Revision 3:e5d5e2fe4bf6, committed 2010-11-28

Comitter:

hlipka

Date:

Sun Nov 28 22:09:54 2010 +0000

Parent:

2:5ac5bab7daaf

Child:

4:aa08e82834dc

Commit message:

Made LCD driver thread safe (to allow usage from timers)

Changed in this revision

--- a/dogm_spi.cpp	Sat Nov 27 22:54:13 2010 +0000
+++ b/dogm_spi.cpp	Sun Nov 28 22:09:54 2010 +0000
@@ -50,15 +50,18 @@
 void DogmLCDSPI::character(int column, int row, int c)
 {
     int address=(row)*0x40+(column);
+    _guard->take();
     sendCmd((char)address|0x80);
     wait_ms(1);
     sendData(c);
+    _guard->release();
     wait_ms(1);
 }
 
 void DogmLCDSPI::writeText(const unsigned int column, const unsigned int row, const char text[])
 {
     int address=(row)*0x40+(column);
+    _guard->take();
     sendCmd((char)address|0x80);
     wait_ms(1);
     
@@ -69,10 +72,13 @@
         wait_ms(1);
         i++;
     }
+    _guard->release();
 }
 
 void DogmLCDSPI::clear()
 {
+    _guard->take();
     sendCmd(1);
+    _guard->release();
 }
 

--- a/dogm_spi.h	Sat Nov 27 22:54:13 2010 +0000
+++ b/dogm_spi.h	Sun Nov 28 22:09:54 2010 +0000
@@ -1,17 +1,17 @@
 /*
  * mbed LCDWindow library
 * Copyright (c) 2010 Hendrik Lipka
-* 
+*
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
-* 
+*
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
-* 
+*
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -28,28 +28,27 @@
 
 #include "DigitalOut.h"
 #include "SPI.h"
+#include "semaphore.h"
 
-using namespace mbed; 
+using namespace mbed;
 
 /**
  * class for connecting a DOGM16x LCD display, from electronic assembly (www.lcd-module.com )
 */
-class DogmLCDSPI: public SPILCDBase
-{
-    public:
-        /**
-         * @param columns number of chars per line
-         * @param rows number of lines (currently only 1 and 2 work)
-         * @param the SPI object used for sending data (set to 1MHz)
-         * @param enable the pin name for the enable line (0=active, connected to /CSB)
-         * @param rs the pin name for the register select line (0=cmd, 1=data)
-        */
-        DogmLCDSPI(unsigned int columns, unsigned int rows, SPI *spi, PinName enable, PinName rs); 
-        virtual void init();
-        virtual void writeText(const unsigned int column, const unsigned int row, const char text[]);
-        virtual void clear();
-        virtual void character(int column, int row, int c);
-
+class DogmLCDSPI: public SPILCDBase {
+public:
+    /**
+     * @param columns number of chars per line
+     * @param rows number of lines (currently only 1 and 2 work)
+     * @param the SPI object used for sending data (set to 1MHz)
+     * @param enable the pin name for the enable line (0=active, connected to /CSB)
+     * @param rs the pin name for the register select line (0=cmd, 1=data)
+    */
+    DogmLCDSPI(unsigned int columns, unsigned int rows, SPI *spi, PinName enable, PinName rs);
+    virtual void init();
+    virtual void writeText(const unsigned int column, const unsigned int row, const char text[]);
+    virtual void clear();
+    virtual void character(int column, int row, int c);
 };
 
 #endif
\ No newline at end of file

--- a/hd44780_8bit.cpp	Sat Nov 27 22:54:13 2010 +0000
+++ b/hd44780_8bit.cpp	Sun Nov 28 22:09:54 2010 +0000
@@ -30,9 +30,11 @@
 void HD44780LCD8bit::character(int column, int row, int c)
 {
     int address=(row)*0x40+(column);
+    _guard->take();
     sendCmd((unsigned char)address|0x80);
     wait_us(30);
     sendData(c);
+    _guard->release();
     wait_us(30);
 }
 
@@ -40,6 +42,7 @@
 void HD44780LCD8bit::writeText(const unsigned int column, const unsigned int row, const char text[]) {
 //    printf("print to %d,%d {%s}\n",line,pos,text);
     int address=row*0x40+column;
+    _guard->take();
     sendCmd((unsigned char)address|0x80);
     wait_us(30);
 
@@ -49,10 +52,13 @@
         wait_us(30);
         i++;
     }
+    _guard->release();
 }
 
 void HD44780LCD8bit::clear() {
+    _guard->take();
     sendCmd(1);
+    _guard->release();
 }
 
 void HD44780LCD8bit::sendCmd(const unsigned char cmd) {

--- a/ks0108_8bit.cpp	Sat Nov 27 22:54:13 2010 +0000
+++ b/ks0108_8bit.cpp	Sun Nov 28 22:09:54 2010 +0000
@@ -39,9 +39,11 @@
 }
 
 void KS0108LCD8bit::clear() {
+    _guard->take();
     clearHalf(_left);
     if (NULL!=_right)
         clearHalf(_right);
+    _guard->release();
 }
 
 void KS0108LCD8bit::clearHalf(DigitalOut* cs) {
@@ -74,6 +76,7 @@
     if (NULL==cs)
         return;
     
+    _guard->take();
     sendCmd(0xb8|row,cs); // set x page    
 
     unsigned int y=icolumn*8;
@@ -85,6 +88,7 @@
         sendData(font_data[c][i],cs);
     }
     
+    _guard->release();
 }
 
 KS0108LCD8bit::KS0108LCD8bit

--- a/lcd.h	Sat Nov 27 22:54:13 2010 +0000
+++ b/lcd.h	Sun Nov 28 22:09:54 2010 +0000
@@ -42,9 +42,10 @@
     protected:
         const unsigned int _columns;
         const unsigned int _rows;
-        TextLCDBase(unsigned int columns, unsigned int rows):_columns(columns),_rows(rows)
+        TextLCDBase(unsigned int columns, unsigned int rows):Window(),_columns(columns),_rows(rows)
         {
-        } 
+        };
+        void test(){printf("x");};
 };
 
 #endif /*LCD_H_*/

--- a/multiwindow.cpp	Sat Nov 27 22:54:13 2010 +0000
+++ b/multiwindow.cpp	Sun Nov 28 22:09:54 2010 +0000
@@ -23,7 +23,7 @@
 
 #include "multiwindow.h"
 
-MultiWindow::MultiWindow(vector<Window*> lcds) {
+MultiWindow::MultiWindow(vector<Window*> lcds):Window() {
     _lcds=lcds;
     int len=_lcds.size();
     _rows=0;

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/semaphore.cpp	Sun Nov 28 22:09:54 2010 +0000
@@ -0,0 +1,39 @@
+/**
+ * code from Igor Skochinsky
+ * taken from http://mbed.org/forum/mbed/post/799/
+*/
+
+#include "semaphore.h"
+
+  Semaphore::Semaphore(): s(SemFree) {};
+  
+  bool Semaphore::take(bool block)
+  {
+    int oldval;
+#if defined(TARGET_LPC1768) // on Cortex-M3 we can use ldrex/strex
+    do {
+      // read the semaphore value
+      oldval = __ldrex(&s);
+      // loop again if it is locked and we are blocking
+      // or setting it with strex failed
+    }
+    while ( (block && oldval == SemTaken) || __strex(SemTaken, &s) != 0 );
+    if ( !block ) __clrex(); // clear exclusive lock set by ldrex
+#else // on arm7 there's only swp
+    do {
+      // swp sets the pointed data to the given value and returns the previous one
+      oldval = __swp(SemTaken, &s);
+      // if blocking, loop until the previous value becomes 0
+      // which would mean we have successfully taken the lock
+    }
+    while (block && oldval == SemTaken);
+#endif
+    return oldval == SemFree;
+  }
+  
+  // release the semaphore
+  void Semaphore::release()
+  {
+    s = SemFree;
+  }
+  
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/semaphore.h	Sun Nov 28 22:09:54 2010 +0000
@@ -0,0 +1,28 @@
+/**
+ * code from Igor Skochinsky
+ * taken from http://mbed.org/forum/mbed/post/799/
+*/
+
+#ifndef SEMAPHORE_H_
+#define SEMAPHORE_H_
+
+class Semaphore
+{
+public:
+  // constructor
+  Semaphore();
+  
+  // try to take the semaphore and return success
+  // by default block until succeeded
+  bool take(bool block = true);
+  // release the semaphore
+  void release();
+  
+ private:
+   enum { SemFree, SemTaken };
+  // semaphore value
+  int s;  
+
+};
+
+#endif

--- a/subwindow.cpp	Sat Nov 27 22:54:13 2010 +0000
+++ b/subwindow.cpp	Sun Nov 28 22:09:54 2010 +0000
@@ -25,7 +25,8 @@
 
 #include "string.h"
 
-SubWindow::SubWindow(Window* lcd, const unsigned int columnOffset, const unsigned int rowOffset, const unsigned int columns, const unsigned int rows) {
+SubWindow::SubWindow(Window* lcd, const unsigned int columnOffset, const unsigned int rowOffset, const unsigned int columns, const unsigned int rows)
+:Window() {
     _lcd=lcd;
     _columnOffset=columnOffset;
     _rowOffset=rowOffset;

--- a/teewindow.cpp	Sat Nov 27 22:54:13 2010 +0000
+++ b/teewindow.cpp	Sun Nov 28 22:09:54 2010 +0000
@@ -23,7 +23,7 @@
 
 #include "teewindow.h"
 
-TeeWindow::TeeWindow(vector<Window*> lcds) {
+TeeWindow::TeeWindow(vector<Window*> lcds):Window() {
     _lcds=lcds;
     int len=_lcds.size();
     _columns=_lcds[0]->getColumns();

--- a/terminal.cpp	Sat Nov 27 22:54:13 2010 +0000
+++ b/terminal.cpp	Sun Nov 28 22:09:54 2010 +0000
@@ -24,7 +24,7 @@
 #include "terminal.h"
 #include "string.h"
 
-Terminal::Terminal(Window* window) {
+Terminal::Terminal(Window* window):Window() {
     _window=window;
     _columns=window->getColumns();
     _rows=window->getRows();

--- a/window.cpp	Sat Nov 27 22:54:13 2010 +0000
+++ b/window.cpp	Sun Nov 28 22:09:54 2010 +0000
@@ -47,4 +47,9 @@
         }
     }
     return value;
+}
+
+Window::Window()
+{
+    _guard=new Semaphore();
 }
\ No newline at end of file

--- a/window.h	Sat Nov 27 22:54:13 2010 +0000
+++ b/window.h	Sun Nov 28 22:09:54 2010 +0000
@@ -25,6 +25,7 @@
 #define WINDOW_H_
 
 #include "Stream.h"
+#include "semaphore.h"
 
 using namespace mbed;
 
@@ -55,7 +56,7 @@
     */
     virtual void clear()=0;
 
-    /** 
+    /**
     * set (internal) cursor to a screen column and row
     *
     * @param column  The horizontal position from the left, indexed from 0
@@ -74,7 +75,7 @@
     virtual void character(int column, int row, int c)=0;
 
 #if DOXYGEN_ONLY
-    /** 
+    /**
      * Write a character to the LCD, on the position specified by the cursor
      * sets the cursor to the next position, and wraps (from right to left, next line, and from bottom back to top)
      *
@@ -82,7 +83,7 @@
      */
     int putc(int c);
 
-    /** 
+    /**
      * Write a formated string to the LCD, on the position specified by the cursor
      * does wrap around (as specified by putc)
      *
@@ -92,6 +93,12 @@
     int printf(const char* format, ...);
 #endif
 protected:
+    /**
+     * base constructor
+     * initializes the _guard semaphore needed for syncing parallel writes
+    */
+    Window();
+
     // Stream implementation functions
     virtual int _putc(int value);
     virtual int _getc() {
@@ -100,6 +107,8 @@
 
     int _column;
     int _row;
+
+    Semaphore *_guard;
 };
 
 #endif /*WINDOW_H_*/