LCD-show/usr/fbcp-ili9341/st7735r.cpp

#include "config.h"

#if defined(ST7735R) || defined(ST7735S) || defined(ST7789)

#include "spi.h"

#include <memory.h>
#include <stdio.h>

void InitST7735R()
{
  // If a Reset pin is defined, toggle it briefly high->low->high to enable the device. Some devices do not have a reset pin, in which case compile with GPIO_TFT_RESET_PIN left undefined.
#if defined(GPIO_TFT_RESET_PIN) && GPIO_TFT_RESET_PIN >= 0
  printf("Resetting display at reset GPIO pin %d\n", GPIO_TFT_RESET_PIN);
  SET_GPIO_MODE(GPIO_TFT_RESET_PIN, 1);
  SET_GPIO(GPIO_TFT_RESET_PIN);
  usleep(120 * 1000);
  CLEAR_GPIO(GPIO_TFT_RESET_PIN);
  usleep(120 * 1000);
  SET_GPIO(GPIO_TFT_RESET_PIN);
  usleep(120 * 1000);
#endif

  // Do the initialization with a very low SPI bus speed, so that it will succeed even if the bus speed chosen by the user is too high.
  spi->clk = 34;
  __sync_synchronize();

  BEGIN_SPI_COMMUNICATION();
  {
#ifndef ST7789VW // For some reason, ST7789VW does not want to accept the Software Reset command, but screen stays black if SWRESET is sent to it.
    SPI_TRANSFER(0x01/*Software Reset*/);
#endif
    usleep(120*1000);
    SPI_TRANSFER(0x11/*Sleep Out*/);
    usleep(120 * 1000);
#ifndef ST7789VW // This is disabled on ST7789VW because it was observed to look visually bad, makes colors a bit too contrasty/deep
    SPI_TRANSFER(0x26/*Gamma Curve Select*/, 0x04/*Gamma curve 3 (2.5x if GS=1, 2.2x otherwise)*/);
#endif
    SPI_TRANSFER(0x3A/*COLMOD: Pixel Format Set*/, 0x05/*16bpp*/);
    usleep(20 * 1000);

#define MADCTL_BGR_PIXEL_ORDER (1<<3)
#define MADCTL_ROW_COLUMN_EXCHANGE (1<<5)
#define MADCTL_COLUMN_ADDRESS_ORDER_SWAP (1<<6)
#define MADCTL_ROW_ADDRESS_ORDER_SWAP (1<<7)
#define MADCTL_ROTATE_180_DEGREES (MADCTL_COLUMN_ADDRESS_ORDER_SWAP | MADCTL_ROW_ADDRESS_ORDER_SWAP)

    uint8_t madctl = 0;
#if defined(ST7735R) || defined(ST7735S)
    madctl |= MADCTL_BGR_PIXEL_ORDER;
#endif
#ifdef DISPLAY_SWAP_BGR
    madctl ^= MADCTL_BGR_PIXEL_ORDER;
#endif
#if defined(DISPLAY_FLIP_ORIENTATION_IN_HARDWARE)
    madctl |= MADCTL_ROW_COLUMN_EXCHANGE;
#endif

    madctl |= MADCTL_ROW_ADDRESS_ORDER_SWAP;

#if defined(WAVESHARE_ST7789VW_HAT) || defined(WAVESHARE_ST7735S_HAT)
    madctl ^= MADCTL_ROTATE_180_DEGREES;
#endif

#ifdef DISPLAY_ROTATE_180_DEGREES
    madctl ^= MADCTL_ROTATE_180_DEGREES;
#endif

    SPI_TRANSFER(0x36/*MADCTL: Memory Access Control*/, madctl);
    usleep(10*1000);

#ifdef ST7789
    SPI_TRANSFER(0xBA/*DGMEN: Enable Gamma*/, 0x04);
    bool invertColors = true;
#else
    bool invertColors = false;
#endif
#ifdef DISPLAY_INVERT_COLORS
    invertColors = !invertColors;
#endif
    if (invertColors)
      SPI_TRANSFER(0x21/*Display Inversion On*/);
    else
      SPI_TRANSFER(0x20/*Display Inversion Off*/);

    SPI_TRANSFER(0x13/*NORON: Partial off (normal)*/);
    usleep(10*1000);

#ifdef ST7789
    // The ST7789 controller is actually a unit with 320x240 graphics memory area, but only 240x240 portion
    // of it is displayed. Therefore if we wanted to swap row address mode above, writes to Y=0...239 range will actually land in
    // memory in row addresses Y = 319-(0...239) = 319...80 range. To view this range, we must scroll the view by +80 units in Y
    // direction so that contents of Y=80...319 is displayed instead of Y=0...239.
    if ((madctl & MADCTL_ROW_ADDRESS_ORDER_SWAP))
      SPI_TRANSFER(0x37/*VSCSAD: Vertical Scroll Start Address of RAM*/, 0, 320 - DISPLAY_WIDTH);
#endif

    // TODO: The 0xB1 command is not Frame Rate Control for ST7789VW, 0xB3 is (add support to it)
#ifndef ST7789VW
    // Frame rate = 850000 / [ (2*RTNA+40) * (162 + FPA+BPA)]
    SPI_TRANSFER(0xB1/*FRMCTR1:Frame Rate Control*/, /*RTNA=*/6, /*FPA=*/1, /*BPA=*/1); // This should set frame rate = 99.67 Hz
#endif

    SPI_TRANSFER(/*Display ON*/0x29);
    usleep(100 * 1000);

#if 0
    // TODO: ST7789VW Python example suggests following, check them against datasheet if there's anything interesting
    SPI_TRANSFER(0xB2, 0xc, 0xc, 0, 0x33, 0x33);
    SPI_TRANSFER(0xB7, 0x35);
    SPI_TRANSFER(0xBb, 0x19);
    SPI_TRANSFER(0xc0, 0x2c);
    SPI_TRANSFER(0xc2, 0x01);
    SPI_TRANSFER(0xc3, 0x12);
    SPI_TRANSFER(0xc4, 0x20);
    SPI_TRANSFER(0xc6, 0x0f);
    SPI_TRANSFER(0xd0, 0xa4, 0xa1);
    SPI_TRANSFER(0xe0, 0xd0, 0x04, 0x0d, 0x11, 0x13, 0x2b, 0x3f, 0x54, 0x4c, 0x18, 0x0d, 0x0b, 0x1f, 0x23);
    SPI_TRANSFER(0xe1, 0xd0, 0x04, 0x0c, 0x11, 0x13, 0x2c, 0x3f, 0x44, 0x51, 0x2f, 0x1f, 0x1f, 0x20, 0x23);
    SPI_TRANSFER(0x21);
    SPI_TRANSFER(0x11);
    SPI_TRANSFER(0x29);
    usleep(100 * 1000);
#endif

#if defined(GPIO_TFT_BACKLIGHT) && defined(BACKLIGHT_CONTROL)
    printf("Setting TFT backlight on at pin %d\n", GPIO_TFT_BACKLIGHT);
    SET_GPIO_MODE(GPIO_TFT_BACKLIGHT, 0x01); // Set backlight pin to digital 0/1 output mode (0x01) in case it had been PWM controlled
    SET_GPIO(GPIO_TFT_BACKLIGHT); // And turn the backlight on.
#endif

    ClearScreen();
  }
#ifndef USE_DMA_TRANSFERS // For DMA transfers, keep SPI CS & TA active.
  END_SPI_COMMUNICATION();
#endif

  // And speed up to the desired operation speed finally after init is done.
  usleep(10 * 1000); // Delay a bit before restoring CLK, or otherwise this has been observed to cause the display not init if done back to back after the clear operation above.
  spi->clk = SPI_BUS_CLOCK_DIVISOR;
}

void TurnDisplayOff()
{
#if defined(GPIO_TFT_BACKLIGHT) && defined(BACKLIGHT_CONTROL)
  SET_GPIO_MODE(GPIO_TFT_BACKLIGHT, 0x01); // Set backlight pin to digital 0/1 output mode (0x01) in case it had been PWM controlled
  CLEAR_GPIO(GPIO_TFT_BACKLIGHT); // And turn the backlight off.
#endif
#if 0
  QUEUE_SPI_TRANSFER(0x28/*Display OFF*/);
  QUEUE_SPI_TRANSFER(0x10/*Enter Sleep Mode*/);
  usleep(120*1000); // Sleep off can be sent 120msecs after entering sleep mode the earliest, so synchronously sleep here for that duration to be safe.
#endif
//  printf("Turned display OFF\n");
}

void TurnDisplayOn()
{
#if 0
  QUEUE_SPI_TRANSFER(0x11/*Sleep Out*/);
  usleep(120 * 1000);
  QUEUE_SPI_TRANSFER(0x29/*Display ON*/);
#endif
#if defined(GPIO_TFT_BACKLIGHT) && defined(BACKLIGHT_CONTROL)
  SET_GPIO_MODE(GPIO_TFT_BACKLIGHT, 0x01); // Set backlight pin to digital 0/1 output mode (0x01) in case it had been PWM controlled
  SET_GPIO(GPIO_TFT_BACKLIGHT); // And turn the backlight on.
#endif
//  printf("Turned display ON\n");
}

void DeinitSPIDisplay()
{
  ClearScreen();
}

#endif