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

From: Takashi Iwai
Date: Tue Sep 02 2014 - 07:04:19 EST


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@xxxxxxxxx> 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
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