buzzer_2/firmware/libs/audio/src/audio.c

#include <zephyr/kernel.h>
#include <zephyr/logging/log.h>
#include <zephyr/fs/fs.h>
#include <zephyr/drivers/i2s.h>

#include "audio.h"
#include "fs_mgmt.h"
#include "event_mgmt.h"

LOG_MODULE_REGISTER(audio, CONFIG_AUDIO_LOG_LEVEL);

const struct device *i2s_dev = DEVICE_DT_GET(DT_ALIAS(i2s_audio));

K_MSGQ_DEFINE(audio_cmd_q, sizeof(struct audio_cmd_msg), 10, 4);
K_SEM_DEFINE(audio_files_count_sem, 0, 1);

K_MEM_SLAB_DEFINE(audio_cache_slab, CONFIG_AUDIO_CACHE_SLAB_SIZE, CONFIG_AUDIO_CACHE_SLAB_COUNT, 4);

enum audio_thread_state_t
{
    AUDIO_IDLE,
    AUDIO_PRECACHING,
    AUDIO_WAIT_FOR_CACHE,
    AUDIO_PLAYING,
    AUDIO_DRAINING,
};

#define EV_PLAY_RANDOM BIT(0)
#define EV_MSGQ_NOT_EMPTY BIT(1)
#define EV_CACHE_READY BIT(2)
#define EV_CACHE_DONE BIT(3)
#define EV_STATE_STEP BIT(4)
#define EV_ALL (EV_PLAY_RANDOM | EV_MSGQ_NOT_EMPTY | EV_CACHE_READY | EV_CACHE_DONE | EV_STATE_STEP)

K_EVENT_DEFINE(audio_events);

#define AUDIO_CACHE_EVT_START BIT(0)
#define AUDIO_CACHE_EVT_STOP BIT(1)

K_EVENT_DEFINE(audio_cache_event);

struct audio_ctx_t
{
    char next_file_name[CONFIG_FS_MGMT_MAX_PATH_LENGTH];
    struct fs_file_t file;
    bool is_file_open;
    bool cache_ready_signaled;
    uint8_t cached_blocks;
    ssize_t audio_size;
    ssize_t cached_bytes;
} audio_ctx;

static struct i2s_config i2s_cfg = {
    .word_size = 16,
    .channels = 1,
    .format = I2S_FMT_DATA_FORMAT_I2S,
    .options = I2S_OPT_BIT_CLK_MASTER | I2S_OPT_FRAME_CLK_MASTER,
    .frame_clk_freq = 16000,
    .mem_slab = &audio_cache_slab,
    .block_size = CONFIG_AUDIO_CACHE_SLAB_SIZE,
    .timeout = SYS_FOREVER_MS,
};

K_MUTEX_DEFINE(audio_ctx_mutex);

atomic_t thread_state = ATOMIC_INIT(0);
atomic_t num_files = ATOMIC_INIT(0);

static const char *audio_state_name(enum audio_thread_state_t state)
{
    switch (state)
    {
    case AUDIO_IDLE:
        return "IDLE";
    case AUDIO_PRECACHING:
        return "PRECACHING";
    case AUDIO_WAIT_FOR_CACHE:
        return "WAIT_FOR_CACHE";
    case AUDIO_PLAYING:
        return "PLAYING";
    case AUDIO_DRAINING:
        return "DRAINING";
    default:
        return "UNKNOWN";
    }
}

static void audio_set_state(enum audio_thread_state_t new_state, const char *reason)
{
    enum audio_thread_state_t old_state = atomic_get(&thread_state);

    if (old_state != new_state)
    {
        LOG_INF("Audio state %s -> %s (%s)",
                audio_state_name(old_state),
                audio_state_name(new_state),
                reason);
    }

    atomic_set(&thread_state, new_state);
}

int audio_queue_play(const char *filename, bool is_interrupt)
{
    if (is_interrupt)
    {
        /* Keep hardware state changes inside audio_thread to avoid cross-thread races. */
        k_msgq_purge(&audio_cmd_q);
    }

    if (strlen(filename) == 0)
    {
        return 0;
    }
    if (k_msgq_num_free_get(&audio_cmd_q) == 0)
    {
        LOG_ERR("Audio command queue is full, cannot enqueue new command");
        return -ENOMEM;
    }
    
    struct audio_cmd_msg cmd;
    strncpy(cmd.filename, filename, sizeof(cmd.filename) - 1);
    cmd.filename[sizeof(cmd.filename) - 1] = '\0';
    cmd.is_interrupt = is_interrupt;

    if (k_msgq_put(&audio_cmd_q, &cmd, K_FOREVER) != 0)
    {
        LOG_ERR("Failed to enqueue audio command");
        return -EFAULT;
    }

    /*
     * Wake immediately for interrupts or when idle.
     * Non-interrupt commands during active playback are picked up after drain.
     */
    if (is_interrupt || (atomic_get(&thread_state) == AUDIO_IDLE))
    {
        k_event_set(&audio_events, EV_MSGQ_NOT_EMPTY);
    }

    LOG_INF("Enqueued audio command: filename='%s', is_interrupt=%d, queued=%u", cmd.filename,
            cmd.is_interrupt, (unsigned int)k_msgq_num_used_get(&audio_cmd_q));
    return 0;
}

static int audio_select_random_to_buf(char *buf, size_t buf_size)
{
    if (k_sem_take(&audio_files_count_sem, K_FOREVER) != 0)
    {
        return -EFAULT;
    }

    int count = atomic_get(&num_files);
    if (count == 0)
    {
        LOG_WRN("No audio files available, using fallback sound");
        snprintf(buf, buf_size, "%s/%s", FS_SYSTEM_PATH, CONFIG_AUDIO_NO_SAMPLES_SAMPLE);
        k_sem_give(&audio_files_count_sem);
        return -ENOENT;
    }

    int random_index = k_cycle_get_32() % count;
    struct fs_dir_t dir;
    struct fs_dirent entry;
    int rc;
    bool found = false;

    fs_dir_t_init(&dir);
    rc = fs_mgmt_pm_opendir(&dir, FS_AUDIO_PATH);
    if (rc < 0)
    {
        LOG_ERR("Failed to open audio directory '%s': %d", FS_AUDIO_PATH, rc);
        k_sem_give(&audio_files_count_sem);
        return rc;
    }

    int current_index = 0;
    while (1)
    {
        rc = fs_readdir(&dir, &entry);
        if (rc < 0 || entry.name[0] == '\0')
        {
            break;
        }
        if (entry.type == FS_DIR_ENTRY_FILE)
        {
            if (current_index == random_index)
            {
                snprintf(buf, buf_size, "%s/%.*s", FS_AUDIO_PATH,
                         (int)(buf_size - sizeof(FS_AUDIO_PATH) - 1U), entry.name);
                LOG_DBG("Selected random audio file: %s", buf);
                found = true;
                break;
            }
            current_index++;
        }
    }

    fs_mgmt_pm_closedir(&dir);
    k_sem_give(&audio_files_count_sem);
    return found ? 0 : -ENOENT;
}

void audio_refresh_files(void)
{
    // Lokale Strukturen verwenden, um Reentrancy-Probleme zu vermeiden
    struct fs_dir_t dir;
    struct fs_dirent entry;
    int count = 0;
    int rc;

    k_sem_reset(&audio_files_count_sem);

    fs_dir_t_init(&dir);
    // Nutze deinen PM-Wrapper für den Flash-Zugriff
    rc = fs_mgmt_pm_opendir(&dir, FS_AUDIO_PATH);
    if (rc < 0)
    {
        LOG_ERR("Failed to open audio directory '%s': %d", FS_AUDIO_PATH, rc);
        atomic_set(&num_files, 0);
        return;
    }

    while (1)
    {
        rc = fs_readdir(&dir, &entry);
        if (rc < 0)
        {
            LOG_ERR("Directory read error: %d", rc);
            break;
        }
        if (entry.name[0] == '\0')
        {
            break;
        }
        if (entry.type == FS_DIR_ENTRY_FILE)
        {
            count++;
        }
    }

    fs_mgmt_pm_closedir(&dir);
    k_sem_give(&audio_files_count_sem);
    atomic_set(&num_files, count);
    LOG_INF("Audio refresh found %d file(s) in %s", count, FS_AUDIO_PATH);
}

static int audio_init(void)
{
    if (!device_is_ready(i2s_dev))
    {
        LOG_ERR("I2S device not ready");
        return -ENODEV;
    }

    int rc = i2s_configure(i2s_dev, I2S_DIR_TX, &i2s_cfg);
    if (rc < 0)
    {
        LOG_ERR("Failed to configure I2S: %d", rc);
        return rc;
    }

    LOG_DBG("Audio module initialized");
    return 0;
}

SYS_INIT(audio_init, APPLICATION, CONFIG_APPLICATION_INIT_PRIORITY);

void audio_start_random_playback(void)
{
    LOG_DBG("audio_start_random_playback called");
    k_event_set(&audio_events, EV_PLAY_RANDOM);
}

void audio_thread(void *arg1, void *arg2, void *arg3)
{
    ARG_UNUSED(arg1);
    ARG_UNUSED(arg2);
    ARG_UNUSED(arg3);

    LOG_INF("Audio thread waiting for filesystem ready event");
    k_event_wait(&event_mgmt_events, EVENT_MGMT_FS_READY, false, K_FOREVER);
    LOG_INF("Audio thread received filesystem ready event");

    audio_refresh_files();
    audio_set_state(AUDIO_IDLE, "filesystem ready");

    while (1)
    {
        enum audio_thread_state_t state = atomic_get(&thread_state);
        k_timeout_t timeout = (state == AUDIO_DRAINING) ? K_MSEC(10) : K_FOREVER;

        uint32_t active_events = k_event_wait(&audio_events, EV_ALL, false, timeout);

        if (active_events & EV_STATE_STEP)
        {
            k_event_clear(&audio_events, EV_STATE_STEP);
        }

        /*
         * EV_PLAY_RANDOM: button press requests a random sound.
         * If idle, start it immediately. Otherwise queue it as a non-interrupt command
         * so it plays after the current sound finishes.
         */
        if (active_events & EV_PLAY_RANDOM)
        {
            k_event_clear(&audio_events, EV_PLAY_RANDOM);

            char random_file[CONFIG_FS_MGMT_MAX_PATH_LENGTH];
            if (audio_select_random_to_buf(random_file, sizeof(random_file)) == 0)
            {
                if (state == AUDIO_IDLE)
                {
                    k_mutex_lock(&audio_ctx_mutex, K_FOREVER);
                    strncpy(audio_ctx.next_file_name, random_file, sizeof(audio_ctx.next_file_name) - 1);
                    audio_ctx.next_file_name[sizeof(audio_ctx.next_file_name) - 1] = '\0';
                    k_mutex_unlock(&audio_ctx_mutex);
                    audio_set_state(AUDIO_PRECACHING, "play random while idle");
                    k_event_set(&audio_events, EV_STATE_STEP);
                }
                else
                {
                    struct audio_cmd_msg cmd;
                    strncpy(cmd.filename, random_file, sizeof(cmd.filename) - 1);
                    cmd.filename[sizeof(cmd.filename) - 1] = '\0';
                    cmd.is_interrupt = false;
                    if (k_msgq_put(&audio_cmd_q, &cmd, K_NO_WAIT) != 0)
                    {
                        LOG_WRN("Random play queue full, discarding");
                    }
                    else
                    {
                        LOG_INF("Random play queued: '%s'", random_file);
                    }
                }
            }
            continue;
        }

        switch (state)
        {
        case AUDIO_IDLE:
            if (active_events & EV_MSGQ_NOT_EMPTY)
            {
                k_event_clear(&audio_events, EV_MSGQ_NOT_EMPTY);

                struct audio_cmd_msg cmd;
                if (k_msgq_get(&audio_cmd_q, &cmd, K_NO_WAIT) != 0)
                {
                    LOG_WRN("EV_MSGQ_NOT_EMPTY set but queue empty");
                    break;
                }

                k_mutex_lock(&audio_ctx_mutex, K_FOREVER);
                strncpy(audio_ctx.next_file_name, cmd.filename, sizeof(audio_ctx.next_file_name) - 1);
                audio_ctx.next_file_name[sizeof(audio_ctx.next_file_name) - 1] = '\0';
                k_mutex_unlock(&audio_ctx_mutex);

                LOG_INF("Dequeued command while idle: '%s'", cmd.filename);
                audio_set_state(AUDIO_PRECACHING, "command while idle");
                k_event_set(&audio_events, EV_STATE_STEP);
            }
            break;

        case AUDIO_PRECACHING:
            LOG_INF("Precaching '%s'", audio_ctx.next_file_name);
            i2s_trigger(i2s_dev, I2S_DIR_TX, I2S_TRIGGER_PREPARE);
            k_event_set(&audio_cache_event, AUDIO_CACHE_EVT_START);
            audio_set_state(AUDIO_WAIT_FOR_CACHE, "cache start requested");
            break;

        case AUDIO_WAIT_FOR_CACHE:
            if (active_events & EV_MSGQ_NOT_EMPTY)
            {
                k_event_clear(&audio_events, EV_MSGQ_NOT_EMPTY);

                struct audio_cmd_msg cmd;
                if (k_msgq_peek(&audio_cmd_q, &cmd) == 0 && cmd.is_interrupt)
                {
                    /* Interrupt while caching: flush and restart for the new file */
                    k_event_set(&audio_cache_event, AUDIO_CACHE_EVT_STOP);
                    i2s_trigger(i2s_dev, I2S_DIR_TX, I2S_TRIGGER_PREPARE);
                    k_msgq_get(&audio_cmd_q, &cmd, K_NO_WAIT);

                    k_mutex_lock(&audio_ctx_mutex, K_FOREVER);
                    strncpy(audio_ctx.next_file_name, cmd.filename, sizeof(audio_ctx.next_file_name) - 1);
                    audio_ctx.next_file_name[sizeof(audio_ctx.next_file_name) - 1] = '\0';
                    k_mutex_unlock(&audio_ctx_mutex);

                    LOG_INF("Interrupt while caching, switching to '%s'", cmd.filename);
                    audio_set_state(AUDIO_PRECACHING, "interrupt while caching");
                    k_event_set(&audio_events, EV_STATE_STEP);
                    break;
                }
                /* Non-interrupt: already queued, will play after current */
            }

            if (active_events & EV_CACHE_READY)
            {
                k_event_clear(&audio_events, EV_CACHE_READY);
                i2s_trigger(i2s_dev, I2S_DIR_TX, I2S_TRIGGER_START);
                audio_set_state(AUDIO_PLAYING, "cache primed, starting");
                LOG_INF("Playback started: '%s'", audio_ctx.next_file_name);
            }
            break;

        case AUDIO_PLAYING:
            if (active_events & EV_MSGQ_NOT_EMPTY)
            {
                k_event_clear(&audio_events, EV_MSGQ_NOT_EMPTY);

                struct audio_cmd_msg cmd;
                if (k_msgq_peek(&audio_cmd_q, &cmd) == 0 && cmd.is_interrupt)
                {
                    k_event_set(&audio_cache_event, AUDIO_CACHE_EVT_STOP);
                    i2s_trigger(i2s_dev, I2S_DIR_TX, I2S_TRIGGER_DROP);
                    k_msgq_get(&audio_cmd_q, &cmd, K_NO_WAIT);

                    k_mutex_lock(&audio_ctx_mutex, K_FOREVER);
                    strncpy(audio_ctx.next_file_name, cmd.filename, sizeof(audio_ctx.next_file_name) - 1);
                    audio_ctx.next_file_name[sizeof(audio_ctx.next_file_name) - 1] = '\0';
                    k_mutex_unlock(&audio_ctx_mutex);

                    LOG_INF("Interrupting playback with '%s'", cmd.filename);
                    audio_set_state(AUDIO_PRECACHING, "interrupt during playback");
                    k_event_set(&audio_events, EV_STATE_STEP);
                }
                else
                {
                    LOG_DBG("Non-interrupt command queued; will play after drain");
                }
                break;
            }

            if (active_events & EV_CACHE_DONE)
            {
                k_event_clear(&audio_events, EV_CACHE_DONE);
                i2s_trigger(i2s_dev, I2S_DIR_TX, I2S_TRIGGER_DRAIN);
                audio_set_state(AUDIO_DRAINING, "cache complete");
            }
            break;

        case AUDIO_DRAINING:
        {
            if (active_events & EV_MSGQ_NOT_EMPTY)
            {
                k_event_clear(&audio_events, EV_MSGQ_NOT_EMPTY);

                struct audio_cmd_msg cmd;
                if (k_msgq_peek(&audio_cmd_q, &cmd) == 0 && cmd.is_interrupt)
                {
                    k_msgq_get(&audio_cmd_q, &cmd, K_NO_WAIT);
                    k_event_set(&audio_cache_event, AUDIO_CACHE_EVT_STOP);
                    i2s_trigger(i2s_dev, I2S_DIR_TX, I2S_TRIGGER_DROP);

                    k_mutex_lock(&audio_ctx_mutex, K_FOREVER);
                    strncpy(audio_ctx.next_file_name, cmd.filename, sizeof(audio_ctx.next_file_name) - 1);
                    audio_ctx.next_file_name[sizeof(audio_ctx.next_file_name) - 1] = '\0';
                    k_mutex_unlock(&audio_ctx_mutex);

                    LOG_INF("Interrupt during drain, switching to '%s'", cmd.filename);
                    audio_set_state(AUDIO_PRECACHING, "interrupt during drain");
                    k_event_set(&audio_events, EV_STATE_STEP);
                    break;
                }
            }

            if (k_mem_slab_num_free_get(&audio_cache_slab) == CONFIG_AUDIO_CACHE_SLAB_COUNT)
            {
                LOG_DBG("Drain complete");
                if (k_msgq_num_used_get(&audio_cmd_q) > 0)
                {
                    struct audio_cmd_msg cmd;
                    k_msgq_get(&audio_cmd_q, &cmd, K_NO_WAIT);

                    k_mutex_lock(&audio_ctx_mutex, K_FOREVER);
                    strncpy(audio_ctx.next_file_name, cmd.filename, sizeof(audio_ctx.next_file_name) - 1);
                    audio_ctx.next_file_name[sizeof(audio_ctx.next_file_name) - 1] = '\0';
                    k_mutex_unlock(&audio_ctx_mutex);

                    LOG_INF("Drain complete, next: '%s'", cmd.filename);
                    audio_set_state(AUDIO_PRECACHING, "drain complete, queued command");
                    k_event_set(&audio_events, EV_STATE_STEP);
                }
                else
                {
                    audio_set_state(AUDIO_IDLE, "drain complete, no more commands");
                }
            }
            break;
        }
        }
    }
}

K_THREAD_DEFINE(audio_thread_id, CONFIG_AUDIO_THREAD_STACK_SIZE, audio_thread, NULL, NULL, NULL,
                CONFIG_AUDIO_THREAD_PRIORITY, 0, 0);

void audio_pump_thread(void *arg1, void *arg2, void *arg3)
{
    ARG_UNUSED(arg1);
    ARG_UNUSED(arg2);
    ARG_UNUSED(arg3);

    void *mem_slab;
    while (1)
    {
        uint32_t events = k_event_wait(&audio_cache_event, AUDIO_CACHE_EVT_START | AUDIO_CACHE_EVT_STOP, false, K_FOREVER);

        if (events & AUDIO_CACHE_EVT_STOP)
        {
            k_mutex_lock(&audio_ctx_mutex, K_FOREVER);
            if (audio_ctx.is_file_open)
            {
                fs_close(&audio_ctx.file);
                audio_ctx.is_file_open = false;
            }
            k_mutex_unlock(&audio_ctx_mutex);

            k_event_clear(&audio_cache_event, AUDIO_CACHE_EVT_START | AUDIO_CACHE_EVT_STOP);
            continue;
        }

        int rc = k_mem_slab_alloc(&audio_cache_slab, &mem_slab, K_NO_WAIT);
        if (rc == -ENOMEM)
        {
            k_event_set(&audio_events, EV_CACHE_READY);
            rc = k_mem_slab_alloc(&audio_cache_slab, &mem_slab, K_FOREVER);
            if (k_event_wait(&audio_cache_event, AUDIO_CACHE_EVT_STOP, false, K_NO_WAIT))
            {
                k_mem_slab_free(&audio_cache_slab, &mem_slab);
                continue;
            }
        }

        if (rc == 0)
        {
            bool signal_cache_ready = false;

            k_mutex_lock(&audio_ctx_mutex, K_FOREVER);

            if (!audio_ctx.is_file_open)
            {
                LOG_INF("Opening audio file '%s' for playback", audio_ctx.next_file_name);
                rc = fs_mgmt_pm_open(&audio_ctx.file, audio_ctx.next_file_name, FS_O_READ);
                if (rc < 0)
                {
                    LOG_ERR("Failed to open audio file '%s': %d", audio_ctx.next_file_name, rc);
                    k_mem_slab_free(&audio_cache_slab, &mem_slab);
                    k_event_clear(&audio_cache_event, AUDIO_CACHE_EVT_START);
                    k_mutex_unlock(&audio_ctx_mutex);
                    continue;
                }

                audio_ctx.is_file_open = true;
                audio_ctx.cache_ready_signaled = false;
                audio_ctx.cached_blocks = 0;

                /* File length and cache position are initialized once per playback start. */
                audio_ctx.audio_size = fs_mgmt_get_audio_data_len(&audio_ctx.file);
                audio_ctx.cached_bytes = 0;

                LOG_DBG("Audio file '%s' opened for caching, size: %d", audio_ctx.next_file_name, (int)audio_ctx.audio_size);
            }

            if (audio_ctx.audio_size <= 0)
            {
                LOG_ERR("Invalid audio size for '%s': %d", audio_ctx.next_file_name, (int)audio_ctx.audio_size);
                k_mem_slab_free(&audio_cache_slab, &mem_slab);
                fs_close(&audio_ctx.file);
                audio_ctx.is_file_open = false;
                k_event_clear(&audio_cache_event, AUDIO_CACHE_EVT_START);
                k_mutex_unlock(&audio_ctx_mutex);
                continue;
            }

            ssize_t remaining_bytes = audio_ctx.audio_size - audio_ctx.cached_bytes;
            if (remaining_bytes <= 0)
            {
                k_mem_slab_free(&audio_cache_slab, &mem_slab);
                fs_close(&audio_ctx.file);
                audio_ctx.is_file_open = false;
                k_event_clear(&audio_cache_event, AUDIO_CACHE_EVT_START);
                k_mutex_unlock(&audio_ctx_mutex);
                k_event_set(&audio_events, EV_CACHE_DONE);
                continue;
            }

            ssize_t bytes_to_read = MIN(CONFIG_AUDIO_CACHE_SLAB_SIZE, remaining_bytes);
            ssize_t bytes_read = fs_read(&audio_ctx.file, mem_slab, bytes_to_read);

            if (bytes_read <= 0) // <= 0, um EOF (0) und Fehler (< 0) abzufangen
            {
                if (bytes_read < 0)
                {
                    LOG_ERR("Failed to read audio data: %d", (int)bytes_read);
                }
                k_mem_slab_free(&audio_cache_slab, &mem_slab);

                // EOF erreicht -> Datei schließen und START-Bit löschen
                fs_close(&audio_ctx.file);
                audio_ctx.is_file_open = false;
                k_event_clear(&audio_cache_event, AUDIO_CACHE_EVT_START);
                k_mutex_unlock(&audio_ctx_mutex);
                k_event_set(&audio_events, EV_CACHE_DONE);
                continue;
            }

            audio_ctx.cached_bytes += bytes_read;
            // LOG_DBG("Cached %u%% ", (int)((audio_ctx.cached_bytes * 100) / audio_ctx.audio_size));

            if (bytes_read > CONFIG_AUDIO_CACHE_SLAB_SIZE)
            {
                LOG_ERR("Read size %d exceeds slab size %d", (int)bytes_read, CONFIG_AUDIO_CACHE_SLAB_SIZE);
                k_mem_slab_free(&audio_cache_slab, &mem_slab);
                fs_close(&audio_ctx.file);
                audio_ctx.is_file_open = false;
                k_event_clear(&audio_cache_event, AUDIO_CACHE_EVT_START);
                k_mutex_unlock(&audio_ctx_mutex);
                continue;
            }

            if ((bytes_read & 0x1) != 0)
            {
                if (bytes_read >= (CONFIG_AUDIO_CACHE_SLAB_SIZE))
                {
                    LOG_ERR("Odd PCM byte count at slab boundary: %d", (int)bytes_read);
                    k_mem_slab_free(&audio_cache_slab, &mem_slab);
                    fs_close(&audio_ctx.file);
                    audio_ctx.is_file_open = false;
                    k_event_clear(&audio_cache_event, AUDIO_CACHE_EVT_START);
                    k_mutex_unlock(&audio_ctx_mutex);
                    continue;
                }

                ((uint8_t *)mem_slab)[bytes_read] = 0;
                bytes_read++;
            }

            if (bytes_read < CONFIG_AUDIO_CACHE_SLAB_SIZE)
            {
                memset((uint8_t *)mem_slab + bytes_read, 0, (CONFIG_AUDIO_CACHE_SLAB_SIZE) - bytes_read);
                bytes_read = CONFIG_AUDIO_CACHE_SLAB_SIZE;
            }

            audio_ctx.cached_blocks++;

            if (!audio_ctx.cache_ready_signaled &&
                (audio_ctx.cached_blocks >= 2 || audio_ctx.cached_bytes >= audio_ctx.audio_size))
            {
                audio_ctx.cache_ready_signaled = true;
                signal_cache_ready = true;
            }

            k_mutex_unlock(&audio_ctx_mutex);
            if (i2s_write(i2s_dev, mem_slab, CONFIG_AUDIO_CACHE_SLAB_SIZE) < 0)
            {
                LOG_ERR("Failed to write audio data to I2S");
                k_mem_slab_free(&audio_cache_slab, &mem_slab);
                continue;
            }

            if (signal_cache_ready)
            {
                LOG_DBG("Cache ready for '%s' after %u block(s)", audio_ctx.next_file_name,
                        (unsigned int)audio_ctx.cached_blocks);
                k_event_set(&audio_events, EV_CACHE_READY);
            }
        }
    }
}

K_THREAD_DEFINE(audio_cache_thread_id, CONFIG_AUDIO_PUMP_THREAD_STACK_SIZE, audio_pump_thread, NULL, NULL, NULL,
                CONFIG_AUDIO_PUMP_THREAD_PRIORITY, 0, 0);