ASoC: fsl_esai: Add ESAI CPU DAI driver

This patch implements a device-tree-only CPU DAI driver for Freescale ESAI
controller that supports:

 - 12 channels playback and 8 channels record.
   [ Some of the inner transmitters and receivers are sharing same group of
     pins. So the maxmium 12 output or 8 input channels are only valid if
     there is no pin conflict occurring to it. ]

 - Independent (asynchronous mode) or shared (synchronous mode) transmit and
   receive sections with separate or shared internal/external clocks and frame
   syncs, operating in Master or Slave mode.
   [ Current ALSA seems not to allow CPU DAI drivers to configure DAI format
     separately for PLAYBACK and CAPTURE. So this first version only supports
     the case that uses the same DAI format for both directions. ]

 - Various DAI formats: I2S, Left-Justified, Right-Justified, DSP-A and DSP-B.

 - Programmable word length (8, 16, 20 or 24bits)

 - Flexible selection between system clock or external oscillator as input
   clock source, programmable internal clock divider and frame sync generation.

Signed-off-by: Nicolin Chen <Guangyu.Chen@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

1 files changed, 815 insertions, 0 deletions

diff --git a/sound/soc/fsl/fsl_esai.c b/sound/soc/fsl/fsl_esai.c
new file mode 100644
index 000000000000..d0c72ed261e7
--- /dev/null
+++ b/sound/soc/fsl/fsl_esai.c
@@ -0,0 +1,815 @@
+/*
+ * Freescale ESAI ALSA SoC Digital Audio Interface (DAI) driver
+ *
+ * Copyright (C) 2014 Freescale Semiconductor, Inc.
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#include <linux/clk.h>
+#include <linux/dmaengine.h>
+#include <linux/module.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <sound/dmaengine_pcm.h>
+#include <sound/pcm_params.h>
+
+#include "fsl_esai.h"
+#include "imx-pcm.h"
+
+#define FSL_ESAI_RATES		SNDRV_PCM_RATE_8000_192000
+#define FSL_ESAI_FORMATS	(SNDRV_PCM_FMTBIT_S8 | \
+				SNDRV_PCM_FMTBIT_S16_LE | \
+				SNDRV_PCM_FMTBIT_S20_3LE | \
+				SNDRV_PCM_FMTBIT_S24_LE)
+
+/**
+ * fsl_esai: ESAI private data
+ *
+ * @dma_params_rx: DMA parameters for receive channel
+ * @dma_params_tx: DMA parameters for transmit channel
+ * @pdev: platform device pointer
+ * @regmap: regmap handler
+ * @coreclk: clock source to access register
+ * @extalclk: esai clock source to derive HCK, SCK and FS
+ * @fsysclk: system clock source to derive HCK, SCK and FS
+ * @fifo_depth: depth of tx/rx FIFO
+ * @slot_width: width of each DAI slot
+ * @hck_rate: clock rate of desired HCKx clock
+ * @sck_div: if using PSR/PM dividers for SCKx clock
+ * @slave_mode: if fully using DAI slave mode
+ * @synchronous: if using tx/rx synchronous mode
+ * @name: driver name
+ */
+struct fsl_esai {
+	struct snd_dmaengine_dai_dma_data dma_params_rx;
+	struct snd_dmaengine_dai_dma_data dma_params_tx;
+	struct platform_device *pdev;
+	struct regmap *regmap;
+	struct clk *coreclk;
+	struct clk *extalclk;
+	struct clk *fsysclk;
+	u32 fifo_depth;
+	u32 slot_width;
+	u32 hck_rate[2];
+	bool sck_div[2];
+	bool slave_mode;
+	bool synchronous;
+	char name[32];
+};
+
+static irqreturn_t esai_isr(int irq, void *devid)
+{
+	struct fsl_esai *esai_priv = (struct fsl_esai *)devid;
+	struct platform_device *pdev = esai_priv->pdev;
+	u32 esr;
+
+	regmap_read(esai_priv->regmap, REG_ESAI_ESR, &esr);
+
+	if (esr & ESAI_ESR_TINIT_MASK)
+		dev_dbg(&pdev->dev, "isr: Transmition Initialized\n");
+
+	if (esr & ESAI_ESR_RFF_MASK)
+		dev_warn(&pdev->dev, "isr: Receiving overrun\n");
+
+	if (esr & ESAI_ESR_TFE_MASK)
+		dev_warn(&pdev->dev, "isr: Transmition underrun\n");
+
+	if (esr & ESAI_ESR_TLS_MASK)
+		dev_dbg(&pdev->dev, "isr: Just transmitted the last slot\n");
+
+	if (esr & ESAI_ESR_TDE_MASK)
+		dev_dbg(&pdev->dev, "isr: Transmition data exception\n");
+
+	if (esr & ESAI_ESR_TED_MASK)
+		dev_dbg(&pdev->dev, "isr: Transmitting even slots\n");
+
+	if (esr & ESAI_ESR_TD_MASK)
+		dev_dbg(&pdev->dev, "isr: Transmitting data\n");
+
+	if (esr & ESAI_ESR_RLS_MASK)
+		dev_dbg(&pdev->dev, "isr: Just received the last slot\n");
+
+	if (esr & ESAI_ESR_RDE_MASK)
+		dev_dbg(&pdev->dev, "isr: Receiving data exception\n");
+
+	if (esr & ESAI_ESR_RED_MASK)
+		dev_dbg(&pdev->dev, "isr: Receiving even slots\n");
+
+	if (esr & ESAI_ESR_RD_MASK)
+		dev_dbg(&pdev->dev, "isr: Receiving data\n");
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * This function is used to calculate the divisors of psr, pm, fp and it is
+ * supposed to be called in set_dai_sysclk() and set_bclk().
+ *
+ * @ratio: desired overall ratio for the paticipating dividers
+ * @usefp: for HCK setting, there is no need to set fp divider
+ * @fp: bypass other dividers by setting fp directly if fp != 0
+ * @tx: current setting is for playback or capture
+ */
+static int fsl_esai_divisor_cal(struct snd_soc_dai *dai, bool tx, u32 ratio,
+				bool usefp, u32 fp)
+{
+	struct fsl_esai *esai_priv = snd_soc_dai_get_drvdata(dai);
+	u32 psr, pm = 999, maxfp, prod, sub, savesub, i, j;
+
+	maxfp = usefp ? 16 : 1;
+
+	if (usefp && fp)
+		goto out_fp;
+
+	if (ratio > 2 * 8 * 256 * maxfp || ratio < 2) {
+		dev_err(dai->dev, "the ratio is out of range (2 ~ %d)\n",
+				2 * 8 * 256 * maxfp);
+		return -EINVAL;
+	} else if (ratio % 2) {
+		dev_err(dai->dev, "the raio must be even if using upper divider\n");
+		return -EINVAL;
+	}
+
+	ratio /= 2;
+
+	psr = ratio <= 256 * maxfp ? ESAI_xCCR_xPSR_BYPASS : ESAI_xCCR_xPSR_DIV8;
+
+	/* Set the max fluctuation -- 0.1% of the max devisor */
+	savesub = (psr ? 1 : 8)  * 256 * maxfp / 1000;
+
+	/* Find the best value for PM */
+	for (i = 1; i <= 256; i++) {
+		for (j = 1; j <= maxfp; j++) {
+			/* PSR (1 or 8) * PM (1 ~ 256) * FP (1 ~ 16) */
+			prod = (psr ? 1 : 8) * i * j;
+
+			if (prod == ratio)
+				sub = 0;
+			else if (prod / ratio == 1)
+				sub = prod - ratio;
+			else if (ratio / prod == 1)
+				sub = ratio - prod;
+			else
+				continue;
+
+			/* Calculate the fraction */
+			sub = sub * 1000 / ratio;
+			if (sub < savesub) {
+				savesub = sub;
+				pm = i;
+				fp = j;
+			}
+
+			/* We are lucky */
+			if (savesub == 0)
+				goto out;
+		}
+	}
+
+	if (pm == 999) {
+		dev_err(dai->dev, "failed to calculate proper divisors\n");
+		return -EINVAL;
+	}
+
+out:
+	regmap_update_bits(esai_priv->regmap, REG_ESAI_xCCR(tx),
+			   ESAI_xCCR_xPSR_MASK | ESAI_xCCR_xPM_MASK,
+			   psr | ESAI_xCCR_xPM(pm));
+
+out_fp:
+	/* Bypass fp if not being required */
+	if (maxfp <= 1)
+		return 0;
+
+	regmap_update_bits(esai_priv->regmap, REG_ESAI_xCCR(tx),
+			   ESAI_xCCR_xFP_MASK, ESAI_xCCR_xFP(fp));
+
+	return 0;
+}
+
+/**
+ * This function mainly configures the clock frequency of MCLK (HCKT/HCKR)
+ *
+ * @Parameters:
+ * clk_id: The clock source of HCKT/HCKR
+ *	  (Input from outside; output from inside, FSYS or EXTAL)
+ * freq: The required clock rate of HCKT/HCKR
+ * dir: The clock direction of HCKT/HCKR
+ *
+ * Note: If the direction is input, we do not care about clk_id.
+ */
+static int fsl_esai_set_dai_sysclk(struct snd_soc_dai *dai, int clk_id,
+				   unsigned int freq, int dir)
+{
+	struct fsl_esai *esai_priv = snd_soc_dai_get_drvdata(dai);
+	struct clk *clksrc = esai_priv->extalclk;
+	bool tx = clk_id <= ESAI_HCKT_EXTAL;
+	bool in = dir == SND_SOC_CLOCK_IN;
+	u32 ret, ratio, ecr = 0;
+	unsigned long clk_rate;
+
+	/* sck_div can be only bypassed if ETO/ERO=0 and SNC_SOC_CLOCK_OUT */
+	esai_priv->sck_div[tx] = true;
+
+	/* Set the direction of HCKT/HCKR pins */
+	regmap_update_bits(esai_priv->regmap, REG_ESAI_xCCR(tx),
+			   ESAI_xCCR_xHCKD, in ? 0 : ESAI_xCCR_xHCKD);
+
+	if (in)
+		goto out;
+
+	switch (clk_id) {
+	case ESAI_HCKT_FSYS:
+	case ESAI_HCKR_FSYS:
+		clksrc = esai_priv->fsysclk;
+		break;
+	case ESAI_HCKT_EXTAL:
+		ecr |= ESAI_ECR_ETI;
+	case ESAI_HCKR_EXTAL:
+		ecr |= ESAI_ECR_ERI;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (IS_ERR(clksrc)) {
+		dev_err(dai->dev, "no assigned %s clock\n",
+				clk_id % 2 ? "extal" : "fsys");
+		return PTR_ERR(clksrc);
+	}
+	clk_rate = clk_get_rate(clksrc);
+
+	ratio = clk_rate / freq;
+	if (ratio * freq > clk_rate)
+		ret = ratio * freq - clk_rate;
+	else if (ratio * freq < clk_rate)
+		ret = clk_rate - ratio * freq;
+	else
+		ret = 0;
+
+	/* Block if clock source can not be divided into the required rate */
+	if (ret != 0 && clk_rate / ret < 1000) {
+		dev_err(dai->dev, "failed to derive required HCK%c rate\n",
+				tx ? 'T' : 'R');
+		return -EINVAL;
+	}
+
+	if (ratio == 1) {
+		/* Bypass all the dividers if not being needed */
+		ecr |= tx ? ESAI_ECR_ETO : ESAI_ECR_ERO;
+		goto out;
+	}
+
+	ret = fsl_esai_divisor_cal(dai, tx, ratio, false, 0);
+	if (ret)
+		return ret;
+
+	esai_priv->sck_div[tx] = false;
+
+out:
+	esai_priv->hck_rate[tx] = freq;
+
+	regmap_update_bits(esai_priv->regmap, REG_ESAI_ECR,
+			   tx ? ESAI_ECR_ETI | ESAI_ECR_ETO :
+			   ESAI_ECR_ERI | ESAI_ECR_ERO, ecr);
+
+	return 0;
+}
+
+/**
+ * This function configures the related dividers according to the bclk rate
+ */
+static int fsl_esai_set_bclk(struct snd_soc_dai *dai, bool tx, u32 freq)
+{
+	struct fsl_esai *esai_priv = snd_soc_dai_get_drvdata(dai);
+	u32 hck_rate = esai_priv->hck_rate[tx];
+	u32 sub, ratio = hck_rate / freq;
+
+	/* Don't apply for fully slave mode*/
+	if (esai_priv->slave_mode)
+		return 0;
+
+	if (ratio * freq > hck_rate)
+		sub = ratio * freq - hck_rate;
+	else if (ratio * freq < hck_rate)
+		sub = hck_rate - ratio * freq;
+	else
+		sub = 0;
+
+	/* Block if clock source can not be divided into the required rate */
+	if (sub != 0 && hck_rate / sub < 1000) {
+		dev_err(dai->dev, "failed to derive required SCK%c rate\n",
+				tx ? 'T' : 'R');
+		return -EINVAL;
+	}
+
+	if (esai_priv->sck_div[tx] && (ratio > 16 || ratio == 0)) {
+		dev_err(dai->dev, "the ratio is out of range (1 ~ 16)\n");
+		return -EINVAL;
+	}
+
+	return fsl_esai_divisor_cal(dai, tx, ratio, true,
+			esai_priv->sck_div[tx] ? 0 : ratio);
+}
+
+static int fsl_esai_set_dai_tdm_slot(struct snd_soc_dai *dai, u32 tx_mask,
+				     u32 rx_mask, int slots, int slot_width)
+{
+	struct fsl_esai *esai_priv = snd_soc_dai_get_drvdata(dai);
+
+	regmap_update_bits(esai_priv->regmap, REG_ESAI_TCCR,
+			   ESAI_xCCR_xDC_MASK, ESAI_xCCR_xDC(slots));
+
+	regmap_update_bits(esai_priv->regmap, REG_ESAI_TSMA,
+			   ESAI_xSMA_xS_MASK, ESAI_xSMA_xS(tx_mask));
+	regmap_update_bits(esai_priv->regmap, REG_ESAI_TSMB,
+			   ESAI_xSMA_xS_MASK, ESAI_xSMB_xS(tx_mask));
+
+	regmap_update_bits(esai_priv->regmap, REG_ESAI_RCCR,
+			   ESAI_xCCR_xDC_MASK, ESAI_xCCR_xDC(slots));
+
+	regmap_update_bits(esai_priv->regmap, REG_ESAI_RSMA,
+			   ESAI_xSMA_xS_MASK, ESAI_xSMA_xS(rx_mask));
+	regmap_update_bits(esai_priv->regmap, REG_ESAI_RSMB,
+			   ESAI_xSMA_xS_MASK, ESAI_xSMB_xS(rx_mask));
+
+	esai_priv->slot_width = slot_width;
+
+	return 0;
+}
+
+static int fsl_esai_set_dai_fmt(struct snd_soc_dai *dai, unsigned int fmt)
+{
+	struct fsl_esai *esai_priv = snd_soc_dai_get_drvdata(dai);
+	u32 xcr = 0, xccr = 0, mask;
+
+	/* DAI mode */
+	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
+	case SND_SOC_DAIFMT_I2S:
+		/* Data on rising edge of bclk, frame low, 1clk before data */
+		xcr |= ESAI_xCR_xFSR;
+		xccr |= ESAI_xCCR_xFSP | ESAI_xCCR_xCKP | ESAI_xCCR_xHCKP;
+		break;
+	case SND_SOC_DAIFMT_LEFT_J:
+		/* Data on rising edge of bclk, frame high */
+		xccr |= ESAI_xCCR_xCKP | ESAI_xCCR_xHCKP;
+		break;
+	case SND_SOC_DAIFMT_RIGHT_J:
+		/* Data on rising edge of bclk, frame high, right aligned */
+		xccr |= ESAI_xCCR_xCKP | ESAI_xCCR_xHCKP | ESAI_xCR_xWA;
+		break;
+	case SND_SOC_DAIFMT_DSP_A:
+		/* Data on rising edge of bclk, frame high, 1clk before data */
+		xcr |= ESAI_xCR_xFSL | ESAI_xCR_xFSR;
+		xccr |= ESAI_xCCR_xCKP | ESAI_xCCR_xHCKP;
+		break;
+	case SND_SOC_DAIFMT_DSP_B:
+		/* Data on rising edge of bclk, frame high */
+		xcr |= ESAI_xCR_xFSL;
+		xccr |= ESAI_xCCR_xCKP | ESAI_xCCR_xHCKP;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* DAI clock inversion */
+	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
+	case SND_SOC_DAIFMT_NB_NF:
+		/* Nothing to do for both normal cases */
+		break;
+	case SND_SOC_DAIFMT_IB_NF:
+		/* Invert bit clock */
+		xccr ^= ESAI_xCCR_xCKP | ESAI_xCCR_xHCKP;
+		break;
+	case SND_SOC_DAIFMT_NB_IF:
+		/* Invert frame clock */
+		xccr ^= ESAI_xCCR_xFSP;
+		break;
+	case SND_SOC_DAIFMT_IB_IF:
+		/* Invert both clocks */
+		xccr ^= ESAI_xCCR_xCKP | ESAI_xCCR_xHCKP | ESAI_xCCR_xFSP;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	esai_priv->slave_mode = false;
+
+	/* DAI clock master masks */
+	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
+	case SND_SOC_DAIFMT_CBM_CFM:
+		esai_priv->slave_mode = true;
+		break;
+	case SND_SOC_DAIFMT_CBS_CFM:
+		xccr |= ESAI_xCCR_xCKD;
+		break;
+	case SND_SOC_DAIFMT_CBM_CFS:
+		xccr |= ESAI_xCCR_xFSD;
+		break;
+	case SND_SOC_DAIFMT_CBS_CFS:
+		xccr |= ESAI_xCCR_xFSD | ESAI_xCCR_xCKD;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	mask = ESAI_xCR_xFSL | ESAI_xCR_xFSR;
+	regmap_update_bits(esai_priv->regmap, REG_ESAI_TCR, mask, xcr);
+	regmap_update_bits(esai_priv->regmap, REG_ESAI_RCR, mask, xcr);
+
+	mask = ESAI_xCCR_xCKP | ESAI_xCCR_xHCKP | ESAI_xCCR_xFSP |
+		ESAI_xCCR_xFSD | ESAI_xCCR_xCKD | ESAI_xCR_xWA;
+	regmap_update_bits(esai_priv->regmap, REG_ESAI_TCCR, mask, xccr);
+	regmap_update_bits(esai_priv->regmap, REG_ESAI_RCCR, mask, xccr);
+
+	return 0;
+}
+
+static int fsl_esai_startup(struct snd_pcm_substream *substream,
+			    struct snd_soc_dai *dai)
+{
+	struct fsl_esai *esai_priv = snd_soc_dai_get_drvdata(dai);
+
+	/*
+	 * Some platforms might use the same bit to gate all three or two of
+	 * clocks, so keep all clocks open/close at the same time for safety
+	 */
+	clk_prepare_enable(esai_priv->coreclk);
+	if (!IS_ERR(esai_priv->extalclk))
+		clk_prepare_enable(esai_priv->extalclk);
+	if (!IS_ERR(esai_priv->fsysclk))
+		clk_prepare_enable(esai_priv->fsysclk);
+
+	if (!dai->active) {
+		/* Reset Port C */
+		regmap_update_bits(esai_priv->regmap, REG_ESAI_PRRC,
+				   ESAI_PRRC_PDC_MASK, ESAI_PRRC_PDC(ESAI_GPIO));
+		regmap_update_bits(esai_priv->regmap, REG_ESAI_PCRC,
+				   ESAI_PCRC_PC_MASK, ESAI_PCRC_PC(ESAI_GPIO));
+
+		/* Set synchronous mode */
+		regmap_update_bits(esai_priv->regmap, REG_ESAI_SAICR,
+				   ESAI_SAICR_SYNC, esai_priv->synchronous ?
+				   ESAI_SAICR_SYNC : 0);
+
+		/* Set a default slot number -- 2 */
+		regmap_update_bits(esai_priv->regmap, REG_ESAI_TCCR,
+				   ESAI_xCCR_xDC_MASK, ESAI_xCCR_xDC(2));
+		regmap_update_bits(esai_priv->regmap, REG_ESAI_RCCR,
+				   ESAI_xCCR_xDC_MASK, ESAI_xCCR_xDC(2));
+	}
+
+	return 0;
+}
+
+static int fsl_esai_hw_params(struct snd_pcm_substream *substream,
+			      struct snd_pcm_hw_params *params,
+			      struct snd_soc_dai *dai)
+{
+	struct fsl_esai *esai_priv = snd_soc_dai_get_drvdata(dai);
+	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
+	u32 width = snd_pcm_format_width(params_format(params));
+	u32 channels = params_channels(params);
+	u32 bclk, mask, val, ret;
+
+	bclk = params_rate(params) * esai_priv->slot_width * 2;
+
+	ret = fsl_esai_set_bclk(dai, tx, bclk);
+	if (ret)
+		return ret;
+
+	/* Use Normal mode to support monaural audio */
+	regmap_update_bits(esai_priv->regmap, REG_ESAI_xCR(tx),
+			   ESAI_xCR_xMOD_MASK, params_channels(params) > 1 ?
+			   ESAI_xCR_xMOD_NETWORK : 0);
+
+	regmap_update_bits(esai_priv->regmap, REG_ESAI_xFCR(tx),
+			   ESAI_xFCR_xFR_MASK, ESAI_xFCR_xFR);
+
+	mask = ESAI_xFCR_xFR_MASK | ESAI_xFCR_xWA_MASK | ESAI_xFCR_xFWM_MASK |
+	      (tx ? ESAI_xFCR_TE_MASK | ESAI_xFCR_TIEN : ESAI_xFCR_RE_MASK);
+	val = ESAI_xFCR_xWA(width) | ESAI_xFCR_xFWM(esai_priv->fifo_depth) |
+	     (tx ? ESAI_xFCR_TE(channels) | ESAI_xFCR_TIEN : ESAI_xFCR_RE(channels));
+
+	regmap_update_bits(esai_priv->regmap, REG_ESAI_xFCR(tx), mask, val);
+
+	mask = ESAI_xCR_xSWS_MASK | (tx ? ESAI_xCR_PADC : 0);
+	val = ESAI_xCR_xSWS(esai_priv->slot_width, width) | (tx ? ESAI_xCR_PADC : 0);
+
+	regmap_update_bits(esai_priv->regmap, REG_ESAI_xCR(tx), mask, val);
+
+	return 0;
+}
+
+static void fsl_esai_shutdown(struct snd_pcm_substream *substream,
+			      struct snd_soc_dai *dai)
+{
+	struct fsl_esai *esai_priv = snd_soc_dai_get_drvdata(dai);
+
+	if (!IS_ERR(esai_priv->fsysclk))
+		clk_disable_unprepare(esai_priv->fsysclk);
+	if (!IS_ERR(esai_priv->extalclk))
+		clk_disable_unprepare(esai_priv->extalclk);
+	clk_disable_unprepare(esai_priv->coreclk);
+}
+
+static int fsl_esai_trigger(struct snd_pcm_substream *substream, int cmd,
+			    struct snd_soc_dai *dai)
+{
+	struct fsl_esai *esai_priv = snd_soc_dai_get_drvdata(dai);
+	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
+	u8 i, channels = substream->runtime->channels;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		regmap_update_bits(esai_priv->regmap, REG_ESAI_xFCR(tx),
+				   ESAI_xFCR_xFEN_MASK, ESAI_xFCR_xFEN);
+
+		/* Write initial words reqiured by ESAI as normal procedure */
+		for (i = 0; tx && i < channels; i++)
+			regmap_write(esai_priv->regmap, REG_ESAI_ETDR, 0x0);
+
+		regmap_update_bits(esai_priv->regmap, REG_ESAI_xCR(tx),
+				   tx ? ESAI_xCR_TE_MASK : ESAI_xCR_RE_MASK,
+				   tx ? ESAI_xCR_TE(channels) : ESAI_xCR_RE(channels));
+		break;
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		regmap_update_bits(esai_priv->regmap, REG_ESAI_xCR(tx),
+				   tx ? ESAI_xCR_TE_MASK : ESAI_xCR_RE_MASK, 0);
+
+		/* Disable and reset FIFO */
+		regmap_update_bits(esai_priv->regmap, REG_ESAI_xFCR(tx),
+				   ESAI_xFCR_xFR | ESAI_xFCR_xFEN, ESAI_xFCR_xFR);
+		regmap_update_bits(esai_priv->regmap, REG_ESAI_xFCR(tx),
+				   ESAI_xFCR_xFR, 0);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static struct snd_soc_dai_ops fsl_esai_dai_ops = {
+	.startup = fsl_esai_startup,
+	.shutdown = fsl_esai_shutdown,
+	.trigger = fsl_esai_trigger,
+	.hw_params = fsl_esai_hw_params,
+	.set_sysclk = fsl_esai_set_dai_sysclk,
+	.set_fmt = fsl_esai_set_dai_fmt,
+	.set_tdm_slot = fsl_esai_set_dai_tdm_slot,
+};
+
+static int fsl_esai_dai_probe(struct snd_soc_dai *dai)
+{
+	struct fsl_esai *esai_priv = snd_soc_dai_get_drvdata(dai);
+
+	snd_soc_dai_init_dma_data(dai, &esai_priv->dma_params_tx,
+				  &esai_priv->dma_params_rx);
+
+	return 0;
+}
+
+static struct snd_soc_dai_driver fsl_esai_dai = {
+	.probe = fsl_esai_dai_probe,
+	.playback = {
+		.channels_min = 1,
+		.channels_max = 12,
+		.rates = FSL_ESAI_RATES,
+		.formats = FSL_ESAI_FORMATS,
+	},
+	.capture = {
+		.channels_min = 1,
+		.channels_max = 8,
+		.rates = FSL_ESAI_RATES,
+		.formats = FSL_ESAI_FORMATS,
+	},
+	.ops = &fsl_esai_dai_ops,
+};
+
+static const struct snd_soc_component_driver fsl_esai_component = {
+	.name		= "fsl-esai",
+};
+
+static bool fsl_esai_readable_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case REG_ESAI_ERDR:
+	case REG_ESAI_ECR:
+	case REG_ESAI_ESR:
+	case REG_ESAI_TFCR:
+	case REG_ESAI_TFSR:
+	case REG_ESAI_RFCR:
+	case REG_ESAI_RFSR:
+	case REG_ESAI_RX0:
+	case REG_ESAI_RX1:
+	case REG_ESAI_RX2:
+	case REG_ESAI_RX3:
+	case REG_ESAI_SAISR:
+	case REG_ESAI_SAICR:
+	case REG_ESAI_TCR:
+	case REG_ESAI_TCCR:
+	case REG_ESAI_RCR:
+	case REG_ESAI_RCCR:
+	case REG_ESAI_TSMA:
+	case REG_ESAI_TSMB:
+	case REG_ESAI_RSMA:
+	case REG_ESAI_RSMB:
+	case REG_ESAI_PRRC:
+	case REG_ESAI_PCRC:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool fsl_esai_writeable_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case REG_ESAI_ETDR:
+	case REG_ESAI_ECR:
+	case REG_ESAI_TFCR:
+	case REG_ESAI_RFCR:
+	case REG_ESAI_TX0:
+	case REG_ESAI_TX1:
+	case REG_ESAI_TX2:
+	case REG_ESAI_TX3:
+	case REG_ESAI_TX4:
+	case REG_ESAI_TX5:
+	case REG_ESAI_TSR:
+	case REG_ESAI_SAICR:
+	case REG_ESAI_TCR:
+	case REG_ESAI_TCCR:
+	case REG_ESAI_RCR:
+	case REG_ESAI_RCCR:
+	case REG_ESAI_TSMA:
+	case REG_ESAI_TSMB:
+	case REG_ESAI_RSMA:
+	case REG_ESAI_RSMB:
+	case REG_ESAI_PRRC:
+	case REG_ESAI_PCRC:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static const struct regmap_config fsl_esai_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+
+	.max_register = REG_ESAI_PCRC,
+	.readable_reg = fsl_esai_readable_reg,
+	.writeable_reg = fsl_esai_writeable_reg,
+};
+
+static int fsl_esai_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct fsl_esai *esai_priv;
+	struct resource *res;
+	const uint32_t *iprop;
+	void __iomem *regs;
+	int irq, ret;
+
+	esai_priv = devm_kzalloc(&pdev->dev, sizeof(*esai_priv), GFP_KERNEL);
+	if (!esai_priv)
+		return -ENOMEM;
+
+	esai_priv->pdev = pdev;
+	strcpy(esai_priv->name, np->name);
+
+	/* Get the addresses and IRQ */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(regs))
+		return PTR_ERR(regs);
+
+	esai_priv->regmap = devm_regmap_init_mmio_clk(&pdev->dev,
+			"core", regs, &fsl_esai_regmap_config);
+	if (IS_ERR(esai_priv->regmap)) {
+		dev_err(&pdev->dev, "failed to init regmap: %ld\n",
+				PTR_ERR(esai_priv->regmap));
+		return PTR_ERR(esai_priv->regmap);
+	}
+
+	esai_priv->coreclk = devm_clk_get(&pdev->dev, "core");
+	if (IS_ERR(esai_priv->coreclk)) {
+		dev_err(&pdev->dev, "failed to get core clock: %ld\n",
+				PTR_ERR(esai_priv->coreclk));
+		return PTR_ERR(esai_priv->coreclk);
+	}
+
+	esai_priv->extalclk = devm_clk_get(&pdev->dev, "extal");
+	if (IS_ERR(esai_priv->extalclk))
+		dev_warn(&pdev->dev, "failed to get extal clock: %ld\n",
+				PTR_ERR(esai_priv->extalclk));
+
+	esai_priv->fsysclk = devm_clk_get(&pdev->dev, "fsys");
+	if (IS_ERR(esai_priv->fsysclk))
+		dev_warn(&pdev->dev, "failed to get fsys clock: %ld\n",
+				PTR_ERR(esai_priv->fsysclk));
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(&pdev->dev, "no irq for node %s\n", np->full_name);
+		return irq;
+	}
+
+	ret = devm_request_irq(&pdev->dev, irq, esai_isr, 0,
+			       esai_priv->name, esai_priv);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to claim irq %u\n", irq);
+		return ret;
+	}
+
+	/* Set a default slot size */
+	esai_priv->slot_width = 32;
+
+	/* Set a default master/slave state */
+	esai_priv->slave_mode = true;
+
+	/* Determine the FIFO depth */
+	iprop = of_get_property(np, "fsl,fifo-depth", NULL);
+	if (iprop)
+		esai_priv->fifo_depth = be32_to_cpup(iprop);
+	else
+		esai_priv->fifo_depth = 64;
+
+	esai_priv->dma_params_tx.maxburst = 16;
+	esai_priv->dma_params_rx.maxburst = 16;
+	esai_priv->dma_params_tx.addr = res->start + REG_ESAI_ETDR;
+	esai_priv->dma_params_rx.addr = res->start + REG_ESAI_ERDR;
+
+	esai_priv->synchronous =
+		of_property_read_bool(np, "fsl,esai-synchronous");
+
+	/* Implement full symmetry for synchronous mode */
+	if (esai_priv->synchronous) {
+		fsl_esai_dai.symmetric_rates = 1;
+		fsl_esai_dai.symmetric_channels = 1;
+		fsl_esai_dai.symmetric_samplebits = 1;
+	}
+
+	dev_set_drvdata(&pdev->dev, esai_priv);
+
+	/* Reset ESAI unit */
+	ret = regmap_write(esai_priv->regmap, REG_ESAI_ECR, ESAI_ECR_ERST);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to reset ESAI: %d\n", ret);
+		return ret;
+	}
+
+	/*
+	 * We need to enable ESAI so as to access some of its registers.
+	 * Otherwise, we would fail to dump regmap from user space.
+	 */
+	ret = regmap_write(esai_priv->regmap, REG_ESAI_ECR, ESAI_ECR_ESAIEN);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to enable ESAI: %d\n", ret);
+		return ret;
+	}
+
+	ret = devm_snd_soc_register_component(&pdev->dev, &fsl_esai_component,
+					      &fsl_esai_dai, 1);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register DAI: %d\n", ret);
+		return ret;
+	}
+
+	ret = imx_pcm_dma_init(pdev);
+	if (ret)
+		dev_err(&pdev->dev, "failed to init imx pcm dma: %d\n", ret);
+
+	return ret;
+}
+
+static const struct of_device_id fsl_esai_dt_ids[] = {
+	{ .compatible = "fsl,imx35-esai", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, fsl_esai_dt_ids);
+
+static struct platform_driver fsl_esai_driver = {
+	.probe = fsl_esai_probe,
+	.driver = {
+		.name = "fsl-esai-dai",
+		.owner = THIS_MODULE,
+		.of_match_table = fsl_esai_dt_ids,
+	},
+};
+
+module_platform_driver(fsl_esai_driver);
+
+MODULE_AUTHOR("Freescale Semiconductor, Inc.");
+MODULE_DESCRIPTION("Freescale ESAI CPU DAI driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:fsl-esai-dai");