// SPDX-License-Identifier: GPL-2.0
//
// Socionext UniPhier AIO DMA driver.
//
// Copyright (c) 2016-2018 Socionext Inc.

#include <linux/dma-mapping.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/soc.h>

#include "aio.h"

static const struct snd_pcm_hardware uniphier_aiodma_hw = {
        .info = SNDRV_PCM_INFO_MMAP |
                SNDRV_PCM_INFO_MMAP_VALID |
                SNDRV_PCM_INFO_INTERLEAVED,
        .period_bytes_min = 256,
        .period_bytes_max = 4096,
        .periods_min      = 4,
        .periods_max      = 1024,
        .buffer_bytes_max = 128 * 1024,
};

static void aiodma_pcm_irq(struct uniphier_aio_sub *sub)
{
        struct snd_pcm_runtime *runtime = sub->substream->runtime;
        int bytes = runtime->period_size *
                runtime->channels * samples_to_bytes(runtime, 1);
        int ret;

        spin_lock(&sub->lock);
        ret = aiodma_rb_set_threshold(sub, runtime->dma_bytes,
                                      sub->threshold + bytes);
        if (!ret)
                sub->threshold += bytes;

        aiodma_rb_sync(sub, runtime->dma_addr, runtime->dma_bytes, bytes);
        aiodma_rb_clear_irq(sub);
        spin_unlock(&sub->lock);

        snd_pcm_period_elapsed(sub->substream);
}

static void aiodma_compr_irq(struct uniphier_aio_sub *sub)
{
        struct snd_compr_runtime *runtime = sub->cstream->runtime;
        int bytes = runtime->fragment_size;
        int ret;

        spin_lock(&sub->lock);
        ret = aiodma_rb_set_threshold(sub, sub->compr_bytes,
                                      sub->threshold + bytes);
        if (!ret)
                sub->threshold += bytes;

        aiodma_rb_sync(sub, sub->compr_addr, sub->compr_bytes, bytes);
        aiodma_rb_clear_irq(sub);
        spin_unlock(&sub->lock);

        snd_compr_fragment_elapsed(sub->cstream);
}

static irqreturn_t aiodma_irq(int irq, void *p)
{
        struct platform_device *pdev = p;
        struct uniphier_aio_chip *chip = platform_get_drvdata(pdev);
        irqreturn_t ret = IRQ_NONE;
        int i, j;

        for (i = 0; i < chip->num_aios; i++) {
                struct uniphier_aio *aio = &chip->aios[i];

                for (j = 0; j < ARRAY_SIZE(aio->sub); j++) {
                        struct uniphier_aio_sub *sub = &aio->sub[j];

                        /* Skip channel that does not trigger */
                        if (!sub->running || !aiodma_rb_is_irq(sub))
                                continue;

                        if (sub->substream)
                                aiodma_pcm_irq(sub);
                        if (sub->cstream)
                                aiodma_compr_irq(sub);

                        ret = IRQ_HANDLED;
                }
        }

        return ret;
}

static int uniphier_aiodma_open(struct snd_soc_component *component,
                                struct snd_pcm_substream *substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;

        snd_soc_set_runtime_hwparams(substream, &uniphier_aiodma_hw);

        return snd_pcm_hw_constraint_step(runtime, 0,
                SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 256);
}

static int uniphier_aiodma_prepare(struct snd_soc_component *component,
                                   struct snd_pcm_substream *substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct uniphier_aio *aio = uniphier_priv(snd_soc_rtd_to_cpu(rtd, 0));
        struct uniphier_aio_sub *sub = &aio->sub[substream->stream];
        int bytes = runtime->period_size *
                runtime->channels * samples_to_bytes(runtime, 1);
        unsigned long flags;
        int ret;

        ret = aiodma_ch_set_param(sub);
        if (ret)
                return ret;

        spin_lock_irqsave(&sub->lock, flags);
        ret = aiodma_rb_set_buffer(sub, runtime->dma_addr,
                                   runtime->dma_addr + runtime->dma_bytes,
                                   bytes);
        spin_unlock_irqrestore(&sub->lock, flags);
        if (ret)
                return ret;

        return 0;
}

static int uniphier_aiodma_trigger(struct snd_soc_component *component,
                                   struct snd_pcm_substream *substream, int cmd)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct uniphier_aio *aio = uniphier_priv(snd_soc_rtd_to_cpu(rtd, 0));
        struct uniphier_aio_sub *sub = &aio->sub[substream->stream];
        struct device *dev = &aio->chip->pdev->dev;
        int bytes = runtime->period_size *
                runtime->channels * samples_to_bytes(runtime, 1);
        unsigned long flags;

        spin_lock_irqsave(&sub->lock, flags);
        switch (cmd) {
        case SNDRV_PCM_TRIGGER_START:
                aiodma_rb_sync(sub, runtime->dma_addr, runtime->dma_bytes,
                               bytes);
                aiodma_ch_set_enable(sub, 1);
                sub->running = 1;

                break;
        case SNDRV_PCM_TRIGGER_STOP:
                sub->running = 0;
                aiodma_ch_set_enable(sub, 0);

                break;
        default:
                dev_warn(dev, "Unknown trigger(%d) ignored\n", cmd);
                break;
        }
        spin_unlock_irqrestore(&sub->lock, flags);

        return 0;
}

static snd_pcm_uframes_t uniphier_aiodma_pointer(
                                        struct snd_soc_component *component,
                                        struct snd_pcm_substream *substream)
{
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct uniphier_aio *aio = uniphier_priv(snd_soc_rtd_to_cpu(rtd, 0));
        struct uniphier_aio_sub *sub = &aio->sub[substream->stream];
        int bytes = runtime->period_size *
                runtime->channels * samples_to_bytes(runtime, 1);
        unsigned long flags;
        snd_pcm_uframes_t pos;

        spin_lock_irqsave(&sub->lock, flags);
        aiodma_rb_sync(sub, runtime->dma_addr, runtime->dma_bytes, bytes);

        if (sub->swm->dir == PORT_DIR_OUTPUT)
                pos = bytes_to_frames(runtime, sub->rd_offs);
        else
                pos = bytes_to_frames(runtime, sub->wr_offs);
        spin_unlock_irqrestore(&sub->lock, flags);

        return pos;
}

static int uniphier_aiodma_mmap(struct snd_soc_component *component,
                                struct snd_pcm_substream *substream,
                                struct vm_area_struct *vma)
{
        vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);

        return remap_pfn_range(vma, vma->vm_start,
                               substream->runtime->dma_addr >> PAGE_SHIFT,
                               vma->vm_end - vma->vm_start, vma->vm_page_prot);
}

static int uniphier_aiodma_new(struct snd_soc_component *component,
                               struct snd_soc_pcm_runtime *rtd)
{
        struct device *dev = rtd->card->snd_card->dev;
        struct snd_pcm *pcm = rtd->pcm;
        int ret;

        ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(33));
        if (ret)
                return ret;

        snd_pcm_set_managed_buffer_all(pcm,
                SNDRV_DMA_TYPE_DEV, dev,
                uniphier_aiodma_hw.buffer_bytes_max,
                uniphier_aiodma_hw.buffer_bytes_max);
        return 0;
}

static const struct snd_soc_component_driver uniphier_soc_platform = {
        .open           = uniphier_aiodma_open,
        .prepare        = uniphier_aiodma_prepare,
        .trigger        = uniphier_aiodma_trigger,
        .pointer        = uniphier_aiodma_pointer,
        .mmap           = uniphier_aiodma_mmap,
        .pcm_construct  = uniphier_aiodma_new,
        .compress_ops   = &uniphier_aio_compress_ops,
};

static const struct regmap_config aiodma_regmap_config = {
        .reg_bits      = 32,
        .reg_stride    = 4,
        .val_bits      = 32,
        .max_register  = 0x7fffc,
        .cache_type    = REGCACHE_NONE,
};

/**
 * uniphier_aiodma_soc_register_platform - register the AIO DMA
 * @pdev: the platform device
 *
 * Register and setup the DMA of AIO to transfer the sound data to device.
 * This function need to call once at driver startup and need NOT to call
 * unregister function.
 *
 * Return: Zero if successful, otherwise a negative value on error.
 */
int uniphier_aiodma_soc_register_platform(struct platform_device *pdev)
{
        struct uniphier_aio_chip *chip = platform_get_drvdata(pdev);
        struct device *dev = &pdev->dev;
        void __iomem *preg;
        int irq, ret;

        preg = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(preg))
                return PTR_ERR(preg);

        chip->regmap = devm_regmap_init_mmio(dev, preg,
                                             &aiodma_regmap_config);
        if (IS_ERR(chip->regmap))
                return PTR_ERR(chip->regmap);

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

        ret = devm_request_irq(dev, irq, aiodma_irq,
                               IRQF_SHARED, dev_name(dev), pdev);
        if (ret)
                return ret;

        return devm_snd_soc_register_component(dev, &uniphier_soc_platform,
                                               NULL, 0);
}
EXPORT_SYMBOL_GPL(uniphier_aiodma_soc_register_platform);