Re: [PATCH v4 8/9] ASoc: sun4i-i2s: Add 20, 24 and 32 bit support

[Maxime Ripard <maxime.ripard-LDxbnhwyfcJBDgjK7y7TUQ@public.gmane.org>]

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On Mon, Jun 03, 2019 at 07:47:34PM +0200, codekipper-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org wrote:
> From: Marcus Cooper <codekipper-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>
> Extend the functionality of the driver to include support of 20 and
> 24 bits per sample for the earlier SoCs.
>
> Newer SoCs can also handle 32bit samples.
>
> Signed-off-by: Marcus Cooper <codekipper-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> ---
>  sound/soc/sunxi/sun4i-i2s.c | 34 +++++++++++++++++++++++++++++++---
>  1 file changed, 31 insertions(+), 3 deletions(-)
>
> diff --git a/sound/soc/sunxi/sun4i-i2s.c b/sound/soc/sunxi/sun4i-i2s.c
> index 3549a87ed9e9..351b8021173b 100644
> --- a/sound/soc/sunxi/sun4i-i2s.c
> +++ b/sound/soc/sunxi/sun4i-i2s.c
> @@ -428,6 +428,11 @@ static int sun4i_i2s_hw_params(struct snd_pcm_substream *substream,
>  	case 16:
>  		width = DMA_SLAVE_BUSWIDTH_2_BYTES;
>  		break;
> +	case 20:
> +	case 24:
> +	case 32:
> +		width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> +		break;

Doesn't this test the physical width? If so, then I'm not sure that 20
even exists, and that we can support 24.

>  	default:
>  		dev_err(dai->dev, "Unsupported physical sample width: %d\n",
>  			params_physical_width(params));
> @@ -440,7 +445,18 @@ static int sun4i_i2s_hw_params(struct snd_pcm_substream *substream,
>  		sr = 0;
>  		wss = 0;
>  		break;
> -
> +	case 20:
> +		sr = 1;
> +		wss = 1;
> +		break;
> +	case 24:
> +		sr = 2;
> +		wss = 2;
> +		break;
> +	case 32:
> +		sr = 4;
> +		wss = 4;
> +		break;

This doesn't really works, wss being the slot size, and you can have a
different slot size and sample size. I have a patch that reworks this,
I'll send it.

Maxime

--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com