From 47895f1e7b2f435d56d81aed2b07fe96c6ebe74c Mon Sep 17 00:00:00 2001
From: Bodmer <bodmer@anola.net>
Date: Thu, 27 Jan 2022 22:15:04 +0000
Subject: [PATCH] Allow RP2040 to read from SPI TFT

---
 Processors/TFT_eSPI_RP2040.c |  4 ++++
 TFT_eSPI.cpp                 | 18 ++++++++++--------
 TFT_eSPI.h                   |  2 +-
 library.json                 |  2 +-
 library.properties           |  2 +-
 5 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/Processors/TFT_eSPI_RP2040.c b/Processors/TFT_eSPI_RP2040.c
index fdea719..2b5486c 100644
--- a/Processors/TFT_eSPI_RP2040.c
+++ b/Processors/TFT_eSPI_RP2040.c
@@ -69,12 +69,16 @@ uint8_t TFT_eSPI::tft_Read_8(void)
 {
   uint8_t  ret = 0;
 
+  /*
   for (uint8_t i = 0; i < 8; i++) {  // read results
     ret <<= 1;
     SCLK_L;
     if (digitalRead(TFT_MOSI)) ret |= 1;
     SCLK_H;
   }
+  */
+  
+  ret = spi.transfer(0x00);
 
   return ret;
 }
diff --git a/TFT_eSPI.cpp b/TFT_eSPI.cpp
index d773240..9703e71 100644
--- a/TFT_eSPI.cpp
+++ b/TFT_eSPI.cpp
@@ -941,10 +941,10 @@ uint16_t TFT_eSPI::readPixel(int32_t x0, int32_t y0)
   // Set masked pins D0- D7 to input
   busDir(dir_mask, INPUT);
 
-#if  !defined (SSD1963_DRIVER)
+  #if  !defined (SSD1963_DRIVER)
   // Dummy read to throw away don't care value
   readByte();
-#endif
+  #endif
 
   // Fetch the 16 bit BRG pixel
   //uint16_t rgb = (readByte() << 8) | readByte();
@@ -989,9 +989,9 @@ uint16_t TFT_eSPI::readPixel(int32_t x0, int32_t y0)
 
   uint16_t color = 0;
 
-  begin_tft_read();
+  begin_tft_read(); // Sets CS low
 
-  readAddrWindow(x0, y0, 1, 1); // Sets CS low
+  readAddrWindow(x0, y0, 1, 1);
 
   #ifdef TFT_SDA_READ
     begin_SDA_Read();
@@ -3171,6 +3171,10 @@ void TFT_eSPI::readAddrWindow(int32_t xs, int32_t ys, int32_t w, int32_t h)
   addr_col = 0xFFFF;
   addr_row = 0xFFFF;
 
+#if defined (SSD1963_DRIVER)
+  if ((rotation & 0x1) == 0) { swap_coord(xs, ys); swap_coord(xe, ye); }
+#endif
+
 #ifdef CGRAM_OFFSET
   xs += colstart;
   xe += colstart;
@@ -3178,12 +3182,10 @@ void TFT_eSPI::readAddrWindow(int32_t xs, int32_t ys, int32_t w, int32_t h)
   ye += rowstart;
 #endif
 
-#if defined (SSD1963_DRIVER)
-  if ((rotation & 0x1) == 0) { swap_coord(xs, ys); swap_coord(xe, ye); }
-#endif
-
   // Temporary solution is to include the RP2040 optimised code here
 #if (defined(ARDUINO_ARCH_RP2040)  || defined (ARDUINO_ARCH_MBED)) && !defined(RP2040_PIO_INTERFACE)
+  // Use hardware SPI port, this code does not swap from 8 to 16 bit
+  // to avoid the spi_set_format() call overhead
   while (spi_get_hw(SPI_X)->sr & SPI_SSPSR_BSY_BITS) {};
   DC_C;
   hw_write_masked(&spi_get_hw(SPI_X)->cr0, (8 - 1) << SPI_SSPCR0_DSS_LSB, SPI_SSPCR0_DSS_BITS);
diff --git a/TFT_eSPI.h b/TFT_eSPI.h
index 9d1a7fd..98189e2 100644
--- a/TFT_eSPI.h
+++ b/TFT_eSPI.h
@@ -16,7 +16,7 @@
 #ifndef _TFT_eSPIH_
 #define _TFT_eSPIH_
 
-#define TFT_ESPI_VERSION "2.4.30"
+#define TFT_ESPI_VERSION "2.4.31"
 
 // Bit level feature flags
 // Bit 0 set: viewport capability
diff --git a/library.json b/library.json
index a0828ca..2aa5c17 100644
--- a/library.json
+++ b/library.json
@@ -1,6 +1,6 @@
 {
   "name": "TFT_eSPI",
-  "version": "2.4.30",
+  "version": "2.4.31",
   "keywords": "Arduino, tft, ePaper, display, Pico, RP2040, STM32, ESP8266, NodeMCU, ESP32, M5Stack, ILI9341, ST7735, ILI9163, S6D02A1, ILI9481, ILI9486, ILI9488, ST7789, RM68140, SSD1351, SSD1963, ILI9225, HX8357D",
   "description": "A TFT and ePaper SPI graphics library with optimisation for Raspberry Pi Pico, ESP8266, ESP32 and STM32",
   "repository":
diff --git a/library.properties b/library.properties
index 1412512..448d498 100644
--- a/library.properties
+++ b/library.properties
@@ -1,5 +1,5 @@
 name=TFT_eSPI
-version=2.4.30
+version=2.4.31
 author=Bodmer
 maintainer=Bodmer
 sentence=TFT graphics library for Arduino processors with performance optimisation for RP2040, STM32, ESP8266 and ESP32