// SPDX-License-Identifier: GPL-2.0
//
// Freescale ASRC ALSA SoC Platform (DMA) driver
//
// Copyright (C) 2014 Freescale Semiconductor, Inc.
//
// Author: Nicolin Chen <nicoleotsuka@gmail.com>

#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <linux/platform_data/dma-imx.h>
#include <sound/dmaengine_pcm.h>
#include <sound/pcm_params.h>

#include "fsl_asrc_common.h"

#define FSL_ASRC_DMABUF_SIZE    (256 * 1024)

static struct snd_pcm_hardware snd_imx_hardware = {
        .info = SNDRV_PCM_INFO_INTERLEAVED |
                SNDRV_PCM_INFO_BLOCK_TRANSFER |
                SNDRV_PCM_INFO_MMAP |
                SNDRV_PCM_INFO_MMAP_VALID,
        .buffer_bytes_max = FSL_ASRC_DMABUF_SIZE,
        .period_bytes_min = 128,
        .period_bytes_max = 65535, /* Limited by SDMA engine */
        .periods_min = 2,
        .periods_max = 255,
        .fifo_size = 0,
};

static bool filter(struct dma_chan *chan, void *param)
{
        if (!imx_dma_is_general_purpose(chan))
                return false;

        chan->private = param;

        return true;
}

static void fsl_asrc_dma_complete(void *arg)
{
        struct snd_pcm_substream *substream = arg;
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct fsl_asrc_pair *pair = runtime->private_data;

        pair->pos += snd_pcm_lib_period_bytes(substream);
        if (pair->pos >= snd_pcm_lib_buffer_bytes(substream))
                pair->pos = 0;

        snd_pcm_period_elapsed(substream);
}

static int fsl_asrc_dma_prepare_and_submit(struct snd_pcm_substream *substream,
                                           struct snd_soc_component *component)
{
        u8 dir = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? OUT : IN;
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct fsl_asrc_pair *pair = runtime->private_data;
        struct device *dev = component->dev;
        unsigned long flags = DMA_CTRL_ACK;

        /* Prepare and submit Front-End DMA channel */
        if (!substream->runtime->no_period_wakeup)
                flags |= DMA_PREP_INTERRUPT;

        pair->pos = 0;
        pair->desc[!dir] = dmaengine_prep_dma_cyclic(
                        pair->dma_chan[!dir], runtime->dma_addr,
                        snd_pcm_lib_buffer_bytes(substream),
                        snd_pcm_lib_period_bytes(substream),
                        dir == OUT ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM, flags);
        if (!pair->desc[!dir]) {
                dev_err(dev, "failed to prepare slave DMA for Front-End\n");
                return -ENOMEM;
        }

        pair->desc[!dir]->callback = fsl_asrc_dma_complete;
        pair->desc[!dir]->callback_param = substream;

        dmaengine_submit(pair->desc[!dir]);

        /* Prepare and submit Back-End DMA channel */
        pair->desc[dir] = dmaengine_prep_dma_cyclic(
                        pair->dma_chan[dir], 0xffff, 64, 64, DMA_DEV_TO_DEV, 0);
        if (!pair->desc[dir]) {
                dev_err(dev, "failed to prepare slave DMA for Back-End\n");
                return -ENOMEM;
        }

        dmaengine_submit(pair->desc[dir]);

        return 0;
}

static int fsl_asrc_dma_trigger(struct snd_soc_component *component,
                                struct snd_pcm_substream *substream, int cmd)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct fsl_asrc_pair *pair = runtime->private_data;
        int ret;

        switch (cmd) {
        case SNDRV_PCM_TRIGGER_START:
        case SNDRV_PCM_TRIGGER_RESUME:
        case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
                ret = fsl_asrc_dma_prepare_and_submit(substream, component);
                if (ret)
                        return ret;
                dma_async_issue_pending(pair->dma_chan[IN]);
                dma_async_issue_pending(pair->dma_chan[OUT]);
                break;
        case SNDRV_PCM_TRIGGER_STOP:
        case SNDRV_PCM_TRIGGER_SUSPEND:
        case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
                dmaengine_terminate_all(pair->dma_chan[OUT]);
                dmaengine_terminate_all(pair->dma_chan[IN]);
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static int fsl_asrc_dma_hw_params(struct snd_soc_component *component,
                                  struct snd_pcm_substream *substream,
                                  struct snd_pcm_hw_params *params)
{
        enum dma_slave_buswidth buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
        struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
        bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
        struct snd_dmaengine_dai_dma_data *dma_params_fe = NULL;
        struct snd_dmaengine_dai_dma_data *dma_params_be = NULL;
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct fsl_asrc_pair *pair = runtime->private_data;
        struct dma_chan *tmp_chan = NULL, *be_chan = NULL;
        struct snd_soc_component *component_be = NULL;
        struct fsl_asrc *asrc = pair->asrc;
        struct dma_slave_config config_fe, config_be;
        enum asrc_pair_index index = pair->index;
        struct device *dev = component->dev;
        struct device_node *of_dma_node;
        int stream = substream->stream;
        struct imx_dma_data *tmp_data;
        struct snd_soc_dpcm *dpcm;
        struct device *dev_be;
        u8 dir = tx ? OUT : IN;
        dma_cap_mask_t mask;
        int ret, width;

        /* Fetch the Back-End dma_data from DPCM */
        for_each_dpcm_be(rtd, stream, dpcm) {
                struct snd_soc_pcm_runtime *be = dpcm->be;
                struct snd_pcm_substream *substream_be;
                struct snd_soc_dai *dai = asoc_rtd_to_cpu(be, 0);

                if (dpcm->fe != rtd)
                        continue;

                substream_be = snd_soc_dpcm_get_substream(be, stream);
                dma_params_be = snd_soc_dai_get_dma_data(dai, substream_be);
                dev_be = dai->dev;
                break;
        }

        if (!dma_params_be) {
                dev_err(dev, "failed to get the substream of Back-End\n");
                return -EINVAL;
        }

        /* Override dma_data of the Front-End and config its dmaengine */
        dma_params_fe = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
        dma_params_fe->addr = asrc->paddr + asrc->get_fifo_addr(!dir, index);
        dma_params_fe->maxburst = dma_params_be->maxburst;

        pair->dma_chan[!dir] = asrc->get_dma_channel(pair, !dir);
        if (!pair->dma_chan[!dir]) {
                dev_err(dev, "failed to request DMA channel\n");
                return -EINVAL;
        }

        memset(&config_fe, 0, sizeof(config_fe));
        ret = snd_dmaengine_pcm_prepare_slave_config(substream, params, &config_fe);
        if (ret) {
                dev_err(dev, "failed to prepare DMA config for Front-End\n");
                return ret;
        }

        ret = dmaengine_slave_config(pair->dma_chan[!dir], &config_fe);
        if (ret) {
                dev_err(dev, "failed to config DMA channel for Front-End\n");
                return ret;
        }

        /* Request and config DMA channel for Back-End */
        dma_cap_zero(mask);
        dma_cap_set(DMA_SLAVE, mask);
        dma_cap_set(DMA_CYCLIC, mask);

        /*
         * The Back-End device might have already requested a DMA channel,
         * so try to reuse it first, and then request a new one upon NULL.
         */
        component_be = snd_soc_lookup_component_nolocked(dev_be, SND_DMAENGINE_PCM_DRV_NAME);
        if (component_be) {
                be_chan = soc_component_to_pcm(component_be)->chan[substream->stream];
                tmp_chan = be_chan;
        }
        if (!tmp_chan)
                tmp_chan = dma_request_slave_channel(dev_be, tx ? "tx" : "rx");

        /*
         * An EDMA DEV_TO_DEV channel is fixed and bound with DMA event of each
         * peripheral, unlike SDMA channel that is allocated dynamically. So no
         * need to configure dma_request and dma_request2, but get dma_chan of
         * Back-End device directly via dma_request_slave_channel.
         */
        if (!asrc->use_edma) {
                /* Get DMA request of Back-End */
                tmp_data = tmp_chan->private;
                pair->dma_data.dma_request = tmp_data->dma_request;
                if (!be_chan)
                        dma_release_channel(tmp_chan);

                /* Get DMA request of Front-End */
                tmp_chan = asrc->get_dma_channel(pair, dir);
                tmp_data = tmp_chan->private;
                pair->dma_data.dma_request2 = tmp_data->dma_request;
                pair->dma_data.peripheral_type = tmp_data->peripheral_type;
                pair->dma_data.priority = tmp_data->priority;
                dma_release_channel(tmp_chan);

                of_dma_node = pair->dma_chan[!dir]->device->dev->of_node;
                pair->dma_chan[dir] =
                        __dma_request_channel(&mask, filter, &pair->dma_data,
                                              of_dma_node);
                pair->req_dma_chan = true;
        } else {
                pair->dma_chan[dir] = tmp_chan;
                /* Do not flag to release if we are reusing the Back-End one */
                pair->req_dma_chan = !be_chan;
        }

        if (!pair->dma_chan[dir]) {
                dev_err(dev, "failed to request DMA channel for Back-End\n");
                return -EINVAL;
        }

        width = snd_pcm_format_physical_width(asrc->asrc_format);
        if (width < 8 || width > 64)
                return -EINVAL;
        else if (width == 8)
                buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
        else if (width == 16)
                buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
        else if (width == 24)
                buswidth = DMA_SLAVE_BUSWIDTH_3_BYTES;
        else if (width <= 32)
                buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
        else
                buswidth = DMA_SLAVE_BUSWIDTH_8_BYTES;

        config_be.direction = DMA_DEV_TO_DEV;
        config_be.src_addr_width = buswidth;
        config_be.src_maxburst = dma_params_be->maxburst;
        config_be.dst_addr_width = buswidth;
        config_be.dst_maxburst = dma_params_be->maxburst;

        if (tx) {
                config_be.src_addr = asrc->paddr + asrc->get_fifo_addr(OUT, index);
                config_be.dst_addr = dma_params_be->addr;
        } else {
                config_be.dst_addr = asrc->paddr + asrc->get_fifo_addr(IN, index);
                config_be.src_addr = dma_params_be->addr;
        }

        ret = dmaengine_slave_config(pair->dma_chan[dir], &config_be);
        if (ret) {
                dev_err(dev, "failed to config DMA channel for Back-End\n");
                if (pair->req_dma_chan)
                        dma_release_channel(pair->dma_chan[dir]);
                return ret;
        }

        snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);

        return 0;
}

static int fsl_asrc_dma_hw_free(struct snd_soc_component *component,
                                struct snd_pcm_substream *substream)
{
        bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct fsl_asrc_pair *pair = runtime->private_data;
        u8 dir = tx ? OUT : IN;

        snd_pcm_set_runtime_buffer(substream, NULL);

        if (pair->dma_chan[!dir])
                dma_release_channel(pair->dma_chan[!dir]);

        /* release dev_to_dev chan if we aren't reusing the Back-End one */
        if (pair->dma_chan[dir] && pair->req_dma_chan)
                dma_release_channel(pair->dma_chan[dir]);

        pair->dma_chan[!dir] = NULL;
        pair->dma_chan[dir] = NULL;

        return 0;
}

static int fsl_asrc_dma_startup(struct snd_soc_component *component,
                                struct snd_pcm_substream *substream)
{
        bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
        struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_dmaengine_dai_dma_data *dma_data;
        struct device *dev = component->dev;
        struct fsl_asrc *asrc = dev_get_drvdata(dev);
        struct fsl_asrc_pair *pair;
        struct dma_chan *tmp_chan = NULL;
        u8 dir = tx ? OUT : IN;
        bool release_pair = true;
        int ret = 0;

        ret = snd_pcm_hw_constraint_integer(substream->runtime,
                                            SNDRV_PCM_HW_PARAM_PERIODS);
        if (ret < 0) {
                dev_err(dev, "failed to set pcm hw params periods\n");
                return ret;
        }

        pair = kzalloc(sizeof(*pair) + asrc->pair_priv_size, GFP_KERNEL);
        if (!pair)
                return -ENOMEM;

        pair->asrc = asrc;
        pair->private = (void *)pair + sizeof(struct fsl_asrc_pair);

        runtime->private_data = pair;

        /* Request a dummy pair, which will be released later.
         * Request pair function needs channel num as input, for this
         * dummy pair, we just request "1" channel temporarily.
         */
        ret = asrc->request_pair(1, pair);
        if (ret < 0) {
                dev_err(dev, "failed to request asrc pair\n");
                goto req_pair_err;
        }

        /* Request a dummy dma channel, which will be released later. */
        tmp_chan = asrc->get_dma_channel(pair, dir);
        if (!tmp_chan) {
                dev_err(dev, "failed to get dma channel\n");
                ret = -EINVAL;
                goto dma_chan_err;
        }

        dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);

        /* Refine the snd_imx_hardware according to caps of DMA. */
        ret = snd_dmaengine_pcm_refine_runtime_hwparams(substream,
                                                        dma_data,
                                                        &snd_imx_hardware,
                                                        tmp_chan);
        if (ret < 0) {
                dev_err(dev, "failed to refine runtime hwparams\n");
                goto out;
        }

        release_pair = false;
        snd_soc_set_runtime_hwparams(substream, &snd_imx_hardware);

out:
        dma_release_channel(tmp_chan);

dma_chan_err:
        asrc->release_pair(pair);

req_pair_err:
        if (release_pair)
                kfree(pair);

        return ret;
}

static int fsl_asrc_dma_shutdown(struct snd_soc_component *component,
                                 struct snd_pcm_substream *substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct fsl_asrc_pair *pair = runtime->private_data;
        struct fsl_asrc *asrc;

        if (!pair)
                return 0;

        asrc = pair->asrc;

        if (asrc->pair[pair->index] == pair)
                asrc->pair[pair->index] = NULL;

        kfree(pair);

        return 0;
}

static snd_pcm_uframes_t
fsl_asrc_dma_pcm_pointer(struct snd_soc_component *component,
                         struct snd_pcm_substream *substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct fsl_asrc_pair *pair = runtime->private_data;

        return bytes_to_frames(substream->runtime, pair->pos);
}

static int fsl_asrc_dma_pcm_new(struct snd_soc_component *component,
                                struct snd_soc_pcm_runtime *rtd)
{
        struct snd_card *card = rtd->card->snd_card;
        struct snd_pcm_substream *substream;
        struct snd_pcm *pcm = rtd->pcm;
        int ret, i;

        ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
        if (ret) {
                dev_err(card->dev, "failed to set DMA mask\n");
                return ret;
        }

        for_each_pcm_streams(i) {
                substream = pcm->streams[i].substream;
                if (!substream)
                        continue;

                ret = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, pcm->card->dev,
                                FSL_ASRC_DMABUF_SIZE, &substream->dma_buffer);
                if (ret) {
                        dev_err(card->dev, "failed to allocate DMA buffer\n");
                        goto err;
                }
        }

        return 0;

err:
        if (--i == 0 && pcm->streams[i].substream)
                snd_dma_free_pages(&pcm->streams[i].substream->dma_buffer);

        return ret;
}

static void fsl_asrc_dma_pcm_free(struct snd_soc_component *component,
                                  struct snd_pcm *pcm)
{
        struct snd_pcm_substream *substream;
        int i;

        for_each_pcm_streams(i) {
                substream = pcm->streams[i].substream;
                if (!substream)
                        continue;

                snd_dma_free_pages(&substream->dma_buffer);
                substream->dma_buffer.area = NULL;
                substream->dma_buffer.addr = 0;
        }
}

struct snd_soc_component_driver fsl_asrc_component = {
        .name           = DRV_NAME,
        .hw_params      = fsl_asrc_dma_hw_params,
        .hw_free        = fsl_asrc_dma_hw_free,
        .trigger        = fsl_asrc_dma_trigger,
        .open           = fsl_asrc_dma_startup,
        .close          = fsl_asrc_dma_shutdown,
        .pointer        = fsl_asrc_dma_pcm_pointer,
        .pcm_construct  = fsl_asrc_dma_pcm_new,
        .pcm_destruct   = fsl_asrc_dma_pcm_free,
};
EXPORT_SYMBOL_GPL(fsl_asrc_component);