110 lines
2.5 KiB
C
110 lines
2.5 KiB
C
/*
|
|
* 8-bit driver module for Hitachi HD44780 based LCD displays.
|
|
* The LCD is operated in it's 8 bit-mode to be connected to a single
|
|
* PC parallel port.
|
|
*
|
|
* Copyright (c) 1999, 1995 Benjamin Tse <blt@Comports.com>
|
|
*
|
|
* The connections are:
|
|
* printer port LCD
|
|
* D0 (2) D0 (7)
|
|
* D1 (3) D1 (8)
|
|
* D2 (4) D2 (9)
|
|
* D3 (5) D3 (10)
|
|
* D4 (6) D4 (11)
|
|
* D5 (7) D5 (12)
|
|
* D6 (8) D6 (13)
|
|
* D7 (9) D7 (14)
|
|
* nSEL (17) -
|
|
* nSTRB (1) RS (4)
|
|
* nLF (14) RW (5) (LCD2 - 6) (optional - pull all LCD RW low)
|
|
* INIT (16) EN (6)
|
|
*
|
|
* Created modular driver Dec 1999, Benjamin Tse <blt@Comports.com>
|
|
*
|
|
* Based on the code in the lcdtime package which uses the LCD
|
|
* controller in its 8-bit mode.
|
|
*
|
|
* This file is released under the GNU General Public License. Refer to the
|
|
* COPYING file distributed with this package.
|
|
*/
|
|
|
|
#include "hd44780-ext8bit.h"
|
|
#include "port.h"
|
|
|
|
#include "lcd_sem.h"
|
|
#include <sys/perm.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <errno.h>
|
|
|
|
// Generally, any function that accesses the LCD control lines needs to be
|
|
// implemented separately for each HW design. This is typically (but not
|
|
// restricted to):
|
|
// HD44780_senddata
|
|
|
|
void lcdtime_HD44780_senddata(unsigned char displayID,
|
|
unsigned char flags,
|
|
unsigned char ch);
|
|
|
|
|
|
#define nRS nSTRB
|
|
#define nRW nLF
|
|
#define EN1 INIT
|
|
#define METER_OFF nSEL
|
|
|
|
#define SETUPLCD (METER_OFF | nRS)
|
|
#define CTRL (nRW | METER_OFF | nRS)
|
|
#define CHAR (nRW | METER_OFF)
|
|
|
|
static unsigned int lptPort;
|
|
static int semid;
|
|
|
|
|
|
// initialise the driver
|
|
int hd_init_ext8bit(HD44780_functions *hd44780_functions,
|
|
lcd_logical_driver *driver,
|
|
char *args,
|
|
unsigned int port)
|
|
{
|
|
lptPort = port;
|
|
semid = sem_get();
|
|
|
|
hd44780_functions->senddata = lcdtime_HD44780_senddata;
|
|
|
|
if ((ioperm(port + 2, 1, 255)) == -1) {
|
|
fprintf(stderr, "HD44780_init: failed (%s)\n", strerror(errno));
|
|
return -1;
|
|
}
|
|
|
|
common_init(IF_8bit);
|
|
return 0;
|
|
}
|
|
|
|
|
|
// lcdtime_HD44780_senddata
|
|
void lcdtime_HD44780_senddata(unsigned char displayID,
|
|
unsigned char flags,
|
|
unsigned char ch)
|
|
{
|
|
unsigned char dispID = 0, portControl;
|
|
|
|
if (displayID == 1)
|
|
dispID |= EN1;
|
|
else //if (displayID == 0)
|
|
dispID |= EN1;
|
|
|
|
if (flags == RS_DATA)
|
|
portControl = CHAR;
|
|
else
|
|
portControl = CTRL;
|
|
|
|
sem_wait(semid);
|
|
port_out(lptPort + 2, SETUPLCD);
|
|
port_out(lptPort, ch);
|
|
port_out(lptPort + 2, dispID | portControl);
|
|
hd44780_functions->uPause(1);
|
|
port_out(lptPort + 2, portControl);
|
|
sem_signal(semid);
|
|
}
|