From 744c797e30da38683e4988283c0734be6b025a19 Mon Sep 17 00:00:00 2001
From: JivaroFAD <jivarofad@gmail.com>
Date: Sun, 17 May 2015 20:26:41 +0200
Subject: [PATCH] ST7920 support added for 9x and M2560 boards

Merge of olterion ST7920 driver, thanks :)
Draft... please check !
---
 radio/src/Makefile                     |  20 ++--
 radio/src/targets/stock/lcd_driver.cpp | 145 +++++++++++++++++--------
 2 files changed, 113 insertions(+), 52 deletions(-)

diff --git a/radio/src/Makefile b/radio/src/Makefile
index be8eb81f8..0419170fa 100644
--- a/radio/src/Makefile
+++ b/radio/src/Makefile
@@ -57,6 +57,10 @@ PCB = 9X
 # PCB revision
 PCBREV =
 
+# LCD
+# Values: DEFAULT, ST7565P, ST7565R, ERC12864FSF, ST7920
+LCD = DEFAULT
+
 # Enable JETI-Telemetry or FrSky Telemetry reception on UART0
 # For this option you need to modify your hardware!
 # More information at [insertURLhere]
@@ -681,13 +685,7 @@ ifeq ($(PCB), MEGA2560)
   BITMAPS += bitmaps/9X/splash.lbm bitmaps/9X/asterisk.lbm bitmaps/9X/about.lbm
   GUIGENERALSRC += gui/$(GUIDIRECTORY)/menu_general_diagkeys.cpp gui/$(GUIDIRECTORY)/menu_general_diaganas.cpp
 
-  # LCD driver
-  # Values: ST7565P(default), ST7565R 
-  LCD = ST7565P
-  ifeq ($(LCD), ST7565R)
-    CPPDEFS += -DLCD_ST7565R
-  endif   
-    EXTRABOARDSRC = targets/common_avr/adc_driver.cpp targets/stock/lcd_driver.cpp targets/common_avr/telemetry_driver.cpp
+  EXTRABOARDSRC = targets/common_avr/adc_driver.cpp targets/stock/lcd_driver.cpp targets/common_avr/telemetry_driver.cpp
 
   ifeq ($(SDCARD), YES)
     EXTRABOARDSRC += $(FATFSDIR)/ff.c $(FATFSDIR)/fattime.c $(FATFSDIR)/option/ccsbcs.c targets/gruvin9x/diskio.cpp
@@ -1072,6 +1070,14 @@ ifeq ($(TURNIGY_TRANSMITTER_FIX), YES)
   endif
 endif
 
+ifeq ($(LCD), ST7565R)
+  CPPDEFS += -DLCD_ST7565R
+else ifeq ($(LCD), ERC12864FSF)
+  CPPDEFS += -DLCD_ERC12864FSF
+else ifeq ($(LCD), ST7920)
+  CPPDEFS += -DLCD_ST7920
+endif   
+
 ifeq ($(AUTOSWITCH), YES)
   CPPDEFS += -DAUTOSWITCH
 endif
diff --git a/radio/src/targets/stock/lcd_driver.cpp b/radio/src/targets/stock/lcd_driver.cpp
index ed5323c47..7eb774336 100644
--- a/radio/src/targets/stock/lcd_driver.cpp
+++ b/radio/src/targets/stock/lcd_driver.cpp
@@ -47,7 +47,7 @@ void lcdSendCtl(uint8_t val)
 {
   PORTC_LCD_CTRL &= ~(1<<OUT_C_LCD_CS1);
 #ifdef LCD_MULTIPLEX
-  DDRA = 0xFF; // set LCD_DAT pins to output
+  DDRA = 0xFF; //Set LCD_DAT pins to output
 #endif
   PORTC_LCD_CTRL &= ~(1<<OUT_C_LCD_A0);
   PORTC_LCD_CTRL &= ~(1<<OUT_C_LCD_RnW);
@@ -56,7 +56,7 @@ void lcdSendCtl(uint8_t val)
   PORTC_LCD_CTRL &= ~(1<<OUT_C_LCD_E);
   PORTC_LCD_CTRL |=  (1<<OUT_C_LCD_A0);
 #ifdef LCD_MULTIPLEX
-  DDRA = 0x00; // set LCD_DAT pins to input
+  DDRA = 0x00; //Set LCD_DAT pins to input
 #endif
   PORTC_LCD_CTRL |=  (1<<OUT_C_LCD_CS1);
 }
@@ -72,7 +72,7 @@ volatile uint8_t LcdLock ;
 
 const static pm_uchar lcdInitSequence[] PROGMEM =
 {
-#ifdef LCD_ST7565R
+#if defined(LCD_ST7565R)
    0xE2, //Initialize the internal functions
    0xAE, //DON = 0: display OFF
    0xA0, //ADC = 0: normal direction(SEG132->SEG1)
@@ -86,7 +86,7 @@ const static pm_uchar lcdInitSequence[] PROGMEM =
    0x22, //24 SV5 SV4 SV3 SV2 SV1 SV0 = 0x18
    0xAF, //DON = 1: display ON
    0x60  //sets the display start line to zero
-#elif LCD_ERC12864FSF
+#elif defined(LCD_ERC12864FSF)
    0xE2, //Initialize the internal functions
    0xAE, //DON = 0: display OFF
    0xA1, //ADC = 1: reverse direction(SEG132->SEG1)
@@ -99,7 +99,13 @@ const static pm_uchar lcdInitSequence[] PROGMEM =
    0x81, //Set reference voltage Mode
    0x2D, //24 SV5 SV4 SV3 SV2 SV1 SV0
    0xAF  //DON = 1: display ON
-#else
+#elif defined(LCD_ST7920)
+   0x30, //Set 8-bit interface
+   0x36, //Repeat with graphics bit set to ON
+   0x0C, //Display ON, cursor and blink OFF
+   0x01, //Clear display, reset address
+   0x06  //Display ON, no cursor
+#else    //ST7565P (default 9x LCD)
    0xE2, //Initialize the internal functions
    0xAE, //DON = 0: display OFF
    0xA1, //ADC = 1: reverse direction(SEG132->SEG1)
@@ -121,58 +127,107 @@ inline void lcdInit()
   // ~/txt/flieger/ST7565RV17.pdf  from http://www.glyn.de/content.asp?wdid=132&sid=
 
   LCD_LOCK();
-  PORTC_LCD_CTRL &= ~(1<<OUT_C_LCD_RES);  //LCD_RES
-  delay_2us();
-  PORTC_LCD_CTRL |= (1<<OUT_C_LCD_RES); //  f524  sbi 0x15, 2 IOADR-PORTC_LCD_CTRL; 21           1
-  delay_1_5us(1500);
+  PORTC_LCD_CTRL &= ~(1<<OUT_C_LCD_RES);  //LCD reset
+  #ifdef LCD_ST7920
+    _delay_ms(1);
+  #else
+    delay_2us();       //TODO : verify if can be set to 1ms => so some value for both screen and no #ifdef
+  #endif
+  PORTC_LCD_CTRL |= (1<<OUT_C_LCD_RES);  //LCD normal operation
+  #ifdef LCD_ST7920
+    _delay_ms(40);
+  #else
+    delay_1_5us(1500); //TODO : verify if can be set to 40 ms instead of 1.5 ms
+  #endif    
   for (uint8_t i=0; i<DIM(lcdInitSequence); i++) {
     lcdSendCtl(pgm_read_byte(&lcdInitSequence[i])) ;
+    #ifdef LCD_ST7920
+      _delay_us(80);
+    #endif   
   }
-#ifdef LCD_ERC12864FSF
-  g_eeGeneral.contrast = 0x2D;
-#else
-  g_eeGeneral.contrast = 0x22;
-#endif
+  #ifdef LCD_ERC12864FSF
+    g_eeGeneral.contrast = 0x2D;
+  #else
+    g_eeGeneral.contrast = 0x22;
+  #endif
   LCD_UNLOCK();
 }
 
 void lcdSetRefVolt(uint8_t val)
 {
-  LCD_LOCK();
-  lcdSendCtl(0x81);
-  lcdSendCtl(val);
-  LCD_UNLOCK();
+  #ifndef LCD_ST7920 //No contrast setting in the ST7920 controller
+    LCD_LOCK();
+    lcdSendCtl(0x81);
+    lcdSendCtl(val);
+    LCD_UNLOCK();
+  #endif
 }
 
 void lcdRefresh()
 {
   LCD_LOCK();
-  uint8_t *p=displayBuf;
-  for(uint8_t y=0; y < 8; y++) {
-  
-#ifdef LCD_ST7565R
-    lcdSendCtl(0x01);
-#else
-    lcdSendCtl(0x04);
-#endif
-
-    lcdSendCtl(0x10); //column addr 0
-    lcdSendCtl( y | 0xB0); //page addr y
-    PORTC_LCD_CTRL &= ~(1<<OUT_C_LCD_CS1);
-#ifdef LCD_MULTIPLEX
-    DDRA = 0xFF; // set LCD_DAT pins to output
-#endif
-    PORTC_LCD_CTRL |=  (1<<OUT_C_LCD_A0);
-    PORTC_LCD_CTRL &= ~(1<<OUT_C_LCD_RnW);
-    for (coord_t x=LCD_W; x>0; --x) {
-      PORTA_LCD_DAT = *p++;
-      PORTC_LCD_CTRL |= (1<<OUT_C_LCD_E);
-      PORTC_LCD_CTRL &= ~(1<<OUT_C_LCD_E);
-    }
-    PORTC_LCD_CTRL |=  (1<<OUT_C_LCD_A0);
-    PORTC_LCD_CTRL |=  (1<<OUT_C_LCD_CS1);
+#ifdef LCD_ST7920
+	uint8_t x_addr = 0;
+	uint8_t y_addr = 0;
+	uint16_t line_offset = 0;
+	uint8_t col_offset = 0;
+	uint16_t byte_offset = 0;
+	uint8_t bit_count = 0;	
+	for(uint8_t y=0; y < 64; y++) {
+		x_addr = 0;
+		//Convert coordinates to weirdly-arranged 128x64 screen (the ST7920 is mapped for 256x32 displays)
+		if (y > 31)
+		{
+			y_addr = y - 32;    //Because there are only 31 addressable lines in the ST7920
+			x_addr += 8;        //so we overflow x (7 visible bytes per line) to reach the bottom half
+		}else{
+			y_addr = y;
+		}
+		lcdSendCtl( 0x80 | y_addr ); 	//Set Vertical Address 
+		_delay_us(49); 
+		lcdSendCtl( 0x80 | x_addr ); 	//Set Horizontal Address
+		_delay_us(49); 
+		PORTC_LCD_CTRL |= (1<<OUT_C_LCD_A0);	  //HIGH RS and LOW RW will put the LCD to    
+		PORTC_LCD_CTRL &= ~(1<<OUT_C_LCD_RnW);	//Write data register mode	
+		bit_count = y & 0x07; //Count from 0 bis 7 -> 0=0, 1=1..7=7, 8=0, 9=1...
+		col_offset = 1 << bit_count; //Build a value for a AND operation with the vorrect bitposition
+		line_offset = ( y / 8 ) * 128; //On the ST7565 there are 8 lines with each 128 bytes width
+		for (coord_t x=0; x < 16; x++) { //Walk through 16 bytes form left to right (128 Pixel)	
+			byte_offset = line_offset + ( x * 8 ); //Calculate the position of the first byte im array
+			//adressing the bytes sequential and shift the bits at the correct position, afterwards a OR operation to get all bits in one byte
+			//the position of the LSB is the left-most position of the byte to the ST7920
+			PORTA_LCD_DAT = (((displayBuf[byte_offset] & col_offset) >> bit_count) << 7) | (((displayBuf[byte_offset + 1] & col_offset) >> bit_count) << 6) | (((displayBuf[byte_offset + 2] & col_offset) >> bit_count ) << 5) | (((displayBuf[byte_offset + 3] & col_offset) >> bit_count ) << 4) | (((displayBuf[byte_offset + 4] & col_offset) >> bit_count ) << 3) | (((displayBuf[byte_offset + 5] & col_offset) >> bit_count ) << 2) | (((displayBuf[byte_offset + 6] & col_offset) >> bit_count ) << 1) | (((displayBuf[byte_offset + 7] & col_offset) >> bit_count ) << 0); 
+			PORTC_LCD_CTRL |= (1<<OUT_C_LCD_E);
+			_delay_us(8); 
+			PORTC_LCD_CTRL &= ~(1<<OUT_C_LCD_E);
+			_delay_us(49); 
+		}
+	}
+#else  //All other LCD
+  uint8_t *p=displayBuf;  
+  for(uint8_t y=0; y < 8; y++) { 
+    #ifdef LCD_ST7565R
+      lcdSendCtl(0x01);
+    #else
+      lcdSendCtl(0x04);
+    #endif
+      lcdSendCtl(0x10); //Column addr 0
+      lcdSendCtl( y | 0xB0); //Page addr y
+      PORTC_LCD_CTRL &= ~(1<<OUT_C_LCD_CS1);
+    #ifdef LCD_MULTIPLEX
+      DDRA = 0xFF; //Set LCD_DAT pins to output
+    #endif
+      PORTC_LCD_CTRL |=  (1<<OUT_C_LCD_A0);
+      PORTC_LCD_CTRL &= ~(1<<OUT_C_LCD_RnW);
+      for (coord_t x=LCD_W; x>0; --x) {
+        PORTA_LCD_DAT = *p++;
+        PORTC_LCD_CTRL |= (1<<OUT_C_LCD_E);
+        PORTC_LCD_CTRL &= ~(1<<OUT_C_LCD_E);
+      }
+      PORTC_LCD_CTRL |=  (1<<OUT_C_LCD_A0);
+      PORTC_LCD_CTRL |=  (1<<OUT_C_LCD_CS1);
   }
+#endif  
   LCD_UNLOCK();
-} 
-
- 
+}
+   
\ No newline at end of file