root/sound/soc/fsl/fsl_esai.c 
// SPDX-License-Identifier: GPL-2.0
//
// Freescale ESAI ALSA SoC Digital Audio Interface (DAI) driver
//
// Copyright (C) 2014 Freescale Semiconductor, Inc.

#include <linux/clk.h>
#include <linux/dmaengine.h>
#include <linux/module.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/pm_runtime.h>
#include <sound/dmaengine_pcm.h>
#include <sound/pcm_params.h>

#include "fsl_esai.h"
#include "imx-pcm.h"

#define FSL_ESAI_FORMATS        (SNDRV_PCM_FMTBIT_S8 | \
                                SNDRV_PCM_FMTBIT_S16_LE | \
                                SNDRV_PCM_FMTBIT_S20_3LE | \
                                SNDRV_PCM_FMTBIT_S24_LE)

/**
 * struct fsl_esai_soc_data - soc specific data
 * @reset_at_xrun: flags for enable reset operaton
 */
struct fsl_esai_soc_data {
        bool reset_at_xrun;
};

/**
 * struct 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
 * @spbaclk: SPBA clock (optional, depending on SoC design)
 * @work: work to handle the reset operation
 * @soc: soc specific data
 * @lock: spin lock between hw_reset() and trigger()
 * @fifo_depth: depth of tx/rx FIFO
 * @slot_width: width of each DAI slot
 * @slots: number of slots
 * @tx_mask: slot mask for TX
 * @rx_mask: slot mask for RX
 * @channels: channel num for tx or rx
 * @hck_rate: clock rate of desired HCKx clock
 * @sck_rate: clock rate of desired SCKx clock
 * @hck_dir: the direction of HCKx pads
 * @sck_div: if using PSR/PM dividers for SCKx clock
 * @consumer_mode: if fully using DAI clock consumer 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;
        struct clk *spbaclk;
        struct work_struct work;
        const struct fsl_esai_soc_data *soc;
        spinlock_t lock; /* Protect hw_reset and trigger */
        u32 fifo_depth;
        u32 slot_width;
        u32 slots;
        u32 tx_mask;
        u32 rx_mask;
        u32 channels[2];
        u32 hck_rate[2];
        u32 sck_rate[2];
        bool hck_dir[2];
        bool sck_div[2];
        bool consumer_mode;
        bool synchronous;
        char name[32];
};

static struct fsl_esai_soc_data fsl_esai_vf610 = {
        .reset_at_xrun = true,
};

static struct fsl_esai_soc_data fsl_esai_imx35 = {
        .reset_at_xrun = true,
};

static struct fsl_esai_soc_data fsl_esai_imx6ull = {
        .reset_at_xrun = false,
};

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;
        u32 saisr;

        regmap_read(esai_priv->regmap, REG_ESAI_ESR, &esr);
        regmap_read(esai_priv->regmap, REG_ESAI_SAISR, &saisr);

        if ((saisr & (ESAI_SAISR_TUE | ESAI_SAISR_ROE)) &&
            esai_priv->soc->reset_at_xrun) {
                dev_dbg(&pdev->dev, "reset module for xrun\n");
                regmap_update_bits(esai_priv->regmap, REG_ESAI_TCR,
                                   ESAI_xCR_xEIE_MASK, 0);
                regmap_update_bits(esai_priv->regmap, REG_ESAI_RCR,
                                   ESAI_xCR_xEIE_MASK, 0);
                schedule_work(&esai_priv->work);
        }

        if (esr & ESAI_ESR_TINIT_MASK)
                dev_dbg(&pdev->dev, "isr: Transmission Initialized\n");

        if (esr & ESAI_ESR_RFF_MASK)
                dev_dbg(&pdev->dev, "isr: Receiving overrun\n");

        if (esr & ESAI_ESR_TFE_MASK)
                dev_dbg(&pdev->dev, "isr: Transmission 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: Transmission 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;
}

/**
 * fsl_esai_divisor_cal - 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().
 *
 * @dai: pointer to DAI
 * @tx: current setting is for playback or capture
 * @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
 */
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;

        /* Do not loop-search if PM (1 ~ 256) alone can serve the ratio */
        if (ratio <= 256) {
                pm = ratio;
                fp = 1;
                goto out;
        }

        /* 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;
}

/**
 * fsl_esai_set_dai_sysclk - configure the clock frequency of MCLK (HCKT/HCKR)
 * @dai: pointer to DAI
 * @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 || esai_priv->synchronous);
        bool in = dir == SND_SOC_CLOCK_IN;
        u32 ratio, ecr = 0;
        unsigned long clk_rate;
        int ret;

        if (freq == 0) {
                dev_err(dai->dev, "%sput freq of HCK%c should not be 0Hz\n",
                        in ? "in" : "out", tx ? 'T' : 'R');
                return -EINVAL;
        }

        /* Bypass divider settings if the requirement doesn't change */
        if (freq == esai_priv->hck_rate[tx] && dir == esai_priv->hck_dir[tx])
                return 0;

        /* 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;
                break;
        case ESAI_HCKR_EXTAL:
                ecr |= esai_priv->synchronous ? ESAI_ECR_ETI : 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;
        }

        /* Only EXTAL source can be output directly without using PSR and PM */
        if (ratio == 1 && clksrc == esai_priv->extalclk) {
                /* Bypass all the dividers if not being needed */
                ecr |= tx ? ESAI_ECR_ETO : ESAI_ECR_ERO;
                goto out;
        } else if (ratio < 2) {
                /* The ratio should be no less than 2 if using other sources */
                dev_err(dai->dev, "failed to derive required HCK%c rate\n",
                                tx ? 'T' : 'R');
                return -EINVAL;
        }

        ret = fsl_esai_divisor_cal(dai, tx, ratio, false, 0);
        if (ret)
                return ret;

        esai_priv->sck_div[tx] = false;

out:
        esai_priv->hck_dir[tx] = dir;
        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;
}

/**
 * fsl_esai_set_bclk - configure the related dividers according to the bclk rate
 * @dai: pointer to DAI
 * @tx: direction boolean
 * @freq: bclk freq
 */
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;
        int ret;

        /* Don't apply for fully consumer mode or unchanged bclk */
        if (esai_priv->consumer_mode || esai_priv->sck_rate[tx] == freq)
                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;
        }

        /* The ratio should be contented by FP alone if bypassing PM and PSR */
        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;
        }

        ret = fsl_esai_divisor_cal(dai, tx, ratio, true,
                        esai_priv->sck_div[tx] ? 0 : ratio);
        if (ret)
                return ret;

        /* Save current bclk rate */
        esai_priv->sck_rate[tx] = freq;

        return 0;
}

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_RCCR,
                           ESAI_xCCR_xDC_MASK, ESAI_xCCR_xDC(slots));

        esai_priv->slot_width = slot_width;
        esai_priv->slots = slots;
        esai_priv->tx_mask = tx_mask;
        esai_priv->rx_mask = rx_mask;

        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;
                xcr  |= 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->consumer_mode = false;

        /* DAI clock provider masks */
        switch (fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) {
        case SND_SOC_DAIFMT_BC_FC:
                esai_priv->consumer_mode = true;
                break;
        case SND_SOC_DAIFMT_BP_FC:
                xccr |= ESAI_xCCR_xCKD;
                break;
        case SND_SOC_DAIFMT_BC_FP:
                xccr |= ESAI_xCCR_xFSD;
                break;
        case SND_SOC_DAIFMT_BP_FP:
                xccr |= ESAI_xCCR_xFSD | ESAI_xCCR_xCKD;
                break;
        default:
                return -EINVAL;
        }

        mask = ESAI_xCR_xFSL | ESAI_xCR_xFSR | ESAI_xCR_xWA;
        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;
        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);

        if (!snd_soc_dai_active(dai)) {
                /* Set synchronous mode */
                regmap_update_bits(esai_priv->regmap, REG_ESAI_SAICR,
                                   ESAI_SAICR_SYNC, esai_priv->synchronous ?
                                   ESAI_SAICR_SYNC : 0);

                /* Set slots count */
                regmap_update_bits(esai_priv->regmap, REG_ESAI_TCCR,
                                   ESAI_xCCR_xDC_MASK,
                                   ESAI_xCCR_xDC(esai_priv->slots));
                regmap_update_bits(esai_priv->regmap, REG_ESAI_RCCR,
                                   ESAI_xCCR_xDC_MASK,
                                   ESAI_xCCR_xDC(esai_priv->slots));
        }

        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 = params_width(params);
        u32 channels = params_channels(params);
        u32 pins = DIV_ROUND_UP(channels, esai_priv->slots);
        u32 slot_width = width;
        u32 bclk, mask, val;
        int ret;

        /* Override slot_width if being specifically set */
        if (esai_priv->slot_width)
                slot_width = esai_priv->slot_width;

        bclk = params_rate(params) * slot_width * esai_priv->slots;

        ret = fsl_esai_set_bclk(dai, esai_priv->synchronous || tx, bclk);
        if (ret)
                return ret;

        mask = ESAI_xCR_xSWS_MASK;
        val = ESAI_xCR_xSWS(slot_width, width);

        regmap_update_bits(esai_priv->regmap, REG_ESAI_xCR(tx), mask, val);
        /* Recording in synchronous mode needs to set TCR also */
        if (!tx && esai_priv->synchronous)
                regmap_update_bits(esai_priv->regmap, REG_ESAI_TCR, mask, val);

        /* 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(pins) | ESAI_xFCR_TIEN : ESAI_xFCR_RE(pins));

        regmap_update_bits(esai_priv->regmap, REG_ESAI_xFCR(tx), mask, val);

        if (tx)
                regmap_update_bits(esai_priv->regmap, REG_ESAI_TCR,
                                ESAI_xCR_PADC, ESAI_xCR_PADC);

        /* Remove ESAI personal reset by configuring ESAI_PCRC and ESAI_PRRC */
        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));
        return 0;
}

static int fsl_esai_hw_init(struct fsl_esai *esai_priv)
{
        struct platform_device *pdev = esai_priv->pdev;
        int ret;

        /* Reset ESAI unit */
        ret = regmap_update_bits(esai_priv->regmap, REG_ESAI_ECR,
                                 ESAI_ECR_ESAIEN_MASK | ESAI_ECR_ERST_MASK,
                                 ESAI_ECR_ESAIEN | 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_update_bits(esai_priv->regmap, REG_ESAI_ECR,
                                 ESAI_ECR_ESAIEN_MASK | ESAI_ECR_ERST_MASK,
                                 ESAI_ECR_ESAIEN);
        if (ret) {
                dev_err(&pdev->dev, "failed to enable ESAI: %d\n", ret);
                return ret;
        }

        regmap_update_bits(esai_priv->regmap, REG_ESAI_PRRC,
                           ESAI_PRRC_PDC_MASK, 0);
        regmap_update_bits(esai_priv->regmap, REG_ESAI_PCRC,
                           ESAI_PCRC_PC_MASK, 0);

        return 0;
}

static int fsl_esai_register_restore(struct fsl_esai *esai_priv)
{
        int ret;

        /* FIFO reset for safety */
        regmap_update_bits(esai_priv->regmap, REG_ESAI_TFCR,
                           ESAI_xFCR_xFR, ESAI_xFCR_xFR);
        regmap_update_bits(esai_priv->regmap, REG_ESAI_RFCR,
                           ESAI_xFCR_xFR, ESAI_xFCR_xFR);

        regcache_mark_dirty(esai_priv->regmap);
        ret = regcache_sync(esai_priv->regmap);
        if (ret)
                return ret;

        /* FIFO reset done */
        regmap_update_bits(esai_priv->regmap, REG_ESAI_TFCR, ESAI_xFCR_xFR, 0);
        regmap_update_bits(esai_priv->regmap, REG_ESAI_RFCR, ESAI_xFCR_xFR, 0);

        return 0;
}

static void fsl_esai_trigger_start(struct fsl_esai *esai_priv, bool tx)
{
        u8 i, channels = esai_priv->channels[tx];
        u32 pins = DIV_ROUND_UP(channels, esai_priv->slots);
        u32 mask;

        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);

        /*
         * When set the TE/RE in the end of enablement flow, there
         * will be channel swap issue for multi data line case.
         * In order to workaround this issue, we switch the bit
         * enablement sequence to below sequence
         * 1) clear the xSMB & xSMA: which is done in probe and
         *                           stop state.
         * 2) set TE/RE
         * 3) set xSMB
         * 4) set xSMA:  xSMA is the last one in this flow, which
         *               will trigger esai to start.
         */
        regmap_update_bits(esai_priv->regmap, REG_ESAI_xCR(tx),
                           tx ? ESAI_xCR_TE_MASK : ESAI_xCR_RE_MASK,
                           tx ? ESAI_xCR_TE(pins) : ESAI_xCR_RE(pins));
        mask = tx ? esai_priv->tx_mask : esai_priv->rx_mask;

        regmap_update_bits(esai_priv->regmap, REG_ESAI_xSMB(tx),
                           ESAI_xSMB_xS_MASK, ESAI_xSMB_xS(mask));
        regmap_update_bits(esai_priv->regmap, REG_ESAI_xSMA(tx),
                           ESAI_xSMA_xS_MASK, ESAI_xSMA_xS(mask));

        /* Enable Exception interrupt */
        regmap_update_bits(esai_priv->regmap, REG_ESAI_xCR(tx),
                           ESAI_xCR_xEIE_MASK, ESAI_xCR_xEIE);
}

static void fsl_esai_trigger_stop(struct fsl_esai *esai_priv, bool tx)
{
        regmap_update_bits(esai_priv->regmap, REG_ESAI_xCR(tx),
                           ESAI_xCR_xEIE_MASK, 0);

        regmap_update_bits(esai_priv->regmap, REG_ESAI_xCR(tx),
                           tx ? ESAI_xCR_TE_MASK : ESAI_xCR_RE_MASK, 0);
        regmap_update_bits(esai_priv->regmap, REG_ESAI_xSMA(tx),
                           ESAI_xSMA_xS_MASK, 0);
        regmap_update_bits(esai_priv->regmap, REG_ESAI_xSMB(tx),
                           ESAI_xSMB_xS_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);
}

static void fsl_esai_hw_reset(struct work_struct *work)
{
        struct fsl_esai *esai_priv = container_of(work, struct fsl_esai, work);
        bool tx = true, rx = false, enabled[2];
        unsigned long lock_flags;
        u32 tfcr, rfcr;

        spin_lock_irqsave(&esai_priv->lock, lock_flags);
        /* Save the registers */
        regmap_read(esai_priv->regmap, REG_ESAI_TFCR, &tfcr);
        regmap_read(esai_priv->regmap, REG_ESAI_RFCR, &rfcr);
        enabled[tx] = tfcr & ESAI_xFCR_xFEN;
        enabled[rx] = rfcr & ESAI_xFCR_xFEN;

        /* Stop the tx & rx */
        fsl_esai_trigger_stop(esai_priv, tx);
        fsl_esai_trigger_stop(esai_priv, rx);

        /* Reset the esai, and ignore return value */
        fsl_esai_hw_init(esai_priv);

        /* Enforce ESAI personal resets for both TX and RX */
        regmap_update_bits(esai_priv->regmap, REG_ESAI_TCR,
                           ESAI_xCR_xPR_MASK, ESAI_xCR_xPR);
        regmap_update_bits(esai_priv->regmap, REG_ESAI_RCR,
                           ESAI_xCR_xPR_MASK, ESAI_xCR_xPR);

        /* Restore registers by regcache_sync, and ignore return value */
        fsl_esai_register_restore(esai_priv);

        /* Remove ESAI personal resets by configuring PCRC and PRRC also */
        regmap_update_bits(esai_priv->regmap, REG_ESAI_TCR,
                           ESAI_xCR_xPR_MASK, 0);
        regmap_update_bits(esai_priv->regmap, REG_ESAI_RCR,
                           ESAI_xCR_xPR_MASK, 0);
        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));

        /* Restart tx / rx, if they already enabled */
        if (enabled[tx])
                fsl_esai_trigger_start(esai_priv, tx);
        if (enabled[rx])
                fsl_esai_trigger_start(esai_priv, rx);

        spin_unlock_irqrestore(&esai_priv->lock, lock_flags);
}

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;
        unsigned long lock_flags;

        esai_priv->channels[tx] = substream->runtime->channels;

        switch (cmd) {
        case SNDRV_PCM_TRIGGER_START:
        case SNDRV_PCM_TRIGGER_RESUME:
        case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
                spin_lock_irqsave(&esai_priv->lock, lock_flags);
                fsl_esai_trigger_start(esai_priv, tx);
                spin_unlock_irqrestore(&esai_priv->lock, lock_flags);
                break;
        case SNDRV_PCM_TRIGGER_SUSPEND:
        case SNDRV_PCM_TRIGGER_STOP:
        case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
                spin_lock_irqsave(&esai_priv->lock, lock_flags);
                fsl_esai_trigger_stop(esai_priv, tx);
                spin_unlock_irqrestore(&esai_priv->lock, lock_flags);
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

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 const struct snd_soc_dai_ops fsl_esai_dai_ops = {
        .probe          = fsl_esai_dai_probe,
        .startup        = fsl_esai_startup,
        .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 struct snd_soc_dai_driver fsl_esai_dai = {
        .playback = {
                .stream_name = "CPU-Playback",
                .channels_min = 1,
                .channels_max = 12,
                .rates = SNDRV_PCM_RATE_8000_192000,
                .formats = FSL_ESAI_FORMATS,
        },
        .capture = {
                .stream_name = "CPU-Capture",
                .channels_min = 1,
                .channels_max = 8,
                .rates = SNDRV_PCM_RATE_8000_192000,
                .formats = FSL_ESAI_FORMATS,
        },
        .ops = &fsl_esai_dai_ops,
};

static const struct snd_soc_component_driver fsl_esai_component = {
        .name                   = "fsl-esai",
        .legacy_dai_naming      = 1,
};

static const struct reg_default fsl_esai_reg_defaults[] = {
        {REG_ESAI_ETDR,  0x00000000},
        {REG_ESAI_ECR,   0x00000000},
        {REG_ESAI_TFCR,  0x00000000},
        {REG_ESAI_RFCR,  0x00000000},
        {REG_ESAI_TX0,   0x00000000},
        {REG_ESAI_TX1,   0x00000000},
        {REG_ESAI_TX2,   0x00000000},
        {REG_ESAI_TX3,   0x00000000},
        {REG_ESAI_TX4,   0x00000000},
        {REG_ESAI_TX5,   0x00000000},
        {REG_ESAI_TSR,   0x00000000},
        {REG_ESAI_SAICR, 0x00000000},
        {REG_ESAI_TCR,   0x00000000},
        {REG_ESAI_TCCR,  0x00000000},
        {REG_ESAI_RCR,   0x00000000},
        {REG_ESAI_RCCR,  0x00000000},
        {REG_ESAI_TSMA,  0x0000ffff},
        {REG_ESAI_TSMB,  0x0000ffff},
        {REG_ESAI_RSMA,  0x0000ffff},
        {REG_ESAI_RSMB,  0x0000ffff},
        {REG_ESAI_PRRC,  0x00000000},
        {REG_ESAI_PCRC,  0x00000000},
};

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_volatile_reg(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case REG_ESAI_ERDR:
        case REG_ESAI_ESR:
        case REG_ESAI_TFSR:
        case REG_ESAI_RFSR:
        case REG_ESAI_RX0:
        case REG_ESAI_RX1:
        case REG_ESAI_RX2:
        case REG_ESAI_RX3:
        case REG_ESAI_SAISR:
                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,
        .reg_defaults = fsl_esai_reg_defaults,
        .num_reg_defaults = ARRAY_SIZE(fsl_esai_reg_defaults),
        .readable_reg = fsl_esai_readable_reg,
        .volatile_reg = fsl_esai_volatile_reg,
        .writeable_reg = fsl_esai_writeable_reg,
        .cache_type = REGCACHE_FLAT,
};

static int fsl_esai_runtime_resume(struct device *dev);
static int fsl_esai_runtime_suspend(struct device *dev);

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 __be32 *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;
        snprintf(esai_priv->name, sizeof(esai_priv->name), "%pOFn", np);

        esai_priv->soc = of_device_get_match_data(&pdev->dev);

        /* Get the addresses and IRQ */
        regs = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
        if (IS_ERR(regs))
                return PTR_ERR(regs);

        esai_priv->regmap = devm_regmap_init_mmio(&pdev->dev, 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));

        esai_priv->spbaclk = devm_clk_get(&pdev->dev, "spba");
        if (IS_ERR(esai_priv->spbaclk))
                dev_warn(&pdev->dev, "failed to get spba clock: %ld\n",
                                PTR_ERR(esai_priv->spbaclk));

        irq = platform_get_irq(pdev, 0);
        if (irq < 0)
                return irq;

        ret = devm_request_irq(&pdev->dev, irq, esai_isr, IRQF_SHARED,
                               esai_priv->name, esai_priv);
        if (ret) {
                dev_err(&pdev->dev, "failed to claim irq %u\n", irq);
                return ret;
        }

        /* Set a default slot number */
        esai_priv->slots = 2;

        /* Set a default clock provider state */
        esai_priv->consumer_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_rate = 1;
                fsl_esai_dai.symmetric_channels = 1;
                fsl_esai_dai.symmetric_sample_bits = 1;
        }

        dev_set_drvdata(&pdev->dev, esai_priv);
        spin_lock_init(&esai_priv->lock);
        pm_runtime_enable(&pdev->dev);
        if (!pm_runtime_enabled(&pdev->dev)) {
                ret = fsl_esai_runtime_resume(&pdev->dev);
                if (ret)
                        goto err_pm_disable;
        }

        ret = pm_runtime_resume_and_get(&pdev->dev);
        if (ret < 0)
                goto err_pm_get_sync;

        ret = fsl_esai_hw_init(esai_priv);
        if (ret)
                goto err_pm_get_sync;

        esai_priv->tx_mask = 0xFFFFFFFF;
        esai_priv->rx_mask = 0xFFFFFFFF;

        /* Clear the TSMA, TSMB, RSMA, RSMB */
        regmap_write(esai_priv->regmap, REG_ESAI_TSMA, 0);
        regmap_write(esai_priv->regmap, REG_ESAI_TSMB, 0);
        regmap_write(esai_priv->regmap, REG_ESAI_RSMA, 0);
        regmap_write(esai_priv->regmap, REG_ESAI_RSMB, 0);

        ret = pm_runtime_put_sync(&pdev->dev);
        if (ret < 0 && ret != -ENOSYS)
                goto err_pm_get_sync;

        /*
         * Register platform component before registering cpu dai for there
         * is not defer probe for platform component in snd_soc_add_pcm_runtime().
         */
        ret = imx_pcm_dma_init(pdev);
        if (ret) {
                dev_err(&pdev->dev, "failed to init imx pcm dma: %d\n", ret);
                goto err_pm_get_sync;
        }

        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);
                goto err_pm_get_sync;
        }

        INIT_WORK(&esai_priv->work, fsl_esai_hw_reset);

        return ret;

err_pm_get_sync:
        if (!pm_runtime_status_suspended(&pdev->dev))
                fsl_esai_runtime_suspend(&pdev->dev);
err_pm_disable:
        pm_runtime_disable(&pdev->dev);
        return ret;
}

static void fsl_esai_remove(struct platform_device *pdev)
{
        struct fsl_esai *esai_priv = platform_get_drvdata(pdev);

        pm_runtime_disable(&pdev->dev);
        if (!pm_runtime_status_suspended(&pdev->dev))
                fsl_esai_runtime_suspend(&pdev->dev);

        cancel_work_sync(&esai_priv->work);
}

static const struct of_device_id fsl_esai_dt_ids[] = {
        { .compatible = "fsl,imx35-esai", .data = &fsl_esai_imx35 },
        { .compatible = "fsl,vf610-esai", .data = &fsl_esai_vf610 },
        { .compatible = "fsl,imx6ull-esai", .data = &fsl_esai_imx6ull },
        {}
};
MODULE_DEVICE_TABLE(of, fsl_esai_dt_ids);

static int fsl_esai_runtime_resume(struct device *dev)
{
        struct fsl_esai *esai = dev_get_drvdata(dev);
        int ret;

        /*
         * 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
         */
        ret = clk_prepare_enable(esai->coreclk);
        if (ret)
                return ret;
        if (!IS_ERR(esai->spbaclk)) {
                ret = clk_prepare_enable(esai->spbaclk);
                if (ret)
                        goto err_spbaclk;
        }
        if (!IS_ERR(esai->extalclk)) {
                ret = clk_prepare_enable(esai->extalclk);
                if (ret)
                        goto err_extalclk;
        }
        if (!IS_ERR(esai->fsysclk)) {
                ret = clk_prepare_enable(esai->fsysclk);
                if (ret)
                        goto err_fsysclk;
        }

        regcache_cache_only(esai->regmap, false);

        ret = fsl_esai_register_restore(esai);
        if (ret)
                goto err_regcache_sync;

        return 0;

err_regcache_sync:
        if (!IS_ERR(esai->fsysclk))
                clk_disable_unprepare(esai->fsysclk);
err_fsysclk:
        if (!IS_ERR(esai->extalclk))
                clk_disable_unprepare(esai->extalclk);
err_extalclk:
        if (!IS_ERR(esai->spbaclk))
                clk_disable_unprepare(esai->spbaclk);
err_spbaclk:
        clk_disable_unprepare(esai->coreclk);

        return ret;
}

static int fsl_esai_runtime_suspend(struct device *dev)
{
        struct fsl_esai *esai = dev_get_drvdata(dev);

        regcache_cache_only(esai->regmap, true);

        if (!IS_ERR(esai->fsysclk))
                clk_disable_unprepare(esai->fsysclk);
        if (!IS_ERR(esai->extalclk))
                clk_disable_unprepare(esai->extalclk);
        if (!IS_ERR(esai->spbaclk))
                clk_disable_unprepare(esai->spbaclk);
        clk_disable_unprepare(esai->coreclk);

        return 0;
}

static const struct dev_pm_ops fsl_esai_pm_ops = {
        RUNTIME_PM_OPS(fsl_esai_runtime_suspend, fsl_esai_runtime_resume, NULL)
        SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
};

static struct platform_driver fsl_esai_driver = {
        .probe = fsl_esai_probe,
        .remove = fsl_esai_remove,
        .driver = {
                .name = "fsl-esai-dai",
                .pm = pm_ptr(&fsl_esai_pm_ops),
                .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");