From da05b3ba94b9aa688dff2f6de5cef2d3c3c2211c Mon Sep 17 00:00:00 2001
From: Maik Stohn <marlin@stohn.de>
Date: Wed, 5 Jun 2013 16:27:44 +0200
Subject: [PATCH] faster GLCD (ST7920 SW-SPI) implementation / fixes

- fixed long menu entries (>14 or >18 chars) caused overrun in dogm lcd
implementation
- fixed pin set problem when in interrupt
- much faster ST7920 SW-SPI implementation
- increased ST7920 framebuffer size for more speed
---
 Marlin/dogm_lcd_implementation.h    |   9 +-
 Marlin/ultralcd_st7920_u8glib_rrd.h | 131 ++++++++++++++++++++++++++++
 2 files changed, 135 insertions(+), 5 deletions(-)
 create mode 100644 Marlin/ultralcd_st7920_u8glib_rrd.h

diff --git a/Marlin/dogm_lcd_implementation.h b/Marlin/dogm_lcd_implementation.h
index 6b35b6aca..17a56adba 100644
--- a/Marlin/dogm_lcd_implementation.h
+++ b/Marlin/dogm_lcd_implementation.h
@@ -33,11 +33,11 @@
 #define LCD_CLICKED (buttons&EN_C)
 #endif
 
-// CHANGE_DE begin ***
-#include <U8glib.h>	// DE_U8glib
+#include <U8glib.h>
 #include "DOGMbitmaps.h"
 #include "dogm_font_data_marlin.h"
 #include "ultralcd.h"
+#include "ultralcd_st7920_u8glib_rrd.h"
 
 
 /* Russian language not supported yet, needs custom font
@@ -74,11 +74,10 @@
 
 #define FONT_STATUSMENU	u8g_font_6x9
 
-
 // LCD selection
 #ifdef U8GLIB_ST7920
-// SPI Com: SCK = en = (D4), MOSI = rw = (RS), CS = di = (ENABLE)
-U8GLIB_ST7920_128X64_1X u8g(LCD_PINS_D4, LCD_PINS_ENABLE, LCD_PINS_RS);
+//U8GLIB_ST7920_128X64_RRD u8g(0,0,0);
+U8GLIB_ST7920_128X64_RRD u8g(0);
 #else
 U8GLIB_DOGM128 u8g(DOGLCD_CS, DOGLCD_A0);	// HW-SPI Com: CS, A0
 #endif
diff --git a/Marlin/ultralcd_st7920_u8glib_rrd.h b/Marlin/ultralcd_st7920_u8glib_rrd.h
new file mode 100644
index 000000000..e198a858a
--- /dev/null
+++ b/Marlin/ultralcd_st7920_u8glib_rrd.h
@@ -0,0 +1,131 @@
+#ifndef ULCDST7920_H
+#define ULCDST7920_H
+
+#include "Marlin.h"
+
+#ifdef U8GLIB_ST7920
+
+//set optimization so ARDUINO optimizes this file
+#pragma GCC optimize (3)
+
+#define ST7920_CLK_PIN  LCD_PINS_D4
+#define ST7920_DAT_PIN  LCD_PINS_ENABLE
+#define ST7920_CS_PIN   LCD_PINS_RS
+
+//#define PAGE_HEIGHT 8   //128 byte frambuffer
+//#define PAGE_HEIGHT 16  //256 byte frambuffer
+#define PAGE_HEIGHT 32  //512 byte framebuffer
+
+#define WIDTH 128
+#define HEIGHT 64
+
+#include <U8glib.h>
+
+static void ST7920_SWSPI_SND_8BIT(uint8_t val)
+{
+  uint8_t i;
+  for( i=0; i<8; i++ )
+  {
+    WRITE(ST7920_CLK_PIN,0);
+    WRITE(ST7920_DAT_PIN,val&0x80); 
+    val<<=1;
+    WRITE(ST7920_CLK_PIN,1);
+  }
+}
+
+#define ST7920_CS()              {WRITE(ST7920_CS_PIN,1);u8g_10MicroDelay();}
+#define ST7920_NCS()             {WRITE(ST7920_CS_PIN,0);}
+#define ST7920_SET_CMD()         {ST7920_SWSPI_SND_8BIT(0xf8);u8g_10MicroDelay();}
+#define ST7920_SET_DAT()         {ST7920_SWSPI_SND_8BIT(0xfa);u8g_10MicroDelay();}
+#define ST7920_WRITE_BYTE(a)     {ST7920_SWSPI_SND_8BIT((a)&0xf0);ST7920_SWSPI_SND_8BIT((a)<<4);u8g_10MicroDelay();}
+#define ST7920_WRITE_BYTES(p,l)  {uint8_t i;for(i=0;i<l;i++){ST7920_SWSPI_SND_8BIT(*p&0xf0);ST7920_SWSPI_SND_8BIT(*p<<4);p++;}u8g_10MicroDelay();}
+
+uint8_t u8g_dev_rrd_st7920_128x64_fn(u8g_t *u8g, u8g_dev_t *dev, uint8_t msg, void *arg)
+{
+  uint8_t i,y;
+  switch(msg)
+  {
+    case U8G_DEV_MSG_INIT:
+      {
+        SET_OUTPUT(ST7920_CS_PIN);
+        WRITE(ST7920_CS_PIN,0);
+        SET_OUTPUT(ST7920_DAT_PIN);
+        WRITE(ST7920_DAT_PIN,0);
+        SET_OUTPUT(ST7920_CLK_PIN);
+        WRITE(ST7920_CLK_PIN,1);
+
+        ST7920_CS();
+        u8g_Delay(90);                 //initial delay for boot up
+        ST7920_SET_CMD();
+        ST7920_WRITE_BYTE(0x08);       //display off, cursor+blink off
+        ST7920_WRITE_BYTE(0x01);       //clear CGRAM ram
+        u8g_Delay(10);                 //delay for cgram clear
+        ST7920_WRITE_BYTE(0x3E);       //extended mode + gdram active
+        for(y=0;y<HEIGHT/2;y++)        //clear GDRAM
+        {
+          ST7920_WRITE_BYTE(0x80|y);   //set y
+          ST7920_WRITE_BYTE(0x80);     //set x = 0
+          ST7920_SET_DAT();
+          for(i=0;i<2*WIDTH/8;i++)     //2x width clears both segments
+            ST7920_WRITE_BYTE(0);
+          ST7920_SET_CMD();
+        }
+        ST7920_WRITE_BYTE(0x0C); //display on, cursor+blink off
+        ST7920_NCS();
+      }
+      break;
+
+    case U8G_DEV_MSG_STOP:
+      break;
+    case U8G_DEV_MSG_PAGE_NEXT:
+      {
+        uint8_t *ptr;
+        u8g_pb_t *pb = (u8g_pb_t *)(dev->dev_mem);
+        y = pb->p.page_y0;
+        ptr = (uint8_t*)pb->buf;
+
+        ST7920_CS();
+        for( i = 0; i < PAGE_HEIGHT; i ++ )
+        {
+          ST7920_SET_CMD();
+          if ( y < 32 )
+          {
+            ST7920_WRITE_BYTE(0x80 | y);       //y
+            ST7920_WRITE_BYTE(0x80);           //x=0
+          }
+          else
+          {
+            ST7920_WRITE_BYTE(0x80 | (y-32));  //y
+            ST7920_WRITE_BYTE(0x80 | 8);       //x=64
+          }
+
+          ST7920_SET_DAT();
+          ST7920_WRITE_BYTES(ptr,WIDTH/8); //ptr is incremented inside of macro
+          y++;
+        }
+        ST7920_NCS();
+      }
+      break;
+  }
+#if PAGE_HEIGHT == 8
+  return u8g_dev_pb8h1_base_fn(u8g, dev, msg, arg);
+#elif PAGE_HEIGHT == 16
+  return u8g_dev_pb16h1_base_fn(u8g, dev, msg, arg);
+#else
+  return u8g_dev_pb32h1_base_fn(u8g, dev, msg, arg);
+#endif
+}
+
+uint8_t   u8g_dev_st7920_128x64_rrd_buf[WIDTH*(PAGE_HEIGHT/8)] U8G_NOCOMMON;
+u8g_pb_t  u8g_dev_st7920_128x64_rrd_pb = {{PAGE_HEIGHT,HEIGHT,0,0,0},WIDTH,u8g_dev_st7920_128x64_rrd_buf};
+u8g_dev_t u8g_dev_st7920_128x64_rrd_sw_spi = {u8g_dev_rrd_st7920_128x64_fn,&u8g_dev_st7920_128x64_rrd_pb,&u8g_com_null_fn};
+
+class U8GLIB_ST7920_128X64_RRD : public U8GLIB
+{
+  public:
+    U8GLIB_ST7920_128X64_RRD(uint8_t dummy) : U8GLIB(&u8g_dev_st7920_128x64_rrd_sw_spi) {}
+};
+
+
+#endif //U8GLIB_ST7920
+#endif //ULCDST7920_H