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 = substream->private_data;
	struct snd_dmaengine_dai_dma_data *dma_params;
	struct dma_slave_config config;
	int ret;

	dma_params = snd_soc_dai_get_dma_data(rtd->cpu_dai, 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(rtd->cpu_dai, substream),
			&config);

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

	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);

	return 0;
}
EXPORT_SYMBOL(pxa2xx_pcm_hw_params);

int pxa2xx_pcm_hw_free(struct snd_pcm_substream *substream)
{
	snd_pcm_set_runtime_buffer(substream, NULL);
	return 0;
}
EXPORT_SYMBOL(pxa2xx_pcm_hw_free);

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 = substream->private_data;
	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(rtd->cpu_dai, 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(rtd->cpu_dai->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_mmap(struct snd_pcm_substream *substream,
	struct vm_area_struct *vma)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	return dma_mmap_wc(substream->pcm->card->dev, vma, runtime->dma_area,
			   runtime->dma_addr, runtime->dma_bytes);
}
EXPORT_SYMBOL(pxa2xx_pcm_mmap);

int pxa2xx_pcm_preallocate_dma_buffer(struct snd_pcm *pcm, int stream)
{
	struct snd_pcm_substream *substream = pcm->streams[stream].substream;
	struct snd_dma_buffer *buf = &substream->dma_buffer;
	size_t size = pxa2xx_pcm_hardware.buffer_bytes_max;
	buf->dev.type = SNDRV_DMA_TYPE_DEV;
	buf->dev.dev = pcm->card->dev;
	buf->private_data = NULL;
	buf->area = dma_alloc_wc(pcm->card->dev, size, &buf->addr, GFP_KERNEL);
	if (!buf->area)
		return -ENOMEM;
	buf->bytes = size;
	return 0;
}
EXPORT_SYMBOL(pxa2xx_pcm_preallocate_dma_buffer);

void pxa2xx_pcm_free_dma_buffers(struct snd_pcm *pcm)
{
	struct snd_pcm_substream *substream;
	struct snd_dma_buffer *buf;
	int stream;

	for (stream = 0; stream < 2; stream++) {
		substream = pcm->streams[stream].substream;
		if (!substream)
			continue;
		buf = &substream->dma_buffer;
		if (!buf->area)
			continue;
		dma_free_wc(pcm->card->dev, buf->bytes, buf->area, buf->addr);
		buf->area = NULL;
	}
}
EXPORT_SYMBOL(pxa2xx_pcm_free_dma_buffers);

int pxa2xx_soc_pcm_new(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;

	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
		ret = pxa2xx_pcm_preallocate_dma_buffer(pcm,
			SNDRV_PCM_STREAM_PLAYBACK);
		if (ret)
			goto out;
	}

	if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
		ret = pxa2xx_pcm_preallocate_dma_buffer(pcm,
			SNDRV_PCM_STREAM_CAPTURE);
		if (ret)
			goto out;
	}
 out:
	return ret;
}
EXPORT_SYMBOL(pxa2xx_soc_pcm_new);

const struct snd_pcm_ops pxa2xx_pcm_ops = {
	.open		= pxa2xx_pcm_open,
	.close		= pxa2xx_pcm_close,
	.ioctl		= snd_pcm_lib_ioctl,
	.hw_params	= pxa2xx_pcm_hw_params,
	.hw_free	= pxa2xx_pcm_hw_free,
	.prepare	= pxa2xx_pcm_prepare,
	.trigger	= pxa2xx_pcm_trigger,
	.pointer	= pxa2xx_pcm_pointer,
	.mmap		= pxa2xx_pcm_mmap,
};
EXPORT_SYMBOL(pxa2xx_pcm_ops);

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