RP2040 18bit PIO SPI update

Update RP2040 18bit PIO SPI code for 18 bit SPI displays (tested on  ILI9488)
Add ILI9342_DRIVER option for default landscape display.

Processors/TFT_eSPI_RP2040.c

@@ -21,8 +21,15 @@
 #else // PIO interface used (8 bit parallel or SPI)
 
   #ifdef RP2040_PIO_SPI
-    #include "pio_SPI.pio.h"
+    #if  defined (SPI_18BIT_DRIVER)
+      // SPI PIO code for 18 bit colour transmit
+      #include "pio_SPI_18bit.pio.h"
     #else
+      // SPI PIO code for 16 bit colour transmit
+      #include "pio_SPI.pio.h"
+    #endif
+  #else
+    // SPI PIO code for 8 bit parallel interface (16 bit colour)
     #include "pio_8bit_parallel.pio.h"
   #endif
 
@@ -166,7 +173,7 @@ void pioinit(uint32_t clock_freq) {
   // The OSR register shifts to the left, sm designed to send MS byte of a colour first, autopull off
   sm_config_set_out_shift(&c, false, false, 0);
   // Now load the configuration
-  pio_sm_init(tft_pio, pio_sm, program_offset + tft_io_offset_start_16, &c);
+  pio_sm_init(tft_pio, pio_sm, program_offset + tft_io_offset_start_tx, &c);
 
   // Start the state machine.
   pio_sm_set_enabled(tft_pio, pio_sm, true);
@@ -236,7 +243,7 @@ void pioinit(uint16_t clock_div, uint16_t fract_div) {
   // The OSR register shifts to the left, sm designed to send MS byte of a colour first
   sm_config_set_out_shift(&c, false, false, 0);
   // Now load the configuration
-  pio_sm_init(tft_pio, pio_sm, program_offset + tft_io_offset_start_16, &c);
+  pio_sm_init(tft_pio, pio_sm, program_offset + tft_io_offset_start_tx, &c);
 
   // Start the state machine.
   pio_sm_set_enabled(tft_pio, pio_sm, true);
@@ -263,6 +270,16 @@ void pioinit(uint16_t clock_div, uint16_t fract_div) {
 // PIO handles pixel block fill writes
 void TFT_eSPI::pushBlock(uint16_t color, uint32_t len)
 {
+#if  defined (SPI_18BIT_DRIVER)
+  uint32_t col = ((color & 0xF800)<<8) | ((color & 0x07E0)<<5) | ((color & 0x001F)<<3);
+  if (len) {
+    WAIT_FOR_STALL;
+    tft_pio->sm[pio_sm].instr = pio_instr_fill;
+
+    TX_FIFO = col;
+    TX_FIFO = --len; // Decrement first as PIO sends n+1
+  }
+#else
   if (len) {
     WAIT_FOR_STALL;
     tft_pio->sm[pio_sm].instr = pio_instr_fill;
@@ -270,6 +287,7 @@ void TFT_eSPI::pushBlock(uint16_t color, uint32_t len)
     TX_FIFO = color;
     TX_FIFO = --len; // Decrement first as PIO sends n+1
   }
+#endif
 }
 
 #else
@@ -300,7 +318,21 @@ void TFT_eSPI::pushBlock(uint16_t color, uint32_t len){
 ** Description:             Write a sequence of pixels
 ***************************************************************************************/
 void TFT_eSPI::pushPixels(const void* data_in, uint32_t len){
-
+#if  defined (SPI_18BIT_DRIVER)
+  uint16_t *data = (uint16_t*)data_in;
+  if (_swapBytes) {
+    while ( len-- ) {
+      uint32_t col = *data++;
+      tft_Write_16(col);
+    }
+  }
+  else {
+    while ( len-- ) {
+      uint32_t col = *data++;
+      tft_Write_16S(col);
+    }
+  }
+#else
   const uint16_t *data = (uint16_t*)data_in;
 
   // PIO sends MS byte first, so bytes are already swapped on transmit
@@ -341,6 +373,7 @@ void TFT_eSPI::pushPixels(const void* data_in, uint32_t len){
       }
     }
   }
+#endif
 }
 
 /***************************************************************************************

Processors/TFT_eSPI_RP2040.h

@@ -335,7 +335,34 @@
   // Temporary - to be deleted
   #define dir_mask 0
 
+  #if  defined (SPI_18BIT_DRIVER) // SPI 18 bit colour
+      // This writes 8 bits, then switches back to 16 bit mode automatically
+      // Have already waited for pio stalled (last data write complete) when DC switched to command mode
+      // The wait for stall allows DC to be changed immediately afterwards
+      #define tft_Write_8(C)      tft_pio->sm[pio_sm].instr = pio_instr_jmp8; \
+                                  TX_FIFO = (C); \
+                                  WAIT_FOR_STALL
 
+      // Used to send last byte for 32 bit macros below since PIO sends 24 bits
+      #define tft_Write_8L(C)     WAIT_FOR_STALL; \
+                                  tft_pio->sm[pio_sm].instr = pio_instr_jmp8; \
+                                  TX_FIFO = (C)
+
+      // Note: the following macros do not wait for the end of transmission
+
+      #define tft_Write_16(C)     WAIT_FOR_FIFO_FREE(1); TX_FIFO = ((((uint32_t)(C) & 0xF800)<<8) | (((C) & 0x07E0)<<5) | (((C) & 0x001F)<<3))
+
+      #define tft_Write_16N(C)    WAIT_FOR_FIFO_FREE(1); TX_FIFO = ((((uint32_t)(C) & 0xF800)<<8) | (((C) & 0x07E0)<<5) | (((C) & 0x001F)<<3))
+
+      #define tft_Write_16S(C)    WAIT_FOR_FIFO_FREE(1); TX_FIFO = ((((uint32_t)(C) & 0xF8) << 16) | (((C) & 0xE000)>>3) | (((C) & 0x07)<<13) | (((C) & 0x1F00)>>5))
+
+      #define tft_Write_32(C)     WAIT_FOR_FIFO_FREE(2); TX_FIFO = ((C)>>8); WAIT_FOR_STALL; tft_Write_8(C)
+
+      #define tft_Write_32C(C,D)  WAIT_FOR_FIFO_FREE(2); TX_FIFO = (((C)<<8) | ((D)>>8)); tft_Write_8L(D)
+
+      #define tft_Write_32D(C)    WAIT_FOR_FIFO_FREE(2); TX_FIFO = (((C)<<8) | ((C)>>8)); tft_Write_8L(C)
+
+  #else
       // This writes 8 bits, then switches back to 16 bit mode automatically
       // Have already waited for pio stalled (last data write complete) when DC switched to command mode
       // The wait for stall allows DC to be changed immediately afterwards
@@ -356,7 +383,7 @@
       #define tft_Write_32C(C,D)  WAIT_FOR_FIFO_FREE(2); TX_FIFO = (C); TX_FIFO = (D)
 
       #define tft_Write_32D(C)    WAIT_FOR_FIFO_FREE(2); TX_FIFO = (C); TX_FIFO = (C)
-
+  #endif
 #endif
 
 #ifndef tft_Write_16N

Processors/pio_8bit_parallel.pio

@@ -38,7 +38,7 @@ next:
 
 .wrap_target
 // Transmit a 16 bit value (LS 16 bits of 32 bits).
-public start_16:
+public start_tx:
    // Fetch the next 32 bit value from the TX FIFO and set TFT_WR high.
    pull side 1
    // Write the first byte (MSB) and set WR low. This also
@@ -49,7 +49,7 @@ public start_16:
    // Output the second byte and set TFT_WRITE low.
    out pins, 8 side 0 [1]
    // Set WR high and jump back to start.
-   jmp start_16 side 1
+   jmp start_tx side 1
 
 // Transmit an 8 bit value (LS 8 bits of 32 bits).
 public start_8:
@@ -59,7 +59,7 @@ public start_8:
    // shifts the unused top 24 bits through.
    out pins, 32 side 0 [1]     
    // Jump to start
-   jmp start_16 side 1
+   jmp start_tx side 1
 
 // Transmit a set window command sequence.
 public set_addr_window:
@@ -88,5 +88,5 @@ end_set_addr:
    jmp x--, pull_cmd side 1
    // Set DC high.
    set pins, 1
-   // Auto-wrap back to start_16.
+   // Auto-wrap back to start_tx.
 .wrap

Processors/pio_8bit_parallel.pio.h

@@ -16,7 +16,7 @@
 #define tft_io_wrap 27
 
 #define tft_io_offset_block_fill 0u
-#define tft_io_offset_start_16 9u
+#define tft_io_offset_start_tx 9u
 #define tft_io_offset_start_8 14u
 #define tft_io_offset_set_addr_window 17u
 

Processors/pio_SPI.pio

@@ -37,7 +37,7 @@ next_cmd_bit:
    // Set DC high
    set pins, 1 side 0
    // Finish if 3rd cmd byte ramwr sent (x == 0)
-   jmp !x, start_16
+   jmp !x, start_tx
    pull
 next_xy:
    // send 32 bit start and end coordinates
@@ -46,7 +46,7 @@ next_xy:
    // Loop back for next command
    jmp x--, pull_cmd side 0
    // End
-   jmp start_16
+   jmp start_tx
 
 public block_fill:
    // Fetch colour value
@@ -73,7 +73,7 @@ next_bit:
    // Now drop back to 16 bit output
 
 .wrap_target
-public start_16:
+public start_tx:
    // Pull the next 32 bit value from the TX FIFO. 
    // Send the bottom 16 bits
    pull side 0

Processors/pio_SPI.pio.h

@@ -18,7 +18,7 @@
 #define tft_io_offset_start_8 0u
 #define tft_io_offset_set_addr_window 3u
 #define tft_io_offset_block_fill 17u
-#define tft_io_offset_start_16 27u
+#define tft_io_offset_start_tx 27u
 
 static const uint16_t tft_io_program_instructions[] = {
     0x90a0, //  0: pull   block           side 0     

TFT_Drivers/ILI9341_Defines.h

@@ -1,8 +1,13 @@
 // Change the width and height if required (defined in portrait mode)
 // or use the constructor to over-ride defaults
+
+#if defined (ILI9341_DRIVER) || ILI9341_2_DRIVER
   #define TFT_WIDTH  240
   #define TFT_HEIGHT 320
-
+#elif defined (ILI9342_DRIVER)
+  #define TFT_WIDTH  320
+  #define TFT_HEIGHT 240
+#endif
 
 // Color definitions for backwards compatibility with old sketches
 // use colour definitions like TFT_BLACK to make sketches more portable

TFT_Drivers/ILI9341_Init.h

@@ -5,7 +5,7 @@
 //
 // See ST7735_Setup.h file for an alternative format
 
-#if defined (ILI9341_DRIVER)
+#if defined (ILI9341_DRIVER) | defined (ILI9342_DRIVER)
 {
   writecommand(0xEF);
   writedata(0x03);

TFT_eSPI.cpp

@@ -685,7 +685,7 @@ void TFT_eSPI::init(uint8_t tc)
   tc = tc; // Suppress warning
 
   // This loads the driver specific initialisation code  <<<<<<<<<<<<<<<<<<<<< ADD NEW DRIVERS TO THE LIST HERE <<<<<<<<<<<<<<<<<<<<<<<
-#if   defined (ILI9341_DRIVER) || defined(ILI9341_2_DRIVER)
+#if   defined (ILI9341_DRIVER) || defined(ILI9341_2_DRIVER) || defined (ILI9342_DRIVER)
     #include "TFT_Drivers/ILI9341_Init.h"
 
 #elif defined (ST7735_DRIVER)
@@ -777,7 +777,7 @@ void TFT_eSPI::setRotation(uint8_t m)
   begin_tft_write();
 
     // This loads the driver specific rotation code  <<<<<<<<<<<<<<<<<<<<< ADD NEW DRIVERS TO THE LIST HERE <<<<<<<<<<<<<<<<<<<<<<<
-#if   defined (ILI9341_DRIVER) || defined(ILI9341_2_DRIVER)
+#if   defined (ILI9341_DRIVER) || defined(ILI9341_2_DRIVER) || defined (ILI9342_DRIVER)
     #include "TFT_Drivers/ILI9341_Rotation.h"
 
 #elif defined (ST7735_DRIVER)
@@ -3484,7 +3484,11 @@ void TFT_eSPI::drawPixel(int32_t x, int32_t y, uint32_t color)
     TX_FIFO = (y<<16) | y;
     TX_FIFO = TFT_RAMWR;
     //DC set high by PIO
+    #if  defined (SPI_18BIT_DRIVER)
+      TX_FIFO = ((color & 0xF800)<<8) | ((color & 0x07E0)<<5) | ((color & 0x001F)<<3);
+    #else
       TX_FIFO = color;
+    #endif
 
   #endif