ASoC: sunxi: Add support for the SPDIF block

The sun4i, sun5i and sun7i SoC families have an SPDIF
block which is capable of playback and capture.

This patch enables the playback of this block for
the sun4i families.
Signed-off-by: Marcus Cooper <codekipper@gmail.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sunxi/Kconfig

@@ -8,4 +8,12 @@ config SND_SUN4I_CODEC
 	  Select Y or M to add support for the Codec embedded in the Allwinner
 	  A10 and affiliated SoCs.
 
+config SND_SUN4I_SPDIF
+	tristate "Allwinner A10 SPDIF Support"
+	depends on OF
+	select SND_SOC_GENERIC_DMAENGINE_PCM
+	select REGMAP_MMIO
+	help
+	  Say Y or M to add support for the S/PDIF audio block in the Allwinner
+	  A10 and affiliated SoCs.
 endmenu

sound/soc/sunxi/Makefile

 obj-$(CONFIG_SND_SUN4I_CODEC) += sun4i-codec.o
 
+obj-$(CONFIG_SND_SUN4I_SPDIF) += sun4i-spdif.o

sound/soc/sunxi/sun4i-spdif.c

+/*
+ * ALSA SoC SPDIF Audio Layer
+ *
+ * Copyright 2015 Andrea Venturi <be17068@iperbole.bo.it>
+ * Copyright 2015 Marcus Cooper <codekipper@gmail.com>
+ *
+ * Based on the Allwinner SDK driver, released under the GPL.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/regmap.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/ioport.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <sound/dmaengine_pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+
+#define	SUN4I_SPDIF_CTL		(0x00)
+	#define SUN4I_SPDIF_CTL_MCLKDIV(v)		((v) << 4) /* v even */
+	#define SUN4I_SPDIF_CTL_MCLKOUTEN		BIT(2)
+	#define SUN4I_SPDIF_CTL_GEN			BIT(1)
+	#define SUN4I_SPDIF_CTL_RESET			BIT(0)
+
+#define SUN4I_SPDIF_TXCFG	(0x04)
+	#define SUN4I_SPDIF_TXCFG_SINGLEMOD		BIT(31)
+	#define SUN4I_SPDIF_TXCFG_ASS			BIT(17)
+	#define SUN4I_SPDIF_TXCFG_NONAUDIO		BIT(16)
+	#define SUN4I_SPDIF_TXCFG_TXRATIO(v)		((v) << 4)
+	#define SUN4I_SPDIF_TXCFG_TXRATIO_MASK		GENMASK(8, 4)
+	#define SUN4I_SPDIF_TXCFG_FMTRVD		GENMASK(3, 2)
+	#define SUN4I_SPDIF_TXCFG_FMT16BIT		(0 << 2)
+	#define SUN4I_SPDIF_TXCFG_FMT20BIT		(1 << 2)
+	#define SUN4I_SPDIF_TXCFG_FMT24BIT		(2 << 2)
+	#define SUN4I_SPDIF_TXCFG_CHSTMODE		BIT(1)
+	#define SUN4I_SPDIF_TXCFG_TXEN			BIT(0)
+
+#define SUN4I_SPDIF_RXCFG	(0x08)
+	#define SUN4I_SPDIF_RXCFG_LOCKFLAG		BIT(4)
+	#define SUN4I_SPDIF_RXCFG_CHSTSRC		BIT(3)
+	#define SUN4I_SPDIF_RXCFG_CHSTCP		BIT(1)
+	#define SUN4I_SPDIF_RXCFG_RXEN			BIT(0)
+
+#define SUN4I_SPDIF_TXFIFO	(0x0C)
+
+#define SUN4I_SPDIF_RXFIFO	(0x10)
+
+#define SUN4I_SPDIF_FCTL	(0x14)
+	#define SUN4I_SPDIF_FCTL_FIFOSRC		BIT(31)
+	#define SUN4I_SPDIF_FCTL_FTX			BIT(17)
+	#define SUN4I_SPDIF_FCTL_FRX			BIT(16)
+	#define SUN4I_SPDIF_FCTL_TXTL(v)		((v) << 8)
+	#define SUN4I_SPDIF_FCTL_TXTL_MASK		GENMASK(12, 8)
+	#define SUN4I_SPDIF_FCTL_RXTL(v)		((v) << 3)
+	#define SUN4I_SPDIF_FCTL_RXTL_MASK		GENMASK(7, 3)
+	#define SUN4I_SPDIF_FCTL_TXIM			BIT(2)
+	#define SUN4I_SPDIF_FCTL_RXOM(v)		((v) << 0)
+	#define SUN4I_SPDIF_FCTL_RXOM_MASK		GENMASK(1, 0)
+
+#define SUN4I_SPDIF_FSTA	(0x18)
+	#define SUN4I_SPDIF_FSTA_TXE			BIT(14)
+	#define SUN4I_SPDIF_FSTA_TXECNTSHT		(8)
+	#define SUN4I_SPDIF_FSTA_RXA			BIT(6)
+	#define SUN4I_SPDIF_FSTA_RXACNTSHT		(0)
+
+#define SUN4I_SPDIF_INT		(0x1C)
+	#define SUN4I_SPDIF_INT_RXLOCKEN		BIT(18)
+	#define SUN4I_SPDIF_INT_RXUNLOCKEN		BIT(17)
+	#define SUN4I_SPDIF_INT_RXPARERREN		BIT(16)
+	#define SUN4I_SPDIF_INT_TXDRQEN			BIT(7)
+	#define SUN4I_SPDIF_INT_TXUIEN			BIT(6)
+	#define SUN4I_SPDIF_INT_TXOIEN			BIT(5)
+	#define SUN4I_SPDIF_INT_TXEIEN			BIT(4)
+	#define SUN4I_SPDIF_INT_RXDRQEN			BIT(2)
+	#define SUN4I_SPDIF_INT_RXOIEN			BIT(1)
+	#define SUN4I_SPDIF_INT_RXAIEN			BIT(0)
+
+#define SUN4I_SPDIF_ISTA	(0x20)
+	#define SUN4I_SPDIF_ISTA_RXLOCKSTA		BIT(18)
+	#define SUN4I_SPDIF_ISTA_RXUNLOCKSTA		BIT(17)
+	#define SUN4I_SPDIF_ISTA_RXPARERRSTA		BIT(16)
+	#define SUN4I_SPDIF_ISTA_TXUSTA			BIT(6)
+	#define SUN4I_SPDIF_ISTA_TXOSTA			BIT(5)
+	#define SUN4I_SPDIF_ISTA_TXESTA			BIT(4)
+	#define SUN4I_SPDIF_ISTA_RXOSTA			BIT(1)
+	#define SUN4I_SPDIF_ISTA_RXASTA			BIT(0)
+
+#define SUN4I_SPDIF_TXCNT	(0x24)
+
+#define SUN4I_SPDIF_RXCNT	(0x28)
+
+#define SUN4I_SPDIF_TXCHSTA0	(0x2C)
+	#define SUN4I_SPDIF_TXCHSTA0_CLK(v)		((v) << 28)
+	#define SUN4I_SPDIF_TXCHSTA0_SAMFREQ(v)		((v) << 24)
+	#define SUN4I_SPDIF_TXCHSTA0_SAMFREQ_MASK	GENMASK(27, 24)
+	#define SUN4I_SPDIF_TXCHSTA0_CHNUM(v)		((v) << 20)
+	#define SUN4I_SPDIF_TXCHSTA0_CHNUM_MASK		GENMASK(23, 20)
+	#define SUN4I_SPDIF_TXCHSTA0_SRCNUM(v)		((v) << 16)
+	#define SUN4I_SPDIF_TXCHSTA0_CATACOD(v)		((v) << 8)
+	#define SUN4I_SPDIF_TXCHSTA0_MODE(v)		((v) << 6)
+	#define SUN4I_SPDIF_TXCHSTA0_EMPHASIS(v)	((v) << 3)
+	#define SUN4I_SPDIF_TXCHSTA0_CP			BIT(2)
+	#define SUN4I_SPDIF_TXCHSTA0_AUDIO		BIT(1)
+	#define SUN4I_SPDIF_TXCHSTA0_PRO		BIT(0)
+
+#define SUN4I_SPDIF_TXCHSTA1	(0x30)
+	#define SUN4I_SPDIF_TXCHSTA1_CGMSA(v)		((v) << 8)
+	#define SUN4I_SPDIF_TXCHSTA1_ORISAMFREQ(v)	((v) << 4)
+	#define SUN4I_SPDIF_TXCHSTA1_ORISAMFREQ_MASK	GENMASK(7, 4)
+	#define SUN4I_SPDIF_TXCHSTA1_SAMWORDLEN(v)	((v) << 1)
+	#define SUN4I_SPDIF_TXCHSTA1_MAXWORDLEN		BIT(0)
+
+#define SUN4I_SPDIF_RXCHSTA0	(0x34)
+	#define SUN4I_SPDIF_RXCHSTA0_CLK(v)		((v) << 28)
+	#define SUN4I_SPDIF_RXCHSTA0_SAMFREQ(v)		((v) << 24)
+	#define SUN4I_SPDIF_RXCHSTA0_CHNUM(v)		((v) << 20)
+	#define SUN4I_SPDIF_RXCHSTA0_SRCNUM(v)		((v) << 16)
+	#define SUN4I_SPDIF_RXCHSTA0_CATACOD(v)		((v) << 8)
+	#define SUN4I_SPDIF_RXCHSTA0_MODE(v)		((v) << 6)
+	#define SUN4I_SPDIF_RXCHSTA0_EMPHASIS(v)	((v) << 3)
+	#define SUN4I_SPDIF_RXCHSTA0_CP			BIT(2)
+	#define SUN4I_SPDIF_RXCHSTA0_AUDIO		BIT(1)
+	#define SUN4I_SPDIF_RXCHSTA0_PRO		BIT(0)
+
+#define SUN4I_SPDIF_RXCHSTA1	(0x38)
+	#define SUN4I_SPDIF_RXCHSTA1_CGMSA(v)		((v) << 8)
+	#define SUN4I_SPDIF_RXCHSTA1_ORISAMFREQ(v)	((v) << 4)
+	#define SUN4I_SPDIF_RXCHSTA1_SAMWORDLEN(v)	((v) << 1)
+	#define SUN4I_SPDIF_RXCHSTA1_MAXWORDLEN		BIT(0)
+
+/* Defines for Sampling Frequency */
+#define SUN4I_SPDIF_SAMFREQ_44_1KHZ		0x0
+#define SUN4I_SPDIF_SAMFREQ_NOT_INDICATED	0x1
+#define SUN4I_SPDIF_SAMFREQ_48KHZ		0x2
+#define SUN4I_SPDIF_SAMFREQ_32KHZ		0x3
+#define SUN4I_SPDIF_SAMFREQ_22_05KHZ		0x4
+#define SUN4I_SPDIF_SAMFREQ_24KHZ		0x6
+#define SUN4I_SPDIF_SAMFREQ_88_2KHZ		0x8
+#define SUN4I_SPDIF_SAMFREQ_76_8KHZ		0x9
+#define SUN4I_SPDIF_SAMFREQ_96KHZ		0xa
+#define SUN4I_SPDIF_SAMFREQ_176_4KHZ		0xc
+#define SUN4I_SPDIF_SAMFREQ_192KHZ		0xe
+
+struct sun4i_spdif_dev {
+	struct platform_device *pdev;
+	struct clk *spdif_clk;
+	struct clk *apb_clk;
+	struct snd_soc_dai_driver cpu_dai_drv;
+	struct regmap *regmap;
+	struct snd_dmaengine_dai_dma_data dma_params_tx;
+};
+
+static void sun4i_spdif_configure(struct sun4i_spdif_dev *host)
+{
+	/* soft reset SPDIF */
+	regmap_write(host->regmap, SUN4I_SPDIF_CTL, SUN4I_SPDIF_CTL_RESET);
+
+	/* flush TX FIFO */
+	regmap_update_bits(host->regmap, SUN4I_SPDIF_FCTL,
+			   SUN4I_SPDIF_FCTL_FTX, SUN4I_SPDIF_FCTL_FTX);
+
+	/* clear TX counter */
+	regmap_write(host->regmap, SUN4I_SPDIF_TXCNT, 0);
+}
+
+static void sun4i_snd_txctrl_on(struct snd_pcm_substream *substream,
+				struct sun4i_spdif_dev *host)
+{
+	if (substream->runtime->channels == 1)
+		regmap_update_bits(host->regmap, SUN4I_SPDIF_TXCFG,
+				   SUN4I_SPDIF_TXCFG_SINGLEMOD,
+				   SUN4I_SPDIF_TXCFG_SINGLEMOD);
+
+	/* SPDIF TX ENABLE */
+	regmap_update_bits(host->regmap, SUN4I_SPDIF_TXCFG,
+			   SUN4I_SPDIF_TXCFG_TXEN, SUN4I_SPDIF_TXCFG_TXEN);
+
+	/* DRQ ENABLE */
+	regmap_update_bits(host->regmap, SUN4I_SPDIF_INT,
+			   SUN4I_SPDIF_INT_TXDRQEN, SUN4I_SPDIF_INT_TXDRQEN);
+
+	/* Global enable */
+	regmap_update_bits(host->regmap, SUN4I_SPDIF_CTL,
+			   SUN4I_SPDIF_CTL_GEN, SUN4I_SPDIF_CTL_GEN);
+}
+
+static void sun4i_snd_txctrl_off(struct snd_pcm_substream *substream,
+				 struct sun4i_spdif_dev *host)
+{
+	/* SPDIF TX DISABLE */
+	regmap_update_bits(host->regmap, SUN4I_SPDIF_TXCFG,
+			   SUN4I_SPDIF_TXCFG_TXEN, 0);
+
+	/* DRQ DISABLE */
+	regmap_update_bits(host->regmap, SUN4I_SPDIF_INT,
+			   SUN4I_SPDIF_INT_TXDRQEN, 0);
+
+	/* Global disable */
+	regmap_update_bits(host->regmap, SUN4I_SPDIF_CTL,
+			   SUN4I_SPDIF_CTL_GEN, 0);
+}
+
+static int sun4i_spdif_startup(struct snd_pcm_substream *substream,
+			       struct snd_soc_dai *cpu_dai)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct sun4i_spdif_dev *host = snd_soc_dai_get_drvdata(rtd->cpu_dai);
+
+	if (substream->stream != SNDRV_PCM_STREAM_PLAYBACK)
+		return -EINVAL;
+
+	sun4i_spdif_configure(host);
+
+	return 0;
+}
+
+static int sun4i_spdif_hw_params(struct snd_pcm_substream *substream,
+				 struct snd_pcm_hw_params *params,
+				 struct snd_soc_dai *cpu_dai)
+{
+	int ret = 0;
+	int fmt;
+	unsigned long rate = params_rate(params);
+	u32 mclk_div = 0;
+	unsigned int mclk = 0;
+	u32 reg_val;
+	struct sun4i_spdif_dev *host = snd_soc_dai_get_drvdata(cpu_dai);
+	struct platform_device *pdev = host->pdev;
+
+	/* Add the PCM and raw data select interface */
+	switch (params_channels(params)) {
+	case 1: /* PCM mode */
+	case 2:
+		fmt = 0;
+		break;
+	case 4: /* raw data mode */
+		fmt = SUN4I_SPDIF_TXCFG_NONAUDIO;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	switch (params_format(params)) {
+	case SNDRV_PCM_FORMAT_S16_LE:
+		fmt |= SUN4I_SPDIF_TXCFG_FMT16BIT;
+		break;
+	case SNDRV_PCM_FORMAT_S20_3LE:
+		fmt |= SUN4I_SPDIF_TXCFG_FMT20BIT;
+		break;
+	case SNDRV_PCM_FORMAT_S24_LE:
+		fmt |= SUN4I_SPDIF_TXCFG_FMT24BIT;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	switch (rate) {
+	case 22050:
+	case 44100:
+	case 88200:
+	case 176400:
+		mclk = 22579200;
+		break;
+	case 24000:
+	case 32000:
+	case 48000:
+	case 96000:
+	case 192000:
+		mclk = 24576000;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ret = clk_set_rate(host->spdif_clk, mclk);
+	if (ret < 0) {
+		dev_err(&pdev->dev,
+			"Setting SPDIF clock rate for %d Hz failed!\n", mclk);
+		return ret;
+	}
+
+	regmap_update_bits(host->regmap, SUN4I_SPDIF_FCTL,
+			   SUN4I_SPDIF_FCTL_TXIM, SUN4I_SPDIF_FCTL_TXIM);
+
+	switch (rate) {
+	case 22050:
+	case 24000:
+		mclk_div = 8;
+		break;
+	case 32000:
+		mclk_div = 6;
+		break;
+	case 44100:
+	case 48000:
+		mclk_div = 4;
+		break;
+	case 88200:
+	case 96000:
+		mclk_div = 2;
+		break;
+	case 176400:
+	case 192000:
+		mclk_div = 1;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	reg_val = 0;
+	reg_val |= SUN4I_SPDIF_TXCFG_ASS;
+	reg_val |= fmt; /* set non audio and bit depth */
+	reg_val |= SUN4I_SPDIF_TXCFG_CHSTMODE;
+	reg_val |= SUN4I_SPDIF_TXCFG_TXRATIO(mclk_div - 1);
+	regmap_write(host->regmap, SUN4I_SPDIF_TXCFG, reg_val);
+
+	return 0;
+}
+
+static int sun4i_spdif_trigger(struct snd_pcm_substream *substream, int cmd,
+			       struct snd_soc_dai *dai)
+{
+	int ret = 0;
+	struct sun4i_spdif_dev *host = snd_soc_dai_get_drvdata(dai);
+
+	if (substream->stream != SNDRV_PCM_STREAM_PLAYBACK)
+		return -EINVAL;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		sun4i_snd_txctrl_on(substream, host);
+		break;
+
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		sun4i_snd_txctrl_off(substream, host);
+		break;
+
+	default:
+		ret = -EINVAL;
+		break;
+	}
+	return ret;
+}
+
+static int sun4i_spdif_soc_dai_probe(struct snd_soc_dai *dai)
+{
+	struct sun4i_spdif_dev *host = snd_soc_dai_get_drvdata(dai);
+
+	snd_soc_dai_init_dma_data(dai, &host->dma_params_tx, NULL);
+	return 0;
+}
+
+static const struct snd_soc_dai_ops sun4i_spdif_dai_ops = {
+	.startup	= sun4i_spdif_startup,
+	.trigger	= sun4i_spdif_trigger,
+	.hw_params	= sun4i_spdif_hw_params,
+};
+
+static const struct regmap_config sun4i_spdif_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.max_register = SUN4I_SPDIF_RXCHSTA1,
+};
+
+#define SUN4I_RATES	SNDRV_PCM_RATE_8000_192000
+
+#define SUN4I_FORMATS	(SNDRV_PCM_FORMAT_S16_LE | \
+				SNDRV_PCM_FORMAT_S20_3LE | \
+				SNDRV_PCM_FORMAT_S24_LE)
+
+static struct snd_soc_dai_driver sun4i_spdif_dai = {
+	.playback = {
+		.channels_min = 1,
+		.channels_max = 2,
+		.rates = SUN4I_RATES,
+		.formats = SUN4I_FORMATS,
+	},
+	.probe = sun4i_spdif_soc_dai_probe,
+	.ops = &sun4i_spdif_dai_ops,
+	.name = "spdif",
+};
+
+static const struct snd_soc_dapm_widget dit_widgets[] = {
+	SND_SOC_DAPM_OUTPUT("spdif-out"),
+};
+
+static const struct snd_soc_dapm_route dit_routes[] = {
+	{ "spdif-out", NULL, "Playback" },
+};
+
+static const struct of_device_id sun4i_spdif_of_match[] = {
+	{ .compatible = "allwinner,sun4i-a10-spdif", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sun4i_spdif_of_match);
+
+static const struct snd_soc_component_driver sun4i_spdif_component = {
+	.name		= "sun4i-spdif",
+};
+
+static int sun4i_spdif_runtime_suspend(struct device *dev)
+{
+	struct sun4i_spdif_dev *host  = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(host->spdif_clk);
+	clk_disable_unprepare(host->apb_clk);
+
+	return 0;
+}
+
+static int sun4i_spdif_runtime_resume(struct device *dev)
+{
+	struct sun4i_spdif_dev *host  = dev_get_drvdata(dev);
+
+	clk_prepare_enable(host->spdif_clk);
+	clk_prepare_enable(host->apb_clk);
+
+	return 0;
+}
+
+static int sun4i_spdif_probe(struct platform_device *pdev)
+{
+	struct sun4i_spdif_dev *host;
+	struct resource *res;
+	int ret;
+	void __iomem *base;
+
+	dev_dbg(&pdev->dev, "Entered %s\n", __func__);
+
+	host = devm_kzalloc(&pdev->dev, sizeof(*host), GFP_KERNEL);
+	if (!host)
+		return -ENOMEM;
+
+	host->pdev = pdev;
+
+	/* Initialize this copy of the CPU DAI driver structure */
+	memcpy(&host->cpu_dai_drv, &sun4i_spdif_dai, sizeof(sun4i_spdif_dai));
+	host->cpu_dai_drv.name = dev_name(&pdev->dev);
+
+	/* Get the addresses */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	host->regmap = devm_regmap_init_mmio(&pdev->dev, base,
+						&sun4i_spdif_regmap_config);
+
+	/* Clocks */
+	host->apb_clk = devm_clk_get(&pdev->dev, "apb");
+	if (IS_ERR(host->apb_clk)) {
+		dev_err(&pdev->dev, "failed to get a apb clock.\n");
+		return PTR_ERR(host->apb_clk);
+	}
+
+	host->spdif_clk = devm_clk_get(&pdev->dev, "spdif");
+	if (IS_ERR(host->spdif_clk)) {
+		dev_err(&pdev->dev, "failed to get a spdif clock.\n");
+		ret = PTR_ERR(host->spdif_clk);
+		goto err_disable_apb_clk;
+	}
+
+	host->dma_params_tx.addr = res->start + SUN4I_SPDIF_TXFIFO;
+	host->dma_params_tx.maxburst = 4;
+	host->dma_params_tx.addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
+
+	platform_set_drvdata(pdev, host);
+
+	ret = devm_snd_soc_register_component(&pdev->dev,
+				&sun4i_spdif_component, &sun4i_spdif_dai, 1);
+	if (ret)
+		goto err_disable_apb_clk;
+
+	pm_runtime_enable(&pdev->dev);
+	if (!pm_runtime_enabled(&pdev->dev)) {
+		ret = sun4i_spdif_runtime_resume(&pdev->dev);
+		if (ret)
+			goto err_unregister;
+	}
+
+	ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
+	if (ret)
+		goto err_suspend;
+	return 0;
+err_suspend:
+	if (!pm_runtime_status_suspended(&pdev->dev))
+		sun4i_spdif_runtime_suspend(&pdev->dev);
+err_unregister:
+	pm_runtime_disable(&pdev->dev);
+	snd_soc_unregister_component(&pdev->dev);
+err_disable_apb_clk:
+	clk_disable_unprepare(host->apb_clk);
+	return ret;
+}
+
+static int sun4i_spdif_remove(struct platform_device *pdev)
+{
+	pm_runtime_disable(&pdev->dev);
+	if (!pm_runtime_status_suspended(&pdev->dev))
+		sun4i_spdif_runtime_suspend(&pdev->dev);
+
+	snd_soc_unregister_platform(&pdev->dev);
+	snd_soc_unregister_component(&pdev->dev);
+
+	return 0;
+}
+
+static const struct dev_pm_ops sun4i_spdif_pm = {
+	SET_RUNTIME_PM_OPS(sun4i_spdif_runtime_suspend,
+			   sun4i_spdif_runtime_resume, NULL)
+};
+
+static struct platform_driver sun4i_spdif_driver = {
+	.driver		= {
+		.name	= "sun4i-spdif",
+		.of_match_table = of_match_ptr(sun4i_spdif_of_match),
+		.pm	= &sun4i_spdif_pm,
+	},
+	.probe		= sun4i_spdif_probe,
+	.remove		= sun4i_spdif_remove,
+};
+
+module_platform_driver(sun4i_spdif_driver);
+
+MODULE_AUTHOR("Marcus Cooper <codekipper@gmail.com>");
+MODULE_AUTHOR("Andrea Venturi <be17068@iperbole.bo.it>");
+MODULE_DESCRIPTION("Allwinner sun4i SPDIF SoC Interface");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:sun4i-spdif");