root/sound/arm/pxa2xx-pcm-lib.c
// SPDX-License-Identifier: GPL-2.0-only

#include <linux/slab.h>
#include <linux/module.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/dma/pxa-dma.h>

#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/pxa2xx-lib.h>
#include <sound/dmaengine_pcm.h>

static const struct snd_pcm_hardware pxa2xx_pcm_hardware = {
        .info                   = SNDRV_PCM_INFO_MMAP |
                                  SNDRV_PCM_INFO_MMAP_VALID |
                                  SNDRV_PCM_INFO_INTERLEAVED |
                                  SNDRV_PCM_INFO_PAUSE |
                                  SNDRV_PCM_INFO_RESUME,
        .formats                = SNDRV_PCM_FMTBIT_S16_LE |
                                  SNDRV_PCM_FMTBIT_S24_LE |
                                  SNDRV_PCM_FMTBIT_S32_LE,
        .period_bytes_min       = 32,
        .period_bytes_max       = 8192 - 32,
        .periods_min            = 1,
        .periods_max            = 256,
        .buffer_bytes_max       = 128 * 1024,
        .fifo_size              = 32,
};

int pxa2xx_pcm_hw_params(struct snd_pcm_substream *substream,
                         struct snd_pcm_hw_params *params)
{
        struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream);
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct snd_dmaengine_dai_dma_data *dma_params;
        struct dma_slave_config config;
        int ret;

        dma_params = snd_soc_dai_get_dma_data(snd_soc_rtd_to_cpu(rtd, 0), substream);
        if (!dma_params)
                return 0;

        ret = snd_hwparams_to_dma_slave_config(substream, params, &config);
        if (ret)
                return ret;

        snd_dmaengine_pcm_set_config_from_dai_data(substream,
                        snd_soc_dai_get_dma_data(snd_soc_rtd_to_cpu(rtd, 0), substream),
                        &config);

        ret = dmaengine_slave_config(chan, &config);
        if (ret)
                return ret;

        return 0;
}
EXPORT_SYMBOL(pxa2xx_pcm_hw_params);

int pxa2xx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
        return snd_dmaengine_pcm_trigger(substream, cmd);
}
EXPORT_SYMBOL(pxa2xx_pcm_trigger);

snd_pcm_uframes_t
pxa2xx_pcm_pointer(struct snd_pcm_substream *substream)
{
        return snd_dmaengine_pcm_pointer(substream);
}
EXPORT_SYMBOL(pxa2xx_pcm_pointer);

int pxa2xx_pcm_prepare(struct snd_pcm_substream *substream)
{
        return 0;
}
EXPORT_SYMBOL(pxa2xx_pcm_prepare);

int pxa2xx_pcm_open(struct snd_pcm_substream *substream)
{
        struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct snd_dmaengine_dai_dma_data *dma_params;
        int ret;

        runtime->hw = pxa2xx_pcm_hardware;

        dma_params = snd_soc_dai_get_dma_data(snd_soc_rtd_to_cpu(rtd, 0), substream);
        if (!dma_params)
                return 0;

        /*
         * For mysterious reasons (and despite what the manual says)
         * playback samples are lost if the DMA count is not a multiple
         * of the DMA burst size.  Let's add a rule to enforce that.
         */
        ret = snd_pcm_hw_constraint_step(runtime, 0,
                SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 32);
        if (ret)
                return ret;

        ret = snd_pcm_hw_constraint_step(runtime, 0,
                SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 32);
        if (ret)
                return ret;

        ret = snd_pcm_hw_constraint_integer(runtime,
                                            SNDRV_PCM_HW_PARAM_PERIODS);
        if (ret < 0)
                return ret;

        return snd_dmaengine_pcm_open(
                substream, dma_request_slave_channel(snd_soc_rtd_to_cpu(rtd, 0)->dev,
                                                     dma_params->chan_name));
}
EXPORT_SYMBOL(pxa2xx_pcm_open);

int pxa2xx_pcm_close(struct snd_pcm_substream *substream)
{
        return snd_dmaengine_pcm_close_release_chan(substream);
}
EXPORT_SYMBOL(pxa2xx_pcm_close);

int pxa2xx_pcm_preallocate_dma_buffer(struct snd_pcm *pcm)
{
        size_t size = pxa2xx_pcm_hardware.buffer_bytes_max;

        return snd_pcm_set_fixed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV_WC,
                                            pcm->card->dev, size);
}
EXPORT_SYMBOL(pxa2xx_pcm_preallocate_dma_buffer);

int pxa2xx_soc_pcm_new(struct snd_soc_component *component,
                       struct snd_soc_pcm_runtime *rtd)
{
        struct snd_card *card = rtd->card->snd_card;
        struct snd_pcm *pcm = rtd->pcm;
        int ret;

        ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
        if (ret)
                return ret;

        return pxa2xx_pcm_preallocate_dma_buffer(pcm);
}
EXPORT_SYMBOL(pxa2xx_soc_pcm_new);

int pxa2xx_soc_pcm_open(struct snd_soc_component *component,
                        struct snd_pcm_substream *substream)
{
        return pxa2xx_pcm_open(substream);
}
EXPORT_SYMBOL(pxa2xx_soc_pcm_open);

int pxa2xx_soc_pcm_close(struct snd_soc_component *component,
                         struct snd_pcm_substream *substream)
{
        return pxa2xx_pcm_close(substream);
}
EXPORT_SYMBOL(pxa2xx_soc_pcm_close);

int pxa2xx_soc_pcm_hw_params(struct snd_soc_component *component,
                             struct snd_pcm_substream *substream,
                             struct snd_pcm_hw_params *params)
{
        return pxa2xx_pcm_hw_params(substream, params);
}
EXPORT_SYMBOL(pxa2xx_soc_pcm_hw_params);

int pxa2xx_soc_pcm_prepare(struct snd_soc_component *component,
                           struct snd_pcm_substream *substream)
{
        return pxa2xx_pcm_prepare(substream);
}
EXPORT_SYMBOL(pxa2xx_soc_pcm_prepare);

int pxa2xx_soc_pcm_trigger(struct snd_soc_component *component,
                           struct snd_pcm_substream *substream, int cmd)
{
        return pxa2xx_pcm_trigger(substream, cmd);
}
EXPORT_SYMBOL(pxa2xx_soc_pcm_trigger);

snd_pcm_uframes_t
pxa2xx_soc_pcm_pointer(struct snd_soc_component *component,
                       struct snd_pcm_substream *substream)
{
        return pxa2xx_pcm_pointer(substream);
}
EXPORT_SYMBOL(pxa2xx_soc_pcm_pointer);

MODULE_AUTHOR("Nicolas Pitre");
MODULE_DESCRIPTION("Intel PXA2xx sound library");
MODULE_LICENSE("GPL");