[alsa-devel] [PATCH] ASoC: AMD: Enable clk in startup intead of hw_params

[Agrawal, Akshu]

On 11/26/2019 1:24 PM, Yu-Hsuan Hsu wrote:
> Some usages only call startup and shutdown without setting hw_params
> (e.g. arecord --dump-hw-params). If we don't enable clk in startup, it
> will cause ref count error because the clk will be disabled in shutdown.
> For this reason, we should move enabling clk from hw_params to startup.
>
> In addition, the hw_params is fixed in this driver(48000 rate, 2
> channels, S16_LE format) so we don't need to change the clk rate after
> the hw_params is set.
>
> Signed-off-by: Yu-Hsuan Hsu <yuhsuan at chromium.org>
> ---
>   sound/soc/amd/acp-da7219-max98357a.c | 46 +++++++++-------------------
>   1 file changed, 14 insertions(+), 32 deletions(-)
>
> diff --git a/sound/soc/amd/acp-da7219-max98357a.c b/sound/soc/amd/acp-da7219-max98357a.c
> index f4ee6798154af5..7a5621e5e2330d 100644
> --- a/sound/soc/amd/acp-da7219-max98357a.c
> +++ b/sound/soc/amd/acp-da7219-max98357a.c
> @@ -96,14 +96,19 @@ static int cz_da7219_init(struct snd_soc_pcm_runtime *rtd)
>   	return 0;
>   }
>   
> -static int da7219_clk_enable(struct snd_pcm_substream *substream,
> -			     int wclk_rate, int bclk_rate)
> +static int da7219_clk_enable(struct snd_pcm_substream *substream)
>   {
>   	int ret = 0;
>   	struct snd_soc_pcm_runtime *rtd = substream->private_data;
>   
> -	clk_set_rate(da7219_dai_wclk, wclk_rate);
> -	clk_set_rate(da7219_dai_bclk, bclk_rate);
> +	/*
> +	 * Set wclk to 48000 because the rate constraint of this driver is
> +	 * 48000. ADAU7002 spec: "The ADAU7002 requires a BCLK rate that is
> +	 * minimum of 64x the LRCLK sample rate." DA7219 is the only clk
> +	 * source so for all codecs we have to limit bclk to 64X lrclk.
> +	 */
> +	clk_set_rate(da7219_dai_wclk, 48000);
> +	clk_set_rate(da7219_dai_bclk, 48000 * 64);
>   	ret = clk_prepare_enable(da7219_dai_bclk);
>   	if (ret < 0) {
>   		dev_err(rtd->dev, "can't enable master clock %d\n", ret);
> @@ -156,7 +161,7 @@ static int cz_da7219_play_startup(struct snd_pcm_substream *substream)
>   				   &constraints_rates);
>   
>   	machine->play_i2s_instance = I2S_SP_INSTANCE;
> -	return 0;
> +	return da7219_clk_enable(substream);
>   }
>   
>   static int cz_da7219_cap_startup(struct snd_pcm_substream *substream)
> @@ -178,7 +183,7 @@ static int cz_da7219_cap_startup(struct snd_pcm_substream *substream)
>   
>   	machine->cap_i2s_instance = I2S_SP_INSTANCE;
>   	machine->capture_channel = CAP_CHANNEL1;
> -	return 0;
> +	return da7219_clk_enable(substream);
>   }
>   
>   static int cz_max_startup(struct snd_pcm_substream *substream)
> @@ -199,7 +204,7 @@ static int cz_max_startup(struct snd_pcm_substream *substream)
>   				   &constraints_rates);
>   
>   	machine->play_i2s_instance = I2S_BT_INSTANCE;
> -	return 0;
> +	return da7219_clk_enable(substream);
>   }
>   
>   static int cz_dmic0_startup(struct snd_pcm_substream *substream)
> @@ -220,7 +225,7 @@ static int cz_dmic0_startup(struct snd_pcm_substream *substream)
>   				   &constraints_rates);
>   
>   	machine->cap_i2s_instance = I2S_BT_INSTANCE;
> -	return 0;
> +	return da7219_clk_enable(substream);
>   }
>   
>   static int cz_dmic1_startup(struct snd_pcm_substream *substream)
> @@ -242,25 +247,7 @@ static int cz_dmic1_startup(struct snd_pcm_substream *substream)
>   
>   	machine->cap_i2s_instance = I2S_SP_INSTANCE;
>   	machine->capture_channel = CAP_CHANNEL0;
> -	return 0;
> -}
> -
> -static int cz_da7219_params(struct snd_pcm_substream *substream,
> -				      struct snd_pcm_hw_params *params)
> -{
> -	int wclk, bclk;
> -
> -	wclk = params_rate(params);
> -	bclk = wclk * params_channels(params) *
> -		snd_pcm_format_width(params_format(params));
> -	/* ADAU7002 spec: "The ADAU7002 requires a BCLK rate
> -	 * that is minimum of 64x the LRCLK sample rate."
> -	 * DA7219 is the only clk source so for all codecs
> -	 * we have to limit bclk to 64X lrclk.
> -	 */
> -	if (bclk < (wclk * 64))
> -		bclk = wclk * 64;
> -	return da7219_clk_enable(substream, wclk, bclk);
> +	return da7219_clk_enable(substream);
>   }
>   
>   static void cz_da7219_shutdown(struct snd_pcm_substream *substream)
> @@ -271,31 +258,26 @@ static void cz_da7219_shutdown(struct snd_pcm_substream *substream)
>   static const struct snd_soc_ops cz_da7219_play_ops = {
>   	.startup = cz_da7219_play_startup,
>   	.shutdown = cz_da7219_shutdown,
> -	.hw_params = cz_da7219_params,
>   };
>   
>   static const struct snd_soc_ops cz_da7219_cap_ops = {
>   	.startup = cz_da7219_cap_startup,
>   	.shutdown = cz_da7219_shutdown,
> -	.hw_params = cz_da7219_params,
>   };
>   
>   static const struct snd_soc_ops cz_max_play_ops = {
>   	.startup = cz_max_startup,
>   	.shutdown = cz_da7219_shutdown,
> -	.hw_params = cz_da7219_params,
>   };
>   
>   static const struct snd_soc_ops cz_dmic0_cap_ops = {
>   	.startup = cz_dmic0_startup,
>   	.shutdown = cz_da7219_shutdown,
> -	.hw_params = cz_da7219_params,
>   };
>   
>   static const struct snd_soc_ops cz_dmic1_cap_ops = {
>   	.startup = cz_dmic1_startup,
>   	.shutdown = cz_da7219_shutdown,
> -	.hw_params = cz_da7219_params,
>   };
>   
>   SND_SOC_DAILINK_DEF(designware1,

Acked-by: Akshu Agrawal <akshu.agarawal at amd.com>