ASoC: sunxi: Add Allwinner A10 Digital Audio driver

The Allwinner A10 and later come with a hardware block that used for the
PCM and I2S interfaces.

Add a driver for it in ASoC.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Tested-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sunxi/Kconfig

@@ -8,6 +8,15 @@ 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_I2S
+	tristate "Allwinner A10 I2S Support"
+	select SND_SOC_GENERIC_DMAENGINE_PCM
+	select REGMAP_MMIO
+	help
+	  Say Y or M if you want to add support for codecs attached to
+	  the Allwinner A10 I2S. You will also need to select the
+	  individual machine drivers to support below.
+
 config SND_SUN4I_SPDIF
 	tristate "Allwinner A10 SPDIF Support"
 	depends on OF

sound/soc/sunxi/Makefile

 obj-$(CONFIG_SND_SUN4I_CODEC) += sun4i-codec.o
-
+obj-$(CONFIG_SND_SUN4I_I2S) += sun4i-i2s.o
 obj-$(CONFIG_SND_SUN4I_SPDIF) += sun4i-spdif.o

sound/soc/sunxi/sun4i-i2s.c

+/*
+ * Copyright (C) 2015 Andrea Venturi
+ * Andrea Venturi <be17068@iperbole.bo.it>
+ *
+ * Copyright (C) 2016 Maxime Ripard
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * 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.
+ */
+
+#include <linux/clk.h>
+#include <linux/dmaengine.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+
+#include <sound/dmaengine_pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include <sound/soc-dai.h>
+
+#define SUN4I_I2S_CTRL_REG		0x00
+#define SUN4I_I2S_CTRL_SDO_EN_MASK		GENMASK(11, 8)
+#define SUN4I_I2S_CTRL_SDO_EN(sdo)			BIT(8 + (sdo))
+#define SUN4I_I2S_CTRL_MODE_MASK		BIT(5)
+#define SUN4I_I2S_CTRL_MODE_SLAVE			(1 << 5)
+#define SUN4I_I2S_CTRL_MODE_MASTER			(0 << 5)
+#define SUN4I_I2S_CTRL_TX_EN			BIT(2)
+#define SUN4I_I2S_CTRL_RX_EN			BIT(1)
+#define SUN4I_I2S_CTRL_GL_EN			BIT(0)
+
+#define SUN4I_I2S_FMT0_REG		0x04
+#define SUN4I_I2S_FMT0_LRCLK_POLARITY_MASK	BIT(7)
+#define SUN4I_I2S_FMT0_LRCLK_POLARITY_INVERTED		(1 << 7)
+#define SUN4I_I2S_FMT0_LRCLK_POLARITY_NORMAL		(0 << 7)
+#define SUN4I_I2S_FMT0_BCLK_POLARITY_MASK	BIT(6)
+#define SUN4I_I2S_FMT0_BCLK_POLARITY_INVERTED		(1 << 6)
+#define SUN4I_I2S_FMT0_BCLK_POLARITY_NORMAL		(0 << 6)
+#define SUN4I_I2S_FMT0_SR_MASK			GENMASK(5, 4)
+#define SUN4I_I2S_FMT0_SR(sr)				((sr) << 4)
+#define SUN4I_I2S_FMT0_WSS_MASK			GENMASK(3, 2)
+#define SUN4I_I2S_FMT0_WSS(wss)				((wss) << 2)
+#define SUN4I_I2S_FMT0_FMT_MASK			GENMASK(1, 0)
+#define SUN4I_I2S_FMT0_FMT_RIGHT_J			(2 << 0)
+#define SUN4I_I2S_FMT0_FMT_LEFT_J			(1 << 0)
+#define SUN4I_I2S_FMT0_FMT_I2S				(0 << 0)
+
+#define SUN4I_I2S_FMT1_REG		0x08
+#define SUN4I_I2S_FIFO_TX_REG		0x0c
+#define SUN4I_I2S_FIFO_RX_REG		0x10
+
+#define SUN4I_I2S_FIFO_CTRL_REG		0x14
+#define SUN4I_I2S_FIFO_CTRL_FLUSH_TX		BIT(25)
+#define SUN4I_I2S_FIFO_CTRL_FLUSH_RX		BIT(24)
+#define SUN4I_I2S_FIFO_CTRL_TX_MODE_MASK	BIT(2)
+#define SUN4I_I2S_FIFO_CTRL_TX_MODE(mode)		((mode) << 2)
+#define SUN4I_I2S_FIFO_CTRL_RX_MODE_MASK	GENMASK(1, 0)
+#define SUN4I_I2S_FIFO_CTRL_RX_MODE(mode)		(mode)
+
+#define SUN4I_I2S_FIFO_STA_REG		0x18
+
+#define SUN4I_I2S_DMA_INT_CTRL_REG	0x1c
+#define SUN4I_I2S_DMA_INT_CTRL_TX_DRQ_EN	BIT(7)
+#define SUN4I_I2S_DMA_INT_CTRL_RX_DRQ_EN	BIT(3)
+
+#define SUN4I_I2S_INT_STA_REG		0x20
+
+#define SUN4I_I2S_CLK_DIV_REG		0x24
+#define SUN4I_I2S_CLK_DIV_MCLK_EN		BIT(7)
+#define SUN4I_I2S_CLK_DIV_BCLK_MASK		GENMASK(6, 4)
+#define SUN4I_I2S_CLK_DIV_BCLK(bclk)			((bclk) << 4)
+#define SUN4I_I2S_CLK_DIV_MCLK_MASK		GENMASK(3, 0)
+#define SUN4I_I2S_CLK_DIV_MCLK(mclk)			((mclk) << 0)
+
+#define SUN4I_I2S_RX_CNT_REG		0x28
+#define SUN4I_I2S_TX_CNT_REG		0x2c
+
+#define SUN4I_I2S_TX_CHAN_SEL_REG	0x30
+#define SUN4I_I2S_TX_CHAN_SEL(num_chan)		(((num_chan) - 1) << 0)
+
+#define SUN4I_I2S_TX_CHAN_MAP_REG	0x34
+#define SUN4I_I2S_TX_CHAN_MAP(chan, sample)	((sample) << (chan << 2))
+
+#define SUN4I_I2S_RX_CHAN_SEL_REG	0x38
+#define SUN4I_I2S_RX_CHAN_MAP_REG	0x3c
+
+struct sun4i_i2s {
+	struct clk	*bus_clk;
+	struct clk	*mod_clk;
+	struct regmap	*regmap;
+
+	struct snd_dmaengine_dai_dma_data	playback_dma_data;
+};
+
+struct sun4i_i2s_clk_div {
+	u8	div;
+	u8	val;
+};
+
+static const struct sun4i_i2s_clk_div sun4i_i2s_bclk_div[] = {
+	{ .div = 2, .val = 0 },
+	{ .div = 4, .val = 1 },
+	{ .div = 6, .val = 2 },
+	{ .div = 8, .val = 3 },
+	{ .div = 12, .val = 4 },
+	{ .div = 16, .val = 5 },
+};
+
+static const struct sun4i_i2s_clk_div sun4i_i2s_mclk_div[] = {
+	{ .div = 1, .val = 0 },
+	{ .div = 2, .val = 1 },
+	{ .div = 4, .val = 2 },
+	{ .div = 6, .val = 3 },
+	{ .div = 8, .val = 4 },
+	{ .div = 12, .val = 5 },
+	{ .div = 16, .val = 6 },
+	{ .div = 24, .val = 7 },
+};
+
+static int sun4i_i2s_get_bclk_div(struct sun4i_i2s *i2s,
+				  unsigned int oversample_rate,
+				  unsigned int word_size)
+{
+	int div = oversample_rate / word_size / 2;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(sun4i_i2s_bclk_div); i++) {
+		const struct sun4i_i2s_clk_div *bdiv = &sun4i_i2s_bclk_div[i];
+
+		if (bdiv->div == div)
+			return bdiv->val;
+	}
+
+	return -EINVAL;
+}
+
+static int sun4i_i2s_get_mclk_div(struct sun4i_i2s *i2s,
+				  unsigned int oversample_rate,
+				  unsigned int module_rate,
+				  unsigned int sampling_rate)
+{
+	int div = module_rate / sampling_rate / oversample_rate;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(sun4i_i2s_mclk_div); i++) {
+		const struct sun4i_i2s_clk_div *mdiv = &sun4i_i2s_mclk_div[i];
+
+		if (mdiv->div == div)
+			return mdiv->val;
+	}
+
+	return -EINVAL;
+}
+
+static int sun4i_i2s_oversample_rates[] = { 128, 192, 256, 384, 512, 768 };
+
+static int sun4i_i2s_set_clk_rate(struct sun4i_i2s *i2s,
+				  unsigned int rate,
+				  unsigned int word_size)
+{
+	unsigned int clk_rate;
+	int bclk_div, mclk_div;
+	int ret, i;
+
+	switch (rate) {
+	case 176400:
+	case 88200:
+	case 44100:
+	case 22050:
+	case 11025:
+		clk_rate = 22579200;
+		break;
+
+	case 192000:
+	case 128000:
+	case 96000:
+	case 64000:
+	case 48000:
+	case 32000:
+	case 24000:
+	case 16000:
+	case 12000:
+	case 8000:
+		clk_rate = 24576000;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	ret = clk_set_rate(i2s->mod_clk, clk_rate);
+	if (ret)
+		return ret;
+
+	/* Always favor the highest oversampling rate */
+	for (i = (ARRAY_SIZE(sun4i_i2s_oversample_rates) - 1); i >= 0; i--) {
+		unsigned int oversample_rate = sun4i_i2s_oversample_rates[i];
+
+		bclk_div = sun4i_i2s_get_bclk_div(i2s, oversample_rate,
+						  word_size);
+		mclk_div = sun4i_i2s_get_mclk_div(i2s, oversample_rate,
+						  clk_rate,
+						  rate);
+
+		if ((bclk_div >= 0) && (mclk_div >= 0))
+			break;
+	}
+
+	if ((bclk_div < 0) || (mclk_div < 0))
+		return -EINVAL;
+
+	regmap_write(i2s->regmap, SUN4I_I2S_CLK_DIV_REG,
+		     SUN4I_I2S_CLK_DIV_BCLK(bclk_div) |
+		     SUN4I_I2S_CLK_DIV_MCLK(mclk_div) |
+		     SUN4I_I2S_CLK_DIV_MCLK_EN);
+
+	return 0;
+}
+
+static int sun4i_i2s_hw_params(struct snd_pcm_substream *substream,
+			       struct snd_pcm_hw_params *params,
+			       struct snd_soc_dai *dai)
+{
+	struct sun4i_i2s *i2s = snd_soc_dai_get_drvdata(dai);
+	int sr, wss;
+	u32 width;
+
+	if (params_channels(params) != 2)
+		return -EINVAL;
+
+	switch (params_physical_width(params)) {
+	case 16:
+		width = DMA_SLAVE_BUSWIDTH_2_BYTES;
+		break;
+	default:
+		return -EINVAL;
+	}
+	i2s->playback_dma_data.addr_width = width;
+
+	switch (params_width(params)) {
+	case 16:
+		sr = 0;
+		wss = 0;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	regmap_update_bits(i2s->regmap, SUN4I_I2S_FMT0_REG,
+			   SUN4I_I2S_FMT0_WSS_MASK | SUN4I_I2S_FMT0_SR_MASK,
+			   SUN4I_I2S_FMT0_WSS(wss) | SUN4I_I2S_FMT0_SR(sr));
+
+	return sun4i_i2s_set_clk_rate(i2s, params_rate(params),
+				      params_width(params));
+}
+
+static int sun4i_i2s_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
+{
+	struct sun4i_i2s *i2s = snd_soc_dai_get_drvdata(dai);
+	u32 val;
+
+	/* DAI Mode */
+	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
+	case SND_SOC_DAIFMT_I2S:
+		val = SUN4I_I2S_FMT0_FMT_I2S;
+		break;
+	case SND_SOC_DAIFMT_LEFT_J:
+		val = SUN4I_I2S_FMT0_FMT_LEFT_J;
+		break;
+	case SND_SOC_DAIFMT_RIGHT_J:
+		val = SUN4I_I2S_FMT0_FMT_RIGHT_J;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	regmap_update_bits(i2s->regmap, SUN4I_I2S_FMT0_REG,
+			   SUN4I_I2S_FMT0_FMT_MASK,
+			   val);
+
+	/* DAI clock polarity */
+	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
+	case SND_SOC_DAIFMT_IB_IF:
+		/* Invert both clocks */
+		val = SUN4I_I2S_FMT0_BCLK_POLARITY_INVERTED |
+			SUN4I_I2S_FMT0_LRCLK_POLARITY_INVERTED;
+		break;
+	case SND_SOC_DAIFMT_IB_NF:
+		/* Invert bit clock */
+		val = SUN4I_I2S_FMT0_BCLK_POLARITY_INVERTED |
+			SUN4I_I2S_FMT0_LRCLK_POLARITY_NORMAL;
+		break;
+	case SND_SOC_DAIFMT_NB_IF:
+		/* Invert frame clock */
+		val = SUN4I_I2S_FMT0_LRCLK_POLARITY_INVERTED |
+			SUN4I_I2S_FMT0_BCLK_POLARITY_NORMAL;
+		break;
+	case SND_SOC_DAIFMT_NB_NF:
+		/* Nothing to do for both normal cases */
+		val = SUN4I_I2S_FMT0_BCLK_POLARITY_NORMAL |
+			SUN4I_I2S_FMT0_LRCLK_POLARITY_NORMAL;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	regmap_update_bits(i2s->regmap, SUN4I_I2S_FMT0_REG,
+			   SUN4I_I2S_FMT0_BCLK_POLARITY_MASK |
+			   SUN4I_I2S_FMT0_LRCLK_POLARITY_MASK,
+			   val);
+
+	/* DAI clock master masks */
+	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
+	case SND_SOC_DAIFMT_CBS_CFS:
+		/* BCLK and LRCLK master */
+		val = SUN4I_I2S_CTRL_MODE_MASTER;
+		break;
+	case SND_SOC_DAIFMT_CBM_CFM:
+		/* BCLK and LRCLK slave */
+		val = SUN4I_I2S_CTRL_MODE_SLAVE;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	regmap_update_bits(i2s->regmap, SUN4I_I2S_CTRL_REG,
+			   SUN4I_I2S_CTRL_MODE_MASK,
+			   val);
+
+	/* Set significant bits in our FIFOs */
+	regmap_update_bits(i2s->regmap, SUN4I_I2S_FIFO_CTRL_REG,
+			   SUN4I_I2S_FIFO_CTRL_TX_MODE_MASK |
+			   SUN4I_I2S_FIFO_CTRL_RX_MODE_MASK,
+			   SUN4I_I2S_FIFO_CTRL_TX_MODE(1) |
+			   SUN4I_I2S_FIFO_CTRL_RX_MODE(1));
+	return 0;
+}
+
+static void sun4i_i2s_start_playback(struct sun4i_i2s *i2s)
+{
+	/* Flush TX FIFO */
+	regmap_update_bits(i2s->regmap, SUN4I_I2S_FIFO_CTRL_REG,
+			   SUN4I_I2S_FIFO_CTRL_FLUSH_TX,
+			   SUN4I_I2S_FIFO_CTRL_FLUSH_TX);
+
+	/* Clear TX counter */
+	regmap_write(i2s->regmap, SUN4I_I2S_TX_CNT_REG, 0);
+
+	/* Enable TX Block */
+	regmap_update_bits(i2s->regmap, SUN4I_I2S_CTRL_REG,
+			   SUN4I_I2S_CTRL_TX_EN,
+			   SUN4I_I2S_CTRL_TX_EN);
+
+	/* Enable TX DRQ */
+	regmap_update_bits(i2s->regmap, SUN4I_I2S_DMA_INT_CTRL_REG,
+			   SUN4I_I2S_DMA_INT_CTRL_TX_DRQ_EN,
+			   SUN4I_I2S_DMA_INT_CTRL_TX_DRQ_EN);
+}
+
+
+static void sun4i_i2s_stop_playback(struct sun4i_i2s *i2s)
+{
+	/* Disable TX Block */
+	regmap_update_bits(i2s->regmap, SUN4I_I2S_CTRL_REG,
+			   SUN4I_I2S_CTRL_TX_EN,
+			   0);
+
+	/* Disable TX DRQ */
+	regmap_update_bits(i2s->regmap, SUN4I_I2S_DMA_INT_CTRL_REG,
+			   SUN4I_I2S_DMA_INT_CTRL_TX_DRQ_EN,
+			   0);
+}
+
+static int sun4i_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
+			     struct snd_soc_dai *dai)
+{
+	struct sun4i_i2s *i2s = snd_soc_dai_get_drvdata(dai);
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+	case SNDRV_PCM_TRIGGER_RESUME:
+		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+			sun4i_i2s_start_playback(i2s);
+		else
+			return -EINVAL;
+		break;
+
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+			sun4i_i2s_stop_playback(i2s);
+		else
+			return -EINVAL;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int sun4i_i2s_startup(struct snd_pcm_substream *substream,
+			     struct snd_soc_dai *dai)
+{
+	struct sun4i_i2s *i2s = snd_soc_dai_get_drvdata(dai);
+
+	/* Enable the whole hardware block */
+	regmap_write(i2s->regmap, SUN4I_I2S_CTRL_REG,
+		     SUN4I_I2S_CTRL_GL_EN);
+
+	/* Enable the first output line */
+	regmap_update_bits(i2s->regmap, SUN4I_I2S_CTRL_REG,
+			   SUN4I_I2S_CTRL_SDO_EN_MASK,
+			   SUN4I_I2S_CTRL_SDO_EN(0));
+
+	/* Enable the first two channels */
+	regmap_write(i2s->regmap, SUN4I_I2S_TX_CHAN_SEL_REG,
+		     SUN4I_I2S_TX_CHAN_SEL(2));
+
+	/* Map them to the two first samples coming in */
+	regmap_write(i2s->regmap, SUN4I_I2S_TX_CHAN_MAP_REG,
+		     SUN4I_I2S_TX_CHAN_MAP(0, 0) | SUN4I_I2S_TX_CHAN_MAP(1, 1));
+
+	return clk_prepare_enable(i2s->mod_clk);
+}
+
+static void sun4i_i2s_shutdown(struct snd_pcm_substream *substream,
+			       struct snd_soc_dai *dai)
+{
+	struct sun4i_i2s *i2s = snd_soc_dai_get_drvdata(dai);
+
+	clk_disable_unprepare(i2s->mod_clk);
+
+	/* Disable our output lines */
+	regmap_update_bits(i2s->regmap, SUN4I_I2S_CTRL_REG,
+			   SUN4I_I2S_CTRL_SDO_EN_MASK, 0);
+
+	/* Disable the whole hardware block */
+	regmap_write(i2s->regmap, SUN4I_I2S_CTRL_REG, 0);
+}
+
+static const struct snd_soc_dai_ops sun4i_i2s_dai_ops = {
+	.hw_params	= sun4i_i2s_hw_params,
+	.set_fmt	= sun4i_i2s_set_fmt,
+	.shutdown	= sun4i_i2s_shutdown,
+	.startup	= sun4i_i2s_startup,
+	.trigger	= sun4i_i2s_trigger,
+};
+
+static int sun4i_i2s_dai_probe(struct snd_soc_dai *dai)
+{
+	struct sun4i_i2s *i2s = snd_soc_dai_get_drvdata(dai);
+
+	snd_soc_dai_init_dma_data(dai, &i2s->playback_dma_data, NULL);
+
+	snd_soc_dai_set_drvdata(dai, i2s);
+
+	return 0;
+}
+
+static struct snd_soc_dai_driver sun4i_i2s_dai = {
+	.probe = sun4i_i2s_dai_probe,
+	.playback = {
+		.stream_name = "Playback",
+		.channels_min = 2,
+		.channels_max = 2,
+		.rates = SNDRV_PCM_RATE_8000_192000,
+		.formats = SNDRV_PCM_FMTBIT_S16_LE,
+	},
+	.ops = &sun4i_i2s_dai_ops,
+	.symmetric_rates = 1,
+};
+
+static const struct snd_soc_component_driver sun4i_i2s_component = {
+	.name	= "sun4i-dai",
+};
+
+static bool sun4i_i2s_rd_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case SUN4I_I2S_FIFO_TX_REG:
+		return false;
+
+	default:
+		return true;
+	}
+}
+
+static bool sun4i_i2s_wr_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case SUN4I_I2S_FIFO_RX_REG:
+	case SUN4I_I2S_FIFO_STA_REG:
+		return false;
+
+	default:
+		return true;
+	}
+}
+
+static bool sun4i_i2s_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case SUN4I_I2S_FIFO_RX_REG:
+	case SUN4I_I2S_INT_STA_REG:
+	case SUN4I_I2S_RX_CNT_REG:
+	case SUN4I_I2S_TX_CNT_REG:
+		return true;
+
+	default:
+		return false;
+	}
+}
+
+static const struct reg_default sun4i_i2s_reg_defaults[] = {
+	{ SUN4I_I2S_CTRL_REG, 0x00000000 },
+	{ SUN4I_I2S_FMT0_REG, 0x0000000c },
+	{ SUN4I_I2S_FMT1_REG, 0x00004020 },
+	{ SUN4I_I2S_FIFO_CTRL_REG, 0x000400f0 },
+	{ SUN4I_I2S_DMA_INT_CTRL_REG, 0x00000000 },
+	{ SUN4I_I2S_CLK_DIV_REG, 0x00000000 },
+	{ SUN4I_I2S_TX_CHAN_SEL_REG, 0x00000001 },
+	{ SUN4I_I2S_TX_CHAN_MAP_REG, 0x76543210 },
+	{ SUN4I_I2S_RX_CHAN_SEL_REG, 0x00000001 },
+	{ SUN4I_I2S_RX_CHAN_MAP_REG, 0x00003210 },
+};
+
+static const struct regmap_config sun4i_i2s_regmap_config = {
+	.reg_bits	= 32,
+	.reg_stride	= 4,
+	.val_bits	= 32,
+	.max_register	= SUN4I_I2S_RX_CHAN_MAP_REG,
+
+	.cache_type	= REGCACHE_FLAT,
+	.reg_defaults	= sun4i_i2s_reg_defaults,
+	.num_reg_defaults	= ARRAY_SIZE(sun4i_i2s_reg_defaults),
+	.writeable_reg	= sun4i_i2s_wr_reg,
+	.readable_reg	= sun4i_i2s_rd_reg,
+	.volatile_reg	= sun4i_i2s_volatile_reg,
+};
+
+static int sun4i_i2s_runtime_resume(struct device *dev)
+{
+	struct sun4i_i2s *i2s = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_prepare_enable(i2s->bus_clk);
+	if (ret) {
+		dev_err(dev, "Failed to enable bus clock\n");
+		return ret;
+	}
+
+	regcache_cache_only(i2s->regmap, false);
+	regcache_mark_dirty(i2s->regmap);
+
+	ret = regcache_sync(i2s->regmap);
+	if (ret) {
+		dev_err(dev, "Failed to sync regmap cache\n");
+		goto err_disable_clk;
+	}
+
+	return 0;
+
+err_disable_clk:
+	clk_disable_unprepare(i2s->bus_clk);
+	return ret;
+}
+
+static int sun4i_i2s_runtime_suspend(struct device *dev)
+{
+	struct sun4i_i2s *i2s = dev_get_drvdata(dev);
+
+	regcache_cache_only(i2s->regmap, true);
+
+	clk_disable_unprepare(i2s->bus_clk);
+
+	return 0;
+}
+
+static int sun4i_i2s_probe(struct platform_device *pdev)
+{
+	struct sun4i_i2s *i2s;
+	struct resource *res;
+	void __iomem *regs;
+	int irq, ret;
+
+	i2s = devm_kzalloc(&pdev->dev, sizeof(*i2s), GFP_KERNEL);
+	if (!i2s)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, i2s);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(regs)) {
+		dev_err(&pdev->dev, "Can't request IO region\n");
+		return PTR_ERR(regs);
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(&pdev->dev, "Can't retrieve our interrupt\n");
+		return irq;
+	}
+
+	i2s->bus_clk = devm_clk_get(&pdev->dev, "apb");
+	if (IS_ERR(i2s->bus_clk)) {
+		dev_err(&pdev->dev, "Can't get our bus clock\n");
+		return PTR_ERR(i2s->bus_clk);
+	}
+
+	i2s->regmap = devm_regmap_init_mmio(&pdev->dev, regs,
+					    &sun4i_i2s_regmap_config);
+	if (IS_ERR(i2s->regmap)) {
+		dev_err(&pdev->dev, "Regmap initialisation failed\n");
+		return PTR_ERR(i2s->regmap);
+	};
+
+	i2s->mod_clk = devm_clk_get(&pdev->dev, "mod");
+	if (IS_ERR(i2s->mod_clk)) {
+		dev_err(&pdev->dev, "Can't get our mod clock\n");
+		return PTR_ERR(i2s->mod_clk);
+	}
+	
+	i2s->playback_dma_data.addr = res->start + SUN4I_I2S_FIFO_TX_REG;
+	i2s->playback_dma_data.maxburst = 4;
+
+	pm_runtime_enable(&pdev->dev);
+	if (!pm_runtime_enabled(&pdev->dev)) {
+		ret = sun4i_i2s_runtime_resume(&pdev->dev);
+		if (ret)
+			goto err_pm_disable;
+	}
+
+	ret = devm_snd_soc_register_component(&pdev->dev,
+					      &sun4i_i2s_component,
+					      &sun4i_i2s_dai, 1);
+	if (ret) {
+		dev_err(&pdev->dev, "Could not register DAI\n");
+		goto err_suspend;
+	}
+
+	ret = snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
+	if (ret) {
+		dev_err(&pdev->dev, "Could not register PCM\n");
+		goto err_suspend;
+	}
+
+	return 0;
+
+err_suspend:
+	if (!pm_runtime_status_suspended(&pdev->dev))
+		sun4i_i2s_runtime_suspend(&pdev->dev);
+err_pm_disable:
+	pm_runtime_disable(&pdev->dev);
+
+	return ret;
+}
+
+static int sun4i_i2s_remove(struct platform_device *pdev)
+{
+	snd_dmaengine_pcm_unregister(&pdev->dev);
+
+	pm_runtime_disable(&pdev->dev);
+	if (!pm_runtime_status_suspended(&pdev->dev))
+		sun4i_i2s_runtime_suspend(&pdev->dev);
+
+	return 0;
+}
+
+static const struct of_device_id sun4i_i2s_match[] = {
+	{ .compatible = "allwinner,sun4i-a10-i2s", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, sun4i_i2s_match);
+
+static const struct dev_pm_ops sun4i_i2s_pm_ops = {
+	.runtime_resume		= sun4i_i2s_runtime_resume,
+	.runtime_suspend	= sun4i_i2s_runtime_suspend,
+};
+
+static struct platform_driver sun4i_i2s_driver = {
+	.probe	= sun4i_i2s_probe,
+	.remove	= sun4i_i2s_remove,
+	.driver	= {
+		.name		= "sun4i-i2s",
+		.of_match_table	= sun4i_i2s_match,
+		.pm		= &sun4i_i2s_pm_ops,
+	},
+};
+module_platform_driver(sun4i_i2s_driver);
+
+MODULE_AUTHOR("Andrea Venturi <be17068@iperbole.bo.it>");
+MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
+MODULE_DESCRIPTION("Allwinner A10 I2S driver");
+MODULE_LICENSE("GPL");