sound/soc/dwc/dwc-pcm.c - linux - Git at Google

 /*
  * ALSA SoC Synopsys PIO PCM for I2S driver
  *
  * sound/soc/dwc/designware_pcm.c
  *
  * Copyright (C) 2016 Synopsys
  * Jose Abreu <joabreu@synopsys.com>
  *
  * This file is licensed under the terms of the GNU General Public
  * License version 2. This program is licensed "as is" without any
  * warranty of any kind, whether express or implied.
  */

 #include <linux/io.h>
 #include <linux/rcupdate.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 #include "local.h"

 #define BUFFER_BYTES_MAX	(3 * 2 * 8 * PERIOD_BYTES_MIN)
 #define PERIOD_BYTES_MIN	4096
 #define PERIODS_MIN		2

 #define dw_pcm_tx_fn(sample_bits) \
 static unsigned int dw_pcm_tx_##sample_bits(struct dw_i2s_dev *dev, \
 		struct snd_pcm_runtime *runtime, unsigned int tx_ptr, \
 		bool *period_elapsed) \
 { \
 	const u##sample_bits (*p)[2] = (void *)runtime->dma_area; \
 	unsigned int period_pos = tx_ptr % runtime->period_size; \
 	int i; \
 \
 	for (i = 0; i < dev->fifo_th; i++) { \
 		iowrite32(p[tx_ptr][0], dev->i2s_base + LRBR_LTHR(0)); \
 		iowrite32(p[tx_ptr][1], dev->i2s_base + RRBR_RTHR(0)); \
 		period_pos++; \
 		if (++tx_ptr >= runtime->buffer_size) \
 			tx_ptr = 0; \
 	} \
 	*period_elapsed = period_pos >= runtime->period_size; \
 	return tx_ptr; \
 }

 #define dw_pcm_rx_fn(sample_bits) \
 static unsigned int dw_pcm_rx_##sample_bits(struct dw_i2s_dev *dev, \
 		struct snd_pcm_runtime *runtime, unsigned int rx_ptr, \
 		bool *period_elapsed) \
 { \
 	u##sample_bits (*p)[2] = (void *)runtime->dma_area; \
 	unsigned int period_pos = rx_ptr % runtime->period_size; \
 	int i; \
 \
 	for (i = 0; i < dev->fifo_th; i++) { \
 		p[rx_ptr][0] = ioread32(dev->i2s_base + LRBR_LTHR(0)); \
 		p[rx_ptr][1] = ioread32(dev->i2s_base + RRBR_RTHR(0)); \
 		period_pos++; \
 		if (++rx_ptr >= runtime->buffer_size) \
 			rx_ptr = 0; \
 	} \
 	*period_elapsed = period_pos >= runtime->period_size; \
 	return rx_ptr; \
 }

 dw_pcm_tx_fn(16);
 dw_pcm_tx_fn(32);
 dw_pcm_rx_fn(16);
 dw_pcm_rx_fn(32);

 #undef dw_pcm_tx_fn
 #undef dw_pcm_rx_fn

 static const struct snd_pcm_hardware dw_pcm_hardware = {
 	.info = SNDRV_PCM_INFO_INTERLEAVED |
 		SNDRV_PCM_INFO_MMAP |
 		SNDRV_PCM_INFO_MMAP_VALID |
 		SNDRV_PCM_INFO_BLOCK_TRANSFER,
 	.rates = SNDRV_PCM_RATE_32000 |
 		SNDRV_PCM_RATE_44100 |
 		SNDRV_PCM_RATE_48000,
 	.rate_min = 32000,
 	.rate_max = 48000,
 	.formats = SNDRV_PCM_FMTBIT_S16_LE |
 		SNDRV_PCM_FMTBIT_S24_LE |
 		SNDRV_PCM_FMTBIT_S32_LE,
 	.channels_min = 2,
 	.channels_max = 2,
 	.buffer_bytes_max = BUFFER_BYTES_MAX,
 	.period_bytes_min = PERIOD_BYTES_MIN,
 	.period_bytes_max = BUFFER_BYTES_MAX / PERIODS_MIN,
 	.periods_min = PERIODS_MIN,
 	.periods_max = BUFFER_BYTES_MAX / PERIOD_BYTES_MIN,
 	.fifo_size = 16,
 };

 static void dw_pcm_transfer(struct dw_i2s_dev *dev, bool push)
 {
 	struct snd_pcm_substream *substream;
 	bool active, period_elapsed;

 	rcu_read_lock();
 	if (push)
 		substream = rcu_dereference(dev->tx_substream);
 	else
 		substream = rcu_dereference(dev->rx_substream);
 	active = substream && snd_pcm_running(substream);
 	if (active) {
 		unsigned int ptr;
 		unsigned int new_ptr;

 		if (push) {
 			ptr = READ_ONCE(dev->tx_ptr);
 			new_ptr = dev->tx_fn(dev, substream->runtime, ptr,
 					&period_elapsed);
 			cmpxchg(&dev->tx_ptr, ptr, new_ptr);
 		} else {
 			ptr = READ_ONCE(dev->rx_ptr);
 			new_ptr = dev->rx_fn(dev, substream->runtime, ptr,
 					&period_elapsed);
 			cmpxchg(&dev->rx_ptr, ptr, new_ptr);
 		}

 		if (period_elapsed)
 			snd_pcm_period_elapsed(substream);
 	}
 	rcu_read_unlock();
 }

 void dw_pcm_push_tx(struct dw_i2s_dev *dev)
 {
 	dw_pcm_transfer(dev, true);
 }

 void dw_pcm_pop_rx(struct dw_i2s_dev *dev)
 {
 	dw_pcm_transfer(dev, false);
 }

 static int dw_pcm_open(struct snd_pcm_substream *substream)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct dw_i2s_dev *dev = snd_soc_dai_get_drvdata(rtd->cpu_dai);

 	snd_soc_set_runtime_hwparams(substream, &dw_pcm_hardware);
 	snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 	runtime->private_data = dev;

 	return 0;
 }

 static int dw_pcm_close(struct snd_pcm_substream *substream)
 {
 	synchronize_rcu();
 	return 0;
 }

 static int dw_pcm_hw_params(struct snd_pcm_substream *substream,
 		struct snd_pcm_hw_params *hw_params)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct dw_i2s_dev *dev = runtime->private_data;
 	int ret;

 	switch (params_channels(hw_params)) {
 	case 2:
 		break;
 	default:
 		dev_err(dev->dev, "invalid channels number\n");
 		return -EINVAL;
 	}

 	switch (params_format(hw_params)) {
 	case SNDRV_PCM_FORMAT_S16_LE:
 		dev->tx_fn = dw_pcm_tx_16;
 		dev->rx_fn = dw_pcm_rx_16;
 		break;
 	case SNDRV_PCM_FORMAT_S24_LE:
 	case SNDRV_PCM_FORMAT_S32_LE:
 		dev->tx_fn = dw_pcm_tx_32;
 		dev->rx_fn = dw_pcm_rx_32;
 		break;
 	default:
 		dev_err(dev->dev, "invalid format\n");
 		return -EINVAL;
 	}

 	ret = snd_pcm_lib_malloc_pages(substream,
 			params_buffer_bytes(hw_params));
 	if (ret < 0)
 		return ret;
 	else
 		return 0;
 }

 static int dw_pcm_hw_free(struct snd_pcm_substream *substream)
 {
 	return snd_pcm_lib_free_pages(substream);
 }

 static int dw_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct dw_i2s_dev *dev = runtime->private_data;
 	int ret = 0;

 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 	case SNDRV_PCM_TRIGGER_RESUME:
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 			WRITE_ONCE(dev->tx_ptr, 0);
 			rcu_assign_pointer(dev->tx_substream, substream);
 		} else {
 			WRITE_ONCE(dev->rx_ptr, 0);
 			rcu_assign_pointer(dev->rx_substream, substream);
 		}
 		break;
 	case SNDRV_PCM_TRIGGER_STOP:
 	case SNDRV_PCM_TRIGGER_SUSPEND:
 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 			rcu_assign_pointer(dev->tx_substream, NULL);
 		else
 			rcu_assign_pointer(dev->rx_substream, NULL);
 		break;
 	default:
 		ret = -EINVAL;
 		break;
 	}

 	return ret;
 }

 static snd_pcm_uframes_t dw_pcm_pointer(struct snd_pcm_substream *substream)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct dw_i2s_dev *dev = runtime->private_data;
 	snd_pcm_uframes_t pos;

 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 		pos = READ_ONCE(dev->tx_ptr);
 	else
 		pos = READ_ONCE(dev->rx_ptr);

 	return pos < runtime->buffer_size ? pos : 0;
 }

 static int dw_pcm_new(struct snd_soc_pcm_runtime *rtd)
 {
 	size_t size = dw_pcm_hardware.buffer_bytes_max;

 	snd_pcm_lib_preallocate_pages_for_all(rtd->pcm,
 			SNDRV_DMA_TYPE_CONTINUOUS,
 			snd_dma_continuous_data(GFP_KERNEL), size, size);
 	return 0;
 }

 static void dw_pcm_free(struct snd_pcm *pcm)
 {
 	snd_pcm_lib_preallocate_free_for_all(pcm);
 }

 static const struct snd_pcm_ops dw_pcm_ops = {
 	.open = dw_pcm_open,
 	.close = dw_pcm_close,
 	.ioctl = snd_pcm_lib_ioctl,
 	.hw_params = dw_pcm_hw_params,
 	.hw_free = dw_pcm_hw_free,
 	.trigger = dw_pcm_trigger,
 	.pointer = dw_pcm_pointer,
 };

 static const struct snd_soc_component_driver dw_pcm_component = {
 	.pcm_new = dw_pcm_new,
 	.pcm_free = dw_pcm_free,
 	.ops = &dw_pcm_ops,
 };

 int dw_pcm_register(struct platform_device *pdev)
 {
 	return devm_snd_soc_register_component(&pdev->dev, &dw_pcm_component,
 					       NULL, 0);
 }
	/*
	* ALSA SoC Synopsys PIO PCM for I2S driver
	*
	* sound/soc/dwc/designware_pcm.c
	*
	* Copyright (C) 2016 Synopsys
	* Jose Abreu <joabreu@synopsys.com>
	*
	* This file is licensed under the terms of the GNU General Public
	* License version 2. This program is licensed "as is" without any
	* warranty of any kind, whether express or implied.
	*/

	#include <linux/io.h>
	#include <linux/rcupdate.h>
	#include <sound/pcm.h>
	#include <sound/pcm_params.h>
	#include "local.h"

	#define BUFFER_BYTES_MAX (3 * 2 * 8 * PERIOD_BYTES_MIN)
	#define PERIOD_BYTES_MIN 4096
	#define PERIODS_MIN 2

	#define dw_pcm_tx_fn(sample_bits) \
	static unsigned int dw_pcm_tx_##sample_bits(struct dw_i2s_dev *dev, \
	struct snd_pcm_runtime *runtime, unsigned int tx_ptr, \
	bool *period_elapsed) \
	{ \
	const u##sample_bits (p)[2] = (void )runtime->dma_area; \
	unsigned int period_pos = tx_ptr % runtime->period_size; \
	int i; \
	\
	for (i = 0; i < dev->fifo_th; i++) { \
	iowrite32(p[tx_ptr][0], dev->i2s_base + LRBR_LTHR(0)); \
	iowrite32(p[tx_ptr][1], dev->i2s_base + RRBR_RTHR(0)); \
	period_pos++; \
	if (++tx_ptr >= runtime->buffer_size) \
	tx_ptr = 0; \
	} \
	*period_elapsed = period_pos >= runtime->period_size; \
	return tx_ptr; \
	}

	#define dw_pcm_rx_fn(sample_bits) \
	static unsigned int dw_pcm_rx_##sample_bits(struct dw_i2s_dev *dev, \
	struct snd_pcm_runtime *runtime, unsigned int rx_ptr, \
	bool *period_elapsed) \
	{ \
	u##sample_bits (p)[2] = (void )runtime->dma_area; \
	unsigned int period_pos = rx_ptr % runtime->period_size; \
	int i; \
	\
	for (i = 0; i < dev->fifo_th; i++) { \
	p[rx_ptr][0] = ioread32(dev->i2s_base + LRBR_LTHR(0)); \
	p[rx_ptr][1] = ioread32(dev->i2s_base + RRBR_RTHR(0)); \
	period_pos++; \
	if (++rx_ptr >= runtime->buffer_size) \
	rx_ptr = 0; \
	} \
	*period_elapsed = period_pos >= runtime->period_size; \
	return rx_ptr; \
	}

	dw_pcm_tx_fn(16);
	dw_pcm_tx_fn(32);
	dw_pcm_rx_fn(16);
	dw_pcm_rx_fn(32);

	#undef dw_pcm_tx_fn
	#undef dw_pcm_rx_fn

	static const struct snd_pcm_hardware dw_pcm_hardware = {
	.info = SNDRV_PCM_INFO_INTERLEAVED \|
	SNDRV_PCM_INFO_MMAP \|
	SNDRV_PCM_INFO_MMAP_VALID \|
	SNDRV_PCM_INFO_BLOCK_TRANSFER,
	.rates = SNDRV_PCM_RATE_32000 \|
	SNDRV_PCM_RATE_44100 \|
	SNDRV_PCM_RATE_48000,
	.rate_min = 32000,
	.rate_max = 48000,
	.formats = SNDRV_PCM_FMTBIT_S16_LE \|
	SNDRV_PCM_FMTBIT_S24_LE \|
	SNDRV_PCM_FMTBIT_S32_LE,
	.channels_min = 2,
	.channels_max = 2,
	.buffer_bytes_max = BUFFER_BYTES_MAX,
	.period_bytes_min = PERIOD_BYTES_MIN,
	.period_bytes_max = BUFFER_BYTES_MAX / PERIODS_MIN,
	.periods_min = PERIODS_MIN,
	.periods_max = BUFFER_BYTES_MAX / PERIOD_BYTES_MIN,
	.fifo_size = 16,
	};

	static void dw_pcm_transfer(struct dw_i2s_dev *dev, bool push)
	{
	struct snd_pcm_substream *substream;
	bool active, period_elapsed;

	rcu_read_lock();
	if (push)
	substream = rcu_dereference(dev->tx_substream);
	else
	substream = rcu_dereference(dev->rx_substream);
	active = substream && snd_pcm_running(substream);
	if (active) {
	unsigned int ptr;
	unsigned int new_ptr;

	if (push) {
	ptr = READ_ONCE(dev->tx_ptr);
	new_ptr = dev->tx_fn(dev, substream->runtime, ptr,
	&period_elapsed);
	cmpxchg(&dev->tx_ptr, ptr, new_ptr);
	} else {
	ptr = READ_ONCE(dev->rx_ptr);
	new_ptr = dev->rx_fn(dev, substream->runtime, ptr,
	&period_elapsed);
	cmpxchg(&dev->rx_ptr, ptr, new_ptr);
	}

	if (period_elapsed)
	snd_pcm_period_elapsed(substream);
	}
	rcu_read_unlock();
	}

	void dw_pcm_push_tx(struct dw_i2s_dev *dev)
	{
	dw_pcm_transfer(dev, true);
	}

	void dw_pcm_pop_rx(struct dw_i2s_dev *dev)
	{
	dw_pcm_transfer(dev, false);
	}

	static int dw_pcm_open(struct snd_pcm_substream *substream)
	{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct dw_i2s_dev *dev = snd_soc_dai_get_drvdata(rtd->cpu_dai);

	snd_soc_set_runtime_hwparams(substream, &dw_pcm_hardware);
	snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
	runtime->private_data = dev;

	return 0;
	}

	static int dw_pcm_close(struct snd_pcm_substream *substream)
	{
	synchronize_rcu();
	return 0;
	}

	static int dw_pcm_hw_params(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *hw_params)
	{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct dw_i2s_dev *dev = runtime->private_data;
	int ret;

	switch (params_channels(hw_params)) {
	case 2:
	break;
	default:
	dev_err(dev->dev, "invalid channels number\n");
	return -EINVAL;
	}

	switch (params_format(hw_params)) {
	case SNDRV_PCM_FORMAT_S16_LE:
	dev->tx_fn = dw_pcm_tx_16;
	dev->rx_fn = dw_pcm_rx_16;
	break;
	case SNDRV_PCM_FORMAT_S24_LE:
	case SNDRV_PCM_FORMAT_S32_LE:
	dev->tx_fn = dw_pcm_tx_32;
	dev->rx_fn = dw_pcm_rx_32;
	break;
	default:
	dev_err(dev->dev, "invalid format\n");
	return -EINVAL;
	}

	ret = snd_pcm_lib_malloc_pages(substream,
	params_buffer_bytes(hw_params));
	if (ret < 0)
	return ret;
	else
	return 0;
	}

	static int dw_pcm_hw_free(struct snd_pcm_substream *substream)
	{
	return snd_pcm_lib_free_pages(substream);
	}

	static int dw_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
	{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct dw_i2s_dev *dev = runtime->private_data;
	int ret = 0;

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	case SNDRV_PCM_TRIGGER_RESUME:
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
	WRITE_ONCE(dev->tx_ptr, 0);
	rcu_assign_pointer(dev->tx_substream, substream);
	} else {
	WRITE_ONCE(dev->rx_ptr, 0);
	rcu_assign_pointer(dev->rx_substream, substream);
	}
	break;
	case SNDRV_PCM_TRIGGER_STOP:
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
	rcu_assign_pointer(dev->tx_substream, NULL);
	else
	rcu_assign_pointer(dev->rx_substream, NULL);
	break;
	default:
	ret = -EINVAL;
	break;
	}

	return ret;
	}

	static snd_pcm_uframes_t dw_pcm_pointer(struct snd_pcm_substream *substream)
	{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct dw_i2s_dev *dev = runtime->private_data;
	snd_pcm_uframes_t pos;

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
	pos = READ_ONCE(dev->tx_ptr);
	else
	pos = READ_ONCE(dev->rx_ptr);

	return pos < runtime->buffer_size ? pos : 0;
	}

	static int dw_pcm_new(struct snd_soc_pcm_runtime *rtd)
	{
	size_t size = dw_pcm_hardware.buffer_bytes_max;

	snd_pcm_lib_preallocate_pages_for_all(rtd->pcm,
	SNDRV_DMA_TYPE_CONTINUOUS,
	snd_dma_continuous_data(GFP_KERNEL), size, size);
	return 0;
	}

	static void dw_pcm_free(struct snd_pcm *pcm)
	{
	snd_pcm_lib_preallocate_free_for_all(pcm);
	}

	static const struct snd_pcm_ops dw_pcm_ops = {
	.open = dw_pcm_open,
	.close = dw_pcm_close,
	.ioctl = snd_pcm_lib_ioctl,
	.hw_params = dw_pcm_hw_params,
	.hw_free = dw_pcm_hw_free,
	.trigger = dw_pcm_trigger,
	.pointer = dw_pcm_pointer,
	};

	static const struct snd_soc_component_driver dw_pcm_component = {
	.pcm_new = dw_pcm_new,
	.pcm_free = dw_pcm_free,
	.ops = &dw_pcm_ops,
	};

	int dw_pcm_register(struct platform_device *pdev)
	{
	return devm_snd_soc_register_component(&pdev->dev, &dw_pcm_component,
	NULL, 0);
	}