[lcd4linux @ 2000-04-12 08:05:45 by reinelt]

first version of the HD44780 driver

1 files changed, 496 insertions, 0 deletions

diff --git a/HD44780.c b/HD44780.c
new file mode 100644
index 0000000..cdea5bf
--- /dev/null
+++ b/HD44780.c
@@ -0,0 +1,496 @@
+/* $Id: HD44780.c,v 1.1 2000/04/12 08:05:45 reinelt Exp $
+ *
+ * driver for display modules based on the HD44780 chip
+ *
+ * Copyright 1999, 2000 by Michael Reinelt (reinelt@eunet.at)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ *
+ * $Log: HD44780.c,v $
+ * Revision 1.1  2000/04/12 08:05:45  reinelt
+ *
+ * first version of the HD44780 driver
+ *
+ */
+
+/* 
+ *
+ * exported fuctions:
+ *
+ * struct LCD HD44780[]
+ *
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <signal.h>
+#include <errno.h>
+#include <asm/io.h>
+
+#include "cfg.h"
+#include "display.h"
+
+#define XRES 5
+#define YRES 8
+#define CHARS 8
+#define BARS ( BAR_L | BAR_R | BAR_U | BAR_D | BAR_H2 )
+
+static LCD Lcd;
+
+typedef struct {
+  int len1;
+  int len2;
+  int type;
+  int segment;
+} BAR;
+
+typedef struct {
+  int len1;
+  int len2;
+  int type;
+  int used;
+  int ascii;
+} SEGMENT;
+
+static unsigned short Port=0;
+
+static char Txt[4][40];
+static BAR  Bar[4][40];
+
+static int nSegment=2;
+static SEGMENT Segment[128] = {{ len1:0,   len2:0,   type:255, used:0, ascii:32 },
+			       { len1:255, len2:255, type:255, used:0, ascii:255 }};
+
+
+static void HD_delay (unsigned long usec)
+{
+  usleep(usec);
+}
+
+static void HD_command (unsigned char cmd)
+{
+  outb (cmd, Port);    // put data on DB1..DB8
+  outb (0x02, Port+2); // set Enable = bit 0 invertet
+  HD_delay(1);
+  outb (0x03, Port+2); // clear Enable
+}
+
+static void HD_write (char *string, int len)
+{
+  while (len--) {
+    outb (*string++, Port); // put data on DB1..DB8
+    outb (0x00, Port+2); // set Enable = bit 0 invertet
+    HD_delay(1);
+    outb (0x01, Port+2); // clear Enable
+    HD_delay(40);
+  }
+}
+
+static int HD_open (void)
+{
+  if (ioperm(Port, 3, 1)!=0) {
+    fprintf (stderr, "HD44780: ioperm() failed: %s\n", strerror(errno));
+    return -1;
+  }
+
+  HD_command (0x30);  // 8 Bit mode
+  HD_delay (4100);      // wait 4.1 ms
+  HD_command (0x30);  // 8 Bit mode
+  HD_delay (100);       // wait 100 us
+  HD_command (0x30);  // 8 Bit mode
+  HD_delay (4100);      // wait 4.1 ms
+  HD_command (0x38);  // 8 Bit mode, 1/16 duty cycle, 5x8 font
+  HD_delay (40);        // wait 40 us
+  HD_command (0x08);  // Display off, cursor off, blink off
+  HD_delay (40);        // wait 40 us
+  HD_command (0x0c);  // Display on, cursor off, blink off
+  HD_delay (1640);      // wait 1.64 ms
+  HD_command (0x06);  // curser moves to right, no shift
+  HD_delay (40);        // wait 40 us
+
+  return 0;
+}
+
+static void HD_process_bars (void)
+{
+  int row, col;
+  int i, j;
+  
+  for (i=2; i<nSegment && Segment[i].used; i++);
+  for (j=i+1; j<nSegment; j++) {
+    if (Segment[j].used)
+      Segment[i++]=Segment[j];
+  }
+  nSegment=i;
+  
+  for (row=0; row<Lcd.rows; row++) {
+    for (col=0; col<Lcd.cols; col++) {
+      if (Bar[row][col].type==0) continue;
+      for (i=0; i<nSegment; i++) {
+	if (Segment[i].type & Bar[row][col].type &&
+	    Segment[i].len1== Bar[row][col].len1 &&
+	    Segment[i].len2== Bar[row][col].len2) break;
+      }
+      if (i==nSegment) {
+	nSegment++;
+	Segment[i].len1=Bar[row][col].len1;
+	Segment[i].len2=Bar[row][col].len2;
+	Segment[i].type=Bar[row][col].type;
+	Segment[i].used=0;
+	Segment[i].ascii=-1;
+      }
+      Bar[row][col].segment=i;
+    }
+  }
+}
+
+static int HD_segment_diff (int i, int j)
+{
+  int RES;
+  int i1, i2, j1, j2;
+  
+  if (i==j) return 65535;
+  if (!(Segment[i].type & Segment[j].type)) return 65535;
+  if (Segment[i].len1==0 && Segment[j].len1!=0) return 65535;
+  if (Segment[i].len2==0 && Segment[j].len2!=0) return 65535;
+  RES=Segment[i].type & BAR_H ? XRES:YRES;
+  if (Segment[i].len1>=RES && Segment[j].len1<RES) return 65535;
+  if (Segment[i].len2>=RES && Segment[j].len2<RES) return 65535;
+  if (Segment[i].len1==Segment[i].len2 && Segment[j].len1!=Segment[j].len2) return 65535;
+
+  i1=Segment[i].len1; if (i1>RES) i1=RES;
+  i2=Segment[i].len2; if (i2>RES) i2=RES;
+  j1=Segment[j].len1; if (j1>RES) i1=RES;
+  j2=Segment[j].len2; if (j2>RES) i2=RES;
+  
+  return (i1-i2)*(i1-i2)+(j1-j2)*(j1-j2);
+}
+
+static void HD_compact_bars (void)
+{
+  int i, j, r, c, min;
+  int pack_i, pack_j;
+  int pass1=1;
+  int error[nSegment][nSegment];
+  
+  if (nSegment>CHARS+2) {
+
+    for (i=2; i<nSegment; i++) {
+      for (j=0; j<nSegment; j++) {
+	error[i][j]=HD_segment_diff(i,j);
+      }
+    }
+    
+    while (nSegment>CHARS+2) {
+      min=65535;
+      pack_i=-1;
+      pack_j=-1;
+      for (i=2; i<nSegment; i++) {
+	if (pass1 && Segment[i].used) continue;
+	for (j=0; j<nSegment; j++) {
+	  if (error[i][j]<min) {
+	    min=error[i][j];
+	    pack_i=i;
+	    pack_j=j;
+	  }
+	}
+      }
+      if (pack_i==-1) {
+	if (pass1) {
+	  pass1=0;
+	  continue;
+	} else {
+	  fprintf (stderr, "HD44780: unable to compact bar characters\n");
+	  nSegment=CHARS;
+	  break;
+	}
+      } 
+      
+      nSegment--;
+      Segment[pack_i]=Segment[nSegment];
+      
+      for (i=0; i<nSegment; i++) {
+	error[pack_i][i]=error[nSegment][i];
+	error[i][pack_i]=error[i][nSegment];
+      }
+      
+      for (r=0; r<Lcd.rows; r++) {
+	for (c=0; c<Lcd.cols; c++) {
+	  if (Bar[r][c].segment==pack_i)
+	    Bar[r][c].segment=pack_j;
+	  if (Bar[r][c].segment==nSegment)
+	    Bar[r][c].segment=pack_i;
+	}
+      }
+    }
+  }
+}
+
+static void HD_define_chars (void)
+{
+  int c, i, j;
+  char buffer[8];
+
+  for (i=2; i<nSegment; i++) {
+    if (Segment[i].used) continue;
+    if (Segment[i].ascii!=-1) continue;
+    for (c=0; c<CHARS; c++) {
+      for (j=2; j<nSegment; j++) {
+	if (Segment[j].ascii==c) break;
+      }
+      if (j==nSegment) break;
+    }
+    Segment[i].ascii=c;
+    switch (Segment[i].type) {
+    case BAR_L:
+      for (j=0; j<4; j++) {
+	char Pixel[] = { 0, 1, 3, 7, 15, 31 };
+	buffer[j]=Pixel[Segment[i].len1];
+	buffer[j+4]=Pixel[Segment[i].len2];
+      }
+      break;
+    case BAR_R:
+      for (j=0; j<4; j++) {
+	char Pixel[] = { 0, 16, 24, 28, 30, 31 };
+	buffer[j]=Pixel[Segment[i].len1];
+	buffer[j+4]=Pixel[Segment[i].len2];
+      }
+      break;
+    case BAR_U:
+      for (j=0; j<Segment[i].len1; j++) {
+	buffer[7-j]=31;
+      }
+      for (; j<YRES; j++) {
+	buffer[7-j]=0;
+      }
+      break;
+    case BAR_D:
+      for (j=0; j<Segment[i].len1; j++) {
+	buffer[j]=31;
+      }
+      for (; j<YRES; j++) {
+	buffer[j]=0;
+      }
+      break;
+    }
+    HD_command (0x40|8*c);
+    HD_write (buffer, 8);
+  }
+}
+
+int HD_clear (void)
+{
+  int row, col;
+
+  for (row=0; row<Lcd.rows; row++) {
+    for (col=0; col<Lcd.cols; col++) {
+      Txt[row][col]='\t';
+      Bar[row][col].len1=-1;
+      Bar[row][col].len2=-1;
+      Bar[row][col].type=0;
+      Bar[row][col].segment=-1;
+    }
+  }
+  HD_command (0x01); // clear display
+  HD_delay (1640);
+  return 0;
+}
+
+static void HD_quit (int signal); //forward declaration
+
+int HD_init (LCD *Self)
+{
+  int rows=-1, cols=-1;
+  char *s, *e;
+  
+  s=cfg_get ("Port");
+  if (s==NULL || *s=='\0') {
+    fprintf (stderr, "HD44780: no 'Port' entry in %s\n", cfg_file());
+    return -1;
+  }
+  if ((Port=strtol(s, &e, 0))==0 || *e!='\0') {
+    fprintf (stderr, "HD44780: bad port '%s' in %s\n", s, cfg_file());
+    return -1;
+  }    
+
+  s=cfg_get("Size");
+  if (s==NULL || *s=='\0') {
+    fprintf (stderr, "HD44780: no 'Size' entry in %s\n", cfg_file());
+    return -1;
+  }
+  
+  if (sscanf(s,"%dx%d",&cols,&rows)!=2 || rows<1 || cols<1) {
+    fprintf(stderr,"HD44780: bad size '%s'\n",s);
+    return -1;
+  }
+  
+  Self->rows=rows;
+  Self->cols=cols;
+  Lcd=*Self;
+  
+  if (HD_open()!=0)
+    return -1;
+  
+  HD_clear();
+
+  signal(SIGINT,  HD_quit);
+  signal(SIGQUIT, HD_quit);
+  signal(SIGTERM, HD_quit);
+
+  return 0;
+}
+
+void HD_goto (int row, int col)
+{
+  int pos;
+  pos=(row%2)*64+col;
+  if (row>2) pos+=20;
+  HD_command (0x80|pos);
+  HD_delay(40);
+}
+
+int HD_put (int row, int col, char *text)
+{
+  char *p=&Txt[row][col];
+  char *t=text;
+  
+  while (*t && col++<=Lcd.cols) {
+    *p++=*t++;
+  }
+  return 0;
+}
+
+int HD_bar (int type, int row, int col, int max, int len1, int len2)
+{
+  int rev=0;
+  
+  if (len1<1) len1=1;
+  else if (len1>max) len1=max;
+  
+  if (len2<1) len2=1;
+  else if (len2>max) len2=max;
+  
+  switch (type) {
+  case BAR_L:
+    len1=max-len1;
+    len2=max-len2;
+    rev=1;
+    
+  case BAR_R:
+    while (max>0 && col<=Lcd.cols) {
+      Bar[row][col].type=type;
+      Bar[row][col].segment=-1;
+      if (len1>=XRES) {
+	Bar[row][col].len1=rev?0:XRES;
+	len1-=XRES;
+      } else {
+	Bar[row][col].len1=rev?XRES-len1:len1;
+	len1=0;
+      }
+      if (len2>=XRES) {
+	Bar[row][col].len2=rev?0:XRES;
+	len2-=XRES;
+      } else {
+	Bar[row][col].len2=rev?XRES-len2:len2;
+	len2=0;
+      }
+      max-=XRES;
+      col++;
+    }
+    break;
+
+  case BAR_U:
+    len1=max-len1;
+    len2=max-len2;
+    rev=1;
+    
+  case BAR_D:
+    while (max>0 && row<=Lcd.rows) {
+      Bar[row][col].type=type;
+      Bar[row][col].segment=-1;
+      if (len1>=YRES) {
+	Bar[row][col].len1=rev?0:YRES;
+	len1-=YRES;
+      } else {
+	Bar[row][col].len1=rev?YRES-len1:len1;
+	len1=0;
+      }
+      if (len2>=YRES) {
+	Bar[row][col].len2=rev?0:YRES;
+	len2-=YRES;
+      } else {
+	Bar[row][col].len2=rev?YRES-len2:len2;
+	len2=0;
+      }
+      max-=YRES;
+      row++;
+    }
+    break;
+
+  }
+  return 0;
+}
+
+int HD_flush (void)
+{
+  char buffer[256];
+  char *p;
+  int s, row, col;
+  
+  HD_process_bars();
+  HD_compact_bars();
+  HD_define_chars();
+  
+  for (s=0; s<nSegment; s++) {
+    Segment[s].used=0;
+  }
+
+  for (row=0; row<Lcd.rows; row++) {
+    for (col=0; col<Lcd.cols; col++) {
+      s=Bar[row][col].segment;
+      if (s!=-1) {
+	Segment[s].used=1;
+	Txt[row][col]=Segment[s].ascii;
+      }
+    }
+    for (col=0; col<Lcd.cols; col++) {
+      if (Txt[row][col]=='\t') continue;
+      HD_goto (row, col);
+      for (p=buffer; col<Lcd.cols; col++, p++) {
+	if (Txt[row][col]=='\t') break;
+	*p=Txt[row][col];
+      }
+      HD_write (buffer, p-buffer);
+    }
+  }
+  return 0;
+}
+
+int lcd_hello (void); // prototype from lcd4linux.c
+
+static void HD_quit (int signal)
+{
+  HD_clear();
+  lcd_hello();
+  // Fixme: ioperm rückgängig machen?
+  exit (0);
+}
+
+LCD HD44780[] = {
+  { "HD44780", 0, 0, XRES, YRES, BARS, HD_init, HD_clear, HD_put, HD_bar, HD_flush },
+  { NULL }
+};