[PATCH v3 1/2] ASoC: samsung: Snow DT bindings update

[PATCH v3 1/2] ASoC: samsung: Snow DT bindings update

[Sylwester Nawrocki]

The new DT bindings are introduced so sound on the HDMI interface
can also be supported. The exisiting CPU and CODEC DAI phandle
properties are marked as deprecated.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
Changes since v2:
 - edited summary line.
---
 Documentation/devicetree/bindings/sound/snow.txt | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/sound/snow.txt b/Documentation/devicetree/bindings/sound/snow.txt
index 6df74f15687f..80fd9a87bb3f 100644
--- a/Documentation/devicetree/bindings/sound/snow.txt
+++ b/Documentation/devicetree/bindings/sound/snow.txt
@@ -5,8 +5,17 @@ Required properties:
 			"google,snow-audio-max98090" or
 			"google,snow-audio-max98091" or
 			"google,snow-audio-max98095"
-- samsung,i2s-controller: The phandle of the Samsung I2S controller
-- samsung,audio-codec: The phandle of the audio codec
+- samsung,i2s-controller (deprecated): The phandle of the Samsung I2S controller
+- samsung,audio-codec (deprecated): The phandle of the audio codec
+
+Required sub-nodes:
+
+ - 'cpu' subnode with a 'sound-dai' property containing the phandle of the I2S
+    controller
+ - 'codec' subnode with a 'sound-dai' property containing list of phandles
+    to the CODEC nodes, first entry must be the phandle of the MAX98090,
+    MAX98091 or MAX98095 CODEC (exact device type is indicated by the compatible
+    string) and the second entry must be the phandle of the HDMI IP block node
 
 Optional:
 - samsung,model: The name of the sound-card
-- 
2.14.2

[PATCH v3 2/2] ASoC: samsung: Add HDMI audio support for Snow

[Sylwester Nawrocki]

This patch updates the driver so, in addition to current DT bindings, it
also can also use the new DT bindings with cpu, codec subnodes which allow
to support sound on the HDMI interface.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
---
Changes since v2:
 - dropped addition of UL postfix in the FIN_PLL_RATE constant
   definition from this patch,
 - edited summary line.

Changes since v1:
 - adjustments to changed order of codecs in codec/cpu-dai property,
 - fixed errors in snow_remove().
---
 sound/soc/samsung/snow.c | 224 +++++++++++++++++++++++++++++++++++++----------
 1 file changed, 177 insertions(+), 47 deletions(-)

diff --git a/sound/soc/samsung/snow.c b/sound/soc/samsung/snow.c
index fc62110f500f..5d8efc2d5c38 100644
--- a/sound/soc/samsung/snow.c
+++ b/sound/soc/samsung/snow.c
@@ -11,92 +11,207 @@
  * General Public License for more details.
  */
 
+#include <linux/clk.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
-
+#include <sound/pcm_params.h>
 #include <sound/soc.h>
 
 #include "i2s.h"
 
 #define FIN_PLL_RATE		24000000
 
-static struct snd_soc_dai_link snow_dai[] = {
-	{
-		.name = "Primary",
-		.stream_name = "Primary",
-		.codec_dai_name = "HiFi",
-		.dai_fmt = SND_SOC_DAIFMT_I2S |
-				SND_SOC_DAIFMT_NB_NF |
-				SND_SOC_DAIFMT_CBS_CFS,
-	},
+struct snow_priv {
+	struct snd_soc_dai_link dai_link;
+	struct clk *clk_i2s_bus;
+};
+
+static int snow_card_hw_params(struct snd_pcm_substream *substream,
+				      struct snd_pcm_hw_params *params)
+{
+	static const unsigned int pll_rate[] = {
+		73728000U, 67737602U, 49152000U, 45158401U, 32768001U
+	};
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snow_priv *priv = snd_soc_card_get_drvdata(rtd->card);
+	int bfs, psr, rfs, bitwidth;
+	unsigned long int rclk;
+	long int freq = -EINVAL;
+	int ret, i;
+
+	bitwidth = snd_pcm_format_width(params_format(params));
+	if (bitwidth < 0) {
+		dev_err(rtd->card->dev, "Invalid bit-width: %d\n", bitwidth);
+		return bitwidth;
+	}
+
+	if (bitwidth != 16 && bitwidth != 24) {
+		dev_err(rtd->card->dev, "Unsupported bit-width: %d\n", bitwidth);
+		return -EINVAL;
+	}
+
+	bfs = 2 * bitwidth;
+
+	switch (params_rate(params)) {
+	case 16000:
+	case 22050:
+	case 24000:
+	case 32000:
+	case 44100:
+	case 48000:
+	case 88200:
+	case 96000:
+		rfs = 8 * bfs;
+		break;
+	case 64000:
+		rfs = 384;
+		break;
+	case 8000:
+	case 11025:
+	case 12000:
+		rfs = 16 * bfs;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	rclk = params_rate(params) * rfs;
+
+	for (psr = 8; psr > 0; psr /= 2) {
+		for (i = 0; i < ARRAY_SIZE(pll_rate); i++) {
+			if ((pll_rate[i] - rclk * psr) <= 2) {
+				freq = pll_rate[i];
+				break;
+			}
+		}
+	}
+	if (freq < 0) {
+		dev_err(rtd->card->dev, "Unsupported RCLK rate: %lu\n", rclk);
+		return -EINVAL;
+	}
+
+	ret = clk_set_rate(priv->clk_i2s_bus, freq);
+	if (ret < 0) {
+		dev_err(rtd->card->dev, "I2S bus clock rate set failed\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct snd_soc_ops snow_card_ops = {
+	.hw_params = snow_card_hw_params,
 };
 
 static int snow_late_probe(struct snd_soc_card *card)
 {
 	struct snd_soc_pcm_runtime *rtd;
 	struct snd_soc_dai *codec_dai;
-	struct snd_soc_dai *cpu_dai;
-	int ret;
 
 	rtd = snd_soc_get_pcm_runtime(card, card->dai_link[0].name);
-	codec_dai = rtd->codec_dai;
-	cpu_dai = rtd->cpu_dai;
-
-	/* Set the MCLK rate for the codec */
-	ret = snd_soc_dai_set_sysclk(codec_dai, 0,
-					FIN_PLL_RATE, SND_SOC_CLOCK_IN);
-	if (ret < 0)
-		return ret;
 
+	/* In the multi-codec case codec_dais 0 is MAX98095 and 1 is HDMI. */
+	if (rtd->num_codecs > 1)
+		codec_dai = rtd->codec_dais[0];
+	else
+		codec_dai = rtd->codec_dai;
 
-	return 0;
+	/* Set the MCLK rate for the codec */
+	return snd_soc_dai_set_sysclk(codec_dai, 0,
+				FIN_PLL_RATE, SND_SOC_CLOCK_IN);
 }
 
 static struct snd_soc_card snow_snd = {
 	.name = "Snow-I2S",
 	.owner = THIS_MODULE,
-	.dai_link = snow_dai,
-	.num_links = ARRAY_SIZE(snow_dai),
-
 	.late_probe = snow_late_probe,
 };
 
 static int snow_probe(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
 	struct snd_soc_card *card = &snow_snd;
-	struct device_node *i2s_node, *codec_node;
-	int i, ret;
-
-	i2s_node = of_parse_phandle(pdev->dev.of_node,
-				    "samsung,i2s-controller", 0);
-	if (!i2s_node) {
-		dev_err(&pdev->dev,
-			"Property 'i2s-controller' missing or invalid\n");
-		return -EINVAL;
-	}
+	struct device_node *cpu, *codec;
+	struct snd_soc_dai_link *link;
+	struct snow_priv *priv;
+	int ret;
 
-	codec_node = of_parse_phandle(pdev->dev.of_node,
-				      "samsung,audio-codec", 0);
-	if (!codec_node) {
-		dev_err(&pdev->dev,
-			"Property 'audio-codec' missing or invalid\n");
-		return -EINVAL;
-	}
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	link = &priv->dai_link;
+
+	link->dai_fmt = SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_NB_NF |
+			SND_SOC_DAIFMT_CBS_CFS;
+
+	link->name = "Primary";
+	link->stream_name = link->name;
+
+	card->dai_link = link;
+	card->num_links = 1;
+	card->dev = dev;
+
+	/* Try new DT bindings with HDMI support first. */
+	cpu = of_get_child_by_name(dev->of_node, "cpu");
+
+	if (cpu) {
+		link->ops = &snow_card_ops;
 
-	for (i = 0; i < ARRAY_SIZE(snow_dai); i++) {
-		snow_dai[i].codec_of_node = codec_node;
-		snow_dai[i].cpu_of_node = i2s_node;
-		snow_dai[i].platform_of_node = i2s_node;
+		link->cpu_of_node = of_parse_phandle(cpu, "sound-dai", 0);
+		of_node_put(cpu);
+
+		if (!link->cpu_of_node) {
+			dev_err(dev, "Failed parsing cpu/sound-dai property\n");
+			return -EINVAL;
+		}
+
+		codec = of_get_child_by_name(dev->of_node, "codec");
+		ret = snd_soc_of_get_dai_link_codecs(dev, codec, link);
+		of_node_put(codec);
+
+		if (ret < 0) {
+			of_node_put(link->cpu_of_node);
+			dev_err(dev, "Failed parsing codec node\n");
+			return ret;
+		}
+
+		priv->clk_i2s_bus = of_clk_get_by_name(link->cpu_of_node,
+						       "i2s_opclk0");
+		if (IS_ERR(priv->clk_i2s_bus)) {
+			snd_soc_of_put_dai_link_codecs(link);
+			of_node_put(link->cpu_of_node);
+			return PTR_ERR(priv->clk_i2s_bus);
+		}
+	} else {
+		link->codec_dai_name = "HiFi",
+
+		link->cpu_of_node = of_parse_phandle(dev->of_node,
+						"samsung,i2s-controller", 0);
+		if (!link->cpu_of_node) {
+			dev_err(dev, "i2s-controller property parse error\n");
+			return -EINVAL;
+		}
+
+		link->codec_of_node = of_parse_phandle(dev->of_node,
+						"samsung,audio-codec", 0);
+		if (!link->codec_of_node) {
+			of_node_put(link->cpu_of_node);
+			dev_err(dev, "audio-codec property parse error\n");
+			return -EINVAL;
+		}
 	}
 
-	card->dev = &pdev->dev;
+	link->platform_of_node = link->cpu_of_node;
 
 	/* Update card-name if provided through DT, else use default name */
 	snd_soc_of_parse_card_name(card, "samsung,model");
 
-	ret = devm_snd_soc_register_card(&pdev->dev, card);
+	snd_soc_card_set_drvdata(card, priv);
+
+	ret = devm_snd_soc_register_card(dev, card);
 	if (ret) {
 		dev_err(&pdev->dev, "snd_soc_register_card failed (%d)\n", ret);
 		return ret;
@@ -105,6 +220,20 @@ static int snow_probe(struct platform_device *pdev)
 	return ret;
 }
 
+static int snow_remove(struct platform_device *pdev)
+{
+	struct snow_priv *priv = platform_get_drvdata(pdev);
+	struct snd_soc_dai_link *link = &priv->dai_link;
+
+	of_node_put(link->cpu_of_node);
+	of_node_put(link->codec_of_node);
+	snd_soc_of_put_dai_link_codecs(link);
+
+	clk_put(priv->clk_i2s_bus);
+
+	return 0;
+}
+
 static const struct of_device_id snow_of_match[] = {
 	{ .compatible = "google,snow-audio-max98090", },
 	{ .compatible = "google,snow-audio-max98091", },
@@ -120,6 +249,7 @@ static struct platform_driver snow_driver = {
 		.of_match_table = snow_of_match,
 	},
 	.probe = snow_probe,
+	.remove = snow_remove,
 };
 
 module_platform_driver(snow_driver);
-- 
2.14.2

Re: [PATCH v3 2/2] ASoC: samsung: Add HDMI audio support for Snow

[Sylwester Nawrocki]

On 03/12/2018 07:49 PM, Sylwester Nawrocki wrote:
> This patch updates the driver so, in addition to current DT bindings, it
> also can also use the new DT bindings with cpu, codec subnodes which allow
> to support sound on the HDMI interface.
> 
> Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>

I've forgotten to add Krzysztof's tag:

Acked-by: Krzysztof Kozlowski <krzk@kernel.org>

Re: [PATCH v3 2/2] ASoC: samsung: Add HDMI audio support for Snow

[Krzysztof Kozlowski]

On Mon, Mar 12, 2018 at 7:54 PM, Sylwester Nawrocki
<s.nawrocki@samsung.com> wrote:
> On 03/12/2018 07:49 PM, Sylwester Nawrocki wrote:
>> This patch updates the driver so, in addition to current DT bindings, it
>> also can also use the new DT bindings with cpu, codec subnodes which allow
>> to support sound on the HDMI interface.
>>
>> Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
>
> I've forgotten to add Krzysztof's tag:
>
> Acked-by: Krzysztof Kozlowski <krzk@kernel.org>

Yes, thanks :)

Best regards,
Krzysztof

Applied "ASoC: samsung: Add HDMI audio support for Snow" to the asoc tree

[Mark Brown]

The patch

   ASoC: samsung: Add HDMI audio support for Snow

has been applied to the asoc tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From aff8d2bed9e5a33f40611063de62003c0f3abe9f Mon Sep 17 00:00:00 2001
From: Sylwester Nawrocki <s.nawrocki@samsung.com>
Date: Mon, 12 Mar 2018 19:49:39 +0100
Subject: [PATCH] ASoC: samsung: Add HDMI audio support for Snow

This patch updates the driver so, in addition to current DT bindings, it
also can also use the new DT bindings with cpu, codec subnodes which allow
to support sound on the HDMI interface.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 sound/soc/samsung/snow.c | 224 +++++++++++++++++++++++++++++++++++++----------
 1 file changed, 177 insertions(+), 47 deletions(-)

diff --git a/sound/soc/samsung/snow.c b/sound/soc/samsung/snow.c
index fc62110f500f..5d8efc2d5c38 100644
--- a/sound/soc/samsung/snow.c
+++ b/sound/soc/samsung/snow.c
@@ -11,92 +11,207 @@
  * General Public License for more details.
  */
 
+#include <linux/clk.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
-
+#include <sound/pcm_params.h>
 #include <sound/soc.h>
 
 #include "i2s.h"
 
 #define FIN_PLL_RATE		24000000
 
-static struct snd_soc_dai_link snow_dai[] = {
-	{
-		.name = "Primary",
-		.stream_name = "Primary",
-		.codec_dai_name = "HiFi",
-		.dai_fmt = SND_SOC_DAIFMT_I2S |
-				SND_SOC_DAIFMT_NB_NF |
-				SND_SOC_DAIFMT_CBS_CFS,
-	},
+struct snow_priv {
+	struct snd_soc_dai_link dai_link;
+	struct clk *clk_i2s_bus;
+};
+
+static int snow_card_hw_params(struct snd_pcm_substream *substream,
+				      struct snd_pcm_hw_params *params)
+{
+	static const unsigned int pll_rate[] = {
+		73728000U, 67737602U, 49152000U, 45158401U, 32768001U
+	};
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snow_priv *priv = snd_soc_card_get_drvdata(rtd->card);
+	int bfs, psr, rfs, bitwidth;
+	unsigned long int rclk;
+	long int freq = -EINVAL;
+	int ret, i;
+
+	bitwidth = snd_pcm_format_width(params_format(params));
+	if (bitwidth < 0) {
+		dev_err(rtd->card->dev, "Invalid bit-width: %d\n", bitwidth);
+		return bitwidth;
+	}
+
+	if (bitwidth != 16 && bitwidth != 24) {
+		dev_err(rtd->card->dev, "Unsupported bit-width: %d\n", bitwidth);
+		return -EINVAL;
+	}
+
+	bfs = 2 * bitwidth;
+
+	switch (params_rate(params)) {
+	case 16000:
+	case 22050:
+	case 24000:
+	case 32000:
+	case 44100:
+	case 48000:
+	case 88200:
+	case 96000:
+		rfs = 8 * bfs;
+		break;
+	case 64000:
+		rfs = 384;
+		break;
+	case 8000:
+	case 11025:
+	case 12000:
+		rfs = 16 * bfs;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	rclk = params_rate(params) * rfs;
+
+	for (psr = 8; psr > 0; psr /= 2) {
+		for (i = 0; i < ARRAY_SIZE(pll_rate); i++) {
+			if ((pll_rate[i] - rclk * psr) <= 2) {
+				freq = pll_rate[i];
+				break;
+			}
+		}
+	}
+	if (freq < 0) {
+		dev_err(rtd->card->dev, "Unsupported RCLK rate: %lu\n", rclk);
+		return -EINVAL;
+	}
+
+	ret = clk_set_rate(priv->clk_i2s_bus, freq);
+	if (ret < 0) {
+		dev_err(rtd->card->dev, "I2S bus clock rate set failed\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct snd_soc_ops snow_card_ops = {
+	.hw_params = snow_card_hw_params,
 };
 
 static int snow_late_probe(struct snd_soc_card *card)
 {
 	struct snd_soc_pcm_runtime *rtd;
 	struct snd_soc_dai *codec_dai;
-	struct snd_soc_dai *cpu_dai;
-	int ret;
 
 	rtd = snd_soc_get_pcm_runtime(card, card->dai_link[0].name);
-	codec_dai = rtd->codec_dai;
-	cpu_dai = rtd->cpu_dai;
-
-	/* Set the MCLK rate for the codec */
-	ret = snd_soc_dai_set_sysclk(codec_dai, 0,
-					FIN_PLL_RATE, SND_SOC_CLOCK_IN);
-	if (ret < 0)
-		return ret;
 
+	/* In the multi-codec case codec_dais 0 is MAX98095 and 1 is HDMI. */
+	if (rtd->num_codecs > 1)
+		codec_dai = rtd->codec_dais[0];
+	else
+		codec_dai = rtd->codec_dai;
 
-	return 0;
+	/* Set the MCLK rate for the codec */
+	return snd_soc_dai_set_sysclk(codec_dai, 0,
+				FIN_PLL_RATE, SND_SOC_CLOCK_IN);
 }
 
 static struct snd_soc_card snow_snd = {
 	.name = "Snow-I2S",
 	.owner = THIS_MODULE,
-	.dai_link = snow_dai,
-	.num_links = ARRAY_SIZE(snow_dai),
-
 	.late_probe = snow_late_probe,
 };
 
 static int snow_probe(struct platform_device *pdev)
 {
+	struct device *dev = &pdev->dev;
 	struct snd_soc_card *card = &snow_snd;
-	struct device_node *i2s_node, *codec_node;
-	int i, ret;
-
-	i2s_node = of_parse_phandle(pdev->dev.of_node,
-				    "samsung,i2s-controller", 0);
-	if (!i2s_node) {
-		dev_err(&pdev->dev,
-			"Property 'i2s-controller' missing or invalid\n");
-		return -EINVAL;
-	}
+	struct device_node *cpu, *codec;
+	struct snd_soc_dai_link *link;
+	struct snow_priv *priv;
+	int ret;
 
-	codec_node = of_parse_phandle(pdev->dev.of_node,
-				      "samsung,audio-codec", 0);
-	if (!codec_node) {
-		dev_err(&pdev->dev,
-			"Property 'audio-codec' missing or invalid\n");
-		return -EINVAL;
-	}
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	link = &priv->dai_link;
+
+	link->dai_fmt = SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_NB_NF |
+			SND_SOC_DAIFMT_CBS_CFS;
+
+	link->name = "Primary";
+	link->stream_name = link->name;
+
+	card->dai_link = link;
+	card->num_links = 1;
+	card->dev = dev;
+
+	/* Try new DT bindings with HDMI support first. */
+	cpu = of_get_child_by_name(dev->of_node, "cpu");
+
+	if (cpu) {
+		link->ops = &snow_card_ops;
 
-	for (i = 0; i < ARRAY_SIZE(snow_dai); i++) {
-		snow_dai[i].codec_of_node = codec_node;
-		snow_dai[i].cpu_of_node = i2s_node;
-		snow_dai[i].platform_of_node = i2s_node;
+		link->cpu_of_node = of_parse_phandle(cpu, "sound-dai", 0);
+		of_node_put(cpu);
+
+		if (!link->cpu_of_node) {
+			dev_err(dev, "Failed parsing cpu/sound-dai property\n");
+			return -EINVAL;
+		}
+
+		codec = of_get_child_by_name(dev->of_node, "codec");
+		ret = snd_soc_of_get_dai_link_codecs(dev, codec, link);
+		of_node_put(codec);
+
+		if (ret < 0) {
+			of_node_put(link->cpu_of_node);
+			dev_err(dev, "Failed parsing codec node\n");
+			return ret;
+		}
+
+		priv->clk_i2s_bus = of_clk_get_by_name(link->cpu_of_node,
+						       "i2s_opclk0");
+		if (IS_ERR(priv->clk_i2s_bus)) {
+			snd_soc_of_put_dai_link_codecs(link);
+			of_node_put(link->cpu_of_node);
+			return PTR_ERR(priv->clk_i2s_bus);
+		}
+	} else {
+		link->codec_dai_name = "HiFi",
+
+		link->cpu_of_node = of_parse_phandle(dev->of_node,
+						"samsung,i2s-controller", 0);
+		if (!link->cpu_of_node) {
+			dev_err(dev, "i2s-controller property parse error\n");
+			return -EINVAL;
+		}
+
+		link->codec_of_node = of_parse_phandle(dev->of_node,
+						"samsung,audio-codec", 0);
+		if (!link->codec_of_node) {
+			of_node_put(link->cpu_of_node);
+			dev_err(dev, "audio-codec property parse error\n");
+			return -EINVAL;
+		}
 	}
 
-	card->dev = &pdev->dev;
+	link->platform_of_node = link->cpu_of_node;
 
 	/* Update card-name if provided through DT, else use default name */
 	snd_soc_of_parse_card_name(card, "samsung,model");
 
-	ret = devm_snd_soc_register_card(&pdev->dev, card);
+	snd_soc_card_set_drvdata(card, priv);
+
+	ret = devm_snd_soc_register_card(dev, card);
 	if (ret) {
 		dev_err(&pdev->dev, "snd_soc_register_card failed (%d)\n", ret);
 		return ret;
@@ -105,6 +220,20 @@ static int snow_probe(struct platform_device *pdev)
 	return ret;
 }
 
+static int snow_remove(struct platform_device *pdev)
+{
+	struct snow_priv *priv = platform_get_drvdata(pdev);
+	struct snd_soc_dai_link *link = &priv->dai_link;
+
+	of_node_put(link->cpu_of_node);
+	of_node_put(link->codec_of_node);
+	snd_soc_of_put_dai_link_codecs(link);
+
+	clk_put(priv->clk_i2s_bus);
+
+	return 0;
+}
+
 static const struct of_device_id snow_of_match[] = {
 	{ .compatible = "google,snow-audio-max98090", },
 	{ .compatible = "google,snow-audio-max98091", },
@@ -120,6 +249,7 @@ static struct platform_driver snow_driver = {
 		.of_match_table = snow_of_match,
 	},
 	.probe = snow_probe,
+	.remove = snow_remove,
 };
 
 module_platform_driver(snow_driver);
-- 
2.16.2