diff mbox

Applied "ASoC: atmel-i2s: add driver for the new Atmel I2S controller" to the asoc tree

Message ID E1fNg5W-0005nL-TG@debutante (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Mark Brown May 29, 2018, 2:59 p.m. UTC
The patch

   ASoC: atmel-i2s: add driver for the new Atmel I2S controller

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 b543e467d1a9451013cd89ddcacde07dda9e7f32 Mon Sep 17 00:00:00 2001
From: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Date: Fri, 25 May 2018 15:34:26 +0300
Subject: [PATCH] ASoC: atmel-i2s: add driver for the new Atmel I2S controller

This patch adds support for the Atmel I2S controller embedded into
sama5d2x SoCs.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 sound/soc/atmel/Kconfig     |   9 +
 sound/soc/atmel/Makefile    |   2 +
 sound/soc/atmel/atmel-i2s.c | 765 ++++++++++++++++++++++++++++++++++++
 3 files changed, 776 insertions(+)
 create mode 100644 sound/soc/atmel/atmel-i2s.c
diff mbox

Patch

diff --git a/sound/soc/atmel/Kconfig b/sound/soc/atmel/Kconfig
index dcee145dd179..64b784e96f84 100644
--- a/sound/soc/atmel/Kconfig
+++ b/sound/soc/atmel/Kconfig
@@ -88,4 +88,13 @@  config SND_ATMEL_SOC_TSE850_PCM5142
 	help
 	  Say Y if you want to add support for the ASoC driver for the
 	  Axentia TSE-850 with a PCM5142 codec.
+
+config SND_ATMEL_SOC_I2S
+	tristate "Atmel ASoC driver for boards using I2S"
+	depends on OF && (ARCH_AT91 || COMPILE_TEST)
+	select SND_SOC_GENERIC_DMAENGINE_PCM
+	select REGMAP_MMIO
+	help
+	  Say Y or M if you want to add support for Atmel ASoc driver for boards
+	  using I2S.
 endif
diff --git a/sound/soc/atmel/Makefile b/sound/soc/atmel/Makefile
index 4440646416e8..cd87cb4bcff5 100644
--- a/sound/soc/atmel/Makefile
+++ b/sound/soc/atmel/Makefile
@@ -3,10 +3,12 @@ 
 snd-soc-atmel-pcm-pdc-objs := atmel-pcm-pdc.o
 snd-soc-atmel-pcm-dma-objs := atmel-pcm-dma.o
 snd-soc-atmel_ssc_dai-objs := atmel_ssc_dai.o
+snd-soc-atmel-i2s-objs := atmel-i2s.o
 
 obj-$(CONFIG_SND_ATMEL_SOC_PDC) += snd-soc-atmel-pcm-pdc.o
 obj-$(CONFIG_SND_ATMEL_SOC_DMA) += snd-soc-atmel-pcm-dma.o
 obj-$(CONFIG_SND_ATMEL_SOC_SSC) += snd-soc-atmel_ssc_dai.o
+obj-$(CONFIG_SND_ATMEL_SOC_I2S) += snd-soc-atmel-i2s.o
 
 # AT91 Machine Support
 snd-soc-sam9g20-wm8731-objs := sam9g20_wm8731.o
diff --git a/sound/soc/atmel/atmel-i2s.c b/sound/soc/atmel/atmel-i2s.c
new file mode 100644
index 000000000000..5d3b5af9fd92
--- /dev/null
+++ b/sound/soc/atmel/atmel-i2s.c
@@ -0,0 +1,765 @@ 
+/*
+ * Driver for Atmel I2S controller
+ *
+ * Copyright (C) 2015 Atmel Corporation
+ *
+ * Author: Cyrille Pitchen <cyrille.pitchen@atmel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/mfd/syscon.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/initval.h>
+#include <sound/soc.h>
+#include <sound/dmaengine_pcm.h>
+
+#define ATMEL_I2SC_MAX_TDM_CHANNELS	8
+
+/*
+ * ---- I2S Controller Register map ----
+ */
+#define ATMEL_I2SC_CR		0x0000	/* Control Register */
+#define ATMEL_I2SC_MR		0x0004	/* Mode Register */
+#define ATMEL_I2SC_SR		0x0008	/* Status Register */
+#define ATMEL_I2SC_SCR		0x000c	/* Status Clear Register */
+#define ATMEL_I2SC_SSR		0x0010	/* Status Set Register */
+#define ATMEL_I2SC_IER		0x0014	/* Interrupt Enable Register */
+#define ATMEL_I2SC_IDR		0x0018	/* Interrupt Disable Register */
+#define ATMEL_I2SC_IMR		0x001c	/* Interrupt Mask Register */
+#define ATMEL_I2SC_RHR		0x0020	/* Receiver Holding Register */
+#define ATMEL_I2SC_THR		0x0024	/* Transmitter Holding Register */
+#define ATMEL_I2SC_VERSION	0x0028	/* Version Register */
+
+/*
+ * ---- Control Register (Write-only) ----
+ */
+#define ATMEL_I2SC_CR_RXEN	BIT(0)	/* Receiver Enable */
+#define ATMEL_I2SC_CR_RXDIS	BIT(1)	/* Receiver Disable */
+#define ATMEL_I2SC_CR_CKEN	BIT(2)	/* Clock Enable */
+#define ATMEL_I2SC_CR_CKDIS	BIT(3)	/* Clock Disable */
+#define ATMEL_I2SC_CR_TXEN	BIT(4)	/* Transmitter Enable */
+#define ATMEL_I2SC_CR_TXDIS	BIT(5)	/* Transmitter Disable */
+#define ATMEL_I2SC_CR_SWRST	BIT(7)	/* Software Reset */
+
+/*
+ * ---- Mode Register (Read/Write) ----
+ */
+#define ATMEL_I2SC_MR_MODE_MASK		GENMASK(0, 0)
+#define ATMEL_I2SC_MR_MODE_SLAVE	(0 << 0)
+#define ATMEL_I2SC_MR_MODE_MASTER	(1 << 0)
+
+#define ATMEL_I2SC_MR_DATALENGTH_MASK		GENMASK(4, 2)
+#define ATMEL_I2SC_MR_DATALENGTH_32_BITS	(0 << 2)
+#define ATMEL_I2SC_MR_DATALENGTH_24_BITS	(1 << 2)
+#define ATMEL_I2SC_MR_DATALENGTH_20_BITS	(2 << 2)
+#define ATMEL_I2SC_MR_DATALENGTH_18_BITS	(3 << 2)
+#define ATMEL_I2SC_MR_DATALENGTH_16_BITS	(4 << 2)
+#define ATMEL_I2SC_MR_DATALENGTH_16_BITS_COMPACT	(5 << 2)
+#define ATMEL_I2SC_MR_DATALENGTH_8_BITS		(6 << 2)
+#define ATMEL_I2SC_MR_DATALENGTH_8_BITS_COMPACT	(7 << 2)
+
+#define ATMEL_I2SC_MR_FORMAT_MASK	GENMASK(7, 6)
+#define ATMEL_I2SC_MR_FORMAT_I2S	(0 << 6)
+#define ATMEL_I2SC_MR_FORMAT_LJ		(1 << 6)  /* Left Justified */
+#define ATMEL_I2SC_MR_FORMAT_TDM	(2 << 6)
+#define ATMEL_I2SC_MR_FORMAT_TDMLJ	(3 << 6)
+
+/* Left audio samples duplicated to right audio channel */
+#define ATMEL_I2SC_MR_RXMONO		BIT(8)
+
+/* Receiver uses one DMA channel ... */
+#define ATMEL_I2SC_MR_RXDMA_MASK	GENMASK(9, 9)
+#define ATMEL_I2SC_MR_RXDMA_SINGLE	(0 << 9)  /* for all audio channels */
+#define ATMEL_I2SC_MR_RXDMA_MULTIPLE	(1 << 9)  /* per audio channel */
+
+/* I2SDO output of I2SC is internally connected to I2SDI input */
+#define ATMEL_I2SC_MR_RXLOOP		BIT(10)
+
+/* Left audio samples duplicated to right audio channel */
+#define ATMEL_I2SC_MR_TXMONO		BIT(12)
+
+/* Transmitter uses one DMA channel ... */
+#define ATMEL_I2SC_MR_TXDMA_MASK	GENMASK(13, 13)
+#define ATMEL_I2SC_MR_TXDMA_SINGLE	(0 << 13)  /* for all audio channels */
+#define ATMEL_I2SC_MR_TXDME_MULTIPLE	(1 << 13)  /* per audio channel */
+
+/* x sample transmitted when underrun */
+#define ATMEL_I2SC_MR_TXSAME_MASK	GENMASK(14, 14)
+#define ATMEL_I2SC_MR_TXSAME_ZERO	(0 << 14)  /* Zero sample */
+#define ATMEL_I2SC_MR_TXSAME_PREVIOUS	(1 << 14)  /* Previous sample */
+
+/* Audio Clock to I2SC Master Clock ratio */
+#define ATMEL_I2SC_MR_IMCKDIV_MASK	GENMASK(21, 16)
+#define ATMEL_I2SC_MR_IMCKDIV(div) \
+	(((div) << 16) & ATMEL_I2SC_MR_IMCKDIV_MASK)
+
+/* Master Clock to fs ratio */
+#define ATMEL_I2SC_MR_IMCKFS_MASK	GENMASK(29, 24)
+#define ATMEL_I2SC_MR_IMCKFS(fs) \
+	(((fs) << 24) & ATMEL_I2SC_MR_IMCKFS_MASK)
+
+/* Master Clock mode */
+#define ATMEL_I2SC_MR_IMCKMODE_MASK	GENMASK(30, 30)
+/* 0: No master clock generated (selected clock drives I2SCK pin) */
+#define ATMEL_I2SC_MR_IMCKMODE_I2SCK	(0 << 30)
+/* 1: master clock generated (internally generated clock drives I2SMCK pin) */
+#define ATMEL_I2SC_MR_IMCKMODE_I2SMCK	(1 << 30)
+
+/* Slot Width */
+/* 0: slot is 32 bits wide for DATALENGTH = 18/20/24 bits. */
+/* 1: slot is 24 bits wide for DATALENGTH = 18/20/24 bits. */
+#define ATMEL_I2SC_MR_IWS		BIT(31)
+
+/*
+ * ---- Status Registers ----
+ */
+#define ATMEL_I2SC_SR_RXEN	BIT(0)	/* Receiver Enabled */
+#define ATMEL_I2SC_SR_RXRDY	BIT(1)	/* Receive Ready */
+#define ATMEL_I2SC_SR_RXOR	BIT(2)	/* Receive Overrun */
+
+#define ATMEL_I2SC_SR_TXEN	BIT(4)	/* Transmitter Enabled */
+#define ATMEL_I2SC_SR_TXRDY	BIT(5)	/* Transmit Ready */
+#define ATMEL_I2SC_SR_TXUR	BIT(6)	/* Transmit Underrun */
+
+/* Receive Overrun Channel */
+#define ATMEL_I2SC_SR_RXORCH_MASK	GENMASK(15, 8)
+#define ATMEL_I2SC_SR_RXORCH(ch)	(1 << (((ch) & 0x7) + 8))
+
+/* Transmit Underrun Channel */
+#define ATMEL_I2SC_SR_TXURCH_MASK	GENMASK(27, 20)
+#define ATMEL_I2SC_SR_TXURCH(ch)	(1 << (((ch) & 0x7) + 20))
+
+/*
+ * ---- Interrupt Enable/Disable/Mask Registers ----
+ */
+#define ATMEL_I2SC_INT_RXRDY	ATMEL_I2SC_SR_RXRDY
+#define ATMEL_I2SC_INT_RXOR	ATMEL_I2SC_SR_RXOR
+#define ATMEL_I2SC_INT_TXRDY	ATMEL_I2SC_SR_TXRDY
+#define ATMEL_I2SC_INT_TXUR	ATMEL_I2SC_SR_TXUR
+
+static const struct regmap_config atmel_i2s_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.max_register = ATMEL_I2SC_VERSION,
+};
+
+struct atmel_i2s_gck_param {
+	int		fs;
+	unsigned long	mck;
+	int		imckdiv;
+	int		imckfs;
+};
+
+#define I2S_MCK_12M288		12288000UL
+#define I2S_MCK_11M2896		11289600UL
+
+/* mck = (32 * (imckfs+1) / (imckdiv+1)) * fs */
+static const struct atmel_i2s_gck_param gck_params[] = {
+	/* mck = 12.288MHz */
+	{  8000, I2S_MCK_12M288, 0, 47},	/* mck = 1536 fs */
+	{ 16000, I2S_MCK_12M288, 1, 47},	/* mck =  768 fs */
+	{ 24000, I2S_MCK_12M288, 3, 63},	/* mck =  512 fs */
+	{ 32000, I2S_MCK_12M288, 3, 47},	/* mck =  384 fs */
+	{ 48000, I2S_MCK_12M288, 7, 63},	/* mck =  256 fs */
+	{ 64000, I2S_MCK_12M288, 7, 47},	/* mck =  192 fs */
+	{ 96000, I2S_MCK_12M288, 7, 31},	/* mck =  128 fs */
+	{192000, I2S_MCK_12M288, 7, 15},	/* mck =   64 fs */
+
+	/* mck = 11.2896MHz */
+	{ 11025, I2S_MCK_11M2896, 1, 63},	/* mck = 1024 fs */
+	{ 22050, I2S_MCK_11M2896, 3, 63},	/* mck =  512 fs */
+	{ 44100, I2S_MCK_11M2896, 7, 63},	/* mck =  256 fs */
+	{ 88200, I2S_MCK_11M2896, 7, 31},	/* mck =  128 fs */
+	{176400, I2S_MCK_11M2896, 7, 15},	/* mck =   64 fs */
+};
+
+struct atmel_i2s_dev;
+
+struct atmel_i2s_caps {
+	int	(*mck_init)(struct atmel_i2s_dev *, struct device_node *np);
+};
+
+struct atmel_i2s_dev {
+	struct device				*dev;
+	struct regmap				*regmap;
+	struct clk				*pclk;
+	struct clk				*gclk;
+	struct clk				*aclk;
+	struct snd_dmaengine_dai_dma_data	playback;
+	struct snd_dmaengine_dai_dma_data	capture;
+	unsigned int				fmt;
+	const struct atmel_i2s_gck_param	*gck_param;
+	const struct atmel_i2s_caps		*caps;
+};
+
+static irqreturn_t atmel_i2s_interrupt(int irq, void *dev_id)
+{
+	struct atmel_i2s_dev *dev = dev_id;
+	unsigned int sr, imr, pending, ch, mask;
+	irqreturn_t ret = IRQ_NONE;
+
+	regmap_read(dev->regmap, ATMEL_I2SC_SR, &sr);
+	regmap_read(dev->regmap, ATMEL_I2SC_IMR, &imr);
+	pending = sr & imr;
+
+	if (!pending)
+		return IRQ_NONE;
+
+	if (pending & ATMEL_I2SC_INT_RXOR) {
+		mask = ATMEL_I2SC_SR_RXOR;
+
+		for (ch = 0; ch < ATMEL_I2SC_MAX_TDM_CHANNELS; ++ch) {
+			if (sr & ATMEL_I2SC_SR_RXORCH(ch)) {
+				mask |= ATMEL_I2SC_SR_RXORCH(ch);
+				dev_err(dev->dev,
+					"RX overrun on channel %d\n", ch);
+			}
+		}
+		regmap_write(dev->regmap, ATMEL_I2SC_SCR, mask);
+		ret = IRQ_HANDLED;
+	}
+
+	if (pending & ATMEL_I2SC_INT_TXUR) {
+		mask = ATMEL_I2SC_SR_TXUR;
+
+		for (ch = 0; ch < ATMEL_I2SC_MAX_TDM_CHANNELS; ++ch) {
+			if (sr & ATMEL_I2SC_SR_TXURCH(ch)) {
+				mask |= ATMEL_I2SC_SR_TXURCH(ch);
+				dev_err(dev->dev,
+					"TX underrun on channel %d\n", ch);
+			}
+		}
+		regmap_write(dev->regmap, ATMEL_I2SC_SCR, mask);
+		ret = IRQ_HANDLED;
+	}
+
+	return ret;
+}
+
+#define ATMEL_I2S_RATES		SNDRV_PCM_RATE_8000_192000
+
+#define ATMEL_I2S_FORMATS	(SNDRV_PCM_FMTBIT_S8 |		\
+				 SNDRV_PCM_FMTBIT_S16_LE |	\
+				 SNDRV_PCM_FMTBIT_S18_3LE |	\
+				 SNDRV_PCM_FMTBIT_S20_3LE |	\
+				 SNDRV_PCM_FMTBIT_S24_3LE |	\
+				 SNDRV_PCM_FMTBIT_S24_LE |	\
+				 SNDRV_PCM_FMTBIT_S32_LE)
+
+static int atmel_i2s_set_dai_fmt(struct snd_soc_dai *dai, unsigned int fmt)
+{
+	struct atmel_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
+
+	dev->fmt = fmt;
+	return 0;
+}
+
+static int atmel_i2s_prepare(struct snd_pcm_substream *substream,
+			     struct snd_soc_dai *dai)
+{
+	struct atmel_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
+	bool is_playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
+	unsigned int rhr, sr = 0;
+
+	if (is_playback) {
+		regmap_read(dev->regmap, ATMEL_I2SC_SR, &sr);
+		if (sr & ATMEL_I2SC_SR_RXRDY) {
+			/*
+			 * The RX Ready flag should not be set. However if here,
+			 * we flush (read) the Receive Holding Register to start
+			 * from a clean state.
+			 */
+			dev_dbg(dev->dev, "RXRDY is set\n");
+			regmap_read(dev->regmap, ATMEL_I2SC_RHR, &rhr);
+		}
+	}
+
+	return 0;
+}
+
+static int atmel_i2s_get_gck_param(struct atmel_i2s_dev *dev, int fs)
+{
+	int i, best;
+
+	if (!dev->gclk || !dev->aclk) {
+		dev_err(dev->dev, "cannot generate the I2S Master Clock\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Find the best possible settings to generate the I2S Master Clock
+	 * from the PLL Audio.
+	 */
+	dev->gck_param = NULL;
+	best = INT_MAX;
+	for (i = 0; i < ARRAY_SIZE(gck_params); ++i) {
+		const struct atmel_i2s_gck_param *gck_param = &gck_params[i];
+		int val = abs(fs - gck_param->fs);
+
+		if (val < best) {
+			best = val;
+			dev->gck_param = gck_param;
+		}
+	}
+
+	return 0;
+}
+
+static int atmel_i2s_hw_params(struct snd_pcm_substream *substream,
+			       struct snd_pcm_hw_params *params,
+			       struct snd_soc_dai *dai)
+{
+	struct atmel_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
+	bool is_playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
+	unsigned int mr = 0;
+	int ret;
+
+	switch (dev->fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
+	case SND_SOC_DAIFMT_I2S:
+		mr |= ATMEL_I2SC_MR_FORMAT_I2S;
+		break;
+
+	default:
+		dev_err(dev->dev, "unsupported bus format\n");
+		return -EINVAL;
+	}
+
+	switch (dev->fmt & SND_SOC_DAIFMT_MASTER_MASK) {
+	case SND_SOC_DAIFMT_CBS_CFS:
+		/* codec is slave, so cpu is master */
+		mr |= ATMEL_I2SC_MR_MODE_MASTER;
+		ret = atmel_i2s_get_gck_param(dev, params_rate(params));
+		if (ret)
+			return ret;
+		break;
+
+	case SND_SOC_DAIFMT_CBM_CFM:
+		/* codec is master, so cpu is slave */
+		mr |= ATMEL_I2SC_MR_MODE_SLAVE;
+		dev->gck_param = NULL;
+		break;
+
+	default:
+		dev_err(dev->dev, "unsupported master/slave mode\n");
+		return -EINVAL;
+	}
+
+	switch (params_channels(params)) {
+	case 1:
+		if (is_playback)
+			mr |= ATMEL_I2SC_MR_TXMONO;
+		else
+			mr |= ATMEL_I2SC_MR_RXMONO;
+		break;
+	case 2:
+		break;
+	default:
+		dev_err(dev->dev, "unsupported number of audio channels\n");
+		return -EINVAL;
+	}
+
+	switch (params_format(params)) {
+	case SNDRV_PCM_FORMAT_S8:
+		mr |= ATMEL_I2SC_MR_DATALENGTH_8_BITS;
+		break;
+
+	case SNDRV_PCM_FORMAT_S16_LE:
+		mr |= ATMEL_I2SC_MR_DATALENGTH_16_BITS;
+		break;
+
+	case SNDRV_PCM_FORMAT_S18_3LE:
+		mr |= ATMEL_I2SC_MR_DATALENGTH_18_BITS | ATMEL_I2SC_MR_IWS;
+		break;
+
+	case SNDRV_PCM_FORMAT_S20_3LE:
+		mr |= ATMEL_I2SC_MR_DATALENGTH_20_BITS | ATMEL_I2SC_MR_IWS;
+		break;
+
+	case SNDRV_PCM_FORMAT_S24_3LE:
+		mr |= ATMEL_I2SC_MR_DATALENGTH_24_BITS | ATMEL_I2SC_MR_IWS;
+		break;
+
+	case SNDRV_PCM_FORMAT_S24_LE:
+		mr |= ATMEL_I2SC_MR_DATALENGTH_24_BITS;
+		break;
+
+	case SNDRV_PCM_FORMAT_S32_LE:
+		mr |= ATMEL_I2SC_MR_DATALENGTH_32_BITS;
+		break;
+
+	default:
+		dev_err(dev->dev, "unsupported size/endianness for audio samples\n");
+		return -EINVAL;
+	}
+
+	return regmap_write(dev->regmap, ATMEL_I2SC_MR, mr);
+}
+
+static int atmel_i2s_switch_mck_generator(struct atmel_i2s_dev *dev,
+					  bool enabled)
+{
+	unsigned int mr, mr_mask;
+	unsigned long aclk_rate;
+	int ret;
+
+	mr = 0;
+	mr_mask = (ATMEL_I2SC_MR_IMCKDIV_MASK |
+		   ATMEL_I2SC_MR_IMCKFS_MASK |
+		   ATMEL_I2SC_MR_IMCKMODE_MASK);
+
+	if (!enabled) {
+		/* Disable the I2S Master Clock generator. */
+		ret = regmap_write(dev->regmap, ATMEL_I2SC_CR,
+				   ATMEL_I2SC_CR_CKDIS);
+		if (ret)
+			return ret;
+
+		/* Reset the I2S Master Clock generator settings. */
+		ret = regmap_update_bits(dev->regmap, ATMEL_I2SC_MR,
+					 mr_mask, mr);
+		if (ret)
+			return ret;
+
+		/* Disable/unprepare the PMC generated clock. */
+		clk_disable_unprepare(dev->gclk);
+
+		/* Disable/unprepare the PLL audio clock. */
+		clk_disable_unprepare(dev->aclk);
+		return 0;
+	}
+
+	if (!dev->gck_param)
+		return -EINVAL;
+
+	aclk_rate = dev->gck_param->mck * (dev->gck_param->imckdiv + 1);
+
+	/* Fist change the PLL audio clock frequency ... */
+	ret = clk_set_rate(dev->aclk, aclk_rate);
+	if (ret)
+		return ret;
+
+	/*
+	 * ... then set the PMC generated clock rate to the very same frequency
+	 * to set the gclk parent to aclk.
+	 */
+	ret = clk_set_rate(dev->gclk, aclk_rate);
+	if (ret)
+		return ret;
+
+	/* Prepare and enable the PLL audio clock first ... */
+	ret = clk_prepare_enable(dev->aclk);
+	if (ret)
+		return ret;
+
+	/* ... then prepare and enable the PMC generated clock. */
+	ret = clk_prepare_enable(dev->gclk);
+	if (ret)
+		return ret;
+
+	/* Update the Mode Register to generate the I2S Master Clock. */
+	mr |= ATMEL_I2SC_MR_IMCKDIV(dev->gck_param->imckdiv);
+	mr |= ATMEL_I2SC_MR_IMCKFS(dev->gck_param->imckfs);
+	mr |= ATMEL_I2SC_MR_IMCKMODE_I2SMCK;
+	ret = regmap_update_bits(dev->regmap, ATMEL_I2SC_MR, mr_mask, mr);
+	if (ret)
+		return ret;
+
+	/* Finally enable the I2S Master Clock generator. */
+	return regmap_write(dev->regmap, ATMEL_I2SC_CR,
+			    ATMEL_I2SC_CR_CKEN);
+}
+
+static int atmel_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
+			     struct snd_soc_dai *dai)
+{
+	struct atmel_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
+	bool is_playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
+	bool is_master, mck_enabled;
+	unsigned int cr, mr;
+	int err;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		cr = is_playback ? ATMEL_I2SC_CR_TXEN : ATMEL_I2SC_CR_RXEN;
+		mck_enabled = true;
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		cr = is_playback ? ATMEL_I2SC_CR_TXDIS : ATMEL_I2SC_CR_RXDIS;
+		mck_enabled = false;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* Read the Mode Register to retrieve the master/slave state. */
+	err = regmap_read(dev->regmap, ATMEL_I2SC_MR, &mr);
+	if (err)
+		return err;
+	is_master = (mr & ATMEL_I2SC_MR_MODE_MASK) == ATMEL_I2SC_MR_MODE_MASTER;
+
+	/* If master starts, enable the audio clock. */
+	if (is_master && mck_enabled)
+		err = atmel_i2s_switch_mck_generator(dev, true);
+	if (err)
+		return err;
+
+	err = regmap_write(dev->regmap, ATMEL_I2SC_CR, cr);
+	if (err)
+		return err;
+
+	/* If master stops, disable the audio clock. */
+	if (is_master && !mck_enabled)
+		err = atmel_i2s_switch_mck_generator(dev, false);
+
+	return err;
+}
+
+static const struct snd_soc_dai_ops atmel_i2s_dai_ops = {
+	.prepare	= atmel_i2s_prepare,
+	.trigger	= atmel_i2s_trigger,
+	.hw_params	= atmel_i2s_hw_params,
+	.set_fmt	= atmel_i2s_set_dai_fmt,
+};
+
+static int atmel_i2s_dai_probe(struct snd_soc_dai *dai)
+{
+	struct atmel_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
+
+	snd_soc_dai_init_dma_data(dai, &dev->playback, &dev->capture);
+	return 0;
+}
+
+static struct snd_soc_dai_driver atmel_i2s_dai = {
+	.probe	= atmel_i2s_dai_probe,
+	.playback = {
+		.channels_min = 1,
+		.channels_max = 2,
+		.rates = ATMEL_I2S_RATES,
+		.formats = ATMEL_I2S_FORMATS,
+	},
+	.capture = {
+		.channels_min = 1,
+		.channels_max = 2,
+		.rates = ATMEL_I2S_RATES,
+		.formats = ATMEL_I2S_FORMATS,
+	},
+	.ops = &atmel_i2s_dai_ops,
+	.symmetric_rates = 1,
+};
+
+static const struct snd_soc_component_driver atmel_i2s_component = {
+	.name	= "atmel-i2s",
+};
+
+static int atmel_i2s_sama5d2_mck_init(struct atmel_i2s_dev *dev,
+				      struct device_node *np)
+{
+	struct clk *muxclk;
+	int err;
+
+	if (!dev->gclk)
+		return 0;
+
+	/* muxclk is optional, so we return error for probe defer only */
+	muxclk = devm_clk_get(dev->dev, "muxclk");
+	if (IS_ERR(muxclk)) {
+		err = PTR_ERR(muxclk);
+		if (err == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+		dev_warn(dev->dev,
+			 "failed to get the I2S clock control: %d\n", err);
+		return 0;
+	}
+
+	return clk_set_parent(muxclk, dev->gclk);
+}
+
+static const struct atmel_i2s_caps atmel_i2s_sama5d2_caps = {
+	.mck_init = atmel_i2s_sama5d2_mck_init,
+};
+
+static const struct of_device_id atmel_i2s_dt_ids[] = {
+	{
+		.compatible = "atmel,sama5d2-i2s",
+		.data = (void *)&atmel_i2s_sama5d2_caps,
+	},
+
+	{ /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, atmel_i2s_dt_ids);
+
+static int atmel_i2s_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	const struct of_device_id *match;
+	struct atmel_i2s_dev *dev;
+	struct resource *mem;
+	struct regmap *regmap;
+	void __iomem *base;
+	int irq;
+	int err = -ENXIO;
+	unsigned int pcm_flags = 0;
+	unsigned int version;
+
+	/* Get memory for driver data. */
+	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+
+	/* Get hardware capabilities. */
+	match = of_match_node(atmel_i2s_dt_ids, np);
+	if (match)
+		dev->caps = match->data;
+
+	/* Map I/O registers. */
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(&pdev->dev, mem);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	regmap = devm_regmap_init_mmio(&pdev->dev, base,
+				       &atmel_i2s_regmap_config);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	/* Request IRQ. */
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	err = devm_request_irq(&pdev->dev, irq, atmel_i2s_interrupt, 0,
+			       dev_name(&pdev->dev), dev);
+	if (err)
+		return err;
+
+	/* Get the peripheral clock. */
+	dev->pclk = devm_clk_get(&pdev->dev, "pclk");
+	if (IS_ERR(dev->pclk)) {
+		err = PTR_ERR(dev->pclk);
+		dev_err(&pdev->dev,
+			"failed to get the peripheral clock: %d\n", err);
+		return err;
+	}
+
+	/* Get audio clocks to generate the I2S Master Clock (I2S_MCK) */
+	dev->aclk = devm_clk_get(&pdev->dev, "aclk");
+	dev->gclk = devm_clk_get(&pdev->dev, "gclk");
+	if (IS_ERR(dev->aclk) && IS_ERR(dev->gclk)) {
+		if (PTR_ERR(dev->aclk) == -EPROBE_DEFER ||
+		    PTR_ERR(dev->gclk) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+		/* Master Mode not supported */
+		dev->aclk = NULL;
+		dev->gclk = NULL;
+	} else if (IS_ERR(dev->gclk)) {
+		err = PTR_ERR(dev->gclk);
+		dev_err(&pdev->dev,
+			"failed to get the PMC generated clock: %d\n", err);
+		return err;
+	} else if (IS_ERR(dev->aclk)) {
+		err = PTR_ERR(dev->aclk);
+		dev_err(&pdev->dev,
+			"failed to get the PLL audio clock: %d\n", err);
+		return err;
+	}
+
+	dev->dev = &pdev->dev;
+	dev->regmap = regmap;
+	platform_set_drvdata(pdev, dev);
+
+	/* Do hardware specific settings to initialize I2S_MCK generator */
+	if (dev->caps && dev->caps->mck_init) {
+		err = dev->caps->mck_init(dev, np);
+		if (err)
+			return err;
+	}
+
+	/* Enable the peripheral clock. */
+	err = clk_prepare_enable(dev->pclk);
+	if (err)
+		return err;
+
+	/* Get IP version. */
+	regmap_read(dev->regmap, ATMEL_I2SC_VERSION, &version);
+	dev_info(&pdev->dev, "hw version: %#x\n", version);
+
+	/* Enable error interrupts. */
+	regmap_write(dev->regmap, ATMEL_I2SC_IER,
+		     ATMEL_I2SC_INT_RXOR | ATMEL_I2SC_INT_TXUR);
+
+	err = devm_snd_soc_register_component(&pdev->dev,
+					      &atmel_i2s_component,
+					      &atmel_i2s_dai, 1);
+	if (err) {
+		dev_err(&pdev->dev, "failed to register DAI: %d\n", err);
+		clk_disable_unprepare(dev->pclk);
+		return err;
+	}
+
+	/* Prepare DMA config. */
+	dev->playback.addr	= (dma_addr_t)mem->start + ATMEL_I2SC_THR;
+	dev->playback.maxburst	= 1;
+	dev->capture.addr	= (dma_addr_t)mem->start + ATMEL_I2SC_RHR;
+	dev->capture.maxburst	= 1;
+
+	if (of_property_match_string(np, "dma-names", "rx-tx") == 0)
+		pcm_flags |= SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX;
+	err = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, pcm_flags);
+	if (err) {
+		dev_err(&pdev->dev, "failed to register PCM: %d\n", err);
+		clk_disable_unprepare(dev->pclk);
+		return err;
+	}
+
+	return 0;
+}
+
+static int atmel_i2s_remove(struct platform_device *pdev)
+{
+	struct atmel_i2s_dev *dev = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(dev->pclk);
+
+	return 0;
+}
+
+static struct platform_driver atmel_i2s_driver = {
+	.driver		= {
+		.name	= "atmel_i2s",
+		.of_match_table	= of_match_ptr(atmel_i2s_dt_ids),
+	},
+	.probe		= atmel_i2s_probe,
+	.remove		= atmel_i2s_remove,
+};
+module_platform_driver(atmel_i2s_driver);
+
+MODULE_DESCRIPTION("Atmel I2S Controller driver");
+MODULE_AUTHOR("Cyrille Pitchen <cyrille.pitchen@atmel.com>");
+MODULE_LICENSE("GPL v2");