Messages in this thread | | | Date | Fri, 19 Apr 2013 19:38:01 +0200 | From | Daniel Mack <> | Subject | Re: [alsa-devel] [PATCH 2/2] ALSA: ASoc: davinci-mcasp: Add Support BCLK-to-LRCLK ratio for TDM modes |
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On 19.04.2013 15:28, Michal Bachraty wrote: > For TDM mode, BCLK-to-LCLK ratio is computed as (tdm_slots) x (word_length). > I2S mode is only subset of TDM mode with specific tdm_slots = 2 channels. > Also bclk_lrclk_ratio can be greater than 255, therefore u16 need to be used. > > Signed-off-by: Michal Bachraty <michal.bachraty@streamunlimited.com>
Acked-by: Daniel Mack <zonque@gmail.com>
> --- > sound/soc/davinci/davinci-mcasp.c | 7 ++++--- > sound/soc/davinci/davinci-mcasp.h | 2 +- > 2 files changed, 5 insertions(+), 4 deletions(-) > > diff --git a/sound/soc/davinci/davinci-mcasp.c b/sound/soc/davinci/davinci-mcasp.c > index 63633e9..d54e0d9 100644 > --- a/sound/soc/davinci/davinci-mcasp.c > +++ b/sound/soc/davinci/davinci-mcasp.c > @@ -636,11 +636,12 @@ static int davinci_config_channel_size(struct davinci_audio_dev *dev, > * callback, take it into account here. That allows us to for example > * send 32 bits per channel to the codec, while only 16 of them carry > * audio payload. > - * The clock ratio is given for a full period of data (both left and > - * right channels), so it has to be divided by 2. > + * The clock ratio is given for a full period of data (for I2S format > + * both left and right channels), so it has to be divided by number of > + * tdm-slots (for I2S - divided by 2). > */ > if (dev->bclk_lrclk_ratio) > - word_length = dev->bclk_lrclk_ratio / 2; > + word_length = dev->bclk_lrclk_ratio / dev->tdm_slots; > > /* mapping of the XSSZ bit-field as described in the datasheet */ > fmt = (word_length >> 1) - 1; > diff --git a/sound/soc/davinci/davinci-mcasp.h b/sound/soc/davinci/davinci-mcasp.h > index 0edd3b5..a9ac0c1 100644 > --- a/sound/soc/davinci/davinci-mcasp.h > +++ b/sound/soc/davinci/davinci-mcasp.h > @@ -38,7 +38,7 @@ struct davinci_audio_dev { > u8 num_serializer; > u8 *serial_dir; > u8 version; > - u8 bclk_lrclk_ratio; > + u16 bclk_lrclk_ratio; > > /* McASP FIFO related */ > u8 txnumevt; >
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