Adafruit_SPITFT.h

/*!
 * @file Adafruit_SPITFT.h
 *
 * Part of Adafruit's GFX graphics library. Originally this class was
 * written to handle a range of color TFT displays connected via SPI,
 * but over time this library and some display-specific subclasses have
 * mutated to include some color OLEDs as well as parallel-interfaced
 * displays. The name's been kept for the sake of older code.
 *
 * Adafruit invests time and resources providing this open source code,
 * please support Adafruit and open-source hardware by purchasing
 * products from Adafruit!
 *
 * Written by Limor "ladyada" Fried for Adafruit Industries,
 * with contributions from the open source community.
 *
 * BSD license, all text here must be included in any redistribution.
 */

#ifndef _ADAFRUIT_SPITFT_H_
#define _ADAFRUIT_SPITFT_H_

// Not for ATtiny, at all
#if !defined(__AVR_ATtiny85__) && !defined(__AVR_ATtiny84__)

#include "Adafruit_GFX.h"
#include <SPI.h>

// HARDWARE CONFIG ---------------------------------------------------------

#if defined(__AVR__)
typedef uint8_t ADAGFX_PORT_t;       ///< PORT values are 8-bit
#define USE_FAST_PINIO               ///< Use direct PORT register access
#elif defined(ARDUINO_STM32_FEATHER) // WICED
typedef class HardwareSPI SPIClass; ///< SPI is a bit odd on WICED
typedef uint32_t ADAGFX_PORT_t;     ///< PORT values are 32-bit
#elif defined(__arm__)
#if defined(ARDUINO_ARCH_SAMD)
// Adafruit M0, M4
typedef uint32_t ADAGFX_PORT_t; ///< PORT values are 32-bit
#define USE_FAST_PINIO   ///< Use direct PORT register access
#define HAS_PORT_SET_CLR ///< PORTs have set & clear registers
#elif defined(CORE_TEENSY)
// PJRC Teensy 4.x
#if defined(__IMXRT1052__) || defined(__IMXRT1062__) // Teensy 4.x
typedef uint32_t ADAGFX_PORT_t; ///< PORT values are 32-bit
                                // PJRC Teensy 3.x
#else
typedef uint8_t ADAGFX_PORT_t; ///< PORT values are 8-bit
#endif
#define USE_FAST_PINIO   ///< Use direct PORT register access
#define HAS_PORT_SET_CLR ///< PORTs have set & clear registers
#else
// Arduino Due?
typedef uint32_t ADAGFX_PORT_t; ///< PORT values are 32-bit
// USE_FAST_PINIO not available here (yet)...Due has a totally different
// GPIO register set and will require some changes elsewhere (e.g. in
// constructors especially).
#endif
#else                                      // !ARM
// Probably ESP8266 or ESP32. USE_FAST_PINIO is not available here (yet)
// but don't worry about it too much...the digitalWrite() implementation
// on these platforms is reasonably efficient and already RAM-resident,
// only gotcha then is no parallel connection support for now.
typedef uint32_t ADAGFX_PORT_t; ///< PORT values are 32-bit
#endif                                     // end !ARM
typedef volatile ADAGFX_PORT_t *PORTreg_t; ///< PORT register type

#if defined(__AVR__) && !defined(__LGT8F__)
#define DEFAULT_SPI_FREQ 8000000L ///< Hardware SPI default speed
#else
#define DEFAULT_SPI_FREQ 16000000L ///< Hardware SPI default speed
#endif

#if defined(ADAFRUIT_PYPORTAL) || defined(ADAFRUIT_PYPORTAL_M4_TITANO) ||      \
    defined(ADAFRUIT_PYBADGE_M4_EXPRESS) ||                                    \
    defined(ADAFRUIT_PYGAMER_M4_EXPRESS) ||                                    \
    defined(ADAFRUIT_MONSTER_M4SK_EXPRESS) || defined(NRF52_SERIES) ||         \
    defined(ADAFRUIT_CIRCUITPLAYGROUND_M0)
#define USE_SPI_DMA ///< Auto DMA
#else
                                           // #define USE_SPI_DMA ///< If set,
                                           //  use DMA if available
#endif
// Another "oops" name -- this now also handles parallel DMA.
// If DMA is enabled, Arduino sketch MUST #include <Adafruit_ZeroDMA.h>
// Estimated RAM usage:
// 4 bytes/pixel on display major axis + 8 bytes/pixel on minor axis,
// e.g. 320x240 pixels = 320 * 4 + 240 * 8 = 3,200 bytes.

#if defined(USE_SPI_DMA) && (defined(__SAMD51__) || defined(ARDUINO_SAMD_ZERO))
#include <Adafruit_ZeroDMA.h>
#endif

// This is kind of a kludge. Needed a way to disambiguate the software SPI
// and parallel constructors via their argument lists. Originally tried a
// bool as the first argument to the parallel constructor (specifying 8-bit
// vs 16-bit interface) but the compiler regards this as equivalent to an
// integer and thus still ambiguous. SO...the parallel constructor requires
// an enumerated type as the first argument: tft8 (for 8-bit parallel) or
// tft16 (for 16-bit)...even though 16-bit isn't fully implemented or tested
// and might never be, still needed that disambiguation from soft SPI.
/*! For first arg to parallel constructor */
enum tftBusWidth { tft8bitbus, tft16bitbus };

// SPI defaults for RP2040
#if defined(ARDUINO_ARCH_RP2040)
#ifndef __SPI0_DEVICE
#define __SPI0_DEVICE spi0
#endif
#ifndef __SPI1_DEVICE
#define __SPI1_DEVICE spi1
#endif
#endif

// CLASS DEFINITION --------------------------------------------------------

/*!
  @brief  Adafruit_SPITFT is an intermediary class between Adafruit_GFX
          and various hardware-specific subclasses for different displays.
          It handles certain operations that are common to a range of
          displays (address window, area fills, etc.). Originally these were
          all color TFT displays interfaced via SPI, but it's since expanded
          to include color OLEDs and parallel-interfaced TFTs. THE NAME HAS
          BEEN KEPT TO AVOID BREAKING A LOT OF SUBCLASSES AND EXAMPLE CODE.
          Many of the class member functions similarly live on with names
          that don't necessarily accurately describe what they're doing,
          again to avoid breaking a lot of other code. If in doubt, read
          the comments.
*/
class Adafruit_SPITFT : public Adafruit_GFX {

public:
  // CONSTRUCTORS --------------------------------------------------------

  // Software SPI constructor: expects width & height (at default rotation
  // setting 0), 4 signal pins (cs, dc, mosi, sclk), 2 optional pins
  // (reset, miso). cs argument is required but can be -1 if unused --
  // rather than moving it to the optional arguments, it was done this way
  // to avoid breaking existing code (-1 option was a later addition).
  Adafruit_SPITFT(uint16_t w, uint16_t h, int8_t cs, int8_t dc, int8_t mosi,
                  int8_t sck, int8_t rst = -1, int8_t miso = -1);

  // Hardware SPI constructor using the default SPI port: expects width &
  // height (at default rotation setting 0), 2 signal pins (cs, dc),
  // optional reset pin. cs is required but can be -1 if unused -- rather
  // than moving it to the optional arguments, it was done this way to
  // avoid breaking existing code (-1 option was a later addition).
  Adafruit_SPITFT(uint16_t w, uint16_t h, int8_t cs, int8_t dc,
                  int8_t rst = -1);

#if !defined(ESP8266) // See notes in .cpp
  // Hardware SPI constructor using an arbitrary SPI peripheral: expects
  // width & height (rotation 0), SPIClass pointer, 2 signal pins (cs, dc)
  // and optional reset pin. cs is required but can be -1 if unused.
  Adafruit_SPITFT(uint16_t w, uint16_t h, SPIClass *spiClass, int8_t cs,
                  int8_t dc, int8_t rst = -1);
#endif // end !ESP8266

  // Parallel constructor: expects width & height (rotation 0), flag
  // indicating whether 16-bit (true) or 8-bit (false) interface, 3 signal
  // pins (d0, wr, dc), 3 optional pins (cs, rst, rd). 16-bit parallel
  // isn't even fully implemented but the 'wide' flag was added as a
  // required argument to avoid ambiguity with other constructors.
  Adafruit_SPITFT(uint16_t w, uint16_t h, tftBusWidth busWidth, int8_t d0,
                  int8_t wr, int8_t dc, int8_t cs = -1, int8_t rst = -1,
                  int8_t rd = -1);

  // DESTRUCTOR ----------------------------------------------------------

  ~Adafruit_SPITFT(){};

  // CLASS MEMBER FUNCTIONS ----------------------------------------------

  // These first two functions MUST be declared by subclasses:

  /*!
      @brief  Display-specific initialization function.
      @param  freq  SPI frequency, in hz (or 0 for default or unused).
  */
  virtual void begin(uint32_t freq) = 0;

  /*!
      @brief  Set up the specific display hardware's "address window"
              for subsequent pixel-pushing operations.
      @param  x  Leftmost pixel of area to be drawn (MUST be within
                 display bounds at current rotation setting).
      @param  y  Topmost pixel of area to be drawn (MUST be within
                 display bounds at current rotation setting).
      @param  w  Width of area to be drawn, in pixels (MUST be >0 and,
                 added to x, within display bounds at current rotation).
      @param  h  Height of area to be drawn, in pixels (MUST be >0 and,
                 added to x, within display bounds at current rotation).
  */
  virtual void setAddrWindow(uint16_t x, uint16_t y, uint16_t w,
                             uint16_t h) = 0;

  // Remaining functions do not need to be declared in subclasses
  // unless they wish to provide hardware-specific optimizations.
  // Brief comments here...documented more thoroughly in .cpp file.

  // Subclass' begin() function invokes this to initialize hardware.
  // freq=0 to use default SPI speed. spiMode must be one of the SPI_MODEn
  // values defined in SPI.h, which are NOT the same as 0 for SPI_MODE0,
  // 1 for SPI_MODE1, etc...use ONLY the SPI_MODEn defines! Only!
  // Name is outdated (interface may be parallel) but for compatibility:
  void initSPI(uint32_t freq = 0, uint8_t spiMode = SPI_MODE0);
  void setSPISpeed(uint32_t freq);
  // Chip select and/or hardware SPI transaction start as needed:
  void startWrite(void);
  // Chip deselect and/or hardware SPI transaction end as needed:
  void endWrite(void);
  void sendCommand(uint8_t commandByte, uint8_t *dataBytes,
                   uint8_t numDataBytes);
  void sendCommand(uint8_t commandByte, const uint8_t *dataBytes = NULL,
                   uint8_t numDataBytes = 0);
  void sendCommand16(uint16_t commandWord, const uint8_t *dataBytes = NULL,
                     uint8_t numDataBytes = 0);
  uint8_t readcommand8(uint8_t commandByte, uint8_t index = 0);
  uint16_t readcommand16(uint16_t addr);

  // These functions require a chip-select and/or SPI transaction
  // around them. Higher-level graphics primitives might start a
  // single transaction and then make multiple calls to these functions
  // (e.g. circle or text rendering might make repeated lines or rects)
  // before ending the transaction. It's more efficient than starting a
  // transaction every time.
  void writePixel(int16_t x, int16_t y, uint16_t color);
  void writePixels(uint16_t *colors, uint32_t len, bool block = true,
                   bool bigEndian = false);
  void writeColor(uint16_t color, uint32_t len);
  void writeFillRect(int16_t x, int16_t y, int16_t w, int16_t h,
                     uint16_t color);
  void writeFastHLine(int16_t x, int16_t y, int16_t w, uint16_t color);
  void writeFastVLine(int16_t x, int16_t y, int16_t h, uint16_t color);
  // This is a new function, similar to writeFillRect() except that
  // all arguments MUST be onscreen, sorted and clipped. If higher-level
  // primitives can handle their own sorting/clipping, it avoids repeating
  // such operations in the low-level code, making it potentially faster.
  // CALLING THIS WITH UNCLIPPED OR NEGATIVE VALUES COULD BE DISASTROUS.
  inline void writeFillRectPreclipped(int16_t x, int16_t y, int16_t w,
                                      int16_t h, uint16_t color);
  // Another new function, companion to the new non-blocking
  // writePixels() variant.
  void dmaWait(void);
  // Used by writePixels() in some situations, but might have rare need in
  // user code, so it's public...
  bool dmaBusy(void) const; // true if DMA is used and busy, false otherwise
  void swapBytes(uint16_t *src, uint32_t len, uint16_t *dest = NULL);

  // These functions are similar to the 'write' functions above, but with
  // a chip-select and/or SPI transaction built-in. They're typically used
  // solo -- that is, as graphics primitives in themselves, not invoked by
  // higher-level primitives (which should use the functions above).
  void drawPixel(int16_t x, int16_t y, uint16_t color);
  void fillRect(int16_t x, int16_t y, int16_t w, int16_t h, uint16_t color);
  void drawFastHLine(int16_t x, int16_t y, int16_t w, uint16_t color);
  void drawFastVLine(int16_t x, int16_t y, int16_t h, uint16_t color);
  // A single-pixel push encapsulated in a transaction. I don't think
  // this is used anymore (BMP demos might've used it?) but is provided
  // for backward compatibility, consider it deprecated:
  void pushColor(uint16_t color);

  using Adafruit_GFX::drawRGBBitmap; // Check base class first
  void drawRGBBitmap(int16_t x, int16_t y, uint16_t *pcolors, int16_t w,
                     int16_t h);

  void invertDisplay(bool i);
  uint16_t color565(uint8_t r, uint8_t g, uint8_t b);

  // Despite parallel additions, function names kept for compatibility:
  void spiWrite(uint8_t b);          // Write single byte as DATA
  void writeCommand(uint8_t cmd);    // Write single byte as COMMAND
  uint8_t spiRead(void);             // Read single byte of data
  void write16(uint16_t w);          // Write 16-bit value as DATA
  void writeCommand16(uint16_t cmd); // Write 16-bit value as COMMAND
  uint16_t read16(void);             // Read single 16-bit value

  // Most of these low-level functions were formerly macros in
  // Adafruit_SPITFT_Macros.h. Some have been made into inline functions
  // to avoid macro mishaps. Despite the addition of code for a parallel
  // display interface, the names have been kept for backward
  // compatibility (some subclasses may be invoking these):
  void SPI_WRITE16(uint16_t w); // Not inline
  void SPI_WRITE32(uint32_t l); // Not inline
  // Old code had both a spiWrite16() function and SPI_WRITE16 macro
  // in addition to the SPI_WRITE32 macro. The latter two have been
  // made into functions here, and spiWrite16() removed (use SPI_WRITE16()
  // instead). It looks like most subclasses had gotten comfortable with
  // SPI_WRITE16 and SPI_WRITE32 anyway so those names were kept rather
  // than the less-obnoxious camelcase variants, oh well.

  // Placing these functions entirely in the class definition inlines
  // them implicitly them while allowing their use in other code:

  /*!
      @brief  Set the chip-select line HIGH. Does NOT check whether CS pin
              is set (>=0), that should be handled in calling function.
              Despite function name, this is used even if the display
              connection is parallel.
  */
  void SPI_CS_HIGH(void) {
#if defined(USE_FAST_PINIO)
#if defined(HAS_PORT_SET_CLR)
#if defined(KINETISK)
    *csPortSet = 1;
#else  // !KINETISK
    *csPortSet = csPinMask;
#endif // end !KINETISK
#else  // !HAS_PORT_SET_CLR
    *csPort |= csPinMaskSet;
#endif // end !HAS_PORT_SET_CLR
#else  // !USE_FAST_PINIO
    digitalWrite(_cs, HIGH);
#endif // end !USE_FAST_PINIO
  }

  /*!
      @brief  Set the chip-select line LOW. Does NOT check whether CS pin
              is set (>=0), that should be handled in calling function.
              Despite function name, this is used even if the display
              connection is parallel.
  */
  void SPI_CS_LOW(void) {
#if defined(USE_FAST_PINIO)
#if defined(HAS_PORT_SET_CLR)
#if defined(KINETISK)
    *csPortClr = 1;
#else  // !KINETISK
    *csPortClr = csPinMask;
#endif // end !KINETISK
#else  // !HAS_PORT_SET_CLR
    *csPort &= csPinMaskClr;
#endif // end !HAS_PORT_SET_CLR
#else  // !USE_FAST_PINIO
    digitalWrite(_cs, LOW);
#endif // end !USE_FAST_PINIO
  }

  /*!
      @brief  Set the data/command line HIGH (data mode).
  */
  void SPI_DC_HIGH(void) {
#if defined(USE_FAST_PINIO)
#if defined(HAS_PORT_SET_CLR)
#if defined(KINETISK)
    *dcPortSet = 1;
#else  // !KINETISK
    *dcPortSet = dcPinMask;
#endif // end !KINETISK
#else  // !HAS_PORT_SET_CLR
    *dcPort |= dcPinMaskSet;
#endif // end !HAS_PORT_SET_CLR
#else  // !USE_FAST_PINIO
    digitalWrite(_dc, HIGH);
#endif // end !USE_FAST_PINIO
  }

  /*!
      @brief  Set the data/command line LOW (command mode).
  */
  void SPI_DC_LOW(void) {
#if defined(USE_FAST_PINIO)
#if defined(HAS_PORT_SET_CLR)
#if defined(KINETISK)
    *dcPortClr = 1;
#else  // !KINETISK
    *dcPortClr = dcPinMask;
#endif // end !KINETISK
#else  // !HAS_PORT_SET_CLR
    *dcPort &= dcPinMaskClr;
#endif // end !HAS_PORT_SET_CLR
#else  // !USE_FAST_PINIO
    digitalWrite(_dc, LOW);
#endif // end !USE_FAST_PINIO
  }

protected:
  // A few more low-level member functions -- some may have previously
  // been macros. Shouldn't have a need to access these externally, so
  // they've been moved to the protected section. Additionally, they're
  // declared inline here and the code is in the .cpp file, since outside
  // code doesn't need to see these.
  inline void SPI_MOSI_HIGH(void);
  inline void SPI_MOSI_LOW(void);
  inline void SPI_SCK_HIGH(void);
  inline void SPI_SCK_LOW(void);
  inline bool SPI_MISO_READ(void);
  inline void SPI_BEGIN_TRANSACTION(void);
  inline void SPI_END_TRANSACTION(void);
  inline void TFT_WR_STROBE(void); // Parallel interface write strobe
  inline void TFT_RD_HIGH(void);   // Parallel interface read high
  inline void TFT_RD_LOW(void);    // Parallel interface read low

  // CLASS INSTANCE VARIABLES --------------------------------------------

  // Here be dragons! There's a big union of three structures here --
  // one each for hardware SPI, software (bitbang) SPI, and parallel
  // interfaces. This is to save some memory, since a display's connection
  // will be only one of these. The order of some things is a little weird
  // in an attempt to get values to align and pack better in RAM.

#if defined(USE_FAST_PINIO)
#if defined(HAS_PORT_SET_CLR)
  PORTreg_t csPortSet; ///< PORT register for chip select SET
  PORTreg_t csPortClr; ///< PORT register for chip select CLEAR
  PORTreg_t dcPortSet; ///< PORT register for data/command SET
  PORTreg_t dcPortClr; ///< PORT register for data/command CLEAR
#else                  // !HAS_PORT_SET_CLR
  PORTreg_t csPort; ///< PORT register for chip select
  PORTreg_t dcPort; ///< PORT register for data/command
#endif                 // end HAS_PORT_SET_CLR
#endif                 // end USE_FAST_PINIO
#if defined(__cplusplus) && (__cplusplus >= 201100)
  union {
#endif
    struct {          //   Values specific to HARDWARE SPI:
      SPIClass *_spi; ///< SPI class pointer
#if defined(SPI_HAS_TRANSACTION)
      SPISettings settings; ///< SPI transaction settings
#else
    uint32_t _freq; ///< SPI bitrate (if no SPI transactions)
#endif
      uint32_t _mode; ///< SPI data mode (transactions or no)
    } hwspi;          ///< Hardware SPI values
    struct {          //   Values specific to SOFTWARE SPI:
#if defined(USE_FAST_PINIO)
      PORTreg_t misoPort; ///< PORT (PIN) register for MISO
#if defined(HAS_PORT_SET_CLR)
      PORTreg_t mosiPortSet; ///< PORT register for MOSI SET
      PORTreg_t mosiPortClr; ///< PORT register for MOSI CLEAR
      PORTreg_t sckPortSet;  ///< PORT register for SCK SET
      PORTreg_t sckPortClr;  ///< PORT register for SCK CLEAR
#if !defined(KINETISK)
      ADAGFX_PORT_t mosiPinMask; ///< Bitmask for MOSI
      ADAGFX_PORT_t sckPinMask;  ///< Bitmask for SCK
#endif                           // end !KINETISK
#else                            // !HAS_PORT_SET_CLR
      PORTreg_t mosiPort;           ///< PORT register for MOSI
      PORTreg_t sckPort;            ///< PORT register for SCK
      ADAGFX_PORT_t mosiPinMaskSet; ///< Bitmask for MOSI SET (OR)
      ADAGFX_PORT_t mosiPinMaskClr; ///< Bitmask for MOSI CLEAR (AND)
      ADAGFX_PORT_t sckPinMaskSet;  ///< Bitmask for SCK SET (OR bitmask)
      ADAGFX_PORT_t sckPinMaskClr;  ///< Bitmask for SCK CLEAR (AND)
#endif                           // end HAS_PORT_SET_CLR
#if !defined(KINETISK)
      ADAGFX_PORT_t misoPinMask; ///< Bitmask for MISO
#endif                           // end !KINETISK
#endif                           // end USE_FAST_PINIO
      int8_t _mosi;              ///< MOSI pin #
      int8_t _miso;              ///< MISO pin #
      int8_t _sck;               ///< SCK pin #
    } swspi;                     ///< Software SPI values
    struct {                     //   Values specific to 8-bit parallel:
#if defined(USE_FAST_PINIO)

#if defined(__IMXRT1052__) || defined(__IMXRT1062__) // Teensy 4.x
      volatile uint32_t *writePort; ///< PORT register for DATA WRITE
      volatile uint32_t *readPort;  ///< PORT (PIN) register for DATA READ
#else
      volatile uint8_t *writePort; ///< PORT register for DATA WRITE
      volatile uint8_t *readPort;  ///< PORT (PIN) register for DATA READ
#endif
#if defined(HAS_PORT_SET_CLR)
      // Port direction register pointers are always 8-bit regardless of
      // PORTreg_t -- even if 32-bit port, we modify a byte-aligned 8 bits.
#if defined(__IMXRT1052__) || defined(__IMXRT1062__) // Teensy 4.x
      volatile uint32_t *dirSet; ///< PORT byte data direction SET
      volatile uint32_t *dirClr; ///< PORT byte data direction CLEAR
#else
      volatile uint8_t *dirSet; ///< PORT byte data direction SET
      volatile uint8_t *dirClr; ///< PORT byte data direction CLEAR
#endif
      PORTreg_t wrPortSet; ///< PORT register for write strobe SET
      PORTreg_t wrPortClr; ///< PORT register for write strobe CLEAR
      PORTreg_t rdPortSet; ///< PORT register for read strobe SET
      PORTreg_t rdPortClr; ///< PORT register for read strobe CLEAR
#if !defined(KINETISK)
      ADAGFX_PORT_t wrPinMask; ///< Bitmask for write strobe
#endif                         // end !KINETISK
      ADAGFX_PORT_t rdPinMask; ///< Bitmask for read strobe
#else                          // !HAS_PORT_SET_CLR
      // Port direction register pointer is always 8-bit regardless of
      // PORTreg_t -- even if 32-bit port, we modify a byte-aligned 8 bits.
      volatile uint8_t *portDir;  ///< PORT direction register
      PORTreg_t wrPort;           ///< PORT register for write strobe
      PORTreg_t rdPort;           ///< PORT register for read strobe
      ADAGFX_PORT_t wrPinMaskSet; ///< Bitmask for write strobe SET (OR)
      ADAGFX_PORT_t wrPinMaskClr; ///< Bitmask for write strobe CLEAR (AND)
      ADAGFX_PORT_t rdPinMaskSet; ///< Bitmask for read strobe SET (OR)
      ADAGFX_PORT_t rdPinMaskClr; ///< Bitmask for read strobe CLEAR (AND)
#endif                         // end HAS_PORT_SET_CLR
#endif                         // end USE_FAST_PINIO
      int8_t _d0;              ///< Data pin 0 #
      int8_t _wr;              ///< Write strobe pin #
      int8_t _rd;              ///< Read strobe pin # (or -1)
      bool wide = 0;           ///< If true, is 16-bit interface
    } tft8;                    ///< Parallel interface settings
#if defined(__cplusplus) && (__cplusplus >= 201100)
  }; ///< Only one interface is active
#endif
#if defined(USE_SPI_DMA) &&                                                    \
    (defined(__SAMD51__) ||                                                    \
     defined(ARDUINO_SAMD_ZERO))     // Used by hardware SPI and tft8
  Adafruit_ZeroDMA dma;              ///< DMA instance
  DmacDescriptor *dptr = NULL;       ///< 1st descriptor
  DmacDescriptor *descriptor = NULL; ///< Allocated descriptor list
  uint16_t *pixelBuf[2];             ///< Working buffers
  uint16_t maxFillLen;               ///< Max pixels per DMA xfer
  uint16_t lastFillColor = 0;        ///< Last color used w/fill
  uint32_t lastFillLen = 0;          ///< # of pixels w/last fill
  uint8_t onePixelBuf;               ///< For hi==lo fill
#endif
#if defined(USE_FAST_PINIO)
#if defined(HAS_PORT_SET_CLR)
#if !defined(KINETISK)
  ADAGFX_PORT_t csPinMask; ///< Bitmask for chip select
  ADAGFX_PORT_t dcPinMask; ///< Bitmask for data/command
#endif                     // end !KINETISK
#else                      // !HAS_PORT_SET_CLR
  ADAGFX_PORT_t csPinMaskSet; ///< Bitmask for chip select SET (OR)
  ADAGFX_PORT_t csPinMaskClr; ///< Bitmask for chip select CLEAR (AND)
  ADAGFX_PORT_t dcPinMaskSet; ///< Bitmask for data/command SET (OR)
  ADAGFX_PORT_t dcPinMaskClr; ///< Bitmask for data/command CLEAR (AND)
#endif                     // end HAS_PORT_SET_CLR
#endif                     // end USE_FAST_PINIO
  uint8_t connection;      ///< TFT_HARD_SPI, TFT_SOFT_SPI, etc.
  int8_t _rst;             ///< Reset pin # (or -1)
  int8_t _cs;              ///< Chip select pin # (or -1)
  int8_t _dc;              ///< Data/command pin #

  int16_t _xstart = 0;          ///< Internal framebuffer X offset
  int16_t _ystart = 0;          ///< Internal framebuffer Y offset
  uint8_t invertOnCommand = 0;  ///< Command to enable invert mode
  uint8_t invertOffCommand = 0; ///< Command to disable invert mode

  uint32_t _freq = 0; ///< Dummy var to keep subclasses happy
};

#endif // end __AVR_ATtiny85__ __AVR_ATtiny84__
#endif // end _ADAFRUIT_SPITFT_H_