S20_3LE | \ + SNDRV_PCM_FORMAT_S24_3LE | SNDRV_PCM_FORMAT_S24_LE | SNDRV_PCM_FORMAT_S32_LE) + + /* codec master */ + {SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_CBM_CFM, SND_SOC_DAITDM_LRDW(0,0), + SNDRV_PCM_FORMAT_S16_LE, SNDRV_PCM_RATE_8000, + SND_SOC_DAIDIR_PLAYBACK | SND_SOC_DAIDIR_CAPTURE, SND_SOC_DAI_BFS_DIV, + 1536, CODEC_FSB}, + + {SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_CBM_CFM, SND_SOC_DAITDM_LRDW(0,0), + SNDRV_PCM_FORMAT_S16_LE, SNDRV_PCM_RATE_44100, + SND_SOC_DAIDIR_PLAYBACK | SND_SOC_DAIDIR_CAPTURE, SND_SOC_DAI_BFS_DIV, + 272, CODEC_FSB}, + + {SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_CBM_CFM, SND_SOC_DAITDM_LRDW(0,0), + SNDRV_PCM_FORMAT_S16_LE, SNDRV_PCM_RATE_48000, + SND_SOC_DAIDIR_PLAYBACK | SND_SOC_DAIDIR_CAPTURE, SND_SOC_DAI_BFS_DIV, + 256, CODEC_FSB}, + + /* codec slave */ + {SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_CBS_CFS, SND_SOC_DAITDM_LRDW(0,0), + SNDRV_PCM_FORMAT_S16_LE, CODEC_RATES, + SND_SOC_DAIDIR_PLAYBACK | SND_SOC_DAIDIR_CAPTURE, 0, + SND_SOC_FS_ALL, SND_SOC_FSB_ALL}, + + +Example 6 +--------- +AC97 Codec that does not support VRA (i.e only runs at 48k). + + #define AC97_DIR \ + (SND_SOC_DAIDIR_PLAYBACK | SND_SOC_DAIDIR_CAPTURE) + + + #define AC97_PCM_FORMATS \ + (SNDRV_PCM_FORMAT_S16_LE | SNDRV_PCM_FORMAT_S18_3LE | \ + SNDRV_PCM_FORMAT_S20_3LE) + + /* AC97 with no VRA */ + {0, 0, AC97_PCM_FORMATS, SNDRV_PCM_RATE_48000}, + + +Example 7 +--------- + +CPU DAI that supports 8k - 48k @ 256FS and BCLK = MCLK / 4 in master mode. +Slave mode (CPU DAI is FRAME master) supports 8k - 96k at any FS as long as +BCLK = 64 * rate. (Intel XScale I2S controller). + + #define PXA_I2S_DAIFMT \ + (SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_LEFT_J | SND_SOC_DAIFMT_NB_NF) + + #define PXA_I2S_DIR \ + (SND_SOC_DAIDIR_PLAYBACK | SND_SOC_DAIDIR_CAPTURE) + + #define PXA_I2S_RATES \ + (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_11025 | SNDRV_PCM_RATE_16000 | \ + SNDRV_PCM_RATE_22050 | SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 | \ + SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_88200 | SNDRV_PCM_RATE_96000) + + /* pxa2xx I2S frame and clock master modes */ + {PXA_I2S_DAIFMT | SND_SOC_DAIFMT_CBS_CFS, SND_SOC_DAITDM_LRDW(0,0), SNDRV_PCM_FORMAT_S16_LE, + SNDRV_PCM_RATE_8000, PXA_I2S_DIR, SND_SOC_DAI_BFS_DIV, 256, + SND_SOC_FSBD(4), 0x48}, + {PXA_I2S_DAIFMT | SND_SOC_DAIFMT_CBS_CFS, SND_SOC_DAITDM_LRDW(0,0), SNDRV_PCM_FORMAT_S16_LE, + SNDRV_PCM_RATE_11025, PXA_I2S_DIR, SND_SOC_DAI_BFS_DIV, 256, + SND_SOC_FSBD(4), 0x34}, + {PXA_I2S_DAIFMT | SND_SOC_DAIFMT_CBS_CFS, SND_SOC_DAITDM_LRDW(0,0), SNDRV_PCM_FORMAT_S16_LE, + SNDRV_PCM_RATE_16000, PXA_I2S_DIR, SND_SOC_DAI_BFS_DIV, 256, + SND_SOC_FSBD(4), 0x24}, + {PXA_I2S_DAIFMT | SND_SOC_DAIFMT_CBS_CFS, SND_SOC_DAITDM_LRDW(0,0), SNDRV_PCM_FORMAT_S16_LE, + SNDRV_PCM_RATE_22050, PXA_I2S_DIR, SND_SOC_DAI_BFS_DIV, 256, + SND_SOC_FSBD(4), 0x1a}, + {PXA_I2S_DAIFMT | SND_SOC_DAIFMT_CBS_CFS, SND_SOC_DAITDM_LRDW(0,0), SNDRV_PCM_FORMAT_S16_LE, + SNDRV_PCM_RATE_44100, PXA_I2S_DIR, SND_SOC_DAI_BFS_DIV, 256, + SND_SOC_FSBD(4), 0xd}, + {PXA_I2S_DAIFMT | SND_SOC_DAIFMT_CBS_CFS, SND_SOC_DAITDM_LRDW(0,0), SNDRV_PCM_FORMAT_S16_LE, + SNDRV_PCM_RATE_48000, PXA_I2S_DIR, SND_SOC_DAI_BFS_DIV, 256, + SND_SOC_FSBD(4), 0xc}, + + /* pxa2xx I2S frame master and clock slave mode */ + {PXA_I2S_DAIFMT | SND_SOC_DAIFMT_CBM_CFS, SND_SOC_DAITDM_LRDW(0,0), SNDRV_PCM_FORMAT_S16_LE, + PXA_I2S_RATES, PXA_I2S_DIR, 0, SND_SOC_FS_ALL, SND_SOC_FSB(64)}, + |