From 80ab5c3060c3a067df06a84665b82f92431feb51 Mon Sep 17 00:00:00 2001
From: Stephan Hadinger <stephan.hadinger@gmail.com>
Date: Sun, 17 Apr 2022 22:47:26 +0200
Subject: [PATCH] LVGL fix conflict between SPI DMA and SD card

---
 .../Display_Renderer-gemu-1.0/src/renderer.h  |  2 +-
 lib/lib_display/UDisplay/uDisplay.cpp         | 30 +++++++------------
 lib/lib_display/UDisplay/uDisplay.h           |  2 +-
 3 files changed, 13 insertions(+), 21 deletions(-)

diff --git a/lib/lib_display/Display_Renderer-gemu-1.0/src/renderer.h b/lib/lib_display/Display_Renderer-gemu-1.0/src/renderer.h
index 925b0ad7d..74d812529 100644
--- a/lib/lib_display/Display_Renderer-gemu-1.0/src/renderer.h
+++ b/lib/lib_display/Display_Renderer-gemu-1.0/src/renderer.h
@@ -34,7 +34,7 @@ typedef struct LVGL_PARAMS {
     struct {
       uint8_t use_dma : 1;
       uint8_t swap_color : 1;
-      uint8_t resvd_0 : 1;
+      uint8_t async_dma : 1;   // force DMA completion before returning, avoid conflict with other devices on same bus. If set you should make sure the display is the only device on the bus
       uint8_t resvd_1 : 1;
       uint8_t resvd_2 : 1;
       uint8_t resvd_3 : 1;
diff --git a/lib/lib_display/UDisplay/uDisplay.cpp b/lib/lib_display/UDisplay/uDisplay.cpp
index a6b8d1e6f..71025069b 100755
--- a/lib/lib_display/UDisplay/uDisplay.cpp
+++ b/lib/lib_display/UDisplay/uDisplay.cpp
@@ -465,7 +465,7 @@ Renderer *uDisplay::Init(void) {
       uspi->begin(spi_clk, spi_miso, spi_mosi, -1);
       if (lvgl_param.use_dma) {
         spi_host = VSPI_HOST;
-        initDMA(spi_cs);
+        initDMA(lvgl_param.async_dma ? spi_cs : -1);   // disable DMA CS if sync, we control it directly
       }
 
     } else if (spi_nr == 2) {
@@ -473,7 +473,7 @@ Renderer *uDisplay::Init(void) {
       uspi->begin(spi_clk, spi_miso, spi_mosi, -1);
       if (lvgl_param.use_dma) {
         spi_host = HSPI_HOST;
-        initDMA(spi_cs);
+        initDMA(lvgl_param.async_dma ? spi_cs : -1);   // disable DMA CS if sync, we control it directly
       }
     } else {
       pinMode(spi_clk, OUTPUT);
@@ -1974,24 +1974,13 @@ void uDisplay::beginTransaction(SPISettings s) {
 #ifdef ESP32
   if (lvgl_param.use_dma) {
     dmaWait();
-  } else {
-    uspi->beginTransaction(s);
   }
-#else
-  uspi->beginTransaction(s);
 #endif
+  uspi->beginTransaction(s);
 }
 
 void uDisplay::endTransaction(void) {
-#ifdef ESP32
-  if (lvgl_param.use_dma) {
-    dmaBusy();
-  } else {
-    uspi->endTransaction();
-  }
-#else
   uspi->endTransaction();
-#endif
 }
 
 
@@ -2002,7 +1991,7 @@ void uDisplay::endTransaction(void) {
 ** Function name:           initDMA
 ** Description:             Initialise the DMA engine - returns true if init OK
 ***************************************************************************************/
-bool uDisplay::initDMA(bool ctrl_cs)
+bool uDisplay::initDMA(int32_t ctrl_cs)
 {
   if (DMA_Enabled) return false;
 
@@ -2018,9 +2007,6 @@ bool uDisplay::initDMA(bool ctrl_cs)
     .intr_flags = 0
   };
 
-  int8_t pin = -1;
-  if (ctrl_cs) pin = spi_cs;
-
   spi_device_interface_config_t devcfg = {
     .command_bits = 0,
     .address_bits = 0,
@@ -2031,7 +2017,7 @@ bool uDisplay::initDMA(bool ctrl_cs)
     .cs_ena_posttrans = 0,
     .clock_speed_hz = spi_speed*1000000,
     .input_delay_ns = 0,
-    .spics_io_num = pin,
+    .spics_io_num = ctrl_cs,
     .flags = SPI_DEVICE_NO_DUMMY, //0,
     .queue_size = 1,
     .pre_cb = 0, //dc_callback, //Callback to handle D/C line
@@ -2119,6 +2105,9 @@ void uDisplay::pushPixelsDMA(uint16_t* image, uint32_t len) {
   assert(ret == ESP_OK);
 
   spiBusyCheck++;
+  if (!lvgl_param.async_dma) {
+    dmaWait();
+  }
 }
 
 /***************************************************************************************
@@ -2145,6 +2134,9 @@ void uDisplay::pushPixels3DMA(uint8_t* image, uint32_t len) {
   assert(ret == ESP_OK);
 
   spiBusyCheck++;
+  if (!lvgl_param.async_dma) {
+    dmaWait();
+  }
 }
 
 
diff --git a/lib/lib_display/UDisplay/uDisplay.h b/lib/lib_display/UDisplay/uDisplay.h
index b5eae65c5..9a233fcff 100755
--- a/lib/lib_display/UDisplay/uDisplay.h
+++ b/lib/lib_display/UDisplay/uDisplay.h
@@ -233,7 +233,7 @@ class uDisplay : public Renderer {
    spi_device_handle_t dmaHAL;
    spi_host_device_t spi_host = VSPI_HOST;
    // spi_host_device_t spi_host = VSPI_HOST;
-   bool initDMA(bool ctrl_cs);
+   bool initDMA(int32_t ctrl_cs);
    void deInitDMA(void);
    bool dmaBusy(void);
    void dmaWait(void);