text: /**
   * @file st7789.c
   *
   * Mostly taken from lbthomsen/esp-idf-littlevgl github.
   */
  
  #include "freertos/FreeRTOS.h"
  #include "freertos/task.h"
  #include "sdkconfig.h"
  
  #include "esp_log.h"
  
  #include "st7789.h"
  
  #include "disp_spi.h"
  #include "driver/gpio.h"
  
  /*********************
   *      DEFINES
   *********************/
  #define TAG "st7789"
  /**********************
   *      TYPEDEFS
   **********************/
  
  /*The LCD needs a bunch of command/argument values to be initialized. They are stored in this struct. */
  typedef struct {
      uint8_t cmd;
      uint8_t data[16];
      uint8_t databytes; //No of data in data; bit 7 = delay after set; 0xFF = end of cmds.
  } lcd_init_cmd_t;
  
  /**********************
   *  STATIC PROTOTYPES
   **********************/
  static void st7789_set_orientation(uint8_t orientation);
  
  static void st7789_send_color(void *data, size_t length);
  
  /**********************
   *  STATIC VARIABLES
   **********************/
  
  /**********************
   *      MACROS
   **********************/
  
  /**********************
   *   GLOBAL FUNCTIONS
   **********************/
  void st7789_init(void)
  {
      lcd_init_cmd_t st7789_init_cmds[] = {
          {0xCF, {0x00, 0x83, 0X30}, 3},
          {0xED, {0x64, 0x03, 0X12, 0X81}, 4},
          {ST7789_PWCTRL2, {0x85, 0x01, 0x79}, 3},
          {0xCB, {0x39, 0x2C, 0x00, 0x34, 0x02}, 5},
          {0xF7, {0x20}, 1},
          {0xEA, {0x00, 0x00}, 2},
          {ST7789_LCMCTRL, {0x26}, 1},
          {ST7789_IDSET, {0x11}, 1},
          {ST7789_VCMOFSET, {0x35, 0x3E}, 2},
          {ST7789_CABCCTRL, {0xBE}, 1},
          {ST7789_MADCTL, {0x00}, 1}, // Set to 0x28 if your display is flipped
          {ST7789_COLMOD, {0x55}, 1},
  
  #if ST7789_INVERT_COLORS == 1
  		{ST7789_INVON, {0}, 0}, // set inverted mode
  #else
   		{ST7789_INVOFF, {0}, 0}, // set non-inverted mode
  #endif
  
          {ST7789_RGBCTRL, {0x00, 0x1B}, 2},
          {0xF2, {0x08}, 1},
          {ST7789_GAMSET, {0x01}, 1},
          {ST7789_PVGAMCTRL, {0xD0, 0x00, 0x02, 0x07, 0x0A, 0x28, 0x32, 0x44, 0x42, 0x06, 0x0E, 0x12, 0x14, 0x17}, 14},
          {ST7789_NVGAMCTRL, {0xD0, 0x00, 0x02, 0x07, 0x0A, 0x28, 0x31, 0x54, 0x47, 0x0E, 0x1C, 0x17, 0x1B, 0x1E}, 14},
          {ST7789_CASET, {0x00, 0x00, 0x00, 0xEF}, 4},
          {ST7789_RASET, {0x00, 0x00, 0x01, 0x3f}, 4},
          {ST7789_RAMWR, {0}, 0},
          {ST7789_GCTRL, {0x07}, 1},
          {0xB6, {0x0A, 0x82, 0x27, 0x00}, 4},
          {ST7789_SLPOUT, {0}, 0x80},
          {ST7789_DISPON, {0}, 0x80},
          {0, {0}, 0xff},
      };
  
      //Initialize non-SPI GPIOs
      gpio_pad_select_gpio(ST7789_DC);
      gpio_set_direction(ST7789_DC, GPIO_MODE_OUTPUT);
  
  #if !defined(ST7789_SOFT_RST)
      gpio_pad_select_gpio(ST7789_RST);
      gpio_set_direction(ST7789_RST, GPIO_MODE_OUTPUT);
  #endif
  
      //Reset the display
  #if !defined(ST7789_SOFT_RST)
      gpio_set_level(ST7789_RST, 0);
      vTaskDelay(100 / portTICK_RATE_MS);
      gpio_set_level(ST7789_RST, 1);
      vTaskDelay(100 / portTICK_RATE_MS);
  #else
      st7789_send_cmd(ST7789_SWRESET);
  #endif
  
      printf("ST7789 initialization.\n");
  
      //Send all the commands
      uint16_t cmd = 0;
      while (st7789_init_cmds[cmd].databytes!=0xff) {
          st7789_send_cmd(st7789_init_cmds[cmd].cmd);
          st7789_send_data(st7789_init_cmds[cmd].data, st7789_init_cmds[cmd].databytes&0x1F);
          if (st7789_init_cmds[cmd].databytes & 0x80) {
                  vTaskDelay(100 / portTICK_RATE_MS);
          }
          cmd++;
      }
  
      st7789_set_orientation(CONFIG_LV_DISPLAY_ORIENTATION);
  }
  
  /* The ST7789 display controller can drive 320*240 displays, when using a 240*240
   * display there's a gap of 80px, we need to edit the coordinates to take into
   * account that gap, this is not necessary in all orientations. */
  void st7789_flush(lv_disp_drv_t * drv, const lv_area_t * area, lv_color_t * color_map)
  {
      uint8_t data[4] = {0};
  
      uint16_t offsetx1 = area->x1;
      uint16_t offsetx2 = area->x2;
      uint16_t offsety1 = area->y1;
      uint16_t offsety2 = area->y2;
  
  #if (CONFIG_LV_TFT_DISPLAY_OFFSETS)
      offsetx1 += CONFIG_LV_TFT_DISPLAY_X_OFFSET;
      offsetx2 += CONFIG_LV_TFT_DISPLAY_X_OFFSET;
      offsety1 += CONFIG_LV_TFT_DISPLAY_Y_OFFSET;
      offsety2 += CONFIG_LV_TFT_DISPLAY_Y_OFFSET;
  
  #elif (LV_HOR_RES_MAX == 240) && (LV_VER_RES_MAX == 240)
  #if (CONFIG_LV_DISPLAY_ORIENTATION_PORTRAIT)
      offsetx1 += 80;
      offsetx2 += 80;
  #elif (CONFIG_LV_DISPLAY_ORIENTATION_LANDSCAPE_INVERTED)
      offsety1 += 80;
      offsety2 += 80;
  #endif
  #endif
  
      /*Column addresses*/
      st7789_send_cmd(ST7789_CASET);
      data[0] = (offsetx1 >> 8) & 0xFF;
      data[1] = offsetx1 & 0xFF;
      data[2] = (offsetx2 >> 8) & 0xFF;
      data[3] = offsetx2 & 0xFF;
      st7789_send_data(data, 4);
  
      /*Page addresses*/
      st7789_send_cmd(ST7789_RASET);
      data[0] = (offsety1 >> 8) & 0xFF;
      data[1] = offsety1 & 0xFF;
      data[2] = (offsety2 >> 8) & 0xFF;
      data[3] = offsety2 & 0xFF;
      st7789_send_data(data, 4);
  
      /*Memory write*/
      st7789_send_cmd(ST7789_RAMWR);
  
      size_t size = (size_t)lv_area_get_width(area) * (size_t)lv_area_get_height(area);
  
      st7789_send_color((void*)color_map, size * 2);
  
  }
  
  /**********************
   *   STATIC FUNCTIONS
   **********************/
  void st7789_send_cmd(uint8_t cmd)
  {
      disp_wait_for_pending_transactions();
      gpio_set_level(ST7789_DC, 0);
      disp_spi_send_data(&cmd, 1);
  }
  
  void st7789_send_data(void * data, uint16_t length)
  {
      disp_wait_for_pending_transactions();
      gpio_set_level(ST7789_DC, 1);
      disp_spi_send_data(data, length);
  }
  
  static void st7789_send_color(void * data, size_t length)
  {
      disp_wait_for_pending_transactions();
      gpio_set_level(ST7789_DC, 1);
      disp_spi_send_colors(data, length);
  }
  
  static void st7789_set_orientation(uint8_t orientation)
  {
      // ESP_ASSERT(orientation < 4);
  
      const char *orientation_str[] = {
          "PORTRAIT", "PORTRAIT_INVERTED", "LANDSCAPE", "LANDSCAPE_INVERTED"
      };
  
      ESP_LOGI(TAG, "Display orientation: %s", orientation_str[orientation]);
  
      uint8_t data[] =
      {
  #if CONFIG_LV_PREDEFINED_DISPLAY_TTGO
  	0x60, 0xA0, 0x00, 0xC0
  #else
  	0xC0, 0x00, 0x60, 0xA0
  #endif
      };
  
      ESP_LOGI(TAG, "0x36 command value: 0x%02X", data[orientation]);
  
      st7789_send_cmd(ST7789_MADCTL);
      st7789_send_data((void *) &data[orientation], 1);
  }
  
  void st7789_sleep_in()
  {
      st7789_send_cmd(ST7789_SLPIN);
      printf("st7789 lcd sleep in\n");
  }
  
  void st7789_sleep_out()
  {
      st7789_send_cmd(ST7789_SLPOUT);
  }
  
  void st7789_enable_backlight(bool backlight)
  {
  #if ST7789_ENABLE_BACKLIGHT_CONTROL
      printf("%s backlight.\n", backlight ? "Enabling" : "Disabling");
      uint32_t tmp = 0;
  
  #if (ST7789_BCKL_ACTIVE_LVL==1)
      tmp = backlight ? 1 : 0;
  #else
      tmp = backlight ? 0 : 1;
  #endif
  
      gpio_set_level(ST7789_BCKL, tmp);
  #endif
  }
  
  
  
  