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authorreinelt <>2000-04-12 08:05:45 +0000
committerreinelt <>2000-04-12 08:05:45 +0000
commit960aa7ec9ab275c7ebeb4bba96dbbd7b9211c000 (patch)
tree00296cc199b3242eb56466e7f19022506839b8f1 /HD44780.c
parent16fc06515887f1bb9ee01feaa7263997bf0f2ef1 (diff)
downloadlcd4linux-960aa7ec9ab275c7ebeb4bba96dbbd7b9211c000.tar.gz
[lcd4linux @ 2000-04-12 08:05:45 by reinelt]
first version of the HD44780 driver
Diffstat (limited to 'HD44780.c')
-rw-r--r--HD44780.c496
1 files changed, 496 insertions, 0 deletions
diff --git a/HD44780.c b/HD44780.c
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--- /dev/null
+++ b/HD44780.c
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+/* $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 }
+};