From 79502da4c9926e3eba920ea3d50ad223ea84c9da Mon Sep 17 00:00:00 2001
From: moononournation <moononournation@gmail.com>
Date: Sun, 23 Jul 2023 15:28:22 +0800
Subject: [PATCH] fine tune writePixels

---
 src/databus/Arduino_ESP32LCD8.cpp | 83 ++++++++++++++++++++++++++++++-
 1 file changed, 82 insertions(+), 1 deletion(-)

diff --git a/src/databus/Arduino_ESP32LCD8.cpp b/src/databus/Arduino_ESP32LCD8.cpp
index fe2f3e8a..febf1209 100644
--- a/src/databus/Arduino_ESP32LCD8.cpp
+++ b/src/databus/Arduino_ESP32LCD8.cpp
@@ -431,6 +431,87 @@ void Arduino_ESP32LCD8::writeRepeat(uint16_t p, uint32_t len)
  */
 void Arduino_ESP32LCD8::writePixels(uint16_t *data, uint32_t len)
 {
+  uint32_t xferLen, l;
+
+  if (esp_ptr_dma_capable(data))
+  {
+    while (len > (USE_DMA_THRESHOLD)) // While pixels remain
+    {
+      xferLen = (len >= LCD_MAX_PIXELS_AT_ONCE) ? (LCD_MAX_PIXELS_AT_ONCE) : len; // How many this pass?
+
+      _data16.value = *data++;
+      _data32.value = 0;
+      _data32.lsb = _data16.msb;
+      _data32.lsb_2 = _data16.lsb;
+
+      LCD_CAM.lcd_cmd_val.val = _data32.value;
+      WAIT_LCD_NOT_BUSY;
+      LCD_CAM.lcd_user.val = LCD_CAM_LCD_CMD | LCD_CAM_LCD_CMD_2_CYCLE_EN | LCD_CAM_LCD_UPDATE_REG | LCD_CAM_LCD_START;
+
+      _data16.value = *data++;
+      _data32.value = 0;
+      _data32.lsb = _data16.msb;
+      _data32.lsb_2 = _data16.lsb;
+
+      l = xferLen - 2;
+      l <<= 1;
+      *(uint32_t *)_dmadesc = ((l + 3) & (~3)) | l << 12 | 0xC0000000;
+      _dmadesc->buffer = data;
+      _dmadesc->next = nullptr;
+      gdma_start(_dma_chan, (intptr_t)(_dmadesc));
+      LCD_CAM.lcd_cmd_val.val = _data32.value;
+      LCD_CAM.lcd_user.val = LCD_CAM_LCD_ALWAYS_OUT_EN | LCD_CAM_LCD_DOUT | LCD_CAM_LCD_CMD | LCD_CAM_LCD_CMD_2_CYCLE_EN | LCD_CAM_LCD_UPDATE_REG;
+
+      data += xferLen - 2;
+      len -= xferLen;
+
+      WAIT_LCD_NOT_BUSY;
+      LCD_CAM.lcd_user.val = LCD_CAM_LCD_ALWAYS_OUT_EN | LCD_CAM_LCD_DOUT | LCD_CAM_LCD_CMD | LCD_CAM_LCD_CMD_2_CYCLE_EN | LCD_CAM_LCD_START;
+    }
+  }
+  else
+  {
+    while (len > (USE_DMA_THRESHOLD)) // While pixels remain
+    {
+      xferLen = (len >= LCD_MAX_PIXELS_AT_ONCE) ? (LCD_MAX_PIXELS_AT_ONCE) : len; // How many this pass?
+
+      _data16.value = *data++;
+      _data32.value = 0;
+      _data32.lsb = _data16.msb;
+      _data32.lsb_2 = _data16.lsb;
+
+      LCD_CAM.lcd_cmd_val.val = _data32.value;
+      WAIT_LCD_NOT_BUSY;
+      LCD_CAM.lcd_user.val = LCD_CAM_LCD_CMD | LCD_CAM_LCD_CMD_2_CYCLE_EN | LCD_CAM_LCD_UPDATE_REG | LCD_CAM_LCD_START;
+
+      _data16.value = *data++;
+      _data32.value = 0;
+      _data32.lsb = _data16.msb;
+      _data32.lsb_2 = _data16.lsb;
+
+      l = xferLen - 2;
+      l <<= 1;
+      for (uint32_t i = 0; i < l;)
+      {
+        _data16.value = *data++;
+        _buffer[i++] = _data16.msb;
+        _buffer[i++] = _data16.lsb;
+      }
+
+      *(uint32_t *)_dmadesc = ((l + 3) & (~3)) | l << 12 | 0xC0000000;
+      _dmadesc->buffer = _buffer32;
+      _dmadesc->next = nullptr;
+      gdma_start(_dma_chan, (intptr_t)(_dmadesc));
+      LCD_CAM.lcd_cmd_val.val = _data32.value;
+      LCD_CAM.lcd_user.val = LCD_CAM_LCD_ALWAYS_OUT_EN | LCD_CAM_LCD_DOUT | LCD_CAM_LCD_CMD | LCD_CAM_LCD_CMD_2_CYCLE_EN | LCD_CAM_LCD_UPDATE_REG;
+
+      len -= xferLen;
+
+      WAIT_LCD_NOT_BUSY;
+      LCD_CAM.lcd_user.val = LCD_CAM_LCD_ALWAYS_OUT_EN | LCD_CAM_LCD_DOUT | LCD_CAM_LCD_CMD | LCD_CAM_LCD_CMD_2_CYCLE_EN | LCD_CAM_LCD_START;
+    }
+  }
+
   while (len--)
   {
     _data16.value = *data++;
@@ -451,7 +532,7 @@ void Arduino_ESP32LCD8::writePixels(uint16_t *data, uint32_t len)
  */
 void Arduino_ESP32LCD8::writeBytes(uint8_t *data, uint32_t len)
 {
-  uint32_t xferLen, l, m;
+  uint32_t xferLen, l;
 
   if (esp_ptr_dma_capable(data))
   {