From b7946a360e1695c9c1431a7e40e078a54a38023b Mon Sep 17 00:00:00 2001
From: Stephan Hadinger <stephan.hadinger@gmail.com>
Date: Sun, 30 May 2021 18:19:14 +0200
Subject: [PATCH] Support for SH1107 over SPI, found in M5Stick

---
 lib/lib_display/UDisplay/uDisplay.cpp  | 84 +++++++++++++++++---------
 tasmota/displaydesc/SH1107_display.ini | 11 ++++
 2 files changed, 68 insertions(+), 27 deletions(-)
 create mode 100644 tasmota/displaydesc/SH1107_display.ini

diff --git a/lib/lib_display/UDisplay/uDisplay.cpp b/lib/lib_display/UDisplay/uDisplay.cpp
index 65644eb04..1b509d3de 100755
--- a/lib/lib_display/UDisplay/uDisplay.cpp
+++ b/lib/lib_display/UDisplay/uDisplay.cpp
@@ -225,7 +225,7 @@ uDisplay::uDisplay(char *lp) : Renderer(800, 600) {
             rot_t[3] = next_hex(&lp1);
             break;
           case 'A':
-            if (interface == _UDSP_I2C) {
+            if (interface == _UDSP_I2C || bpp == 1) {
               saw_1 = next_hex(&lp1);
               i2c_page_start = next_hex(&lp1);
               i2c_page_end = next_hex(&lp1);
@@ -381,6 +381,19 @@ uDisplay::uDisplay(char *lp) : Renderer(800, 600) {
 
 Renderer *uDisplay::Init(void) {
 
+  // for any bpp below native 16 bits, we allocate a local framebuffer to copy into
+  if (ep_mode || bpp < 16) {
+    if (framebuffer) free(framebuffer);
+#ifdef ESP8266
+    framebuffer = (uint8_t*)calloc((gxs * gys * bpp) / 8, 1);
+#else
+    if (psramFound()) {
+      framebuffer = (uint8_t*)heap_caps_malloc((gxs * gys * bpp) / 8, MALLOC_CAP_SPIRAM | MALLOC_CAP_8BIT);
+    } else {
+      framebuffer = (uint8_t*)calloc((gxs * gys * bpp) / 8, 1);
+    }
+    #endif
+  }
 
 
   if (interface == _UDSP_I2C) {
@@ -392,19 +405,7 @@ Renderer *uDisplay::Init(void) {
       wire = &Wire1;
     }
 #endif
-    wire->begin(i2c_sda, i2c_scl);
-    if (bpp < 16) {
-      if (framebuffer) free(framebuffer);
-#ifdef ESP8266
-      framebuffer = (uint8_t*)calloc((gxs * gys * bpp) / 8, 1);
-#else
-      if (psramFound()) {
-        framebuffer = (uint8_t*)heap_caps_malloc((gxs * gys * bpp) / 8, MALLOC_CAP_SPIRAM | MALLOC_CAP_8BIT);
-      } else {
-        framebuffer = (uint8_t*)calloc((gxs * gys * bpp) / 8, 1);
-      }
-#endif
-    }
+    wire->begin(i2c_sda, i2c_scl);    // TODO: aren't I2C buses already initialized? Shouldn't this be moved to display driver?
 
 #ifdef UDSP_DEBUG
     Serial.printf("I2C cmds: %d\n", dsp_ncmds);
@@ -419,18 +420,6 @@ Renderer *uDisplay::Init(void) {
   }
   if (interface == _UDSP_SPI) {
 
-    if (ep_mode) {
-  #ifdef ESP8266
-      framebuffer = (uint8_t*)calloc((gxs * gys * bpp) / 8, 1);
-  #else
-      if (psramFound()) {
-        framebuffer = (uint8_t*)heap_caps_malloc((gxs * gys * bpp) / 8, MALLOC_CAP_SPIRAM | MALLOC_CAP_8BIT);
-      } else {
-        framebuffer = (uint8_t*)calloc((gxs * gys * bpp) / 8, 1);
-      }
-      #endif
-    }
-
     if (bpanel >= 0) {
 #ifdef ESP32
         ledcSetup(ESP32_PWM_CHANNEL, 4000, 8);
@@ -774,9 +763,49 @@ void uDisplay::Updateframe(void) {
 	      }
     }
 #endif
+
  }
 
 
+  if (interface == _UDSP_SPI) {
+    if (framebuffer == nullptr) { return; }
+
+    SPI_BEGIN_TRANSACTION
+    SPI_CS_LOW
+
+    // below commands are not needed for SH1107
+    // spi_command(saw_1 | 0x0);  // set low col = 0, 0x00
+    // spi_command(i2c_page_start | 0x0);  // set hi col = 0, 0x10
+    // spi_command(i2c_page_end | 0x0); // set startline line #0, 0x40
+
+	  uint8_t ys = gys >> 3;
+	  uint8_t xs = gxs >> 3;
+    //uint8_t xs = 132 >> 3;
+	  uint8_t m_row = saw_2;
+	  uint8_t m_col = i2c_col_start;
+    // Serial.printf("m_row=%d m_col=%d xs=%d ys=%d\n", m_row, m_col, xs, ys);
+
+	  uint16_t p = 0;
+
+	  uint8_t i, j, k = 0;
+	  for ( i = 0; i < ys; i++) {   // i = line from 0 to ys
+		    // send a bunch of data in one xmission
+        spi_command(0xB0 + i + m_row); //set page address
+        spi_command(m_col & 0xf); //set lower column address
+        spi_command(0x10 | (m_col >> 4)); //set higher column address
+
+        for ( j = 0; j < 8; j++) {
+            for ( k = 0; k < xs; k++, p++) {
+		            spi_data8(framebuffer[p]);
+            }
+	      }
+    }
+
+    SPI_CS_HIGH
+    SPI_END_TRANSACTION
+
+  }
+
 }
 
 void uDisplay::drawFastVLine(int16_t x, int16_t y, int16_t h, uint16_t color) {
@@ -982,6 +1011,7 @@ void uDisplay::setAddrWindow(uint16_t x0, uint16_t y0, uint16_t x1, uint16_t y1)
       seta_xp2 = x1;
       seta_yp1 = y0;
       seta_yp2 = y1;
+      // Serial.printf("xp1=%d xp2=%d yp1=%d yp2=%d\n", seta_xp1, seta_xp2, seta_yp1, seta_yp2);
     }
     return;
   }
@@ -1206,7 +1236,7 @@ void uDisplay::drawPixel(int16_t x, int16_t y, uint16_t color) {
     return;
   }
 
-  if (interface != _UDSP_SPI) {
+  if (interface != _UDSP_SPI || bpp < 16) {
     Renderer::drawPixel(x, y, color);
     return;
   }
diff --git a/tasmota/displaydesc/SH1107_display.ini b/tasmota/displaydesc/SH1107_display.ini
new file mode 100644
index 000000000..4b644715c
--- /dev/null
+++ b/tasmota/displaydesc/SH1107_display.ini
@@ -0,0 +1,11 @@
+:H,SH1107,64,128,1,SPI,1,*,*,*,*,*,*,*,16
+:S,0,2,1,0,30,20
+:I
+AE,0
+81,0
+2F,0
+:o,AE
+:O,AF
+:A,00,10,40,00,20
+:i,A6,A7
+#