Ben / moon

#include "st7735.h"
#include "pinout.h"

#include <string.h>
#include "driver/gpio.h"
#include "driver/spi_master.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"

// ST7735 commands
#define ST7735_SWRESET 0x01
#define ST7735_SLPOUT 0x11
#define ST7735_INVON 0x21
#define ST7735_DISPON 0x29
#define ST7735_CASET 0x2A
#define ST7735_RASET 0x2B
#define ST7735_RAMWR 0x2C
#define ST7735_MADCTL 0x36
#define ST7735_COLMOD 0x3A

// Display offsets (adjust for your specific module)
#define X_OFFSET 0
#define Y_OFFSET 0

static spi_device_handle_t spi_dev;

// Pre-transfer callback to set DC pin
static void IRAM_ATTR spi_pre_transfer_cb(spi_transaction_t* t) {
	int dc = (int)t->user;
	gpio_set_level(PIN_DC, dc);
}

static void st7735_write_cmd(uint8_t cmd) {
	spi_transaction_t t = {
	    .length = 8,
	    .tx_buffer = &cmd,
	    .user = (void*)0,  // DC=0 for command
	};
	spi_device_polling_transmit(spi_dev, &t);
}

static void st7735_write_data(const uint8_t* data, size_t len) {
	if (len == 0) {
		return;
	}
	spi_transaction_t t = {
	    .length = len * 8,
	    .tx_buffer = data,
	    .user = (void*)1,  // DC=1 for data
	};
	spi_device_polling_transmit(spi_dev, &t);
}

static void st7735_write_data_byte(uint8_t data) {
	st7735_write_data(&data, 1);
}

void st7735_init(void) {
	// Configure GPIO pins
	gpio_config_t io_conf = {
	    .pin_bit_mask = (1ULL << PIN_DC) | (1ULL << PIN_RST),
	    .mode = GPIO_MODE_OUTPUT,
	    .pull_up_en = GPIO_PULLUP_DISABLE,
	    .pull_down_en = GPIO_PULLDOWN_DISABLE,
	    .intr_type = GPIO_INTR_DISABLE,
	};
	gpio_config(&io_conf);

	// Hardware reset
	gpio_set_level(PIN_RST, 0);
	vTaskDelay(pdMS_TO_TICKS(1));
	gpio_set_level(PIN_RST, 1);
	vTaskDelay(pdMS_TO_TICKS(5));

	// Configure SPI bus
	spi_bus_config_t buscfg = {
	    .mosi_io_num = PIN_MOSI,
	    .miso_io_num = -1,
	    .sclk_io_num = PIN_SCK,
	    .quadwp_io_num = -1,
	    .quadhd_io_num = -1,
	    .max_transfer_sz = 160 * 32 * 2,  // 32 lines at 2 bytes/pixel (RGB565)
	};
	spi_bus_initialize(SPI2_HOST, &buscfg, SPI_DMA_CH_AUTO);

	// Configure SPI device
	spi_device_interface_config_t devcfg = {
	    .clock_speed_hz = 20 * 1000 * 1000,  // 20 MHz
	    .mode = 0,
	    .spics_io_num = PIN_CS,
	    .queue_size = 7,
	    .pre_cb = spi_pre_transfer_cb,
	};
	spi_bus_add_device(SPI2_HOST, &devcfg, &spi_dev);

	// ST7735 initialization sequence
	st7735_write_cmd(ST7735_SWRESET);
	vTaskDelay(pdMS_TO_TICKS(5));

	st7735_write_cmd(ST7735_SLPOUT);
	vTaskDelay(pdMS_TO_TICKS(10));

	// Set color mode to RGB565 (16-bit, 2 bytes per pixel)
	st7735_write_cmd(ST7735_COLMOD);
	st7735_write_data_byte(0x05);  // 16-bit RGB565

	// Set display orientation (MV + MX for landscape 160x128)
	st7735_write_cmd(ST7735_MADCTL);
	st7735_write_data_byte(0x60);

	// Enable display
	st7735_write_cmd(ST7735_DISPON);
}

void st7735_set_window(uint16_t x0, uint16_t y0, uint16_t x1, uint16_t y1) {
	// Column address set
	st7735_write_cmd(ST7735_CASET);
	uint8_t caset_data[] = {0, (uint8_t)(x0 + X_OFFSET), 0,
	                        (uint8_t)(x1 + X_OFFSET)};
	st7735_write_data(caset_data, 4);

	// Row address set
	st7735_write_cmd(ST7735_RASET);
	uint8_t raset_data[] = {0, (uint8_t)(y0 + Y_OFFSET), 0,
	                        (uint8_t)(y1 + Y_OFFSET)};
	st7735_write_data(raset_data, 4);

	// Write to RAM
	st7735_write_cmd(ST7735_RAMWR);
}

void st7735_write_pixels(const uint16_t* data, size_t len) {
	st7735_write_data((const uint8_t*)data, len * 2);
}

void st7735_write_pixels_async(const uint16_t* data,
                               size_t len,
                               spi_transaction_t* trans) {
	memset(trans, 0, sizeof(*trans));
	trans->length = len * 16;
	trans->tx_buffer = data;
	trans->user = (void*)1;  // DC=1 for data
	spi_device_queue_trans(spi_dev, trans, portMAX_DELAY);
}

void st7735_wait_async(void) {
	spi_transaction_t* result;
	spi_device_get_trans_result(spi_dev, &result, portMAX_DELAY);
}