RE: [PATCH 4/6] ASoC: samsung: fsd: Add FSD soundcard driver

["Padmanabhan Rajanbabu" <p.rajanbabu@samsung.com>]

> -----Original Message-----
> From: Krzysztof Kozlowski [mailto:krzysztof.kozlowski@linaro.org]
> Sent: 16 October 2022 08:48 PM
> To: Padmanabhan Rajanbabu <p.rajanbabu@samsung.com>;
> lgirdwood@gmail.com; broonie@kernel.org; robh+dt@kernel.org;
> krzysztof.kozlowski+dt@linaro.org; s.nawrocki@samsung.com;
> perex@perex.cz; tiwai@suse.com; pankaj.dubey@samsung.com;
> alim.akhtar@samsung.com; rcsekar@samsung.com;
> aswani.reddy@samsung.com
> Cc: alsa-devel@alsa-project.org; devicetree@vger.kernel.org; linux-
> kernel@vger.kernel.org; linux-samsung-soc@vger.kernel.org
> Subject: Re: [PATCH 4/6] ASoC: samsung: fsd: Add FSD soundcard driver
> 
> On 14/10/2022 06:21, Padmanabhan Rajanbabu wrote:
> > Add a soundcard driver for FSD audio interface to bridge the CPU DAI
> > of samsung I2S with the codec and platform driver.
> >
> 
> Thank you for your patch. There is something to discuss/improve.
> 
> > +
> > +#define FSD_PREFIX		"tesla,"
> > +#define FSD_DAI_SRC_PCLK	3
> > +#define FSD_DAI_RFS_192		192
> > +#define FSD_DAI_BFS_48		48
> > +#define FSD_DAI_BFS_96		96
> > +#define FSD_DAI_BFS_192		192
> > +
> > +struct fsd_card_priv {
> > +	struct snd_soc_card card;
> > +	struct snd_soc_dai_link *dai_link;
> > +	u32 tdm_slots;
> > +	u32 tdm_slot_width;
> > +};
> > +
> > +static unsigned int fsd_card_get_rfs(unsigned int rate) {
> > +	return FSD_DAI_RFS_192;
> 
> This wrapper is a bit silly...
okay, will remove the wrapper and assign the macro value directly
> 
> > +}
> > +
> > +static unsigned int fsd_card_get_bfs(unsigned int channels) {
> > +	switch (channels) {
> > +	case 1:
> > +	case 2:
> > +		return FSD_DAI_BFS_48;
> > +	case 3:
> > +	case 4:
> > +		return FSD_DAI_BFS_96;
> > +	case 5:
> > +	case 6:
> > +	case 7:
> > +	case 8:
> > +		return FSD_DAI_BFS_192;
> > +	default:
> > +		return FSD_DAI_BFS_48;
> > +	}
> > +}
> > +
> > +static unsigned int fsd_card_get_psr(unsigned int rate) {
> > +	switch (rate) {
> > +	case 8000:	return 43;
> > +	case 11025:	return 31;
> > +	case 16000:	return 21;
> > +	case 22050:	return 16;
> > +	case 32000:	return 11;
> > +	case 44100:	return 8;
> > +	case 48000:	return 7;
> > +	case 64000:	return 5;
> > +	case 88200:	return 4;
> > +	case 96000:	return 4;
> > +	case 192000:	return 2;
> > +	default:	return 1;
> > +	}
> > +}
> > +
> > +static int fsd_card_hw_params(struct snd_pcm_substream *substream,
> > +					struct snd_pcm_hw_params
> *params) {
> > +	struct snd_soc_pcm_runtime *rtd	= substream->private_data;
> > +	struct snd_soc_card *card	= rtd->card;
> > +	struct snd_soc_dai *cpu_dai	= asoc_rtd_to_cpu(rtd, 0);
> > +	struct snd_soc_dai_link *link	= rtd->dai_link;
> > +	struct fsd_card_priv *priv	= snd_soc_card_get_drvdata(card);
> > +	unsigned int rfs, bfs, psr;
> > +	int ret = 0, cdclk_dir;
> > +
> > +	rfs = fsd_card_get_rfs(params_rate(params));
> > +	bfs = fsd_card_get_bfs(params_channels(params));
> > +	psr = fsd_card_get_psr(params_rate(params));
> > +
> > +	/* Configure the Root Clock Source */
> > +	ret = snd_soc_dai_set_sysclk(cpu_dai, SAMSUNG_I2S_OPCLK,
> > +					false, FSD_DAI_SRC_PCLK);
> > +	if (ret < 0) {
> > +		dev_err(card->dev, "Failed to set OPCLK: %d\n", ret);
> > +		goto err;
> > +	}
> > +
> > +	ret = snd_soc_dai_set_sysclk(cpu_dai, SAMSUNG_I2S_RCLKSRC_0,
> > +					false, false);
> > +	if (ret < 0) {
> > +		dev_err(card->dev, "Failed to set RCLKSRC: %d\n", ret);
> 
> Don't you need to cleanup on error paths?
we might not be needing, since the sound card neither configures any
clock sources directly nor involves in any memory allocation during
hw_params.
> 
> > +		goto err;
> > +	}
> > +
> > +	/* Set CPU DAI configuration */
> > +	ret = snd_soc_dai_set_fmt(cpu_dai, link->dai_fmt);
> > +	if (ret < 0) {
> > +		dev_err(card->dev, "Failed to set DAIFMT: %d\n", ret);
> > +		goto err;
> > +	}
> > +
> > +	if (link->dai_fmt & SND_SOC_DAIFMT_CBC_CFC) {
> > +		cdclk_dir = SND_SOC_CLOCK_OUT;
> > +	} else if (link->dai_fmt & SND_SOC_DAIFMT_CBP_CFP) {
> > +		cdclk_dir = SND_SOC_CLOCK_IN;
> > +	} else {
> > +		dev_err(card->dev, "Missing Clock Master information\n");
> > +		goto err;
> > +	}
> > +
> > +	/* Set Clock Source for CDCLK */
> > +	ret = snd_soc_dai_set_sysclk(cpu_dai, SAMSUNG_I2S_CDCLK,
> > +					rfs, cdclk_dir);
> > +	if (ret < 0) {
> > +		dev_err(card->dev, "Failed to set CDCLK: %d\n", ret);
> > +		goto err;
> > +	}
> > +
> > +	ret = snd_soc_dai_set_clkdiv(cpu_dai, SAMSUNG_I2S_DIV_RCLK, psr);
> > +	if (ret < 0) {
> > +		dev_err(card->dev, "Failed to set PSR: %d\n", ret);
> > +		goto err;
> > +	}
> > +
> > +	ret = snd_soc_dai_set_clkdiv(cpu_dai, SAMSUNG_I2S_DIV_BCLK, bfs);
> > +	if (ret < 0) {
> > +		dev_err(card->dev, "Failed to set BCLK: %d\n", ret);
> > +		goto err;
> > +	}
> > +
> > +	if (priv->tdm_slots) {
> > +		ret = snd_soc_dai_set_tdm_slot(cpu_dai, false, false,
> > +				priv->tdm_slots, priv->tdm_slot_width);
> > +		if (ret < 0) {
> > +			dev_err(card->dev,
> > +				"Failed to configure in TDM mode:%d\n", ret);
> > +			goto err;
> > +		}
> > +	}
> > +
> > +err:
> > +	return ret;
> > +}
> > +
> > +static const struct snd_soc_ops fsd_card_ops = {
> > +	.hw_params	= fsd_card_hw_params,
> > +};
> > +
> > +static struct fsd_card_priv *fsd_card_parse_of(struct snd_soc_card
> > +*card) {
> > +	struct fsd_card_priv *priv;
> > +	struct snd_soc_dai_link *link;
> > +	struct device *dev = card->dev;
> > +	struct device_node *node = dev->of_node;
> > +	struct device_node *np, *cpu_node, *codec_node;
> > +	struct snd_soc_dai_link_component *dlc;
> > +	int ret, id = 0, num_links;
> > +
> > +	ret = snd_soc_of_parse_card_name(card, "model");
> > +	if (ret) {
> > +		dev_err(dev, "Error parsing card name: %d\n", ret);
> > +		return ERR_PTR(ret);
> 
> return dev_err_probe
Okay
> 
> > +	}
> > +
> > +	if (of_property_read_bool(dev->of_node, "widgets")) {
> > +		ret = snd_soc_of_parse_audio_simple_widgets(card, "widgets");
> > +		if (ret)
> > +			return ERR_PTR(ret);
> > +	}
> > +
> > +	/* Add DAPM routes to the card */
> > +	if (of_property_read_bool(node, "audio-routing")) {
> > +		ret = snd_soc_of_parse_audio_routing(card, "audio-routing");
> > +		if (ret)
> > +			return ERR_PTR(ret);
> > +	}
> > +
> > +	num_links = of_get_child_count(node);
> > +
> > +	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> > +	if (!priv)
> > +		return ERR_PTR(-ENOMEM);
> > +
> > +	priv->dai_link = devm_kzalloc(dev, num_links * sizeof(*priv-
> >dai_link),
> > + 	GFP_KERNEL);
> > +	if (!priv->dai_link)
> > +		return ERR_PTR(-ENOMEM);
> > +
> > +	priv->tdm_slots = 0;
> > +	priv->tdm_slot_width = 0;
> > +
> > +	snd_soc_of_parse_tdm_slot(node, NULL, NULL, &priv->tdm_slots,
> > +			&priv->tdm_slot_width);
> > +
> > +	link = priv->dai_link;
> > +
> > +	for_each_child_of_node(node, np) {
> > +		dlc = devm_kzalloc(dev, 2 * sizeof(*dlc), GFP_KERNEL);
> > +		if (!dlc)
> > +			return ERR_PTR(-ENOMEM);
> > +
> > +		link->id		= id;
> > +		link->cpus		= &dlc[0];
> > +		link->platforms		= &dlc[1];
> > +		link->num_cpus		= 1;
> > +		link->num_codecs	= 1;
> > +		link->num_platforms	= 1;
> > +
> > +		cpu_node = of_get_child_by_name(np, "cpu");
> > +		if (!cpu_node) {
> > +			dev_err(dev, "Missing CPU/Codec node\n");
> > +			ret = -EINVAL;
> > +			goto err_cpu_node;
> > +		}
> > +
> > +		ret = snd_soc_of_get_dai_link_cpus(dev, cpu_node, link);
> > +		if (ret < 0) {
> > +			dev_err(dev, "Error Parsing CPU DAI name\n");
> > +			goto err_cpu_name;
> > +		}
> > +
> > +		link->platforms->of_node = link->cpus->of_node;
> > +
> > +		codec_node = of_get_child_by_name(np, "codec");
> > +		if (codec_node) {
> > +			ret = snd_soc_of_get_dai_link_codecs(dev, codec_node,
> > +					link);
> > +			if (ret < 0) {
> > +				dev_err(dev, "Error Parsing Codec DAI name\n");
> > +				goto err_codec_name;
> > +			}
> > +		} else {
> > +			dlc = devm_kzalloc(dev, sizeof(*dlc), GFP_KERNEL);
> > +			if (!dlc) {
> > +				ret = -ENOMEM;
> > +				goto err_cpu_name;
> > +			}
> > +
> > +			link->codecs = dlc;
> > +
> > +			link->codecs->dai_name = "snd-soc-dummy-dai";
> > +			link->codecs->name = "snd-soc-dummy";
> > +			link->dynamic = 1;
> > +
> > +			snd_soc_dai_link_set_capabilities(link);
> > +			link->ignore_suspend = 1;
> > +			link->nonatomic = 1;
> > +		}
> > +
> > +		ret = asoc_simple_parse_daifmt(dev, np, codec_node,
> > +					FSD_PREFIX, &link->dai_fmt);
> > +		if (ret)
> > +			link->dai_fmt = SND_SOC_DAIFMT_NB_NF |
> > +					SND_SOC_DAIFMT_CBC_CFC |
> > +					SND_SOC_DAIFMT_I2S;
> > +
> > +		ret = of_property_read_string(np, "link-name", &link-
> >name);
> > +		if (ret) {
> > +			dev_err(card->dev, "Error Parsing link name\n");
> > +			goto err_codec_name;
> > +		}
> > +
> > +		link->stream_name = link->name;
> > +		link->ops = &fsd_card_ops;
> > +
> > +		link++;
> > +		id++;
> > +
> > +		of_node_put(cpu_node);
> > +		of_node_put(codec_node);
> > +	}
> > +
> > +	card->dai_link = priv->dai_link;
> > +	card->num_links = num_links;
> > +
> > +	return priv;
> > +
> > +err_codec_name:
> > +	of_node_put(codec_node);
> > +err_cpu_name:
> > +	of_node_put(cpu_node);
> > +err_cpu_node:
> > +	of_node_put(np);
> > +	return ERR_PTR(ret);
> > +}
> > +
> > +static int fsd_platform_probe(struct platform_device *pdev) {
> > +	struct device *dev = &pdev->dev;
> > +	struct snd_soc_card *card;
> > +	struct fsd_card_priv *fsd_priv;
> > +
> > +	card = devm_kzalloc(dev, sizeof(*card), GFP_KERNEL);
> > +	if (!card)
> > +		return -ENOMEM;
> > +
> > +	card->dev	= dev;
> > +	fsd_priv	= fsd_card_parse_of(card);
> 
> Drop the indentation before =
Okay
> 
> > +
> > +	if (IS_ERR(fsd_priv)) {
> > +		dev_err(&pdev->dev, "Error Parsing DAI Link: %ld\n",
> > +				PTR_ERR(fsd_priv));
> > +		return PTR_ERR(fsd_priv);
> 
> return dev_err_probe
Okay
> 
> > +	}
> > +
> > +	snd_soc_card_set_drvdata(card, fsd_priv);
> > +
> > +	return devm_snd_soc_register_card(&pdev->dev, card); }
> > +
> > +static const struct of_device_id fsd_device_id[] = {
> > +	{ .compatible = "tesla,fsd-card" },
> > +	{},
> > +};
> > +MODULE_DEVICE_TABLE(of, fsd_device_id);
> > +
> > +static struct platform_driver fsd_platform_driver = {
> > +	.driver = {
> > +		.name = "fsd-card",
> > +		.of_match_table = of_match_ptr(fsd_device_id),
> 
> of_match_ptr comes with maybe_unused. Or drop it.
Okay
> 
> 
> 
> Best regards,
> Krzysztof
Thank you for reviewing the patch.