[alsa-devel] [PATCHv2 1/4] ASoC: simple-card: add asoc_simple_card_fmt_master() to simplify the code.

[Takashi Iwai]

At Tue, 02 Sep 2014 16:12:40 +0530,
Varka Bhadram wrote:
> 
> On 09/02/2014 04:08 PM, Jean-Francois Moine wrote:
> > On Tue, 02 Sep 2014 15:51:41 +0530
> > Varka Bhadram <varkabhadram at gmail.com> wrote:
> >
> >>> +	switch (((np == bitclkmaster) << 4) | (np == framemaster)) {
> >>> +	case 0x11:
> >>> +		return SND_SOC_DAIFMT_CBS_CFS;
> >>> +	case 0x10:
> >>> +		return SND_SOC_DAIFMT_CBS_CFM;
> >>> +	case 0x01:
> >>> +		return SND_SOC_DAIFMT_CBM_CFS;
> >>> +	default:
> >>> +		return SND_SOC_DAIFMT_CBM_CFM;
> >>> +	}
> >>> +
> >>> +	/* Shouldn't be here */
> >>> +	return -EINVAL;
> >>> +}
> >> It will be nice if we declare the switch case numbers as macros (specific name)...
> > I don't see which macros: the values are just 2 booleans.
> >
> I am talking about 0x11, 0x10, 0x01 values.. We can give any understandable
> names to those...?

The whole switch block is too hackish, makes unnecessarily complex.
It can be more strightforwardly like:

	if (np == bitclkmaster)
		return np == framemater ?
			SND_SOC_DAIFMT_CBS_CFS : SND_SOC_DAIFMT_CBS_CFM;
	else
		return np == framemaster ?
			SND_SOC_DAIFMT_CBM_CFS : SND_SOC_DAIFMT_CBM_CFM;

Or, if you love efficiency and complexity, something like:

#define SND_SOC_DAIFMT(_np, _clk, _frame) \
	((((_np) != (_clk)) | (((_np) != (_frame)) << 1) << 12) + (1 << 12)

Then
	return SND_SOC_DAIFMT(np, blkclkmaster, framemaster);

Takashi