samples: i2s: Add i2s_codec example

This example demonstrates I2S audio playback combined with the codec
API. It can use the dmic API for audio input.

Signed-off-by: Hake Huang <hake.huang@oss.nxp.com>
Signed-off-by: Vit Stanicek <vit.stanicek@nxp.com>

samples/drivers/i2s/i2s_codec/CMakeLists.txt

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+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(i2s_rx_tx)
+
+target_sources(app PRIVATE src/main.c)

samples/drivers/i2s/i2s_codec/Kconfig

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+# Copyright (c) 2024 NXP
+# SPDX-License-Identifier: Apache-2.0
+
+source "Kconfig.zephyr"
+
+config I2S_INIT_BUFFERS
+	int "Initial count of audio data blocks"
+	default 2
+	help
+	  Controls the initial count of audio data blocks, which are (optionally)
+	  filled by data from the DMIC peripheral and played back by the I2S
+	  output perihperal.
+
+config SAMPLE_FREQ
+	int "Sample rate"
+	default 48000
+	help
+	  Sample frequency of the system.
+
+config USE_DMIC
+	bool "Use DMIC as an audio input"
+
+if USE_DMIC
+
+config DMIC_CHANNELS
+	int "Number of DMIC channels"
+	default 1
+	help
+	  Count of DMIC channels to capture and process.
+
+endif

samples/drivers/i2s/i2s_codec/README.rst

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+.. zephyr:code-sample:: i2s_codec
+   :name: I2S codec
+   :relevant-api: i2s_interface
+
+   Process an audio stream to codec.
+
+Overview
+********
+
+This sample demonstrates how to use an I2S driver in a simple processing of
+an audio stream. It configures and starts from memory buffer or from DMIC to
+record i2s data and send to codec with DMA.
+
+Requirements
+************
+
+This sample has been tested on mimxrt595_evk/mimxrt595s/cm33
+
+Building and Running
+********************
+
+The code can be found in :zephyr_file:`samples/drivers/i2s/i2s_codec`.
+
+To build and flash the application:
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/drivers/i2s/i2s_codec
+   :board: mimxrt595_evk/mimxrt595s/cm33
+   :goals: build flash
+   :compact:
+
+To run you can connect earphones to the lineout connect and hear the sound
+from DMIC or from memory buffer.

samples/drivers/i2s/i2s_codec/boards/mimxrt595_evk_mimxrt595s_cm33.conf

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+#
+# Copyright 2024 NXP
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+CONFIG_DMA=y
+CONFIG_I2S_MCUX_FLEXCOMM=y
+CONFIG_I3C=y
+CONFIG_HEAP_MEM_POOL_SIZE=81920
+CONFIG_AUDIO=y
+CONFIG_AUDIO_CODEC=y
+CONFIG_AUDIO_CODEC_WM8904=y
+CONFIG_I2S_INIT_BUFFERS=4
+CONFIG_SAMPLE_FREQ=16000
+CONFIG_USE_DMIC=y

samples/drivers/i2s/i2s_codec/boards/mimxrt595_evk_mimxrt595s_cm33.overlay

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+/ {
+	aliases {
+		i2s-codec-rx = &i2s0;
+		i2s-codec-tx = &i2s1;
+	};
+};
+
+&i3c0 {
+	clk-divider = <20>;
+
+	status = "okay";
+};
+
+&i2s0 {
+	status = "okay";
+};
+
+&i2s1 {
+	status = "okay";
+};
+
+dmic_dev: &dmic0 {
+	status = "okay";
+};

samples/drivers/i2s/i2s_codec/boards/mimxrt685_evk_mimxrt685s_cm33.conf

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+#
+# Copyright 2024 NXP
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+CONFIG_DMA=y
+CONFIG_I2S_MCUX_FLEXCOMM=y
+CONFIG_I3C=y
+CONFIG_HEAP_MEM_POOL_SIZE=81920
+CONFIG_AUDIO=y
+CONFIG_AUDIO_CODEC=y
+CONFIG_AUDIO_CODEC_WM8904=y
+CONFIG_I2S_INIT_BUFFERS=4
+CONFIG_SAMPLE_FREQ=16000
+CONFIG_USE_DMIC=y

samples/drivers/i2s/i2s_codec/boards/mimxrt685_evk_mimxrt685s_cm33.overlay

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+/ {
+	aliases {
+		i2s-codec-rx = &i2s0;
+		i2s-codec-tx = &i2s1;
+	};
+};
+
+&i3c0 {
+	status = "okay";
+};
+
+&i2s0 {
+	status = "okay";
+};
+
+&i2s1 {
+	status = "okay";
+};
+
+dmic_dev: &dmic0 {
+	status = "okay";
+};

samples/drivers/i2s/i2s_codec/prj.conf

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+CONFIG_I2S=y
+CONFIG_AUDIO=y
+CONFIG_AUDIO_DMIC=y

samples/drivers/i2s/i2s_codec/sample.yaml

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+sample:
+  name: codec sample
+tests:
+  sample.drivers.i2s.codec:
+    tags: i2s
+    platform_allow:
+      - mimxrt595_evk/mimxrt595s/cm33
+    harness: console
+    harness_config:
+      type: one_line
+      regex:
+        - "start streams"

samples/drivers/i2s/i2s_codec/src/main.c

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+/*
+ * Copyright 2024 NXP
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/kernel.h>
+#include <zephyr/sys/printk.h>
+#include <zephyr/audio/dmic.h>
+#include <zephyr/drivers/i2s.h>
+#include <zephyr/drivers/gpio.h>
+#include <zephyr/audio/codec.h>
+#include <string.h>
+
+
+#define I2S_CODEC_TX  DT_ALIAS(i2s_codec_tx)
+
+#define SAMPLE_FREQUENCY    CONFIG_SAMPLE_FREQ
+#define SAMPLE_BIT_WIDTH    (16U)
+#define BYTES_PER_SAMPLE    sizeof(int16_t)
+#if CONFIG_USE_DMIC
+#define NUMBER_OF_CHANNELS  CONFIG_DMIC_CHANNELS
+#else
+#define NUMBER_OF_CHANNELS (2U)
+#endif
+/* Such block length provides an echo with the delay of 100 ms. */
+#define SAMPLES_PER_BLOCK   ((SAMPLE_FREQUENCY / 10) * NUMBER_OF_CHANNELS)
+#define INITIAL_BLOCKS      CONFIG_I2S_INIT_BUFFERS
+#define TIMEOUT             (2000U)
+
+#define BLOCK_SIZE  (BYTES_PER_SAMPLE * SAMPLES_PER_BLOCK)
+#define BLOCK_COUNT (INITIAL_BLOCKS + 32)
+K_MEM_SLAB_DEFINE_STATIC(mem_slab, BLOCK_SIZE, BLOCK_COUNT, 4);
+
+static bool configure_tx_streams(const struct device *i2s_dev, struct i2s_config *config)
+{
+	int ret;
+
+	ret = i2s_configure(i2s_dev, I2S_DIR_TX, config);
+	if (ret < 0) {
+		printk("Failed to configure codec stream: %d\n", ret);
+		return false;
+	}
+
+	return true;
+}
+
+static bool trigger_command(const struct device *i2s_dev_codec,
+			    enum i2s_trigger_cmd cmd)
+{
+	int ret;
+
+	ret = i2s_trigger(i2s_dev_codec, I2S_DIR_TX, cmd);
+	if (ret < 0) {
+		printk("Failed to trigger command %d on TX: %d\n", cmd, ret);
+		return false;
+	}
+
+	return true;
+}
+
+int main(void)
+{
+	const struct device *const i2s_dev_codec = DEVICE_DT_GET(I2S_CODEC_TX);
+#if CONFIG_USE_DMIC
+	const struct device *const dmic_dev = DEVICE_DT_GET(DT_NODELABEL(dmic_dev));
+#endif
+	const struct device *const codec_dev = DEVICE_DT_GET(DT_NODELABEL(audio_codec));
+	struct i2s_config config;
+	struct audio_codec_cfg audio_cfg;
+	int ret;
+
+#if CONFIG_USE_DMIC
+	struct pcm_stream_cfg stream = {
+		.pcm_width = SAMPLE_BIT_WIDTH,
+		.mem_slab  = &mem_slab,
+	};
+	struct dmic_cfg cfg = {
+		.io = {
+			/* These fields can be used to limit the PDM clock
+			 * configurations that the driver is allowed to use
+			 * to those supported by the microphone.
+			 */
+			.min_pdm_clk_freq = 1000000,
+			.max_pdm_clk_freq = 3500000,
+			.min_pdm_clk_dc   = 40,
+			.max_pdm_clk_dc   = 60,
+		},
+		.streams = &stream,
+		.channel = {
+			.req_num_streams = 1,
+		},
+	};
+#endif
+	printk("codec sample\n");
+
+#if CONFIG_USE_DMIC
+	if (!device_is_ready(dmic_dev)) {
+		printk("%s is not ready", dmic_dev->name);
+		return 0;
+	}
+#endif
+
+	if (!device_is_ready(i2s_dev_codec)) {
+		printk("%s is not ready\n", i2s_dev_codec->name);
+		return 0;
+	}
+
+
+	if (!device_is_ready(codec_dev)) {
+		printk("%s is not ready", codec_dev->name);
+		return 0;
+	}
+	audio_cfg.dai_route = AUDIO_ROUTE_PLAYBACK;
+	audio_cfg.dai_type = AUDIO_DAI_TYPE_I2S;
+	audio_cfg.dai_cfg.i2s.word_size = SAMPLE_BIT_WIDTH;
+	audio_cfg.dai_cfg.i2s.channels =  2;
+	audio_cfg.dai_cfg.i2s.format = I2S_FMT_DATA_FORMAT_I2S;
+	audio_cfg.dai_cfg.i2s.options = I2S_OPT_FRAME_CLK_MASTER;
+	audio_cfg.dai_cfg.i2s.frame_clk_freq = SAMPLE_FREQUENCY;
+	audio_cfg.dai_cfg.i2s.mem_slab = &mem_slab;
+	audio_cfg.dai_cfg.i2s.block_size = BLOCK_SIZE;
+	audio_codec_configure(codec_dev, &audio_cfg);
+	k_msleep(1000);
+
+#if CONFIG_USE_DMIC
+	cfg.channel.req_num_chan = 2;
+	cfg.channel.req_chan_map_lo =
+		dmic_build_channel_map(0, 0, PDM_CHAN_LEFT) |
+		dmic_build_channel_map(1, 0, PDM_CHAN_RIGHT);
+	cfg.streams[0].pcm_rate = SAMPLE_FREQUENCY;
+	cfg.streams[0].block_size = BLOCK_SIZE;
+
+	printk("PCM output rate: %u, channels: %u\n",
+		cfg.streams[0].pcm_rate, cfg.channel.req_num_chan);
+
+	ret = dmic_configure(dmic_dev, &cfg);
+	if (ret < 0) {
+		printk("Failed to configure the driver: %d", ret);
+		return ret;
+	}
+#endif
+
+	config.word_size = SAMPLE_BIT_WIDTH;
+	config.channels = NUMBER_OF_CHANNELS;
+	config.format = I2S_FMT_DATA_FORMAT_I2S;
+	config.options = I2S_OPT_BIT_CLK_MASTER | I2S_OPT_FRAME_CLK_MASTER;
+	config.frame_clk_freq = SAMPLE_FREQUENCY;
+	config.mem_slab = &mem_slab;
+	config.block_size = BLOCK_SIZE;
+	config.timeout = TIMEOUT;
+	if (!configure_tx_streams(i2s_dev_codec, &config)) {
+		printk("failure to config streams\n");
+		return 0;
+	}
+
+	printk("start streams\n");
+	for (;;) {
+		bool started = false;
+#if CONFIG_USE_DMIC
+		ret = dmic_trigger(dmic_dev, DMIC_TRIGGER_START);
+		if (ret < 0) {
+			printk("START trigger failed: %d", ret);
+			return ret;
+		}
+#endif
+		while (1) {
+			void *mem_block;
+			uint32_t block_size = BLOCK_SIZE;
+			int ret;
+			int i;
+
+			for (i = 0; i < 2; i++) {
+#if CONFIG_USE_DMIC
+				ret = dmic_read(dmic_dev, 0,
+								&mem_block, &block_size, TIMEOUT);
+				if (ret < 0) {
+					printk("read failed: %d", ret);
+					break;
+				}
+#else
+				ret = k_mem_slab_alloc(&mem_slab,
+							&mem_block, Z_TIMEOUT_TICKS(TIMEOUT));
+				if (ret < 0) {
+					printk("Failed to allocate TX block\n");
+					return 0;
+				}
+#endif
+				ret = i2s_write(i2s_dev_codec, mem_block, block_size);
+				if (ret < 0) {
+					printk("Failed to write data: %d\n", ret);
+					break;
+				}
+			}
+			if (ret < 0) {
+				printk("error %d\n", ret);
+				break;
+			}
+			if (!started) {
+				i2s_trigger(i2s_dev_codec, I2S_DIR_TX, I2S_TRIGGER_START);
+				started = true;
+			}
+		}
+		if (!trigger_command(i2s_dev_codec,
+				     I2S_TRIGGER_DROP)) {
+			printk("Send I2S trigger DRAIN failed: %d", ret);
+			return 0;
+		}
+#if CONFIG_USE_DMIC
+		ret = dmic_trigger(dmic_dev, DMIC_TRIGGER_STOP);
+		if (ret < 0) {
+			printk("STOP trigger failed: %d", ret);
+			return 0;
+		}
+#endif
+		printk("Streams stopped\n");
+		return 0;
+	}
+}