/* *INDENT-OFF* */
// Copyright 2015-2020 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at

//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "sdkconfig.h"
#if CONFIG_IDF_TARGET_ESP32S2

#include <stdio.h>
#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/semphr.h"
#include "esp_log.h"
#include "driver/gpio.h"
#include "driver/i2s.h"
#include "esp_heap_caps.h"
#include "esp32s2/rom/lldesc.h"
#include "soc/system_reg.h"
#include "i2s_lcd_driver.h"


static const char *TAG = "ESP32S2_I2S_LCD";

#define I2S_CHECK(a, str, ret) if (!(a)) {                                              \
        ESP_LOGE(TAG,"%s:%d (%s):%s", __FILE__, __LINE__, __FUNCTION__, str);       \
        return ret;                                                                   \
}

#define LCD_CAM_DMA_NODE_BUFFER_MAX_SIZE  (4000) // 4-byte aligned
#define LCD_DATA_MAX_WIDTH (24)  /*!< Maximum width of LCD data bus */

typedef struct {
    uint32_t dma_buffer_size;
    uint32_t dma_half_buffer_size;
    uint32_t dma_node_buffer_size;
    uint32_t dma_node_cnt;
    uint32_t dma_half_node_cnt;
    lldesc_t *dma;
    uint8_t *dma_buffer;
    QueueHandle_t event_queue;
    uint8_t width;
    bool swap_data;
} lcd_obj_t;

typedef struct {
    lcd_obj_t lcd;
    intr_handle_t lcd_cam_intr_handle;
    i2s_dev_t *i2s_dev;
} lcd_cam_obj_t;

typedef struct {
    int rs_io_num;
    lcd_cam_obj_t *lcd_cam_obj;
    SemaphoreHandle_t mutex;
} i2s_lcd_driver_t;

static void IRAM_ATTR i2s_isr(void *arg) {
    BaseType_t HPTaskAwoken = pdFALSE;
    lcd_cam_obj_t *lcd_cam_obj = (lcd_cam_obj_t *)arg;
    i2s_dev_t *i2s_dev = lcd_cam_obj->i2s_dev;

    typeof(i2s_dev->int_st) status = i2s_dev->int_st;
    i2s_dev->int_clr.val = status.val;
    if (status.val == 0) {
        return;
    }

    if (status.out_eof) {
        xQueueSendFromISR(lcd_cam_obj->lcd.event_queue, (void *)&status.val, &HPTaskAwoken);
    }

    if (HPTaskAwoken == pdTRUE) {
        portYIELD_FROM_ISR();
    }
}


static void lcd_dma_set_int(lcd_cam_obj_t *lcd_cam_obj) {
    // Generate a data DMA linked list
    for (int x = 0; x < lcd_cam_obj->lcd.dma_node_cnt; x++) {
        lcd_cam_obj->lcd.dma[x].size = lcd_cam_obj->lcd.dma_node_buffer_size;
        lcd_cam_obj->lcd.dma[x].length = lcd_cam_obj->lcd.dma_node_buffer_size;
        lcd_cam_obj->lcd.dma[x].buf = (lcd_cam_obj->lcd.dma_buffer + lcd_cam_obj->lcd.dma_node_buffer_size * x);
        lcd_cam_obj->lcd.dma[x].eof = !((x + 1) % lcd_cam_obj->lcd.dma_half_node_cnt);
        lcd_cam_obj->lcd.dma[x].empty = (uint32_t)&lcd_cam_obj->lcd.dma[(x + 1) % lcd_cam_obj->lcd.dma_node_cnt];
    }
    lcd_cam_obj->lcd.dma[lcd_cam_obj->lcd.dma_half_node_cnt - 1].empty = (uint32_t)NULL;
    lcd_cam_obj->lcd.dma[lcd_cam_obj->lcd.dma_node_cnt - 1].empty = (uint32_t)NULL;
}

static void lcd_dma_set_left(lcd_cam_obj_t *lcd_cam_obj, int pos, size_t len) {
    int end_pos = 0, size = 0;
    // Processing data length is an integer multiple of lcd_cam_obj->lcd.dma_node_buffer_size
    if (len % lcd_cam_obj->lcd.dma_node_buffer_size) {
        end_pos = (pos % 2) * lcd_cam_obj->lcd.dma_half_node_cnt + len / lcd_cam_obj->lcd.dma_node_buffer_size;
        size = len % lcd_cam_obj->lcd.dma_node_buffer_size;
    } else {
        end_pos = (pos % 2) * lcd_cam_obj->lcd.dma_half_node_cnt + len / lcd_cam_obj->lcd.dma_node_buffer_size - 1;
        size = lcd_cam_obj->lcd.dma_node_buffer_size;
    }
    // Process the tail node to make it a DMA tail
    lcd_cam_obj->lcd.dma[end_pos].size = size;
    lcd_cam_obj->lcd.dma[end_pos].length = size;
    lcd_cam_obj->lcd.dma[end_pos].eof = 1;
    lcd_cam_obj->lcd.dma[end_pos].empty = (uint32_t)NULL;
}

static void lcd_i2s_start(i2s_dev_t *i2s_dev, uint32_t addr, size_t len) {
    while (!i2s_dev->state.tx_idle) {
        ;
    }
    i2s_dev->conf.tx_reset = 1;
    i2s_dev->conf.tx_reset = 0;
    i2s_dev->conf.tx_fifo_reset = 1;
    i2s_dev->conf.tx_fifo_reset = 0;
    i2s_dev->out_link.addr = addr;
    i2s_dev->out_link.start = 1;
    ets_delay_us(1);
    i2s_dev->conf.tx_start = 1;
}

static void i2s_write_data(lcd_cam_obj_t *lcd_cam_obj, uint8_t *data, size_t len) {
    int event = 0;
    int x = 0, y = 0, left = 0, cnt = 0;
    if (len <= 0) {
        ESP_LOGE(TAG, "wrong len!");
        return;
    }
    lcd_dma_set_int(lcd_cam_obj);
    cnt = len / lcd_cam_obj->lcd.dma_half_buffer_size;
    // Start signal
    xQueueSend(lcd_cam_obj->lcd.event_queue, &event, 0);
    // Process a complete piece of data, ping-pong operation
    for (x = 0; x < cnt; x++) {
        uint8_t *out = (uint8_t *)lcd_cam_obj->lcd.dma[(x % 2) * lcd_cam_obj->lcd.dma_half_node_cnt].buf;
        uint8_t *in = data;
        if (lcd_cam_obj->lcd.swap_data) {
            for (y = 0; y < lcd_cam_obj->lcd.dma_half_buffer_size; y += 2) {
                out[y + 1] = in[y + 0];
                out[y + 0] = in[y + 1];
            }
        } else {
            memcpy(out, in, lcd_cam_obj->lcd.dma_half_buffer_size);
        }
        data += lcd_cam_obj->lcd.dma_half_buffer_size;
        xQueueReceive(lcd_cam_obj->lcd.event_queue, (void *)&event, portMAX_DELAY);
        lcd_i2s_start(lcd_cam_obj->i2s_dev, ((uint32_t)&lcd_cam_obj->lcd.dma[(x % 2) * lcd_cam_obj->lcd.dma_half_node_cnt]) & 0xfffff, lcd_cam_obj->lcd.dma_half_buffer_size);
    }
    left = len % lcd_cam_obj->lcd.dma_half_buffer_size;
    // Process remaining incomplete segment data
    if (left) {
        uint8_t *out = (uint8_t *)lcd_cam_obj->lcd.dma[(x % 2) * lcd_cam_obj->lcd.dma_half_node_cnt].buf;
        uint8_t *in = data;
        cnt = left - left % 2;
        if (cnt) {
            if (lcd_cam_obj->lcd.swap_data) {
                for (y = 0; y < cnt; y += 2) {
                    out[y + 1] = in[y + 0];
                    out[y + 0] = in[y + 1];
                }
            } else {
                memcpy(out, in, cnt);
            }
        }

        if (left % 2) {
            out[cnt] = in[cnt];
        }
        lcd_dma_set_left(lcd_cam_obj, x, left);
        xQueueReceive(lcd_cam_obj->lcd.event_queue, (void *)&event, portMAX_DELAY);
        lcd_i2s_start(lcd_cam_obj->i2s_dev, ((uint32_t)&lcd_cam_obj->lcd.dma[(x % 2) * lcd_cam_obj->lcd.dma_half_node_cnt]) & 0xfffff, left);
    }
    xQueueReceive(lcd_cam_obj->lcd.event_queue, (void *)&event, portMAX_DELAY);
}


static esp_err_t i2s_lcd_reg_config(i2s_dev_t *i2s_dev, uint16_t data_width, uint32_t clk_freq) {
    // Configure the clock
    i2s_dev->clkm_conf.clkm_div_num = 2; // 160MHz / 2 = 80MHz
    i2s_dev->clkm_conf.clkm_div_b = 0;
    i2s_dev->clkm_conf.clkm_div_a = 0;
    i2s_dev->clkm_conf.clk_sel = 2;      // PLL_160M_CLK
    i2s_dev->clkm_conf.clk_en = 1;

    i2s_dev->conf.val = 0;
    i2s_dev->fifo_conf.val = 0;
    i2s_dev->fifo_conf.dscr_en = 1;

    i2s_dev->lc_conf.ahbm_fifo_rst = 1;
    i2s_dev->lc_conf.ahbm_fifo_rst = 0;
    i2s_dev->lc_conf.ahbm_rst = 1;
    i2s_dev->lc_conf.ahbm_rst = 0;
    i2s_dev->lc_conf.check_owner = 0;

    i2s_dev->timing.val = 0;

    i2s_dev->int_ena.val = 0;
    i2s_dev->int_clr.val = ~0;

    i2s_dev->conf2.lcd_en = 1;

    // Configure sampling rate
    // The datasheet states that Fws = Fbck / (W*2), but empirically storing
    // 1 in the register gives the highest value of 20MHz, storing 2 gives
    // 10MHz, (and storing 0 causes a freeze instead of acting as though 64 was
    // specified).
    int div_num = (20000000 + clk_freq - 1) / clk_freq;
    if (div_num == 0) {
        div_num = 1;
    }
    if (div_num > 63) {
        div_num = 63;
    }
    i2s_dev->sample_rate_conf.tx_bck_div_num = div_num;
    i2s_dev->sample_rate_conf.tx_bits_mod = data_width;
    // Configuration data format

    i2s_dev->conf.tx_right_first = 1;
    i2s_dev->conf.tx_msb_right = 1;
    i2s_dev->conf.tx_dma_equal = 1;

    i2s_dev->conf1.tx_pcm_bypass = 1;
    i2s_dev->conf1.tx_stop_en = 1;

    i2s_dev->conf2.lcd_en = 1;

    i2s_dev->conf_chan.tx_chan_mod = 1;

    i2s_dev->fifo_conf.tx_fifo_mod_force_en = 1;
    i2s_dev->fifo_conf.tx_data_num = 32;
    i2s_dev->fifo_conf.tx_fifo_mod = 2;
    i2s_dev->fifo_conf.tx_24msb_en = 0;

    i2s_dev->lc_conf.out_rst = 1;
    i2s_dev->lc_conf.out_rst = 0;

    i2s_dev->int_ena.out_eof = 1;


    return ESP_OK;
}

static esp_err_t lcd_set_pin(const i2s_lcd_config_t *config) {
    PIN_FUNC_SELECT(GPIO_PIN_MUX_REG[config->pin_num_wr], PIN_FUNC_GPIO);
    gpio_set_direction(config->pin_num_wr, GPIO_MODE_OUTPUT);
    gpio_set_pull_mode(config->pin_num_wr, GPIO_FLOATING);
    gpio_matrix_out(config->pin_num_wr, I2S0O_WS_OUT_IDX, true, false);

    for (int i = 0; i < config->data_width; i++) {
        PIN_FUNC_SELECT(GPIO_PIN_MUX_REG[config->pin_data_num[i]], PIN_FUNC_GPIO);
        gpio_set_direction(config->pin_data_num[i], GPIO_MODE_OUTPUT);
        gpio_set_pull_mode(config->pin_data_num[i], GPIO_FLOATING);
        // High bit aligned, OUT23 is always the highest bit
        gpio_matrix_out(config->pin_data_num[i], I2S0O_DATA_OUT0_IDX + (LCD_DATA_MAX_WIDTH - config->data_width) + i, false, false);
    }

    return ESP_OK;
}

static esp_err_t lcd_dma_config(lcd_cam_obj_t *lcd_cam_obj, uint32_t max_dma_buffer_size) {
    int cnt = 0;
    if (LCD_CAM_DMA_NODE_BUFFER_MAX_SIZE % 2 != 0) {
        ESP_LOGE(TAG, "ESP32 only supports 2-byte aligned data length");
        return ESP_FAIL;
    }
    if (max_dma_buffer_size >= LCD_CAM_DMA_NODE_BUFFER_MAX_SIZE * 2) {
        lcd_cam_obj->lcd.dma_node_buffer_size = LCD_CAM_DMA_NODE_BUFFER_MAX_SIZE;
        for (cnt = 0; cnt < max_dma_buffer_size - 8; cnt++) { // Find a buffer size that can divide dma_size
            if ((max_dma_buffer_size - cnt) % (lcd_cam_obj->lcd.dma_node_buffer_size * 2) == 0) {
                break;
            }
        }
        lcd_cam_obj->lcd.dma_buffer_size = max_dma_buffer_size - cnt;
    } else {
        lcd_cam_obj->lcd.dma_node_buffer_size = max_dma_buffer_size / 2;
        lcd_cam_obj->lcd.dma_buffer_size = lcd_cam_obj->lcd.dma_node_buffer_size * 2;
    }

    lcd_cam_obj->lcd.dma_half_buffer_size = lcd_cam_obj->lcd.dma_buffer_size / 2;
    lcd_cam_obj->lcd.dma_node_cnt = (lcd_cam_obj->lcd.dma_buffer_size) / lcd_cam_obj->lcd.dma_node_buffer_size; // Number of DMA nodes
    lcd_cam_obj->lcd.dma_half_node_cnt = lcd_cam_obj->lcd.dma_node_cnt / 2;

    ESP_LOGI(TAG, "lcd_buffer_size: %d, lcd_dma_size: %d, lcd_dma_node_cnt: %d", lcd_cam_obj->lcd.dma_buffer_size, lcd_cam_obj->lcd.dma_node_buffer_size, lcd_cam_obj->lcd.dma_node_cnt);

    lcd_cam_obj->lcd.dma = (lldesc_t *)heap_caps_malloc(lcd_cam_obj->lcd.dma_node_cnt * sizeof(lldesc_t), MALLOC_CAP_DMA | MALLOC_CAP_8BIT);
    lcd_cam_obj->lcd.dma_buffer = (uint8_t *)heap_caps_malloc(lcd_cam_obj->lcd.dma_buffer_size * sizeof(uint8_t), MALLOC_CAP_DMA | MALLOC_CAP_8BIT);
    return ESP_OK;
}

static esp_err_t lcd_cam_deinit(i2s_lcd_driver_t *drv) {
    if (!drv->lcd_cam_obj) {
        return ESP_FAIL;
    }

    if (drv->lcd_cam_obj->lcd.event_queue) {
        vQueueDelete(drv->lcd_cam_obj->lcd.event_queue);
    }
    if (drv->lcd_cam_obj->lcd.dma) {
        heap_caps_free(drv->lcd_cam_obj->lcd.dma);
    }
    if (drv->lcd_cam_obj->lcd.dma_buffer) {
        heap_caps_free(drv->lcd_cam_obj->lcd.dma_buffer);
    }

    if (drv->lcd_cam_obj->lcd_cam_intr_handle) {
        esp_intr_free(drv->lcd_cam_obj->lcd_cam_intr_handle);
    }

    heap_caps_free(drv->lcd_cam_obj);
    drv->lcd_cam_obj = NULL;
    return ESP_OK;
}

static esp_err_t lcd_cam_init(i2s_lcd_driver_t *drv, const i2s_lcd_config_t *config) {
    esp_err_t ret = ESP_OK;

    lcd_cam_obj_t *lcd_cam_obj = (lcd_cam_obj_t *)heap_caps_calloc(1, sizeof(lcd_cam_obj_t), MALLOC_CAP_DMA);
    if (lcd_cam_obj == NULL) {
        ESP_LOGE(TAG, "lcd_cam object malloc error");
        return ESP_ERR_NO_MEM;
    }
    drv->lcd_cam_obj = lcd_cam_obj;

    if (I2S_NUM_0 == config->i2s_port) {
        lcd_cam_obj->i2s_dev = &I2S0;
        periph_module_enable(PERIPH_I2S0_MODULE);
    } else {
        ESP_LOGE(TAG, "Designated I2S peripheral not found");
    }

    ret |= i2s_lcd_reg_config(lcd_cam_obj->i2s_dev, config->data_width, config->clk_freq);

    if (ret != ESP_OK) {
        ESP_LOGE(TAG, "lcd_cam config fail!");
        lcd_cam_deinit(drv);
        return ESP_FAIL;
    }

    ret |= lcd_set_pin(config);
    ret |= lcd_dma_config(lcd_cam_obj, config->buffer_size);

    if (ret != ESP_OK) {
        ESP_LOGE(TAG, "lcd config fail!");
        lcd_cam_deinit(drv);
        return ESP_FAIL;
    }

    lcd_cam_obj->lcd.event_queue = xQueueCreate(1, sizeof(int));
    lcd_cam_obj->lcd.width = config->data_width;
    lcd_cam_obj->lcd.swap_data = config->swap_data;

    if (lcd_cam_obj->lcd.event_queue == NULL) {
        ESP_LOGE(TAG, "lcd config fail!");
        lcd_cam_deinit(drv);
        return ESP_FAIL;
    }

    ret |= esp_intr_alloc(ETS_I2S0_INTR_SOURCE, ESP_INTR_FLAG_LOWMED | ESP_INTR_FLAG_IRAM, i2s_isr, lcd_cam_obj, &lcd_cam_obj->lcd_cam_intr_handle);

    if (ret != ESP_OK) {
        ESP_LOGE(TAG, "lcd_cam intr alloc fail!");
        lcd_cam_deinit(drv);
        return ESP_FAIL;
    }

    ESP_LOGI(TAG, "lcd init ok");

    return ESP_OK;
}


/**< Public functions */

i2s_lcd_handle_t i2s_lcd_driver_init(const i2s_lcd_config_t *config) {
    I2S_CHECK(NULL != config, "config pointer invalid", NULL);
    I2S_CHECK(GPIO_IS_VALID_GPIO(config->pin_num_wr), "GPIO WR invalid", NULL);
    I2S_CHECK(GPIO_IS_VALID_GPIO(config->pin_num_rs), "GPIO RS invalid", NULL);
    I2S_CHECK(config->data_width > 0 && config->data_width <= 16, "Bit width out of range", NULL);
    I2S_CHECK(0 == (config->data_width % 8), "Bit width must be a multiple of 8", NULL);
    uint64_t pin_mask = 0;
    for (size_t i = 0; i < config->data_width; i++) {
        uint64_t mask = 1ULL << config->pin_data_num[i];
        I2S_CHECK(!(pin_mask & mask), "Data bus GPIO has a duplicate", NULL);
        I2S_CHECK(GPIO_IS_VALID_GPIO(config->pin_data_num[i]), "Data bus gpio invalid", NULL);
        pin_mask |= mask;
    }

    i2s_lcd_driver_t *i2s_lcd_drv = (i2s_lcd_driver_t *)heap_caps_malloc(sizeof(i2s_lcd_driver_t), MALLOC_CAP_INTERNAL | MALLOC_CAP_8BIT);
    I2S_CHECK(NULL != i2s_lcd_drv, "Error malloc handle of i2s lcd driver", NULL);

    esp_err_t ret = lcd_cam_init(i2s_lcd_drv, config);
    if (ESP_OK != ret) {
        ESP_LOGE(TAG,"%s:%d (%s):%s", __FILE__, __LINE__, __FUNCTION__, "i2s lcd driver initialize failed");
        heap_caps_free(i2s_lcd_drv);
        return NULL;
    }

    i2s_lcd_drv->mutex = xSemaphoreCreateMutex();
    if (i2s_lcd_drv->mutex == NULL) {
        ESP_LOGE(TAG, "%s:%d (%s):%s", __FILE__, __LINE__, __FUNCTION__, "lcd create mutex failed");
        lcd_cam_deinit(i2s_lcd_drv);
        heap_caps_free(i2s_lcd_drv);
        return NULL;
    }

    if (config->pin_num_cs >= 0) {
        gpio_pad_select_gpio(config->pin_num_cs);
        gpio_set_direction(config->pin_num_cs, GPIO_MODE_OUTPUT);
        gpio_set_level(config->pin_num_cs, 0);
    }

    gpio_pad_select_gpio(config->pin_num_rs);
    gpio_set_direction(config->pin_num_rs, GPIO_MODE_OUTPUT);
    i2s_lcd_drv->rs_io_num = config->pin_num_rs;
    return (i2s_lcd_handle_t)i2s_lcd_drv;
}

esp_err_t i2s_lcd_driver_deinit(i2s_lcd_handle_t handle) {
    i2s_lcd_driver_t *i2s_lcd_drv = (i2s_lcd_driver_t *)handle;
    I2S_CHECK(NULL != i2s_lcd_drv, "handle pointer invalid", ESP_ERR_INVALID_ARG);
    lcd_cam_deinit(i2s_lcd_drv);
    vSemaphoreDelete(i2s_lcd_drv->mutex);
    heap_caps_free(handle);
    return ESP_OK;
}

esp_err_t i2s_lcd_write_data(i2s_lcd_handle_t handle, uint16_t data) {
    i2s_lcd_driver_t *i2s_lcd_drv = (i2s_lcd_driver_t *)handle;
    I2S_CHECK(NULL != i2s_lcd_drv, "handle pointer invalid", ESP_ERR_INVALID_ARG);
    i2s_write_data(i2s_lcd_drv->lcd_cam_obj, (uint8_t *)&data, 2);
    return ESP_OK;
}

esp_err_t i2s_lcd_write_cmd(i2s_lcd_handle_t handle, uint16_t cmd) {
    i2s_lcd_driver_t *i2s_lcd_drv = (i2s_lcd_driver_t *)handle;
    I2S_CHECK(NULL != i2s_lcd_drv, "handle pointer invalid", ESP_ERR_INVALID_ARG);
    gpio_set_level(i2s_lcd_drv->rs_io_num, LCD_CMD_LEV);
    i2s_write_data(i2s_lcd_drv->lcd_cam_obj, (uint8_t *)&cmd, 2);
    gpio_set_level(i2s_lcd_drv->rs_io_num, LCD_DATA_LEV);
    return ESP_OK;
}

esp_err_t i2s_lcd_write(i2s_lcd_handle_t handle, const uint8_t *data, uint32_t length) {
    i2s_lcd_driver_t *i2s_lcd_drv = (i2s_lcd_driver_t *)handle;
    I2S_CHECK(NULL != i2s_lcd_drv, "handle pointer invalid", ESP_ERR_INVALID_ARG);
    i2s_write_data(i2s_lcd_drv->lcd_cam_obj, (uint8_t *)data, length);

    return ESP_OK;
}

esp_err_t i2s_lcd_acquire(i2s_lcd_handle_t handle) {
    i2s_lcd_driver_t *i2s_lcd_drv = (i2s_lcd_driver_t *)handle;
    I2S_CHECK(NULL != i2s_lcd_drv, "handle pointer invalid", ESP_ERR_INVALID_ARG);
    BaseType_t ret = xSemaphoreTake(i2s_lcd_drv->mutex, portMAX_DELAY);
    I2S_CHECK(pdTRUE == ret, "Take semaphore failed", ESP_FAIL);
    return ESP_OK;
}

bool i2s_lcd_acquire_nonblocking(i2s_lcd_handle_t handle, TickType_t ticks_to_wait) {
    i2s_lcd_driver_t *i2s_lcd_drv = (i2s_lcd_driver_t *)handle;
    return xSemaphoreTake(i2s_lcd_drv->mutex, ticks_to_wait);
}

esp_err_t i2s_lcd_release(i2s_lcd_handle_t handle) {
    i2s_lcd_driver_t *i2s_lcd_drv = (i2s_lcd_driver_t *)handle;
    I2S_CHECK(NULL != i2s_lcd_drv, "handle pointer invalid", ESP_ERR_INVALID_ARG);
    i2s_dev_t *i2s_dev = &I2S0;
// at this point, the DMA is done but there could still be data in the FIFO. so we need
// to wait for I2S_TX_IDLE so that it's safe e.g., for calling code to deassert CS
    while (!i2s_dev->state.tx_idle) {
        ;
    }
    BaseType_t ret = xSemaphoreGive(i2s_lcd_drv->mutex);
    I2S_CHECK(pdTRUE == ret, "Give semaphore failed", ESP_FAIL);
    return ESP_OK;
}

#endif // CONFIG_IDF_TARGET_ESP32S2