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Subject: Re: [PATCH v2 3/3] ASoC: tlv320adcx140: Add proper support for master
 mode
To:     Camel Guo <camel.guo@axis.com>, <lgirdwood@gmail.com>,
        <broonie@kernel.org>, <tiwai@suse.com>
CC:     <alsa-devel@alsa-project.org>, <linux-kernel@vger.kernel.org>,
        <kernel@axis.com>, Camel Guo <camelg@axis.com>
References: <20200911080753.30342-1-camel.guo@axis.com>
 <20200911080753.30342-3-camel.guo@axis.com>
From:   Dan Murphy <dmurphy@ti.com>
Message-ID: <c2fb617e-fa61-e9d1-449f-7d8806168b9a@ti.com>
Date:   Tue, 15 Sep 2020 13:50:43 -0500
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Camel

On 9/11/20 3:07 AM, Camel Guo wrote:
> From: Camel Guo <camelg@axis.com>
>
> Add setup of bclk-to-ws ratio and sample rate when in master mode,
> as well as MCLK input pin setup.
>
> Signed-off-by: Camel Guo <camelg@axis.com>
> ---
>   v2:
>    - Move GPIO setting into devicetree
>    - Move master config register setting into a new function
>
>   sound/soc/codecs/tlv320adcx140.c | 139 ++++++++++++++++++++++++++++++-
>   sound/soc/codecs/tlv320adcx140.h |  27 ++++++
>   2 files changed, 162 insertions(+), 4 deletions(-)
>
> diff --git a/sound/soc/codecs/tlv320adcx140.c b/sound/soc/codecs/tlv320adcx140.c
> index 97f16fbba441..685f5fd8b537 100644
> --- a/sound/soc/codecs/tlv320adcx140.c
> +++ b/sound/soc/codecs/tlv320adcx140.c
> @@ -35,6 +35,7 @@ struct adcx140_priv {
>   	unsigned int dai_fmt;
>   	unsigned int tdm_delay;
>   	unsigned int slot_width;
> +	bool master;
>   };
>   
>   static const char * const gpo_config_names[] = {
> @@ -651,11 +652,136 @@ static int adcx140_reset(struct adcx140_priv *adcx140)
>   	return ret;
>   }
>   
> +static int adcx140_fs_bclk_ratio(unsigned int bclk_ratio)
> +{
> +	switch (bclk_ratio) {
> +	case 16:
> +		return ADCX140_RATIO_16;
> +	case 24:
> +		return ADCX140_RATIO_24;
> +	case 32:
> +		return ADCX140_RATIO_32;
> +	case 48:
> +		return ADCX140_RATIO_48;
> +	case 64:
> +		return ADCX140_RATIO_64;
> +	case 96:
> +		return ADCX140_RATIO_96;
> +	case 128:
> +		return ADCX140_RATIO_128;
> +	case 192:
> +		return ADCX140_RATIO_192;
> +	case 256:
> +		return ADCX140_RATIO_256;
> +	case 384:
> +		return ADCX140_RATIO_384;
> +	case 512:
> +		return ADCX140_RATIO_512;
> +	case 1024:
> +		return ADCX140_RATIO_1024;
> +	case 2048:
> +		return ADCX140_RATIO_2048;
> +	default:
> +		break;
> +	}
> +	return -EINVAL;
> +}
> +
> +static int adcx140_fs_rate(unsigned int rate)
> +{
> +	switch (rate) {
> +	case 7350:
> +	case 8000:
> +		return ADCX140_8_OR_7_35KHZ;
> +	case 14700:
> +	case 16000:
> +		return ADCX140_16_OR_14_7KHZ;
> +	case 22050:
> +	case 24000:
> +		return ADCX140_24_OR_22_05KHZ;
> +	case 29400:
> +	case 32000:
> +		return ADCX140_32_OR_29_4KHZ;
> +	case 44100:
> +	case 48000:
> +		return ADCX140_48_OR_44_1KHZ;
> +	case 88200:
> +	case 96000:
> +		return ADCX140_96_OR_88_2KHZ;
> +	case 176400:
> +	case 192000:
> +		return ADCX140_192_OR_176_4KHZ;
> +	case 352800:
> +	case 384000:
> +		return ADCX140_384_OR_352_8KHZ;
> +	case 705600:
> +	case 768000:
> +		return ADCX140_768_OR_705_6KHZ;
> +	default:
> +		break;
> +	}
> +	return -EINVAL;
> +}
> +
> +static int adcx140_setup_master_config(struct snd_soc_component *component,
> +				       struct snd_pcm_hw_params *params)
> +{
> +	int ret = 0;
> +	struct adcx140_priv *adcx140 = snd_soc_component_get_drvdata(component);
> +
> +	if (adcx140->master) {

Move this out to hw_params.  No reason to jump here just to jump back.

Check for master and if master then configure

This will eliminate the mixed code and variable declaration below which 
is what I wanted to avoid in v1.

This will also allow you to remove some of the variable initialization.

> +		u8 mst_cfg1 = 0;
> +		u8 mst_cfg0 = 0;
This can be init to mst_cfg0 = ADCX140_BCLK_FSYNC_MASTER no reason to 
set it here and then change it immediately.
> +		unsigned int bclk_ratio;
> +
> +		mst_cfg0 = ADCX140_BCLK_FSYNC_MASTER;
> +		if (params_rate(params) % 1000)
> +			mst_cfg0 |= ADCX140_FSYNCINV_BIT; /* 44.1 kHz et al */
> +
> +		ret = adcx140_fs_rate(params_rate(params));
> +		if (ret < 0) {
> +			dev_err(adcx140->dev, "%s: Unsupported rate %d\n",
> +					__func__, params_rate(params));
> +			return ret;
> +		}
> +		mst_cfg1 |= ret;
Why the | here?  This is initialized to 0 so mst_cfg1 = ret. And why 
even use ret just return into mst_cfg1 and check that variable
> +
> +		/* In slave mode when using automatic clock configuration,
> +		 * the codec figures out the BCLK to FSYNC ratio itself. But
> +		 * here in master mode, we need to tell it.
> +		 */
> +
> +		bclk_ratio = snd_soc_params_to_frame_size(params);
> +		ret = adcx140_fs_bclk_ratio(bclk_ratio);
> +		if (ret < 0) {
> +			dev_err(adcx140->dev, "%s: Unsupported bclk_ratio %d\n",
> +					__func__, bclk_ratio);
> +			return ret;
> +		}
> +		mst_cfg1 |= ret;
> +
> +		snd_soc_component_update_bits(component, ADCX140_MST_CFG1,
> +				ADCX140_FS_RATE_MSK |
> +				ADCX140_RATIO_MSK,
> +				mst_cfg1);

I don't understand the update_bits since you have calcualted both the 
Ratio and rate you can just write the register with the 
snd_soc_component_write.

> +
> +		snd_soc_component_update_bits(component, ADCX140_MST_CFG0,
> +				ADCX140_FSYNCINV_BIT |
> +				ADCX140_BCLK_FSYNC_MASTER,
> +				mst_cfg0);
> +

But this is ok.  I actually have other changes I am posting which move 
this to the set_dai_format.  So I am not sure if this will be needed 
after that patch is applied.

I will CC you on those patches.

Dan