On Mon, Aug 26, 2019 at 03:05:06PM +0000, [email protected] wrote:
> On 24.08.2019 23:26, Michał Mirosław wrote:
> > SSC driver allows only synchronous TX and RX. In slave mode for BCLK
> > it uses only one of TK or RK pin, but for LRCLK it configured separate
> > inputs from TF and RF pins. Allow configuration with common FS signal.
> > 
> > Signed-off-by: Michał Mirosław <[email protected]>
> > 
> > ---
> >   v2: use alternate DT binding
> >       split DT and drivers/misc changes
> > 
> > ---
> >   sound/soc/atmel/atmel_ssc_dai.c | 26 ++++++++++++++++++++++----
> >   1 file changed, 22 insertions(+), 4 deletions(-)
> > 
> > diff --git a/sound/soc/atmel/atmel_ssc_dai.c 
> > b/sound/soc/atmel/atmel_ssc_dai.c
> > index 48e9eef34c0f..035d4da58f2b 100644
> > --- a/sound/soc/atmel/atmel_ssc_dai.c
> > +++ b/sound/soc/atmel/atmel_ssc_dai.c
> > @@ -605,14 +605,32 @@ static int atmel_ssc_hw_params(struct 
> > snd_pcm_substream *substream,
> >             return -EINVAL;
> >     }
> >   
> > -   if (!atmel_ssc_cfs(ssc_p)) {
> > +   if (atmel_ssc_cfs(ssc_p)) {
> > +           /*
> > +            * SSC provides LRCLK
> > +            *
> > +            * Both TF and RF are generated, so use them directly.
> > +            */
> > +           rcmr |=   SSC_BF(RCMR_START, fs_edge);
> > +           tcmr |=   SSC_BF(TCMR_START, fs_edge);
> 
> Hmm, how would this work if capture and playback start/run at the same time?

Same as it did before this patch: as there is only one bi-directional link
between SSC and codec, whichever stream starts first defines the rate.

> > +   } else {
> >             fslen = fslen_ext = 0;
> >             rcmr_period = tcmr_period = 0;
> >             fs_osync = SSC_FSOS_NONE;
> > -   }
> >   
> > -   rcmr |=   SSC_BF(RCMR_START, fs_edge);
> > -   tcmr |=   SSC_BF(TCMR_START, fs_edge);
> > +           if (ssc->lrclk_from_tf_pin) {
> > +                   rcmr |=   SSC_BF(RCMR_START, SSC_START_TX_RX);
> > +                   tcmr |=   SSC_BF(TCMR_START, fs_edge);
> > +           } else if (ssc->lrclk_from_rf_pin) {
> > +                   /* assume RF is to be used when RK is used as BCLK 
> > input */
> 
> This comment is not longer true...

Removed for next version.

> 
> > +                   /* Note: won't work correctly on SAMA5D2 due to errata 
> > */
> > +                   rcmr |=   SSC_BF(RCMR_START, fs_edge);
> > +                   tcmr |=   SSC_BF(TCMR_START, SSC_START_TX_RX);
> > +           } else {
> > +                   rcmr |=   SSC_BF(RCMR_START, fs_edge);
> > +                   tcmr |=   SSC_BF(TCMR_START, fs_edge);
> > +           }
> > +   }
> >   
> >     if (atmel_ssc_cbs(ssc_p)) {
> >             /*
> > 
> 
> Thanks and best regards,
> Codrin

Best Regards,
Michał Mirosław

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