Re: [PATCH 07/13] ASoC: ti: davinci-i2s: Add TDM support

[Bastien Curutchet]

Hi Péter,

> > +static int davinci_i2s_set_tdm_slot(struct snd_soc_dai *cpu_dai,
> > +				    unsigned int tx_mask,
> > +				    unsigned int rx_mask,
> > +				    int slots, int slot_width)
> > +{
> > +	struct davinci_mcbsp_dev *dev = snd_soc_dai_get_drvdata(cpu_dai);
> > +
> > +	dev_dbg(dev->dev, "%s - slots %d, slot_width %d\n", __func__, slots, slot_width);
>
> The __func__ can be ommited, it is better to leave it for dynamic
> debugging by adding "dyndbg=+pmf" module parameter if needed.

True, I'll remove the __func__.

> > +
> > +	if (slots > 128 || !slots) {
> > +		dev_err(dev->dev, "Invalid number of slots\n");
> > +		return -EINVAL;
> > +	}
> > +
> > +	if (rx_mask != (1 << slots) - 1) {
> > +		dev_err(dev->dev, "Invalid RX mask (0x%08x) : all slots must be used by McBSP\n",
> > +			rx_mask);
> > +		return -EINVAL;
>
> This is only a restriction for RX?

Nope you're right, I'll add the same for tx_mask.

> > +	}
> > +
> > +	if (davinci_i2s_tdm_word_length(slot_width) < 0) {
> > +		dev_err(dev->dev, "%s: Unsupported slot_width %d\n", __func__, slot_width);
> > +		return -EINVAL;
> > +	}
> > +
> > +	dev->tdm_slots = slots;
> > +	dev->slot_width = slot_width;
> > +
> > +	return 0;
> > +}
> > +
> >   #define DEFAULT_BITPERSAMPLE	16
> >   
> >   static int davinci_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai,
> > @@ -228,6 +282,13 @@ static int davinci_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai,
> >   		DAVINCI_MCBSP_SRGR_FWID(DEFAULT_BITPERSAMPLE - 1);
> >   
> >   	dev->fmt = fmt;
> > +
> > +	if ((dev->tdm_slots || dev->slot_width) &&
> > +	    ((fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) != SND_SOC_DAIFMT_BP_FC)) {
> > +		dev_err(dev->dev, "TDM is only supported for BP_FC format\n");
> > +		return -EINVAL;
>
> I think this is not a valid statement, Fsync can be generated internally
> or coming from external source in TDM mode also.

My hardware allow me to only test BP_FC so I wished to put some
'barriers' in front of untested things.


Best regards,
Bastien