1 files changed, 637 insertions, 0 deletions

diff --git a/sound/soc/atmel/atmel-classd.c b/sound/soc/atmel/atmel-classd.c
new file mode 100644
index 000000000..87d6d6ed0
--- /dev/null
+++ b/sound/soc/atmel/atmel-classd.c
@@ -0,0 +1,637 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Atmel ALSA SoC Audio Class D Amplifier (CLASSD) driver
+ *
+ * Copyright (C) 2015 Atmel
+ *
+ * Author: Songjun Wu <songjun.wu@atmel.com>
+ */
+
+#include <linux/of.h>
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <sound/core.h>
+#include <sound/dmaengine_pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/tlv.h>
+#include "atmel-classd.h"
+
+struct atmel_classd_pdata {
+	bool non_overlap_enable;
+	int non_overlap_time;
+	int pwm_type;
+	const char *card_name;
+};
+
+struct atmel_classd {
+	dma_addr_t phy_base;
+	struct regmap *regmap;
+	struct clk *pclk;
+	struct clk *gclk;
+	struct device *dev;
+	int irq;
+	const struct atmel_classd_pdata *pdata;
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id atmel_classd_of_match[] = {
+	{
+		.compatible = "atmel,sama5d2-classd",
+	}, {
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(of, atmel_classd_of_match);
+
+static struct atmel_classd_pdata *atmel_classd_dt_init(struct device *dev)
+{
+	struct device_node *np = dev->of_node;
+	struct atmel_classd_pdata *pdata;
+	const char *pwm_type_s;
+	int ret;
+
+	if (!np) {
+		dev_err(dev, "device node not found\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return ERR_PTR(-ENOMEM);
+
+	ret = of_property_read_string(np, "atmel,pwm-type", &pwm_type_s);
+	if ((ret == 0) && (strcmp(pwm_type_s, "diff") == 0))
+		pdata->pwm_type = CLASSD_MR_PWMTYP_DIFF;
+	else
+		pdata->pwm_type = CLASSD_MR_PWMTYP_SINGLE;
+
+	ret = of_property_read_u32(np,
+			"atmel,non-overlap-time", &pdata->non_overlap_time);
+	if (ret)
+		pdata->non_overlap_enable = false;
+	else
+		pdata->non_overlap_enable = true;
+
+	ret = of_property_read_string(np, "atmel,model", &pdata->card_name);
+	if (ret)
+		pdata->card_name = "CLASSD";
+
+	return pdata;
+}
+#else
+static inline struct atmel_classd_pdata *
+atmel_classd_dt_init(struct device *dev)
+{
+	return ERR_PTR(-EINVAL);
+}
+#endif
+
+#define ATMEL_CLASSD_RATES (SNDRV_PCM_RATE_8000 \
+			| SNDRV_PCM_RATE_16000	| SNDRV_PCM_RATE_22050 \
+			| SNDRV_PCM_RATE_32000	| SNDRV_PCM_RATE_44100 \
+			| SNDRV_PCM_RATE_48000	| SNDRV_PCM_RATE_88200 \
+			| SNDRV_PCM_RATE_96000)
+
+static const struct snd_pcm_hardware atmel_classd_hw = {
+	.info			= SNDRV_PCM_INFO_MMAP
+				| SNDRV_PCM_INFO_MMAP_VALID
+				| SNDRV_PCM_INFO_INTERLEAVED
+				| SNDRV_PCM_INFO_RESUME
+				| SNDRV_PCM_INFO_PAUSE,
+	.formats		= (SNDRV_PCM_FMTBIT_S16_LE),
+	.rates			= ATMEL_CLASSD_RATES,
+	.rate_min		= 8000,
+	.rate_max		= 96000,
+	.channels_min		= 1,
+	.channels_max		= 2,
+	.buffer_bytes_max	= 64 * 1024,
+	.period_bytes_min	= 256,
+	.period_bytes_max	= 32 * 1024,
+	.periods_min		= 2,
+	.periods_max		= 256,
+};
+
+#define ATMEL_CLASSD_PREALLOC_BUF_SIZE  (64 * 1024)
+
+/* cpu dai component */
+static int atmel_classd_cpu_dai_startup(struct snd_pcm_substream *substream,
+					struct snd_soc_dai *cpu_dai)
+{
+	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+	struct atmel_classd *dd = snd_soc_card_get_drvdata(rtd->card);
+	int err;
+
+	regmap_write(dd->regmap, CLASSD_THR, 0x0);
+
+	err = clk_prepare_enable(dd->pclk);
+	if (err)
+		return err;
+	err = clk_prepare_enable(dd->gclk);
+	if (err) {
+		clk_disable_unprepare(dd->pclk);
+		return err;
+	}
+	return 0;
+}
+
+/* platform */
+static int
+atmel_classd_platform_configure_dma(struct snd_pcm_substream *substream,
+	struct snd_pcm_hw_params *params,
+	struct dma_slave_config *slave_config)
+{
+	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+	struct atmel_classd *dd = snd_soc_card_get_drvdata(rtd->card);
+
+	if (params_physical_width(params) != 16) {
+		dev_err(dd->dev,
+			"only supports 16-bit audio data\n");
+		return -EINVAL;
+	}
+
+	if (params_channels(params) == 1)
+		slave_config->dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
+	else
+		slave_config->dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+
+	slave_config->direction		= DMA_MEM_TO_DEV;
+	slave_config->dst_addr		= dd->phy_base + CLASSD_THR;
+	slave_config->dst_maxburst	= 1;
+	slave_config->src_maxburst	= 1;
+	slave_config->device_fc		= false;
+
+	return 0;
+}
+
+static const struct snd_dmaengine_pcm_config
+atmel_classd_dmaengine_pcm_config = {
+	.prepare_slave_config	= atmel_classd_platform_configure_dma,
+	.pcm_hardware		= &atmel_classd_hw,
+	.prealloc_buffer_size	= ATMEL_CLASSD_PREALLOC_BUF_SIZE,
+};
+
+/* codec */
+static const char * const mono_mode_text[] = {
+	"mix", "sat", "left", "right"
+};
+
+static SOC_ENUM_SINGLE_DECL(classd_mono_mode_enum,
+			CLASSD_INTPMR, CLASSD_INTPMR_MONO_MODE_SHIFT,
+			mono_mode_text);
+
+static const char * const eqcfg_text[] = {
+	"Treble-12dB", "Treble-6dB",
+	"Medium-8dB", "Medium-3dB",
+	"Bass-12dB", "Bass-6dB",
+	"0 dB",
+	"Bass+6dB", "Bass+12dB",
+	"Medium+3dB", "Medium+8dB",
+	"Treble+6dB", "Treble+12dB",
+};
+
+static const unsigned int eqcfg_value[] = {
+	CLASSD_INTPMR_EQCFG_T_CUT_12, CLASSD_INTPMR_EQCFG_T_CUT_6,
+	CLASSD_INTPMR_EQCFG_M_CUT_8, CLASSD_INTPMR_EQCFG_M_CUT_3,
+	CLASSD_INTPMR_EQCFG_B_CUT_12, CLASSD_INTPMR_EQCFG_B_CUT_6,
+	CLASSD_INTPMR_EQCFG_FLAT,
+	CLASSD_INTPMR_EQCFG_B_BOOST_6, CLASSD_INTPMR_EQCFG_B_BOOST_12,
+	CLASSD_INTPMR_EQCFG_M_BOOST_3, CLASSD_INTPMR_EQCFG_M_BOOST_8,
+	CLASSD_INTPMR_EQCFG_T_BOOST_6, CLASSD_INTPMR_EQCFG_T_BOOST_12,
+};
+
+static SOC_VALUE_ENUM_SINGLE_DECL(classd_eqcfg_enum,
+		CLASSD_INTPMR, CLASSD_INTPMR_EQCFG_SHIFT, 0xf,
+		eqcfg_text, eqcfg_value);
+
+static const DECLARE_TLV_DB_SCALE(classd_digital_tlv, -7800, 100, 1);
+
+static const struct snd_kcontrol_new atmel_classd_snd_controls[] = {
+SOC_DOUBLE_TLV("Playback Volume", CLASSD_INTPMR,
+		CLASSD_INTPMR_ATTL_SHIFT, CLASSD_INTPMR_ATTR_SHIFT,
+		78, 1, classd_digital_tlv),
+
+SOC_SINGLE("Deemphasis Switch", CLASSD_INTPMR,
+		CLASSD_INTPMR_DEEMP_SHIFT, 1, 0),
+
+SOC_SINGLE("Mono Switch", CLASSD_INTPMR, CLASSD_INTPMR_MONO_SHIFT, 1, 0),
+
+SOC_SINGLE("Swap Switch", CLASSD_INTPMR, CLASSD_INTPMR_SWAP_SHIFT, 1, 0),
+
+SOC_ENUM("Mono Mode", classd_mono_mode_enum),
+
+SOC_ENUM("EQ", classd_eqcfg_enum),
+};
+
+static const char * const pwm_type[] = {
+	"Single ended", "Differential"
+};
+
+static int atmel_classd_component_probe(struct snd_soc_component *component)
+{
+	struct snd_soc_card *card = snd_soc_component_get_drvdata(component);
+	struct atmel_classd *dd = snd_soc_card_get_drvdata(card);
+	const struct atmel_classd_pdata *pdata = dd->pdata;
+	u32 mask, val;
+
+	mask = CLASSD_MR_PWMTYP_MASK;
+	val = pdata->pwm_type << CLASSD_MR_PWMTYP_SHIFT;
+
+	mask |= CLASSD_MR_NON_OVERLAP_MASK;
+	if (pdata->non_overlap_enable) {
+		val |= (CLASSD_MR_NON_OVERLAP_EN
+			<< CLASSD_MR_NON_OVERLAP_SHIFT);
+
+		mask |= CLASSD_MR_NOVR_VAL_MASK;
+		switch (pdata->non_overlap_time) {
+		case 5:
+			val |= (CLASSD_MR_NOVR_VAL_5NS
+				<< CLASSD_MR_NOVR_VAL_SHIFT);
+			break;
+		case 10:
+			val |= (CLASSD_MR_NOVR_VAL_10NS
+				<< CLASSD_MR_NOVR_VAL_SHIFT);
+			break;
+		case 15:
+			val |= (CLASSD_MR_NOVR_VAL_15NS
+				<< CLASSD_MR_NOVR_VAL_SHIFT);
+			break;
+		case 20:
+			val |= (CLASSD_MR_NOVR_VAL_20NS
+				<< CLASSD_MR_NOVR_VAL_SHIFT);
+			break;
+		default:
+			val |= (CLASSD_MR_NOVR_VAL_10NS
+				<< CLASSD_MR_NOVR_VAL_SHIFT);
+			dev_warn(component->dev,
+				"non-overlapping value %d is invalid, the default value 10 is specified\n",
+				pdata->non_overlap_time);
+			break;
+		}
+	}
+
+	snd_soc_component_update_bits(component, CLASSD_MR, mask, val);
+
+	dev_info(component->dev,
+		"PWM modulation type is %s, non-overlapping is %s\n",
+		pwm_type[pdata->pwm_type],
+		pdata->non_overlap_enable?"enabled":"disabled");
+
+	return 0;
+}
+
+static int atmel_classd_component_resume(struct snd_soc_component *component)
+{
+	struct snd_soc_card *card = snd_soc_component_get_drvdata(component);
+	struct atmel_classd *dd = snd_soc_card_get_drvdata(card);
+
+	return regcache_sync(dd->regmap);
+}
+
+static int atmel_classd_cpu_dai_mute_stream(struct snd_soc_dai *cpu_dai,
+					    int mute, int direction)
+{
+	struct snd_soc_component *component = cpu_dai->component;
+	u32 mask, val;
+
+	mask = CLASSD_MR_LMUTE_MASK | CLASSD_MR_RMUTE_MASK;
+
+	if (mute)
+		val = mask;
+	else
+		val = 0;
+
+	snd_soc_component_update_bits(component, CLASSD_MR, mask, val);
+
+	return 0;
+}
+
+#define CLASSD_GCLK_RATE_11M2896_MPY_8 (112896 * 100 * 8)
+#define CLASSD_GCLK_RATE_12M288_MPY_8  (12288 * 1000 * 8)
+
+static struct {
+	int rate;
+	int sample_rate;
+	int dsp_clk;
+	unsigned long gclk_rate;
+} const sample_rates[] = {
+	{ 8000,  CLASSD_INTPMR_FRAME_8K,
+	CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_GCLK_RATE_12M288_MPY_8 },
+	{ 16000, CLASSD_INTPMR_FRAME_16K,
+	CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_GCLK_RATE_12M288_MPY_8 },
+	{ 32000, CLASSD_INTPMR_FRAME_32K,
+	CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_GCLK_RATE_12M288_MPY_8 },
+	{ 48000, CLASSD_INTPMR_FRAME_48K,
+	CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_GCLK_RATE_12M288_MPY_8 },
+	{ 96000, CLASSD_INTPMR_FRAME_96K,
+	CLASSD_INTPMR_DSP_CLK_FREQ_12M288, CLASSD_GCLK_RATE_12M288_MPY_8 },
+	{ 22050, CLASSD_INTPMR_FRAME_22K,
+	CLASSD_INTPMR_DSP_CLK_FREQ_11M2896, CLASSD_GCLK_RATE_11M2896_MPY_8 },
+	{ 44100, CLASSD_INTPMR_FRAME_44K,
+	CLASSD_INTPMR_DSP_CLK_FREQ_11M2896, CLASSD_GCLK_RATE_11M2896_MPY_8 },
+	{ 88200, CLASSD_INTPMR_FRAME_88K,
+	CLASSD_INTPMR_DSP_CLK_FREQ_11M2896, CLASSD_GCLK_RATE_11M2896_MPY_8 },
+};
+
+static int
+atmel_classd_cpu_dai_hw_params(struct snd_pcm_substream *substream,
+			       struct snd_pcm_hw_params *params,
+			       struct snd_soc_dai *cpu_dai)
+{
+	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+	struct atmel_classd *dd = snd_soc_card_get_drvdata(rtd->card);
+	struct snd_soc_component *component = cpu_dai->component;
+	int fs;
+	int i, best, best_val, cur_val, ret;
+	u32 mask, val;
+
+	fs = params_rate(params);
+
+	best = 0;
+	best_val = abs(fs - sample_rates[0].rate);
+	for (i = 1; i < ARRAY_SIZE(sample_rates); i++) {
+		/* Closest match */
+		cur_val = abs(fs - sample_rates[i].rate);
+		if (cur_val < best_val) {
+			best = i;
+			best_val = cur_val;
+		}
+	}
+
+	dev_dbg(component->dev,
+		"Selected SAMPLE_RATE of %dHz, GCLK_RATE of %ldHz\n",
+		sample_rates[best].rate, sample_rates[best].gclk_rate);
+
+	clk_disable_unprepare(dd->gclk);
+
+	ret = clk_set_rate(dd->gclk, sample_rates[best].gclk_rate);
+	if (ret)
+		return ret;
+
+	mask = CLASSD_INTPMR_DSP_CLK_FREQ_MASK | CLASSD_INTPMR_FRAME_MASK;
+	val = (sample_rates[best].dsp_clk << CLASSD_INTPMR_DSP_CLK_FREQ_SHIFT)
+	| (sample_rates[best].sample_rate << CLASSD_INTPMR_FRAME_SHIFT);
+
+	snd_soc_component_update_bits(component, CLASSD_INTPMR, mask, val);
+
+	return clk_prepare_enable(dd->gclk);
+}
+
+static void
+atmel_classd_cpu_dai_shutdown(struct snd_pcm_substream *substream,
+			      struct snd_soc_dai *cpu_dai)
+{
+	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+	struct atmel_classd *dd = snd_soc_card_get_drvdata(rtd->card);
+
+	clk_disable_unprepare(dd->gclk);
+}
+
+static int atmel_classd_cpu_dai_prepare(struct snd_pcm_substream *substream,
+					struct snd_soc_dai *cpu_dai)
+{
+	struct snd_soc_component *component = cpu_dai->component;
+
+	snd_soc_component_update_bits(component, CLASSD_MR,
+				CLASSD_MR_LEN_MASK | CLASSD_MR_REN_MASK,
+				(CLASSD_MR_LEN_DIS << CLASSD_MR_LEN_SHIFT)
+				|(CLASSD_MR_REN_DIS << CLASSD_MR_REN_SHIFT));
+
+	return 0;
+}
+
+static int atmel_classd_cpu_dai_trigger(struct snd_pcm_substream *substream,
+					int cmd, struct snd_soc_dai *cpu_dai)
+{
+	struct snd_soc_component *component = cpu_dai->component;
+	u32 mask, val;
+
+	mask = CLASSD_MR_LEN_MASK | CLASSD_MR_REN_MASK;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		val = mask;
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		val = (CLASSD_MR_LEN_DIS << CLASSD_MR_LEN_SHIFT)
+			| (CLASSD_MR_REN_DIS << CLASSD_MR_REN_SHIFT);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	snd_soc_component_update_bits(component, CLASSD_MR, mask, val);
+
+	return 0;
+}
+
+static const struct snd_soc_dai_ops atmel_classd_cpu_dai_ops = {
+	.startup        = atmel_classd_cpu_dai_startup,
+	.shutdown       = atmel_classd_cpu_dai_shutdown,
+	.mute_stream	= atmel_classd_cpu_dai_mute_stream,
+	.hw_params	= atmel_classd_cpu_dai_hw_params,
+	.prepare	= atmel_classd_cpu_dai_prepare,
+	.trigger	= atmel_classd_cpu_dai_trigger,
+	.no_capture_mute = 1,
+};
+
+static struct snd_soc_dai_driver atmel_classd_cpu_dai = {
+	.playback = {
+		.stream_name	= "Playback",
+		.channels_min	= 1,
+		.channels_max	= 2,
+		.rates		= ATMEL_CLASSD_RATES,
+		.formats	= SNDRV_PCM_FMTBIT_S16_LE,
+	},
+	.ops = &atmel_classd_cpu_dai_ops,
+};
+
+static const struct snd_soc_component_driver atmel_classd_cpu_dai_component = {
+	.name			= "atmel-classd",
+	.probe			= atmel_classd_component_probe,
+	.resume			= atmel_classd_component_resume,
+	.controls		= atmel_classd_snd_controls,
+	.num_controls		= ARRAY_SIZE(atmel_classd_snd_controls),
+	.idle_bias_on		= 1,
+	.use_pmdown_time	= 1,
+	.legacy_dai_naming	= 1,
+};
+
+/* ASoC sound card */
+static int atmel_classd_asoc_card_init(struct device *dev,
+					struct snd_soc_card *card)
+{
+	struct snd_soc_dai_link *dai_link;
+	struct atmel_classd *dd = snd_soc_card_get_drvdata(card);
+	struct snd_soc_dai_link_component *comp;
+
+	dai_link = devm_kzalloc(dev, sizeof(*dai_link), GFP_KERNEL);
+	if (!dai_link)
+		return -ENOMEM;
+
+	comp = devm_kzalloc(dev, 3 * sizeof(*comp), GFP_KERNEL);
+	if (!comp)
+		return -ENOMEM;
+
+	dai_link->cpus		= &comp[0];
+	dai_link->codecs	= &comp[1];
+	dai_link->platforms	= &comp[2];
+
+	dai_link->num_cpus	= 1;
+	dai_link->num_codecs	= 1;
+	dai_link->num_platforms	= 1;
+
+	dai_link->name			= "CLASSD";
+	dai_link->stream_name		= "CLASSD PCM";
+	dai_link->codecs->dai_name	= "snd-soc-dummy-dai";
+	dai_link->cpus->dai_name	= dev_name(dev);
+	dai_link->codecs->name		= "snd-soc-dummy";
+	dai_link->platforms->name	= dev_name(dev);
+
+	card->dai_link	= dai_link;
+	card->num_links	= 1;
+	card->name	= dd->pdata->card_name;
+	card->dev	= dev;
+
+	return 0;
+};
+
+/* regmap configuration */
+static const struct reg_default atmel_classd_reg_defaults[] = {
+	{ CLASSD_INTPMR,   0x00301212 },
+};
+
+#define ATMEL_CLASSD_REG_MAX    0xE4
+static const struct regmap_config atmel_classd_regmap_config = {
+	.reg_bits	= 32,
+	.reg_stride	= 4,
+	.val_bits	= 32,
+	.max_register	= ATMEL_CLASSD_REG_MAX,
+
+	.cache_type		= REGCACHE_FLAT,
+	.reg_defaults		= atmel_classd_reg_defaults,
+	.num_reg_defaults	= ARRAY_SIZE(atmel_classd_reg_defaults),
+};
+
+static int atmel_classd_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct atmel_classd *dd;
+	struct resource *res;
+	void __iomem *io_base;
+	const struct atmel_classd_pdata *pdata;
+	struct snd_soc_card *card;
+	int ret;
+
+	pdata = dev_get_platdata(dev);
+	if (!pdata) {
+		pdata = atmel_classd_dt_init(dev);
+		if (IS_ERR(pdata))
+			return PTR_ERR(pdata);
+	}
+
+	dd = devm_kzalloc(dev, sizeof(*dd), GFP_KERNEL);
+	if (!dd)
+		return -ENOMEM;
+
+	dd->pdata = pdata;
+
+	dd->irq = platform_get_irq(pdev, 0);
+	if (dd->irq < 0)
+		return dd->irq;
+
+	dd->pclk = devm_clk_get(dev, "pclk");
+	if (IS_ERR(dd->pclk)) {
+		ret = PTR_ERR(dd->pclk);
+		dev_err(dev, "failed to get peripheral clock: %d\n", ret);
+		return ret;
+	}
+
+	dd->gclk = devm_clk_get(dev, "gclk");
+	if (IS_ERR(dd->gclk)) {
+		ret = PTR_ERR(dd->gclk);
+		dev_err(dev, "failed to get GCK clock: %d\n", ret);
+		return ret;
+	}
+
+	io_base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(io_base))
+		return PTR_ERR(io_base);
+
+	dd->phy_base = res->start;
+	dd->dev = dev;
+
+	dd->regmap = devm_regmap_init_mmio(dev, io_base,
+					&atmel_classd_regmap_config);
+	if (IS_ERR(dd->regmap)) {
+		ret = PTR_ERR(dd->regmap);
+		dev_err(dev, "failed to init register map: %d\n", ret);
+		return ret;
+	}
+
+	ret = devm_snd_soc_register_component(dev,
+					&atmel_classd_cpu_dai_component,
+					&atmel_classd_cpu_dai, 1);
+	if (ret) {
+		dev_err(dev, "could not register CPU DAI: %d\n", ret);
+		return ret;
+	}
+
+	ret = devm_snd_dmaengine_pcm_register(dev,
+					&atmel_classd_dmaengine_pcm_config,
+					0);
+	if (ret) {
+		dev_err(dev, "could not register platform: %d\n", ret);
+		return ret;
+	}
+
+	/* register sound card */
+	card = devm_kzalloc(dev, sizeof(*card), GFP_KERNEL);
+	if (!card) {
+		ret = -ENOMEM;
+		goto unregister_codec;
+	}
+
+	snd_soc_card_set_drvdata(card, dd);
+
+	ret = atmel_classd_asoc_card_init(dev, card);
+	if (ret) {
+		dev_err(dev, "failed to init sound card\n");
+		goto unregister_codec;
+	}
+
+	ret = devm_snd_soc_register_card(dev, card);
+	if (ret) {
+		dev_err(dev, "failed to register sound card: %d\n", ret);
+		goto unregister_codec;
+	}
+
+	return 0;
+
+unregister_codec:
+	return ret;
+}
+
+static int atmel_classd_remove(struct platform_device *pdev)
+{
+	return 0;
+}
+
+static struct platform_driver atmel_classd_driver = {
+	.driver	= {
+		.name		= "atmel-classd",
+		.of_match_table	= of_match_ptr(atmel_classd_of_match),
+		.pm		= &snd_soc_pm_ops,
+	},
+	.probe	= atmel_classd_probe,
+	.remove	= atmel_classd_remove,
+};
+module_platform_driver(atmel_classd_driver);
+
+MODULE_DESCRIPTION("Atmel ClassD driver under ALSA SoC architecture");
+MODULE_AUTHOR("Songjun Wu <songjun.wu@atmel.com>");
+MODULE_LICENSE("GPL");