zephyr/drivers/i2s/i2s_ll_stm32.c

/*
 * Copyright (c) 2018 STMicroelectronics
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#define DT_DRV_COMPAT st_stm32_i2s

#include <string.h>
#include <zephyr/drivers/dma.h>
#include <zephyr/drivers/i2s.h>
#include <zephyr/drivers/dma/dma_stm32.h>
#include <soc.h>
#include <stm32_ll_rcc.h>
#include <stm32_ll_spi.h>
#include <zephyr/drivers/clock_control/stm32_clock_control.h>
#include <zephyr/drivers/clock_control.h>
#include <zephyr/drivers/pinctrl.h>

#include "i2s_ll_stm32.h"
#include <zephyr/logging/log.h>
#include <zephyr/irq.h>
LOG_MODULE_REGISTER(i2s_ll_stm32);

/* FIXME change to
 * #if __DCACHE_PRESENT == 1
 * when cache support is added
 */
#if 0
#define DCACHE_INVALIDATE(addr, size) \
	SCB_InvalidateDCache_by_Addr((uint32_t *)addr, size)
#define DCACHE_CLEAN(addr, size) \
	SCB_CleanDCache_by_Addr((uint32_t *)addr, size)
#else
#define DCACHE_INVALIDATE(addr, size) {; }
#define DCACHE_CLEAN(addr, size) {; }
#endif

#define MODULO_INC(val, max) { val = (++val < max) ? val : 0; }

static unsigned int div_round_closest(uint32_t dividend, uint32_t divisor)
{
	return (dividend + (divisor / 2U)) / divisor;
}

/*
 * Get data from the queue
 */
static int queue_get(struct ring_buf *rb, void **mem_block, size_t *size)
{
	unsigned int key;

	key = irq_lock();

	if (rb->tail == rb->head) {
		/* Ring buffer is empty */
		irq_unlock(key);
		return -ENOMEM;
	}

	*mem_block = rb->buf[rb->tail].mem_block;
	*size = rb->buf[rb->tail].size;
	MODULO_INC(rb->tail, rb->len);

	irq_unlock(key);

	return 0;
}

/*
 * Put data in the queue
 */
static int queue_put(struct ring_buf *rb, void *mem_block, size_t size)
{
	uint16_t head_next;
	unsigned int key;

	key = irq_lock();

	head_next = rb->head;
	MODULO_INC(head_next, rb->len);

	if (head_next == rb->tail) {
		/* Ring buffer is full */
		irq_unlock(key);
		return -ENOMEM;
	}

	rb->buf[rb->head].mem_block = mem_block;
	rb->buf[rb->head].size = size;
	rb->head = head_next;

	irq_unlock(key);

	return 0;
}

static int i2s_stm32_enable_clock(const struct device *dev)
{
	const struct i2s_stm32_cfg *cfg = dev->config;
	const struct device *clk;
	int ret;

	clk = DEVICE_DT_GET(STM32_CLOCK_CONTROL_NODE);

	if (!device_is_ready(clk)) {
		LOG_ERR("clock control device not ready");
		return -ENODEV;
	}

	ret = clock_control_on(clk, (clock_control_subsys_t)&cfg->pclken[0]);
	if (ret != 0) {
		LOG_ERR("Could not enable I2S clock");
		return -EIO;
	}

	if (cfg->pclk_len > 1) {
		/* Enable I2S clock source */
		ret = clock_control_configure(clk,
					      (clock_control_subsys_t)&cfg->pclken[1],
					      NULL);
		if (ret < 0) {
			LOG_ERR("Could not configure I2S domain clock");
			return -EIO;
		}
	}

	return 0;
}

static int i2s_stm32_set_clock(const struct device *dev,
			       uint32_t bit_clk_freq)
{
	const struct i2s_stm32_cfg *cfg = dev->config;
	uint32_t freq_in = 0U;
	uint8_t i2s_div, i2s_odd;

	if (cfg->pclk_len > 1) {
		if (clock_control_get_rate(DEVICE_DT_GET(STM32_CLOCK_CONTROL_NODE),
					   (clock_control_subsys_t)&cfg->pclken[1],
					   &freq_in) < 0) {
			LOG_ERR("Failed call clock_control_get_rate(pclken[1])");
			return -EIO;
		}
	}
	/*
	 * The ratio between input clock (I2SxClk) and output
	 * clock on the pad (I2S_CK) is obtained using the
	 * following formula:
	 *   (i2s_div * 2) + i2s_odd
	 */
	i2s_div = div_round_closest(freq_in, bit_clk_freq);
	i2s_odd = (i2s_div & 0x1) ? 1 : 0;
	i2s_div >>= 1;

	/* i2s_div == 0 || i2s_div == 1 are forbidden */
	if (i2s_div < 2U) {
		LOG_ERR("The linear prescaler value is unsupported");
		return -EINVAL;
	}

	LOG_DBG("i2s_div: %d - i2s_odd: %d", i2s_div, i2s_odd);

	LL_I2S_SetPrescalerLinear(cfg->i2s, i2s_div);
	LL_I2S_SetPrescalerParity(cfg->i2s, i2s_odd);

	return 0;
}

static int i2s_stm32_configure(const struct device *dev, enum i2s_dir dir,
			       const struct i2s_config *i2s_cfg)
{
	const struct i2s_stm32_cfg *const cfg = dev->config;
	struct i2s_stm32_data *const dev_data = dev->data;
	/* For words greater than 16-bit the channel length is considered 32-bit */
	const uint32_t channel_length = i2s_cfg->word_size > 16U ? 32U : 16U;
	/*
	 * comply with the i2s_config driver remark:
	 * When I2S data format is selected parameter channels is ignored,
	 * number of words in a frame is always 2.
	 */
	const uint32_t num_channels = i2s_cfg->format & I2S_FMT_DATA_FORMAT_MASK
				      ? 2U : i2s_cfg->channels;
	struct stream *stream;
	uint32_t bit_clk_freq;
	bool enable_mck;
	int ret;

	if (dir == I2S_DIR_RX) {
		stream = &dev_data->rx;
	} else if (dir == I2S_DIR_TX) {
		stream = &dev_data->tx;
	} else if (dir == I2S_DIR_BOTH) {
		return -ENOSYS;
	} else {
		LOG_ERR("Either RX or TX direction must be selected");
		return -EINVAL;
	}

	if (stream->state != I2S_STATE_NOT_READY &&
	    stream->state != I2S_STATE_READY) {
		LOG_ERR("invalid state");
		return -EINVAL;
	}

	stream->master = true;
	if (i2s_cfg->options & I2S_OPT_FRAME_CLK_SLAVE ||
	    i2s_cfg->options & I2S_OPT_BIT_CLK_SLAVE) {
		stream->master = false;
	}

	if (i2s_cfg->frame_clk_freq == 0U) {
		stream->queue_drop(stream);
		memset(&stream->cfg, 0, sizeof(struct i2s_config));
		stream->state = I2S_STATE_NOT_READY;
		return 0;
	}

	memcpy(&stream->cfg, i2s_cfg, sizeof(struct i2s_config));

	/* conditions to enable master clock output */
	enable_mck = stream->master && cfg->master_clk_sel;

	/* set I2S bitclock */
	bit_clk_freq = i2s_cfg->frame_clk_freq *
		       channel_length * num_channels;

	if (enable_mck) {
		/*
		 * Compensate for the master clock dividers.
		 * MCK = N * CK, where N:
		 * 8 when the channel frame is 16-bit wide
		 * 4 when the channel frame is 32-bit wide
		 */
		bit_clk_freq *= channel_length == 16U ? 4U * 2U : 4U;
	}

	ret = i2s_stm32_set_clock(dev, bit_clk_freq);
	if (ret < 0) {
		return ret;
	}

	/* set I2S Master Clock output in the MCK pin, enabled in the DT */
	if (enable_mck) {
		LL_I2S_EnableMasterClock(cfg->i2s);
	} else {
		LL_I2S_DisableMasterClock(cfg->i2s);
	}

	/*
	 * set I2S Data Format
	 * 16-bit data extended on 32-bit channel length excluded
	 */
	if (i2s_cfg->word_size == 16U) {
		LL_I2S_SetDataFormat(cfg->i2s, LL_I2S_DATAFORMAT_16B);
	} else if (i2s_cfg->word_size == 24U) {
		LL_I2S_SetDataFormat(cfg->i2s, LL_I2S_DATAFORMAT_24B);
	} else if (i2s_cfg->word_size == 32U) {
		LL_I2S_SetDataFormat(cfg->i2s, LL_I2S_DATAFORMAT_32B);
	} else {
		LOG_ERR("invalid word size");
		return -EINVAL;
	}

	/* set I2S Standard */
	switch (i2s_cfg->format & I2S_FMT_DATA_FORMAT_MASK) {
	case I2S_FMT_DATA_FORMAT_I2S:
		LL_I2S_SetStandard(cfg->i2s, LL_I2S_STANDARD_PHILIPS);
		break;

	case I2S_FMT_DATA_FORMAT_PCM_SHORT:
		LL_I2S_SetStandard(cfg->i2s, LL_I2S_STANDARD_PCM_SHORT);
		break;

	case I2S_FMT_DATA_FORMAT_PCM_LONG:
		LL_I2S_SetStandard(cfg->i2s, LL_I2S_STANDARD_PCM_LONG);
		break;

	case I2S_FMT_DATA_FORMAT_LEFT_JUSTIFIED:
		LL_I2S_SetStandard(cfg->i2s, LL_I2S_STANDARD_MSB);
		break;

	case I2S_FMT_DATA_FORMAT_RIGHT_JUSTIFIED:
		LL_I2S_SetStandard(cfg->i2s, LL_I2S_STANDARD_LSB);
		break;

	default:
		LOG_ERR("Unsupported I2S data format");
		return -EINVAL;
	}

	/* set I2S clock polarity */
	if ((i2s_cfg->format & I2S_FMT_CLK_FORMAT_MASK) == I2S_FMT_BIT_CLK_INV)
		LL_I2S_SetClockPolarity(cfg->i2s, LL_I2S_POLARITY_HIGH);
	else
		LL_I2S_SetClockPolarity(cfg->i2s, LL_I2S_POLARITY_LOW);

	stream->state = I2S_STATE_READY;
	return 0;
}

static int i2s_stm32_trigger(const struct device *dev, enum i2s_dir dir,
			     enum i2s_trigger_cmd cmd)
{
	struct i2s_stm32_data *const dev_data = dev->data;
	struct stream *stream;
	unsigned int key;
	int ret;

	if (dir == I2S_DIR_RX) {
		stream = &dev_data->rx;
	} else if (dir == I2S_DIR_TX) {
		stream = &dev_data->tx;
	} else if (dir == I2S_DIR_BOTH) {
		return -ENOSYS;
	} else {
		LOG_ERR("Either RX or TX direction must be selected");
		return -EINVAL;
	}

	switch (cmd) {
	case I2S_TRIGGER_START:
		if (stream->state != I2S_STATE_READY) {
			LOG_ERR("START trigger: invalid state %d",
				    stream->state);
			return -EIO;
		}

		__ASSERT_NO_MSG(stream->mem_block == NULL);

		ret = stream->stream_start(stream, dev);
		if (ret < 0) {
			LOG_ERR("START trigger failed %d", ret);
			return ret;
		}

		stream->state = I2S_STATE_RUNNING;
		stream->last_block = false;
		break;

	case I2S_TRIGGER_STOP:
		key = irq_lock();
		if (stream->state != I2S_STATE_RUNNING) {
			irq_unlock(key);
			LOG_ERR("STOP trigger: invalid state");
			return -EIO;
		}
		irq_unlock(key);
		stream->stream_disable(stream, dev);
		stream->queue_drop(stream);
		stream->state = I2S_STATE_READY;
		stream->last_block = true;
		break;

	case I2S_TRIGGER_DRAIN:
		key = irq_lock();
		if (stream->state != I2S_STATE_RUNNING) {
			irq_unlock(key);
			LOG_ERR("DRAIN trigger: invalid state");
			return -EIO;
		}
		stream->stream_disable(stream, dev);
		stream->queue_drop(stream);
		stream->state = I2S_STATE_READY;
		irq_unlock(key);
		break;

	case I2S_TRIGGER_DROP:
		if (stream->state == I2S_STATE_NOT_READY) {
			LOG_ERR("DROP trigger: invalid state");
			return -EIO;
		}
		stream->stream_disable(stream, dev);
		stream->queue_drop(stream);
		stream->state = I2S_STATE_READY;
		break;

	case I2S_TRIGGER_PREPARE:
		if (stream->state != I2S_STATE_ERROR) {
			LOG_ERR("PREPARE trigger: invalid state");
			return -EIO;
		}
		stream->state = I2S_STATE_READY;
		stream->queue_drop(stream);
		break;

	default:
		LOG_ERR("Unsupported trigger command");
		return -EINVAL;
	}

	return 0;
}

static int i2s_stm32_read(const struct device *dev, void **mem_block,
			  size_t *size)
{
	struct i2s_stm32_data *const dev_data = dev->data;
	int ret;

	if (dev_data->rx.state == I2S_STATE_NOT_READY) {
		LOG_DBG("invalid state");
		return -EIO;
	}

	if (dev_data->rx.state != I2S_STATE_ERROR) {
		ret = k_sem_take(&dev_data->rx.sem,
				 SYS_TIMEOUT_MS(dev_data->rx.cfg.timeout));
		if (ret < 0) {
			return ret;
		}
	}

	/* Get data from the beginning of RX queue */
	ret = queue_get(&dev_data->rx.mem_block_queue, mem_block, size);
	if (ret < 0) {
		return -EIO;
	}

	return 0;
}

static int i2s_stm32_write(const struct device *dev, void *mem_block,
			   size_t size)
{
	struct i2s_stm32_data *const dev_data = dev->data;
	int ret;

	if (dev_data->tx.state != I2S_STATE_RUNNING &&
	    dev_data->tx.state != I2S_STATE_READY) {
		LOG_DBG("invalid state");
		return -EIO;
	}

	ret = k_sem_take(&dev_data->tx.sem,
			 SYS_TIMEOUT_MS(dev_data->tx.cfg.timeout));
	if (ret < 0) {
		return ret;
	}

	/* Add data to the end of the TX queue */
	queue_put(&dev_data->tx.mem_block_queue, mem_block, size);

	return 0;
}

static const struct i2s_driver_api i2s_stm32_driver_api = {
	.configure = i2s_stm32_configure,
	.read = i2s_stm32_read,
	.write = i2s_stm32_write,
	.trigger = i2s_stm32_trigger,
};

#define STM32_DMA_NUM_CHANNELS		8
static const struct device *active_dma_rx_channel[STM32_DMA_NUM_CHANNELS];
static const struct device *active_dma_tx_channel[STM32_DMA_NUM_CHANNELS];

static int reload_dma(const struct device *dev_dma, uint32_t channel,
		      struct dma_config *dcfg, void *src, void *dst,
		      uint32_t blk_size)
{
	int ret;

	ret = dma_reload(dev_dma, channel, (uint32_t)src, (uint32_t)dst, blk_size);
	if (ret < 0) {
		return ret;
	}

	ret = dma_start(dev_dma, channel);

	return ret;
}

static int start_dma(const struct device *dev_dma, uint32_t channel,
		     struct dma_config *dcfg, void *src,
		     bool src_addr_increment, void *dst,
		     bool dst_addr_increment, uint8_t fifo_threshold,
		     uint32_t blk_size)
{
	struct dma_block_config blk_cfg;
	int ret;

	memset(&blk_cfg, 0, sizeof(blk_cfg));
	blk_cfg.block_size = blk_size;
	blk_cfg.source_address = (uint32_t)src;
	blk_cfg.dest_address = (uint32_t)dst;
	if (src_addr_increment) {
		blk_cfg.source_addr_adj = DMA_ADDR_ADJ_INCREMENT;
	} else {
		blk_cfg.source_addr_adj = DMA_ADDR_ADJ_NO_CHANGE;
	}
	if (dst_addr_increment) {
		blk_cfg.dest_addr_adj = DMA_ADDR_ADJ_INCREMENT;
	} else {
		blk_cfg.dest_addr_adj = DMA_ADDR_ADJ_NO_CHANGE;
	}
	blk_cfg.fifo_mode_control = fifo_threshold;

	dcfg->head_block = &blk_cfg;

	ret = dma_config(dev_dma, channel, dcfg);
	if (ret < 0) {
		return ret;
	}

	ret = dma_start(dev_dma, channel);

	return ret;
}

static const struct device *get_dev_from_rx_dma_channel(uint32_t dma_channel);
static const struct device *get_dev_from_tx_dma_channel(uint32_t dma_channel);
static void rx_stream_disable(struct stream *stream, const struct device *dev);
static void tx_stream_disable(struct stream *stream, const struct device *dev);

/* This function is executed in the interrupt context */
static void dma_rx_callback(const struct device *dma_dev, void *arg,
			    uint32_t channel, int status)
{
	const struct device *dev = get_dev_from_rx_dma_channel(channel);
	const struct i2s_stm32_cfg *cfg = dev->config;
	struct i2s_stm32_data *const dev_data = dev->data;
	struct stream *stream = &dev_data->rx;
	void *mblk_tmp;
	int ret;

	if (status < 0) {
		ret = -EIO;
		stream->state = I2S_STATE_ERROR;
		goto rx_disable;
	}

	__ASSERT_NO_MSG(stream->mem_block != NULL);

	/* Stop reception if there was an error */
	if (stream->state == I2S_STATE_ERROR) {
		goto rx_disable;
	}

	mblk_tmp = stream->mem_block;

	/* Prepare to receive the next data block */
	ret = k_mem_slab_alloc(stream->cfg.mem_slab, &stream->mem_block,
			       K_NO_WAIT);
	if (ret < 0) {
		stream->state = I2S_STATE_ERROR;
		goto rx_disable;
	}

	ret = reload_dma(stream->dev_dma, stream->dma_channel,
			&stream->dma_cfg,
			(void *)LL_SPI_DMA_GetRegAddr(cfg->i2s),
			stream->mem_block,
			stream->cfg.block_size);
	if (ret < 0) {
		LOG_DBG("Failed to start RX DMA transfer: %d", ret);
		goto rx_disable;
	}

	/* Assure cache coherency after DMA write operation */
	DCACHE_INVALIDATE(mblk_tmp, stream->cfg.block_size);

	/* All block data received */
	ret = queue_put(&stream->mem_block_queue, mblk_tmp,
			stream->cfg.block_size);
	if (ret < 0) {
		stream->state = I2S_STATE_ERROR;
		goto rx_disable;
	}
	k_sem_give(&stream->sem);

	/* Stop reception if we were requested */
	if (stream->state == I2S_STATE_STOPPING) {
		stream->state = I2S_STATE_READY;
		goto rx_disable;
	}

	return;

rx_disable:
	rx_stream_disable(stream, dev);
}

static void dma_tx_callback(const struct device *dma_dev, void *arg,
			    uint32_t channel, int status)
{
	const struct device *dev = get_dev_from_tx_dma_channel(channel);
	const struct i2s_stm32_cfg *cfg = dev->config;
	struct i2s_stm32_data *const dev_data = dev->data;
	struct stream *stream = &dev_data->tx;
	size_t mem_block_size;
	int ret;

	if (status < 0) {
		ret = -EIO;
		stream->state = I2S_STATE_ERROR;
		goto tx_disable;
	}

	__ASSERT_NO_MSG(stream->mem_block != NULL);

	/* All block data sent */
	k_mem_slab_free(stream->cfg.mem_slab, stream->mem_block);
	stream->mem_block = NULL;

	/* Stop transmission if there was an error */
	if (stream->state == I2S_STATE_ERROR) {
		LOG_ERR("TX error detected");
		goto tx_disable;
	}

	/* Stop transmission if we were requested */
	if (stream->last_block) {
		stream->state = I2S_STATE_READY;
		goto tx_disable;
	}

	/* Prepare to send the next data block */
	ret = queue_get(&stream->mem_block_queue, &stream->mem_block,
			&mem_block_size);
	if (ret < 0) {
		if (stream->state == I2S_STATE_STOPPING) {
			stream->state = I2S_STATE_READY;
		} else {
			stream->state = I2S_STATE_ERROR;
		}
		goto tx_disable;
	}
	k_sem_give(&stream->sem);

	/* Assure cache coherency before DMA read operation */
	DCACHE_CLEAN(stream->mem_block, mem_block_size);

	ret = reload_dma(stream->dev_dma, stream->dma_channel,
			&stream->dma_cfg,
			stream->mem_block,
			(void *)LL_SPI_DMA_GetRegAddr(cfg->i2s),
			stream->cfg.block_size);
	if (ret < 0) {
		LOG_DBG("Failed to start TX DMA transfer: %d", ret);
		goto tx_disable;
	}

	return;

tx_disable:
	tx_stream_disable(stream, dev);
}

static uint32_t i2s_stm32_irq_count;
static uint32_t i2s_stm32_irq_ovr_count;

static void i2s_stm32_isr(const struct device *dev)
{
	const struct i2s_stm32_cfg *cfg = dev->config;
	struct i2s_stm32_data *const dev_data = dev->data;
	struct stream *stream = &dev_data->rx;

	LOG_ERR("%s: err=%d", __func__, (int)LL_I2S_ReadReg(cfg->i2s, SR));
	stream->state = I2S_STATE_ERROR;

	/* OVR error must be explicitly cleared */
	if (LL_I2S_IsActiveFlag_OVR(cfg->i2s)) {
		i2s_stm32_irq_ovr_count++;
		LL_I2S_ClearFlag_OVR(cfg->i2s);
	}

	i2s_stm32_irq_count++;
}

static int i2s_stm32_initialize(const struct device *dev)
{
	const struct i2s_stm32_cfg *cfg = dev->config;
	struct i2s_stm32_data *const dev_data = dev->data;
	int ret, i;

	/* Enable I2S clock propagation */
	ret = i2s_stm32_enable_clock(dev);
	if (ret < 0) {
		LOG_ERR("%s: clock enabling failed: %d",  __func__, ret);
		return -EIO;
	}

	/* Configure dt provided device signals when available */
	ret = pinctrl_apply_state(cfg->pcfg, PINCTRL_STATE_DEFAULT);
	if (ret < 0) {
		LOG_ERR("I2S pinctrl setup failed (%d)", ret);
		return ret;
	}

	cfg->irq_config(dev);

	k_sem_init(&dev_data->rx.sem, 0, CONFIG_I2S_STM32_RX_BLOCK_COUNT);
	k_sem_init(&dev_data->tx.sem, CONFIG_I2S_STM32_TX_BLOCK_COUNT,
		   CONFIG_I2S_STM32_TX_BLOCK_COUNT);

	for (i = 0; i < STM32_DMA_NUM_CHANNELS; i++) {
		active_dma_rx_channel[i] = NULL;
		active_dma_tx_channel[i] = NULL;
	}

	/* Get the binding to the DMA device */
	if (!device_is_ready(dev_data->tx.dev_dma)) {
		LOG_ERR("%s device not ready", dev_data->tx.dev_dma->name);
		return -ENODEV;
	}
	if (!device_is_ready(dev_data->rx.dev_dma)) {
		LOG_ERR("%s device not ready", dev_data->rx.dev_dma->name);
		return -ENODEV;
	}

	LOG_INF("%s inited", dev->name);

	return 0;
}

static int rx_stream_start(struct stream *stream, const struct device *dev)
{
	const struct i2s_stm32_cfg *cfg = dev->config;
	int ret;

	ret = k_mem_slab_alloc(stream->cfg.mem_slab, &stream->mem_block,
			       K_NO_WAIT);
	if (ret < 0) {
		return ret;
	}

	if (stream->master) {
		LL_I2S_SetTransferMode(cfg->i2s, LL_I2S_MODE_MASTER_RX);
	} else {
		LL_I2S_SetTransferMode(cfg->i2s, LL_I2S_MODE_SLAVE_RX);
	}

	/* remember active RX DMA channel (used in callback) */
	active_dma_rx_channel[stream->dma_channel] = dev;

	ret = start_dma(stream->dev_dma, stream->dma_channel,
			&stream->dma_cfg,
			(void *)LL_SPI_DMA_GetRegAddr(cfg->i2s),
			stream->src_addr_increment, stream->mem_block,
			stream->dst_addr_increment, stream->fifo_threshold,
			stream->cfg.block_size);
	if (ret < 0) {
		LOG_ERR("Failed to start RX DMA transfer: %d", ret);
		return ret;
	}

	LL_I2S_EnableDMAReq_RX(cfg->i2s);

	LL_I2S_EnableIT_ERR(cfg->i2s);
	LL_I2S_Enable(cfg->i2s);

	return 0;
}

static int tx_stream_start(struct stream *stream, const struct device *dev)
{
	const struct i2s_stm32_cfg *cfg = dev->config;
	size_t mem_block_size;
	int ret;

	ret = queue_get(&stream->mem_block_queue, &stream->mem_block,
			&mem_block_size);
	if (ret < 0) {
		return ret;
	}
	k_sem_give(&stream->sem);

	/* Assure cache coherency before DMA read operation */
	DCACHE_CLEAN(stream->mem_block, mem_block_size);

	if (stream->master) {
		LL_I2S_SetTransferMode(cfg->i2s, LL_I2S_MODE_MASTER_TX);
	} else {
		LL_I2S_SetTransferMode(cfg->i2s, LL_I2S_MODE_SLAVE_TX);
	}

	/* remember active TX DMA channel (used in callback) */
	active_dma_tx_channel[stream->dma_channel] = dev;

	ret = start_dma(stream->dev_dma, stream->dma_channel,
			&stream->dma_cfg,
			stream->mem_block, stream->src_addr_increment,
			(void *)LL_SPI_DMA_GetRegAddr(cfg->i2s),
			stream->dst_addr_increment, stream->fifo_threshold,
			stream->cfg.block_size);
	if (ret < 0) {
		LOG_ERR("Failed to start TX DMA transfer: %d", ret);
		return ret;
	}

	LL_I2S_EnableDMAReq_TX(cfg->i2s);

	LL_I2S_EnableIT_ERR(cfg->i2s);
	LL_I2S_Enable(cfg->i2s);

	return 0;
}

static void rx_stream_disable(struct stream *stream, const struct device *dev)
{
	const struct i2s_stm32_cfg *cfg = dev->config;

	LL_I2S_DisableDMAReq_RX(cfg->i2s);
	LL_I2S_DisableIT_ERR(cfg->i2s);

	dma_stop(stream->dev_dma, stream->dma_channel);
	if (stream->mem_block != NULL) {
		k_mem_slab_free(stream->cfg.mem_slab, stream->mem_block);
		stream->mem_block = NULL;
	}

	LL_I2S_Disable(cfg->i2s);

	active_dma_rx_channel[stream->dma_channel] = NULL;
}

static void tx_stream_disable(struct stream *stream, const struct device *dev)
{
	const struct i2s_stm32_cfg *cfg = dev->config;

	LL_I2S_DisableDMAReq_TX(cfg->i2s);
	LL_I2S_DisableIT_ERR(cfg->i2s);

	dma_stop(stream->dev_dma, stream->dma_channel);
	if (stream->mem_block != NULL) {
		k_mem_slab_free(stream->cfg.mem_slab, stream->mem_block);
		stream->mem_block = NULL;
	}

	LL_I2S_Disable(cfg->i2s);

	active_dma_tx_channel[stream->dma_channel] = NULL;
}

static void rx_queue_drop(struct stream *stream)
{
	size_t size;
	void *mem_block;

	while (queue_get(&stream->mem_block_queue, &mem_block, &size) == 0) {
		k_mem_slab_free(stream->cfg.mem_slab, mem_block);
	}

	k_sem_reset(&stream->sem);
}

static void tx_queue_drop(struct stream *stream)
{
	size_t size;
	void *mem_block;
	unsigned int n = 0U;

	while (queue_get(&stream->mem_block_queue, &mem_block, &size) == 0) {
		k_mem_slab_free(stream->cfg.mem_slab, mem_block);
		n++;
	}

	for (; n > 0; n--) {
		k_sem_give(&stream->sem);
	}
}

static const struct device *get_dev_from_rx_dma_channel(uint32_t dma_channel)
{
	return active_dma_rx_channel[dma_channel];
}

static const struct device *get_dev_from_tx_dma_channel(uint32_t dma_channel)
{
	return active_dma_tx_channel[dma_channel];
}

/* src_dev and dest_dev should be 'MEMORY' or 'PERIPHERAL'. */
#define I2S_DMA_CHANNEL_INIT(index, dir, dir_cap, src_dev, dest_dev)	\
.dir = {								\
	.dev_dma = DEVICE_DT_GET(STM32_DMA_CTLR(index, dir)),		\
	.dma_channel = DT_INST_DMAS_CELL_BY_NAME(index, dir, channel),	\
	.dma_cfg = {							\
		.block_count = 2,					\
		.dma_slot = STM32_DMA_SLOT(index, dir, slot),\
		.channel_direction = src_dev##_TO_##dest_dev,		\
		.source_data_size = 2,  /* 16bit default */		\
		.dest_data_size = 2,    /* 16bit default */		\
		.source_burst_length = 1, /* SINGLE transfer */		\
		.dest_burst_length = 1,					\
		.channel_priority = STM32_DMA_CONFIG_PRIORITY(		\
					STM32_DMA_CHANNEL_CONFIG(index, dir)),\
		.dma_callback = dma_##dir##_callback,			\
	},								\
	.src_addr_increment = STM32_DMA_CONFIG_##src_dev##_ADDR_INC(	\
				STM32_DMA_CHANNEL_CONFIG(index, dir)),	\
	.dst_addr_increment = STM32_DMA_CONFIG_##dest_dev##_ADDR_INC(	\
				STM32_DMA_CHANNEL_CONFIG(index, dir)),	\
	.fifo_threshold = STM32_DMA_FEATURES_FIFO_THRESHOLD(		\
				STM32_DMA_FEATURES(index, dir)),	\
	.stream_start = dir##_stream_start,				\
	.stream_disable = dir##_stream_disable,				\
	.queue_drop = dir##_queue_drop,					\
	.mem_block_queue.buf = dir##_##index##_ring_buf,		\
	.mem_block_queue.len = ARRAY_SIZE(dir##_##index##_ring_buf)	\
}

#define I2S_STM32_INIT(index)							\
									\
static void i2s_stm32_irq_config_func_##index(const struct device *dev);\
									\
PINCTRL_DT_INST_DEFINE(index);						\
									\
static const struct stm32_pclken clk_##index[] =			\
				 STM32_DT_INST_CLOCKS(index);		\
									\
static const struct i2s_stm32_cfg i2s_stm32_config_##index = {		\
	.i2s = (SPI_TypeDef *)DT_INST_REG_ADDR(index),			\
	.pclken = clk_##index,						\
	.pclk_len = DT_INST_NUM_CLOCKS(index),				\
	.pcfg = PINCTRL_DT_INST_DEV_CONFIG_GET(index),			\
	.irq_config = i2s_stm32_irq_config_func_##index,		\
	.master_clk_sel = DT_INST_PROP(index, mck_enabled)		\
};									\
									\
struct queue_item rx_##index##_ring_buf[CONFIG_I2S_STM32_RX_BLOCK_COUNT + 1];\
struct queue_item tx_##index##_ring_buf[CONFIG_I2S_STM32_TX_BLOCK_COUNT + 1];\
									\
static struct i2s_stm32_data i2s_stm32_data_##index = {			\
	UTIL_AND(DT_INST_DMAS_HAS_NAME(index, rx),			\
		I2S_DMA_CHANNEL_INIT(index, rx, RX, PERIPHERAL, MEMORY)),\
	UTIL_AND(DT_INST_DMAS_HAS_NAME(index, tx),			\
		I2S_DMA_CHANNEL_INIT(index, tx, TX, MEMORY, PERIPHERAL)),\
};									\
DEVICE_DT_INST_DEFINE(index,						\
		      &i2s_stm32_initialize, NULL,			\
		      &i2s_stm32_data_##index,				\
		      &i2s_stm32_config_##index, POST_KERNEL,		\
		      CONFIG_I2S_INIT_PRIORITY, &i2s_stm32_driver_api);	\
									\
static void i2s_stm32_irq_config_func_##index(const struct device *dev)	\
{									\
	IRQ_CONNECT(DT_INST_IRQN(index),				\
		    DT_INST_IRQ(index, priority),			\
		    i2s_stm32_isr, DEVICE_DT_INST_GET(index), 0);	\
	irq_enable(DT_INST_IRQN(index));				\
}

DT_INST_FOREACH_STATUS_OKAY(I2S_STM32_INIT)