linux-nv-oot/sound/soc/tegra-virt-alt/tegra_pcm_virt_alt.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2021-2022 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 */

#include <nvidia/conftest.h>

#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <linux/version.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <sound/dmaengine_pcm.h>

#include "tegra_pcm_alt.h"
#include "tegra_asoc_util_virt_alt.h"

static const struct snd_pcm_hardware tegra_alt_pcm_hardware = {
	.info			= SNDRV_PCM_INFO_MMAP |
				  SNDRV_PCM_INFO_MMAP_VALID |
				  SNDRV_PCM_INFO_PAUSE |
				  SNDRV_PCM_INFO_RESUME |
				  SNDRV_PCM_INFO_INTERLEAVED,
	.formats		= SNDRV_PCM_FMTBIT_S8 |
				  SNDRV_PCM_FMTBIT_S16_LE |
				  SNDRV_PCM_FMTBIT_S32_LE,
	.period_bytes_min	= 128,
	.period_bytes_max	= PAGE_SIZE * 4,
	.periods_min		= 1,
	.periods_max		= 8,
	.buffer_bytes_max	= PAGE_SIZE * 8,
	.fifo_size		= 4,
};

static int tegra_alt_pcm_open(struct snd_soc_component *component,
					struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct tegra_alt_pcm_dma_params *dmap;
	struct dma_chan *chan;
#if defined(NV_SND_SOC_RTD_TO_CODEC_PRESENT) /* Linux 6.7*/
	struct snd_soc_dai *cpu_dai = snd_soc_rtd_to_cpu(rtd, 0);
#else
	struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(rtd, 0);
#endif
	int ret;

	if (rtd->dai_link->no_pcm)
		return 0;

#if defined(NV_SND_SOC_RTD_TO_CODEC_PRESENT) /* Linux 6.7*/
	dmap = snd_soc_dai_get_dma_data(snd_soc_rtd_to_cpu(rtd, 0), substream);
#else
	dmap = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
#endif

	/* Set HW params now that initialization is complete */
	snd_soc_set_runtime_hwparams(substream, &tegra_alt_pcm_hardware);

	/* Update buffer size from device tree */
	if (dmap->buffer_size > substream->runtime->hw.buffer_bytes_max) {
		substream->runtime->hw.buffer_bytes_max = dmap->buffer_size;
		substream->runtime->hw.period_bytes_max = dmap->buffer_size / 2;
	}

	/* Ensure period size is multiple of 8 */
	ret = snd_pcm_hw_constraint_step(substream->runtime, 0,
		SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 0x8);
	if (ret) {
		dev_err(cpu_dai->dev, "failed to set constraint %d\n", ret);
		return ret;
	}

	chan = dma_request_slave_channel(cpu_dai->dev, dmap->chan_name);
	if (!chan) {
		dev_err(cpu_dai->dev,
				"dmaengine request slave channel failed! (%s)\n",
					dmap->chan_name);
		return -ENODEV;
	}
	 ret = snd_dmaengine_pcm_open(substream, chan);

	if (ret) {
		dev_err(cpu_dai->dev, "dmaengine pcm open failed with err %d\n", ret);
		return ret;
	}

	return 0;
}

static int tegra_alt_pcm_close(struct snd_soc_component *component,
					struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;

	if (rtd->dai_link->no_pcm)
		return 0;

	snd_dmaengine_pcm_close_release_chan(substream);

	return 0;
}

static int tegra_alt_pcm_hw_params(struct snd_soc_component *component,
					struct snd_pcm_substream *substream,
					struct snd_pcm_hw_params *params)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct device *dev = rtd->dev;
	struct dma_chan *chan;
	struct tegra_alt_pcm_dma_params *dmap;
	struct dma_slave_config slave_config;
	int ret;

	if (rtd->dai_link->no_pcm)
		return 0;

#if defined(NV_SND_SOC_RTD_TO_CODEC_PRESENT) /* Linux 6.7*/
	dmap = snd_soc_dai_get_dma_data(snd_soc_rtd_to_cpu(rtd, 0), substream);
#else
	dmap = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
#endif
	if (!dmap)
		return 0;

	chan = snd_dmaengine_pcm_get_chan(substream);

	ret = snd_hwparams_to_dma_slave_config(substream, params,
						&slave_config);
	if (ret) {
		dev_err(dev, "hw params config failed with err %d\n", ret);
		return ret;
	}

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
		slave_config.dst_addr = dmap->addr;
		slave_config.dst_maxburst = 8;
	} else {
		slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
		slave_config.src_addr = dmap->addr;
		slave_config.src_maxburst = 8;
	}

	ret = dmaengine_slave_config(chan, &slave_config);
	if (ret < 0) {
		dev_err(dev, "dma slave config failed with err %d\n", ret);
		return ret;
	}

	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
	return 0;
}

static int tegra_alt_pcm_hw_free(struct snd_soc_component *component,
					struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;

	if (rtd->dai_link->no_pcm)
		return 0;

	snd_pcm_set_runtime_buffer(substream, NULL);
	return 0;
}

static int tegra_alt_pcm_mmap(struct snd_soc_component *component,
				struct snd_pcm_substream *substream,
				struct vm_area_struct *vma)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_pcm_runtime *runtime = substream->runtime;

	if (rtd->dai_link->no_pcm)
		return 0;

	return dma_mmap_wc(substream->pcm->card->dev, vma,
					runtime->dma_area,
					runtime->dma_addr,
					runtime->dma_bytes);
}

static snd_pcm_uframes_t tegra_alt_pcm_pointer
				(struct snd_soc_component *component,
					struct snd_pcm_substream *substream)
{

	snd_pcm_uframes_t appl_offset, pos = 0;
	struct snd_pcm_runtime *runtime = substream->runtime;
	char *appl_ptr;

	pos = snd_dmaengine_pcm_pointer(substream);

	/* In DRAINING state pointer callback comes from dma completion, here
	 * we want to make sure if if dma completion callback is late we should
	 * not endup playing stale data.
	 */
	if ((runtime->status->state == SNDRV_PCM_STATE_DRAINING) &&
		(substream->stream == SNDRV_PCM_STREAM_PLAYBACK)) {
		appl_offset = runtime->control->appl_ptr %
					runtime->buffer_size;
		appl_ptr = runtime->dma_area + frames_to_bytes(runtime,
					appl_offset);
		if (pos < appl_offset) {
			memset(appl_ptr, 0, frames_to_bytes(runtime,
					runtime->buffer_size - appl_offset));
			memset(runtime->dma_area, 0, frames_to_bytes(runtime,
					pos));
		} else
			memset(appl_ptr, 0, frames_to_bytes(runtime,
					pos - appl_offset));
	}

	return pos;
}

static int tegra_alt_pcm_preallocate_dma_buffer(struct snd_pcm *pcm,
				unsigned int stream, size_t size)
{
	struct snd_pcm_substream *substream = pcm->streams[stream].substream;
	struct snd_dma_buffer *buf = &substream->dma_buffer;
	buf->area = dma_alloc_coherent(pcm->card->dev, size,
						&buf->addr, GFP_KERNEL);
	if (!buf->area)
		return -ENOMEM;
	buf->private_data = NULL;
	buf->dev.type = SNDRV_DMA_TYPE_DEV;
	buf->dev.dev = pcm->card->dev;
	buf->bytes = size;

	return 0;
}

static void tegra_alt_pcm_deallocate_dma_buffer(struct snd_pcm *pcm, unsigned int stream)
{
	struct snd_pcm_substream *substream;
	struct snd_dma_buffer *buf;

	substream = pcm->streams[stream].substream;
	if (!substream)
		return;

	buf = &substream->dma_buffer;
	if (!buf->area)
		return;

	dma_free_coherent(pcm->card->dev, buf->bytes,
				buf->area, buf->addr);
	buf->area = NULL;
}

static int tegra_alt_pcm_dma_allocate(struct snd_soc_pcm_runtime *rtd,
	size_t size)
{
	struct snd_card *card = rtd->card->snd_card;
	struct snd_pcm *pcm = rtd->pcm;
	struct tegra_alt_pcm_dma_params *dmap;
	size_t buffer_size = size;
	int ret;

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

#if defined(NV_SND_SOC_RTD_TO_CODEC_PRESENT) /* Linux 6.7*/
	dmap = snd_soc_dai_get_dma_data(snd_soc_rtd_to_cpu(rtd, 0),
			pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream);
#else
	dmap = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0),
			pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream);
#endif
	if (dmap->buffer_size > size)
		buffer_size = dmap->buffer_size;
	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
		ret = tegra_alt_pcm_preallocate_dma_buffer(pcm,
						SNDRV_PCM_STREAM_PLAYBACK,
						buffer_size);
		if (ret)
			goto err;
	}

#if defined(NV_SND_SOC_RTD_TO_CODEC_PRESENT) /* Linux 6.7*/
	dmap = snd_soc_dai_get_dma_data(snd_soc_rtd_to_cpu(rtd, 0),
			pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream);
#else
	dmap = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0),
			pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream);
#endif
	if (dmap->buffer_size > size)
		buffer_size = dmap->buffer_size;
	if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
		ret = tegra_alt_pcm_preallocate_dma_buffer(pcm,
						SNDRV_PCM_STREAM_CAPTURE,
						buffer_size);
		if (ret)
			goto err_free_play;
	}

	return 0;

err_free_play:
	tegra_alt_pcm_deallocate_dma_buffer(pcm, SNDRV_PCM_STREAM_PLAYBACK);
err:
	return ret;
}

static int tegra_alt_pcm_new(struct snd_soc_component *c,
					struct snd_soc_pcm_runtime *rtd)
{
	return tegra_alt_pcm_dma_allocate(rtd,
				tegra_alt_pcm_hardware.buffer_bytes_max);
}

static void tegra_alt_pcm_free(struct snd_soc_component *c,
						struct snd_pcm *pcm)
{
	tegra_alt_pcm_deallocate_dma_buffer(pcm, SNDRV_PCM_STREAM_CAPTURE);
	tegra_alt_pcm_deallocate_dma_buffer(pcm, SNDRV_PCM_STREAM_PLAYBACK);
}

static int tegra_alt_pcm_ioctl(struct snd_soc_component *component,
                           struct snd_pcm_substream *substream, unsigned int cmd, void *arg)
{
	return snd_pcm_lib_ioctl(substream, cmd, arg);
}


static int tegra_alt_pcm_probe(struct snd_soc_component *component)
{
	struct snd_soc_dapm_context *dapm = snd_soc_component_get_dapm(component);
	dapm->idle_bias_off = 1;
	return 0;
}

static struct snd_soc_component_driver tegra_alt_pcm_platform = {
	.open		= tegra_alt_pcm_open,
	.close		= tegra_alt_pcm_close,
	.ioctl		= tegra_alt_pcm_ioctl,
	.hw_params	= tegra_alt_pcm_hw_params,
	.hw_free	= tegra_alt_pcm_hw_free,
	.pointer	= tegra_alt_pcm_pointer,
	.mmap		= tegra_alt_pcm_mmap,
	.pcm_construct	= tegra_alt_pcm_new,
	.pcm_destruct	= tegra_alt_pcm_free,
	.probe		= tegra_alt_pcm_probe,
};

int tegra_alt_pcm_platform_register(struct device *dev)
{
	return tegra_register_component(dev, &tegra_alt_pcm_platform, NULL, 0, "pcm");
}
EXPORT_SYMBOL_GPL(tegra_alt_pcm_platform_register);

void tegra_alt_pcm_platform_unregister(struct device *dev)
{
	snd_soc_unregister_component(dev);
}
EXPORT_SYMBOL_GPL(tegra_alt_pcm_platform_unregister);

MODULE_AUTHOR("Stephen Warren <swarren@nvidia.com>");
MODULE_DESCRIPTION("Tegra Alt PCM ASoC driver");
MODULE_LICENSE("GPL");