// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) STMicroelectronics SA 2015
 * Authors: Arnaud Pouliquen <arnaud.pouliquen@st.com>
 *          for STMicroelectronics.
 */

#include <sound/soc.h>

#include "uniperif.h"

#define UNIPERIF_READER_I2S_IN 0 /* reader id connected to I2S/TDM TX bus */
/*
 * Note: snd_pcm_hardware is linked to DMA controller but is declared here to
 * integrate unireader capability in term of rate and supported channels
 */
static const struct snd_pcm_hardware uni_reader_pcm_hw = {
        .info = SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
                SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_MMAP |
                SNDRV_PCM_INFO_MMAP_VALID,
        .formats = SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S16_LE,

        .rates = SNDRV_PCM_RATE_CONTINUOUS,
        .rate_min = 8000,
        .rate_max = 96000,

        .channels_min = 2,
        .channels_max = 8,

        .periods_min = 2,
        .periods_max = 48,

        .period_bytes_min = 128,
        .period_bytes_max = 64 * PAGE_SIZE,
        .buffer_bytes_max = 256 * PAGE_SIZE
};

/*
 * uni_reader_irq_handler
 * In case of error audio stream is stopped; stop action is protected via PCM
 * stream lock  to avoid race condition with trigger callback.
 */
static irqreturn_t uni_reader_irq_handler(int irq, void *dev_id)
{
        irqreturn_t ret = IRQ_NONE;
        struct uniperif *reader = dev_id;
        unsigned int status;

        spin_lock(&reader->irq_lock);
        if (!reader->substream)
                goto irq_spin_unlock;

        snd_pcm_stream_lock(reader->substream);
        if (reader->state == UNIPERIF_STATE_STOPPED) {
                /* Unexpected IRQ: do nothing */
                dev_warn(reader->dev, "unexpected IRQ\n");
                goto stream_unlock;
        }

        /* Get interrupt status & clear them immediately */
        status = GET_UNIPERIF_ITS(reader);
        SET_UNIPERIF_ITS_BCLR(reader, status);

        /* Check for fifo overflow error */
        if (unlikely(status & UNIPERIF_ITS_FIFO_ERROR_MASK(reader))) {
                dev_err(reader->dev, "FIFO error detected\n");

                snd_pcm_stop(reader->substream, SNDRV_PCM_STATE_XRUN);

                ret = IRQ_HANDLED;
        }

stream_unlock:
        snd_pcm_stream_unlock(reader->substream);
irq_spin_unlock:
        spin_unlock(&reader->irq_lock);

        return ret;
}

static int uni_reader_prepare_pcm(struct snd_pcm_runtime *runtime,
                                  struct uniperif *reader)
{
        int slot_width;

        /* Force slot width to 32 in I2S mode */
        if ((reader->daifmt & SND_SOC_DAIFMT_FORMAT_MASK)
                == SND_SOC_DAIFMT_I2S) {
                slot_width = 32;
        } else {
                switch (runtime->format) {
                case SNDRV_PCM_FORMAT_S16_LE:
                        slot_width = 16;
                        break;
                default:
                        slot_width = 32;
                        break;
                }
        }

        /* Number of bits per subframe (i.e one channel sample) on input. */
        switch (slot_width) {
        case 32:
                SET_UNIPERIF_I2S_FMT_NBIT_32(reader);
                SET_UNIPERIF_I2S_FMT_DATA_SIZE_32(reader);
                break;
        case 16:
                SET_UNIPERIF_I2S_FMT_NBIT_16(reader);
                SET_UNIPERIF_I2S_FMT_DATA_SIZE_16(reader);
                break;
        default:
                dev_err(reader->dev, "subframe format not supported\n");
                return -EINVAL;
        }

        /* Configure data memory format */
        switch (runtime->format) {
        case SNDRV_PCM_FORMAT_S16_LE:
                /* One data word contains two samples */
                SET_UNIPERIF_CONFIG_MEM_FMT_16_16(reader);
                break;

        case SNDRV_PCM_FORMAT_S32_LE:
                /*
                 * Actually "16 bits/0 bits" means "32/28/24/20/18/16 bits
                 * on the MSB then zeros (if less than 32 bytes)"...
                 */
                SET_UNIPERIF_CONFIG_MEM_FMT_16_0(reader);
                break;

        default:
                dev_err(reader->dev, "format not supported\n");
                return -EINVAL;
        }

        /* Number of channels must be even */
        if ((runtime->channels % 2) || (runtime->channels < 2) ||
            (runtime->channels > 10)) {
                dev_err(reader->dev, "%s: invalid nb of channels\n", __func__);
                return -EINVAL;
        }

        SET_UNIPERIF_I2S_FMT_NUM_CH(reader, runtime->channels / 2);
        SET_UNIPERIF_I2S_FMT_ORDER_MSB(reader);

        return 0;
}

static int uni_reader_prepare_tdm(struct snd_pcm_runtime *runtime,
                                  struct uniperif *reader)
{
        int frame_size; /* user tdm frame size in bytes */
        /* default unip TDM_WORD_POS_X_Y */
        unsigned int word_pos[4] = {
                0x04060002, 0x0C0E080A, 0x14161012, 0x1C1E181A};

        frame_size = sti_uniperiph_get_user_frame_size(runtime);

        /* fix 16/0 format */
        SET_UNIPERIF_CONFIG_MEM_FMT_16_0(reader);
        SET_UNIPERIF_I2S_FMT_DATA_SIZE_32(reader);

        /* number of words inserted on the TDM line */
        SET_UNIPERIF_I2S_FMT_NUM_CH(reader, frame_size / 4 / 2);

        SET_UNIPERIF_I2S_FMT_ORDER_MSB(reader);
        SET_UNIPERIF_I2S_FMT_ALIGN_LEFT(reader);
        SET_UNIPERIF_TDM_ENABLE_TDM_ENABLE(reader);

        /*
         * set the timeslots allocation for words in FIFO
         *
         * HW bug: (LSB word < MSB word) => this config is not possible
         *         So if we want (LSB word < MSB) word, then it shall be
         *         handled by user
         */
        sti_uniperiph_get_tdm_word_pos(reader, word_pos);
        SET_UNIPERIF_TDM_WORD_POS(reader, 1_2, word_pos[WORD_1_2]);
        SET_UNIPERIF_TDM_WORD_POS(reader, 3_4, word_pos[WORD_3_4]);
        SET_UNIPERIF_TDM_WORD_POS(reader, 5_6, word_pos[WORD_5_6]);
        SET_UNIPERIF_TDM_WORD_POS(reader, 7_8, word_pos[WORD_7_8]);

        return 0;
}

static int uni_reader_prepare(struct snd_pcm_substream *substream,
                              struct snd_soc_dai *dai)
{
        struct sti_uniperiph_data *priv = snd_soc_dai_get_drvdata(dai);
        struct uniperif *reader = priv->dai_data.uni;
        struct snd_pcm_runtime *runtime = substream->runtime;
        int transfer_size, trigger_limit, ret;

        /* The reader should be stopped */
        if (reader->state != UNIPERIF_STATE_STOPPED) {
                dev_err(reader->dev, "%s: invalid reader state %d\n", __func__,
                        reader->state);
                return -EINVAL;
        }

        /* Calculate transfer size (in fifo cells and bytes) for frame count */
        if (reader->type == SND_ST_UNIPERIF_TYPE_TDM) {
                /* transfer size = unip frame size (in 32 bits FIFO cell) */
                transfer_size =
                        sti_uniperiph_get_user_frame_size(runtime) / 4;
        } else {
                transfer_size = runtime->channels * UNIPERIF_FIFO_FRAMES;
        }

        /* Calculate number of empty cells available before asserting DREQ */
        if (reader->ver < SND_ST_UNIPERIF_VERSION_UNI_PLR_TOP_1_0)
                trigger_limit = UNIPERIF_FIFO_SIZE - transfer_size;
        else
                /*
                 * Since SND_ST_UNIPERIF_VERSION_UNI_PLR_TOP_1_0
                 * FDMA_TRIGGER_LIMIT also controls when the state switches
                 * from OFF or STANDBY to AUDIO DATA.
                 */
                trigger_limit = transfer_size;

        /* Trigger limit must be an even number */
        if ((!trigger_limit % 2) ||
            (trigger_limit != 1 && transfer_size % 2) ||
            (trigger_limit > UNIPERIF_CONFIG_DMA_TRIG_LIMIT_MASK(reader))) {
                dev_err(reader->dev, "invalid trigger limit %d\n",
                        trigger_limit);
                return -EINVAL;
        }

        SET_UNIPERIF_CONFIG_DMA_TRIG_LIMIT(reader, trigger_limit);

        if (UNIPERIF_TYPE_IS_TDM(reader))
                ret = uni_reader_prepare_tdm(runtime, reader);
        else
                ret = uni_reader_prepare_pcm(runtime, reader);
        if (ret)
                return ret;

        switch (reader->daifmt & SND_SOC_DAIFMT_FORMAT_MASK) {
        case SND_SOC_DAIFMT_I2S:
                SET_UNIPERIF_I2S_FMT_ALIGN_LEFT(reader);
                SET_UNIPERIF_I2S_FMT_PADDING_I2S_MODE(reader);
                break;
        case SND_SOC_DAIFMT_LEFT_J:
                SET_UNIPERIF_I2S_FMT_ALIGN_LEFT(reader);
                SET_UNIPERIF_I2S_FMT_PADDING_SONY_MODE(reader);
                break;
        case SND_SOC_DAIFMT_RIGHT_J:
                SET_UNIPERIF_I2S_FMT_ALIGN_RIGHT(reader);
                SET_UNIPERIF_I2S_FMT_PADDING_SONY_MODE(reader);
                break;
        default:
                dev_err(reader->dev, "format not supported\n");
                return -EINVAL;
        }

        /* Data clocking (changing) on the rising/falling edge */
        switch (reader->daifmt & SND_SOC_DAIFMT_INV_MASK) {
        case SND_SOC_DAIFMT_NB_NF:
                SET_UNIPERIF_I2S_FMT_LR_POL_LOW(reader);
                SET_UNIPERIF_I2S_FMT_SCLK_EDGE_RISING(reader);
                break;
        case SND_SOC_DAIFMT_NB_IF:
                SET_UNIPERIF_I2S_FMT_LR_POL_HIG(reader);
                SET_UNIPERIF_I2S_FMT_SCLK_EDGE_RISING(reader);
                break;
        case SND_SOC_DAIFMT_IB_NF:
                SET_UNIPERIF_I2S_FMT_LR_POL_LOW(reader);
                SET_UNIPERIF_I2S_FMT_SCLK_EDGE_FALLING(reader);
                break;
        case SND_SOC_DAIFMT_IB_IF:
                SET_UNIPERIF_I2S_FMT_LR_POL_HIG(reader);
                SET_UNIPERIF_I2S_FMT_SCLK_EDGE_FALLING(reader);
                break;
        }

        /* Clear any pending interrupts */
        SET_UNIPERIF_ITS_BCLR(reader, GET_UNIPERIF_ITS(reader));

        SET_UNIPERIF_I2S_FMT_NO_OF_SAMPLES_TO_READ(reader, 0);

        /* Set the interrupt mask */
        SET_UNIPERIF_ITM_BSET_DMA_ERROR(reader);
        SET_UNIPERIF_ITM_BSET_FIFO_ERROR(reader);
        SET_UNIPERIF_ITM_BSET_MEM_BLK_READ(reader);

        /* Enable underflow recovery interrupts */
        if (reader->underflow_enabled) {
                SET_UNIPERIF_ITM_BSET_UNDERFLOW_REC_DONE(reader);
                SET_UNIPERIF_ITM_BSET_UNDERFLOW_REC_FAILED(reader);
        }

        /* Reset uniperipheral reader */
        return sti_uniperiph_reset(reader);
}

static int uni_reader_start(struct uniperif *reader)
{
        /* The reader should be stopped */
        if (reader->state != UNIPERIF_STATE_STOPPED) {
                dev_err(reader->dev, "%s: invalid reader state\n", __func__);
                return -EINVAL;
        }

        /* Enable reader interrupts (and clear possible stalled ones) */
        SET_UNIPERIF_ITS_BCLR_FIFO_ERROR(reader);
        SET_UNIPERIF_ITM_BSET_FIFO_ERROR(reader);

        /* Launch the reader */
        SET_UNIPERIF_CTRL_OPERATION_PCM_DATA(reader);

        /* Update state to started */
        reader->state = UNIPERIF_STATE_STARTED;
        return 0;
}

static int uni_reader_stop(struct uniperif *reader)
{
        /* The reader should not be in stopped state */
        if (reader->state == UNIPERIF_STATE_STOPPED) {
                dev_err(reader->dev, "%s: invalid reader state\n", __func__);
                return -EINVAL;
        }

        /* Turn the reader off */
        SET_UNIPERIF_CTRL_OPERATION_OFF(reader);

        /* Disable interrupts */
        SET_UNIPERIF_ITM_BCLR(reader, GET_UNIPERIF_ITM(reader));

        /* Update state to stopped and return */
        reader->state = UNIPERIF_STATE_STOPPED;

        return 0;
}

static int  uni_reader_trigger(struct snd_pcm_substream *substream,
                               int cmd, struct snd_soc_dai *dai)
{
        struct sti_uniperiph_data *priv = snd_soc_dai_get_drvdata(dai);
        struct uniperif *reader = priv->dai_data.uni;

        switch (cmd) {
        case SNDRV_PCM_TRIGGER_START:
                return  uni_reader_start(reader);
        case SNDRV_PCM_TRIGGER_STOP:
                return  uni_reader_stop(reader);
        default:
                return -EINVAL;
        }
}

static int uni_reader_startup(struct snd_pcm_substream *substream,
                              struct snd_soc_dai *dai)
{
        struct sti_uniperiph_data *priv = snd_soc_dai_get_drvdata(dai);
        struct uniperif *reader = priv->dai_data.uni;
        unsigned long flags;
        int ret;

        spin_lock_irqsave(&reader->irq_lock, flags);
        reader->substream = substream;
        spin_unlock_irqrestore(&reader->irq_lock, flags);

        if (!UNIPERIF_TYPE_IS_TDM(reader))
                return 0;

        /* refine hw constraint in tdm mode */
        ret = snd_pcm_hw_rule_add(substream->runtime, 0,
                                  SNDRV_PCM_HW_PARAM_CHANNELS,
                                  sti_uniperiph_fix_tdm_chan,
                                  reader, SNDRV_PCM_HW_PARAM_CHANNELS,
                                  -1);
        if (ret < 0)
                return ret;

        return snd_pcm_hw_rule_add(substream->runtime, 0,
                                   SNDRV_PCM_HW_PARAM_FORMAT,
                                   sti_uniperiph_fix_tdm_format,
                                   reader, SNDRV_PCM_HW_PARAM_FORMAT,
                                   -1);
}

static void uni_reader_shutdown(struct snd_pcm_substream *substream,
                                struct snd_soc_dai *dai)
{
        struct sti_uniperiph_data *priv = snd_soc_dai_get_drvdata(dai);
        struct uniperif *reader = priv->dai_data.uni;
        unsigned long flags;

        spin_lock_irqsave(&reader->irq_lock, flags);
        if (reader->state != UNIPERIF_STATE_STOPPED) {
                /* Stop the reader */
                uni_reader_stop(reader);
        }
        reader->substream = NULL;
        spin_unlock_irqrestore(&reader->irq_lock, flags);
}

static const struct snd_soc_dai_ops uni_reader_dai_ops = {
                .startup = uni_reader_startup,
                .shutdown = uni_reader_shutdown,
                .prepare = uni_reader_prepare,
                .probe = sti_uniperiph_dai_probe,
                .trigger = uni_reader_trigger,
                .hw_params = sti_uniperiph_dai_hw_params,
                .set_fmt = sti_uniperiph_dai_set_fmt,
                .set_tdm_slot = sti_uniperiph_set_tdm_slot
};

int uni_reader_init(struct platform_device *pdev,
                    struct uniperif *reader)
{
        int ret = 0;

        reader->dev = &pdev->dev;
        reader->state = UNIPERIF_STATE_STOPPED;
        reader->dai_ops = &uni_reader_dai_ops;

        if (UNIPERIF_TYPE_IS_TDM(reader))
                reader->hw = &uni_tdm_hw;
        else
                reader->hw = &uni_reader_pcm_hw;

        ret = devm_request_irq(&pdev->dev, reader->irq,
                               uni_reader_irq_handler, IRQF_SHARED,
                               dev_name(&pdev->dev), reader);
        if (ret < 0) {
                dev_err(&pdev->dev, "Failed to request IRQ\n");
                return -EBUSY;
        }

        spin_lock_init(&reader->irq_lock);

        return 0;
}
EXPORT_SYMBOL_GPL(uni_reader_init);