Re: [alsa-devel] [PATCH 1/3] ASoC: fsl_asrc: Use in(out)put_format instead of in(out)put_word_width

[Nicolin Chen <nicoleotsuka@gmail.com>]

On Mon, Sep 09, 2019 at 06:33:19PM -0400, Shengjiu Wang wrote:
> snd_pcm_format_t is more formal than enum asrc_word_width, which has
> two property, width and physical width, which is more accurate than
> enum asrc_word_width. So it is better to use in(out)put_format
> instead of in(out)put_word_width.

Hmm...I don't really see the benefit of using snd_pcm_format_t
here...I mean, I know it's a generic one, and would understand
if we use it as a param for a common API. But this patch merely
packs the "width" by intentionally using this snd_pcm_format_t
and then adds another translation to unpack it.. I feel it's a
bit overcomplicated. Or am I missing something?

And I feel it's not necessary to use ALSA common format in our
own "struct asrc_config" since it is more IP/register specific. 

Thanks
Nicolin

> Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
> ---
>  sound/soc/fsl/fsl_asrc.c | 56 +++++++++++++++++++++++++++-------------
>  sound/soc/fsl/fsl_asrc.h |  4 +--
>  2 files changed, 40 insertions(+), 20 deletions(-)
> 
> diff --git a/sound/soc/fsl/fsl_asrc.c b/sound/soc/fsl/fsl_asrc.c
> index cfa40ef6b1ca..4d3804a1ea55 100644
> --- a/sound/soc/fsl/fsl_asrc.c
> +++ b/sound/soc/fsl/fsl_asrc.c
> @@ -265,6 +265,8 @@ static int fsl_asrc_config_pair(struct fsl_asrc_pair *pair)
>  	struct asrc_config *config = pair->config;
>  	struct fsl_asrc *asrc_priv = pair->asrc_priv;
>  	enum asrc_pair_index index = pair->index;
> +	enum asrc_word_width input_word_width;
> +	enum asrc_word_width output_word_width;
>  	u32 inrate, outrate, indiv, outdiv;
>  	u32 clk_index[2], div[2];
>  	int in, out, channels;
> @@ -283,9 +285,32 @@ static int fsl_asrc_config_pair(struct fsl_asrc_pair *pair)
>  		return -EINVAL;
>  	}
>  
> -	/* Validate output width */
> -	if (config->output_word_width == ASRC_WIDTH_8_BIT) {
> -		pair_err("does not support 8bit width output\n");
> +	switch (snd_pcm_format_width(config->input_format)) {
> +	case 8:
> +		input_word_width = ASRC_WIDTH_8_BIT;
> +		break;
> +	case 16:
> +		input_word_width = ASRC_WIDTH_16_BIT;
> +		break;
> +	case 24:
> +		input_word_width = ASRC_WIDTH_24_BIT;
> +		break;
> +	default:
> +		pair_err("does not support this input format, %d\n",
> +			 config->input_format);
> +		return -EINVAL;
> +	}
> +
> +	switch (snd_pcm_format_width(config->output_format)) {
> +	case 16:
> +		output_word_width = ASRC_WIDTH_16_BIT;
> +		break;
> +	case 24:
> +		output_word_width = ASRC_WIDTH_24_BIT;
> +		break;
> +	default:
> +		pair_err("does not support this output format, %d\n",
> +			 config->output_format);
>  		return -EINVAL;
>  	}
>  
> @@ -383,8 +408,8 @@ static int fsl_asrc_config_pair(struct fsl_asrc_pair *pair)
>  	/* Implement word_width configurations */
>  	regmap_update_bits(asrc_priv->regmap, REG_ASRMCR1(index),
>  			   ASRMCR1i_OW16_MASK | ASRMCR1i_IWD_MASK,
> -			   ASRMCR1i_OW16(config->output_word_width) |
> -			   ASRMCR1i_IWD(config->input_word_width));
> +			   ASRMCR1i_OW16(output_word_width) |
> +			   ASRMCR1i_IWD(input_word_width));
>  
>  	/* Enable BUFFER STALL */
>  	regmap_update_bits(asrc_priv->regmap, REG_ASRMCR(index),
> @@ -497,13 +522,13 @@ static int fsl_asrc_dai_hw_params(struct snd_pcm_substream *substream,
>  				  struct snd_soc_dai *dai)
>  {
>  	struct fsl_asrc *asrc_priv = snd_soc_dai_get_drvdata(dai);
> -	int width = params_width(params);
>  	struct snd_pcm_runtime *runtime = substream->runtime;
>  	struct fsl_asrc_pair *pair = runtime->private_data;
>  	unsigned int channels = params_channels(params);
>  	unsigned int rate = params_rate(params);
>  	struct asrc_config config;
> -	int word_width, ret;
> +	snd_pcm_format_t format;
> +	int ret;
>  
>  	ret = fsl_asrc_request_pair(channels, pair);
>  	if (ret) {
> @@ -513,15 +538,10 @@ static int fsl_asrc_dai_hw_params(struct snd_pcm_substream *substream,
>  
>  	pair->config = &config;
>  
> -	if (width == 16)
> -		width = ASRC_WIDTH_16_BIT;
> -	else
> -		width = ASRC_WIDTH_24_BIT;
> -
>  	if (asrc_priv->asrc_width == 16)
> -		word_width = ASRC_WIDTH_16_BIT;
> +		format = SNDRV_PCM_FORMAT_S16_LE;
>  	else
> -		word_width = ASRC_WIDTH_24_BIT;
> +		format = SNDRV_PCM_FORMAT_S24_LE;
>  
>  	config.pair = pair->index;
>  	config.channel_num = channels;
> @@ -529,13 +549,13 @@ static int fsl_asrc_dai_hw_params(struct snd_pcm_substream *substream,
>  	config.outclk = OUTCLK_ASRCK1_CLK;
>  
>  	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
> -		config.input_word_width   = width;
> -		config.output_word_width  = word_width;
> +		config.input_format   = params_format(params);
> +		config.output_format  = format;
>  		config.input_sample_rate  = rate;
>  		config.output_sample_rate = asrc_priv->asrc_rate;
>  	} else {
> -		config.input_word_width   = word_width;
> -		config.output_word_width  = width;
> +		config.input_format   = format;
> +		config.output_format  = params_format(params);
>  		config.input_sample_rate  = asrc_priv->asrc_rate;
>  		config.output_sample_rate = rate;
>  	}
> diff --git a/sound/soc/fsl/fsl_asrc.h b/sound/soc/fsl/fsl_asrc.h
> index c60075112570..38af485bdd22 100644
> --- a/sound/soc/fsl/fsl_asrc.h
> +++ b/sound/soc/fsl/fsl_asrc.h
> @@ -342,8 +342,8 @@ struct asrc_config {
>  	unsigned int dma_buffer_size;
>  	unsigned int input_sample_rate;
>  	unsigned int output_sample_rate;
> -	enum asrc_word_width input_word_width;
> -	enum asrc_word_width output_word_width;
> +	snd_pcm_format_t input_format;
> +	snd_pcm_format_t output_format;
>  	enum asrc_inclk inclk;
>  	enum asrc_outclk outclk;
>  };
> -- 
> 2.21.0
> 
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