From 1b54ce87e90865c1f20d8f1aa82108bc64168743 Mon Sep 17 00:00:00 2001
From: Bodmer <bodmer@anola.net>
Date: Fri, 11 Dec 2020 21:10:12 +0000
Subject: [PATCH] Optional ESP32 DMA engine control of TFT_CS

This change has no impact on examples
See also #850
---
 Processors/TFT_eSPI_ESP32.c | 8 ++++++--
 Processors/TFT_eSPI_STM32.c | 4 +++-
 TFT_eSPI.h                  | 6 ++++--
 3 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/Processors/TFT_eSPI_ESP32.c b/Processors/TFT_eSPI_ESP32.c
index 3df895c..0205dc1 100644
--- a/Processors/TFT_eSPI_ESP32.c
+++ b/Processors/TFT_eSPI_ESP32.c
@@ -665,7 +665,7 @@ void IRAM_ATTR dc_callback(spi_transaction_t *spi_tx)
 ** Function name:           initDMA
 ** Description:             Initialise the DMA engine - returns true if init OK
 ***************************************************************************************/
-bool TFT_eSPI::initDMA(void)
+bool TFT_eSPI::initDMA(bool ctrl_cs)
 {
   if (DMA_Enabled) return false;
 
@@ -680,6 +680,10 @@ bool TFT_eSPI::initDMA(void)
     .flags = 0,
     .intr_flags = 0
   };
+
+  int8_t pin = -1;
+  if (ctrl_cs) pin = TFT_CS;
+
   spi_device_interface_config_t devcfg = {
     .command_bits = 0,
     .address_bits = 0,
@@ -690,7 +694,7 @@ bool TFT_eSPI::initDMA(void)
     .cs_ena_posttrans = 0,
     .clock_speed_hz = SPI_FREQUENCY,
     .input_delay_ns = 0,
-    .spics_io_num = TFT_CS,
+    .spics_io_num = pin,
     .flags = SPI_DEVICE_NO_DUMMY, //0,
     .queue_size = 1,
     .pre_cb = 0, //dc_callback, //Callback to handle D/C line
diff --git a/Processors/TFT_eSPI_STM32.c b/Processors/TFT_eSPI_STM32.c
index 6c95d2f..a9951dd 100644
--- a/Processors/TFT_eSPI_STM32.c
+++ b/Processors/TFT_eSPI_STM32.c
@@ -538,8 +538,10 @@ void TFT_eSPI::pushImageDMA(int32_t x, int32_t y, int32_t w, int32_t h, uint16_t
 // This initialisation is for STM32F2xx/4xx/7xx processors and may not work on others
 // Dual core H7xx series not supported yet, they are different and have a DMA MUX: 
 // https://electronics.stackexchange.com/questions/379813/configuring-the-dma-request-multiplexer-on-a-stm32h7-mcu
-bool TFT_eSPI::initDMA(void)
+bool TFT_eSPI::initDMA(bool ctrl_cs)
 {
+  ctrl_cs = ctrl_cs; // Not used for STM32, so stop compiler warning
+
   #if (TFT_SPI_PORT == 1)
     __HAL_RCC_DMA2_CLK_ENABLE();                           // Enable DMA2 clock
     dmaHal.Init.Channel = DMA_CHANNEL_3;                   // DMA channel 3 is for SPI1 TX
diff --git a/TFT_eSPI.h b/TFT_eSPI.h
index 4234199..75dce54 100644
--- a/TFT_eSPI.h
+++ b/TFT_eSPI.h
@@ -16,7 +16,7 @@
 #ifndef _TFT_eSPIH_
 #define _TFT_eSPIH_
 
-#define TFT_ESPI_VERSION "2.3.52"
+#define TFT_ESPI_VERSION "2.3.53"
 
 // Bit level feature flags
 // Bit 0 set: viewport capability
@@ -618,7 +618,9 @@ class TFT_eSPI : public Print { friend class TFT_eSprite; // Sprite class has ac
            // function will wait for the DMA to complete, so this may defeat any DMA performance benefit.
            //
 
-  bool     initDMA(void);     // Initialise the DMA engine and attach to SPI bus - typically used in setup()
+  bool     initDMA(bool ctrl_cs = false);  // Initialise the DMA engine and attach to SPI bus - typically used in setup()
+                                           // Parameter "true" enables DMA engine control of TFT chip select (ESP32 only)
+                                           // For ESP32 only, TFT reads will not work if parameter is true
   void     deInitDMA(void);   // De-initialise the DMA engine and detach from SPI bus - typically not used
   
            // Push an image to the TFT using DMA, buffer is optional and grabs (double buffers) a copy of the image