klips/esp/cpp/components/ssd1306/include/ssd1306.h

/*#############################################################################
## Author: Shaun Reed                                                        ##
## Legal: All Content (c) 2025 Shaun Reed, all rights reserved               ##
##                                                                           ##
## Contact: shaunrd0@gmail.com  | URL: www.shaunreed.com                     ##
##############################################################################
*/

#ifndef SSD1306_H
#define SSD1306_H

#include "panel_device.h"

#include <esp_lcd_panel_ssd1306.h>
#include <lcd.h>

// According to specific display hardware.
// https://www.digikey.com/en/products/detail/winstar-display/WEA012864DWPP3N00003/20533255
#define SCREEN_WIDTH 128 // OLED display width, in pixels.
#define SCREEN_HEIGHT 64 // OLED display height, in pixels.

// According to SSD1306 datasheet.
// https://cdn-shop.adafruit.com/datasheets/SSD1306.pdf
#define I2C_HW_ADDR 0x3C
#define LCD_PIXEL_CLOCK_HZ (400 * 1000)
// Bit number used to represent command and parameter
#define LCD_CMD_BITS 8
#define LCD_PARAM_BITS 8

/**
 * Example of implementing the IPanelDevice interface for SSD1306 LCD device.
 */
struct SSD1306
{
    /// SSD1306 configuration structure.
    esp_lcd_panel_ssd1306_config_t ssd1306_config_;
};

/// Initializes the ESP LCD panel handle for the SSD1306 device.
static void SSD1306_init_panel_cb(esp_lcd_panel_dev_config_t* config,
                                  esp_lcd_panel_io_handle_t io,
                                  esp_lcd_panel_handle_t* panel)
{
    ESP_LOGI(LCD_TAG, "Initializing SSD1306 panel");
    ESP_ERROR_CHECK(esp_lcd_new_panel_ssd1306(io, config, panel));
}

static esp_lcd_panel_ssd1306_config_t SSD1306_config = {
    .height = SCREEN_HEIGHT,
};

/**
 * Provides the SSD1306 vendor configuration to IPanelDevice consumers.
 *
 * @return Address of the SSD1306 vendor configuration structure.
 */
static void* SSD1306_vendor_config_cb()
{
    ESP_LOGI(LCD_TAG, "Fetching global SSD1306 config");
    return &SSD1306_config;
}

/**
 * Construct a new SSD1306 device given a specific SSD1306 configuration.
 *
 * @param vendor_config SSD1306 vendor configuration.
 * @param width Width of the device screen in pixels.
 * @param height Height of the device screen in pixels.
 */
static struct IPanelDevice
SSD1306_config_new(esp_lcd_panel_ssd1306_config_t vendor_config, int width,
                   int height)
{
    // TODO: Make it not global; There could be multiple SSD1306 displays.
    ESP_LOGI(LCD_TAG, "Setting global SSD1306 configuration");
    SSD1306_config = vendor_config;
    // Must initialize device with LCD_new_panel to use default LVGL callbacks.
    struct IPanelDevice device = LCD_new_panel();
    device.width_ = width, device.height_ = height;
    device.esp_io_config_ = (esp_lcd_panel_io_i2c_config_t){
        .dev_addr = I2C_HW_ADDR,
        // User data to pass to the LVGL flush_ready callback.
        // See IPanelDevice::lvgl_flush_ready_cb
        .user_ctx = NULL,
        .control_phase_bytes = 1,
        .dc_bit_offset = 6,
        .lcd_cmd_bits = LCD_CMD_BITS,
        .lcd_param_bits = LCD_PARAM_BITS,
        .scl_speed_hz = LCD_PIXEL_CLOCK_HZ,
    };
    device.init_panel_cb = SSD1306_init_panel_cb;
    device.vendor_config_cb = SSD1306_vendor_config_cb;
    return device;
}

/**
 * Construct a new SSD1306 device.
 */
static struct IPanelDevice SSD1306_new()
{
    return SSD1306_config_new(
        (esp_lcd_panel_ssd1306_config_t){.height = SCREEN_HEIGHT}, SCREEN_WIDTH,
        SCREEN_HEIGHT);
}

#endif // SSD1306_H