/* * 4-bit driver module for Hitachi HD44780 based LCD displays. * The LCD is operated in it's 4 bit-mode to be connected to a single * 8 bit-port. * * Copyright (c) 2000, 1999, 1995 Benjamin Tse * 2001 Joris Robijn * 1999 Andrew McMeikan * 1998 Richard Rognlie * 1997 Matthias Prinke * * The connections are: * printer port LCD * D0 (2) D4 (11) * D1 (3) D5 (12) * D2 (4) D6 (13) * D3 (5) D7 (14) * D4 (6) RS (4) * D5 (7) RW (5) (LCD3 - 6) (optional - pull all LCD RW low) * D6 (8) EN (6) * D7 (9) EN2 (LCD2 - 6) (optional) * * Extended interface (including LCD3 above) * STR (1) EN4 * LF (14) EN5 * INIT (16) EN6 * SEL (17) EN7 * * Keypad connection (optional): * Some diodes and resistors are needed, see further documentation. * printer port keypad * D0 (2) Y0 * D1 (3) Y1 * D2 (4) Y2 * D3 (5) Y3 * D4 (6) Y4 * D5 (7) Y5 * nSTRB (1) Y6 * nLF (14) Y7 * INIT (16) Y8 * nSEL (17) Y9 * nACK (10) X0 * BUSY (11) X1 * PAPEREND (12 X2 * SELIN (13) X3 * nFAULT (15) X4 * * Added support for up to 7 LCDs Jan 2000, Benjamin Tse * Created modular driver Dec 1999, Benjamin Tse * * Based on Matthias Prinke's lcd4.c module * in lcdstat. This was in turn based on Benjamin Tse's 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 "hd44780-4bit.h" #include "hd44780.h" #include "port.h" #include "shared/str.h" #include #include #include // Generally, any function that accesses the LCD control lines needs to be // implemented separately for each HW design. This is typically just // HD44780_senddata and HD44780_readkeypad void lcdstat_HD44780_senddata (unsigned char displayID, unsigned char flags, unsigned char ch); unsigned char lcdstat_HD44780_readkeypad (unsigned int YData); #define RS 0x10 #define RW 0x20 #define EN1 0x40 #define EN2 0x80 #define EN3 0x20 static unsigned char EnMask[] = { EN1, EN2, EN3, STRB, LF, INIT, SEL }; static int EnMaskSize = sizeof (EnMask) / sizeof (unsigned char); static int extIF = 0; // non-zero if extended interface static unsigned int lptPort; static char stuckinputs = 0; // if an input line is stuck, it will be ignored // initialisation function int hd_init_4bit (HD44780_functions * hd44780_functions, lcd_logical_driver * driver, char *args, unsigned int port) { // TODO: remove magic numbers below char *argv[64]; int argc; int i; int displayID = EN1 | EN2; // Reserve the port registers lptPort = port; port_access(lptPort); port_access(lptPort+1); port_access(lptPort+2); hd44780_functions->senddata = lcdstat_HD44780_senddata; hd44780_functions->readkeypad = lcdstat_HD44780_readkeypad; // parse command-line arguments argc = get_args (argv, args, 64); for (i = 0; i < argc; ++i) { if (strcmp (argv[i], "-e") == 0 || strcmp (argv[i], "--extended") == 0) { extIF = 1; } } // powerup the lcd now if (extIF) { displayID |= EN3; port_out (lptPort + 2, 0 ^ OUTMASK); } port_out (lptPort, displayID | 0x03); if (extIF) port_out (lptPort + 2, (EnMask[3] | EnMask[4] | EnMask[5] | EnMask[6]) ^ OUTMASK); hd44780_functions->uPause (1); port_out (lptPort, 0x03); if (extIF) port_out (lptPort + 2, 0 ^ OUTMASK); hd44780_functions->uPause (4100); port_out (lptPort, displayID | 0x03); if (extIF) port_out (lptPort + 2, (EnMask[3] | EnMask[4] | EnMask[5] | EnMask[6]) ^ OUTMASK); hd44780_functions->uPause (1); port_out (lptPort, 0x03); if (extIF) port_out (lptPort + 2, 0 ^ OUTMASK); hd44780_functions->uPause (100); port_out (lptPort, displayID | 0x03); if (extIF) port_out (lptPort + 2, (EnMask[3] | EnMask[4] | EnMask[5] | EnMask[6]) ^ OUTMASK); hd44780_functions->uPause (1); port_out (lptPort, 0x03); if (extIF) port_out (lptPort + 2, 0 ^ OUTMASK); hd44780_functions->uPause (40); // now in 8-bit mode... set 4-bit mode port_out (lptPort, displayID | 0x02); if (extIF) port_out (lptPort + 2, (EnMask[3] | EnMask[4] | EnMask[5] | EnMask[6]) ^ OUTMASK); hd44780_functions->uPause (1); port_out (lptPort, 0x02); if (extIF) port_out (lptPort + 2, 0 ^ OUTMASK); hd44780_functions->uPause (40); common_init (); if (keypad) { // Remember which input lines are stuck stuckinputs = lcdstat_HD44780_readkeypad (0); } return 0; } // lcdstat_HD44780_senddata void lcdstat_HD44780_senddata (unsigned char displayID, unsigned char iflags, unsigned char ch) { unsigned char enableLines = 0, flags = 0; unsigned char h = (ch >> 4) & 0x0f; // high and low nibbles unsigned char l = ch & 0x0f; if (iflags == RS_INSTR) flags = 0; else //if (iflags == RS_DATA) flags = RS; if (displayID <= 3) { if (displayID == 0) enableLines = EnMask[0] | EnMask[1] | EnMask[2]; else enableLines = EnMask[displayID - 1]; port_out (lptPort, flags | h); hd44780_functions->uPause (2); port_out (lptPort, enableLines | flags | h); hd44780_functions->uPause (4); port_out (lptPort, flags | h); port_out (lptPort, enableLines | flags | l); hd44780_functions->uPause (4); port_out (lptPort, flags | l); } if (extIF && (displayID == 0 || displayID >= 4)) { if (displayID == 0) enableLines = EnMask[3] | EnMask[4] | EnMask[5] | EnMask[6]; else enableLines = EnMask[(displayID - 1) % EnMaskSize]; port_out (lptPort, flags | h); hd44780_functions->uPause (2); port_out (lptPort + 2, enableLines ^ OUTMASK); hd44780_functions->uPause (4); port_out (lptPort + 2, 0 ^ OUTMASK); port_out (lptPort, flags | l); port_out (lptPort + 2, enableLines ^ OUTMASK); hd44780_functions->uPause (4); port_out (lptPort + 2, 0 ^ OUTMASK); } } unsigned char lcdstat_HD44780_readkeypad (unsigned int YData) { unsigned char readval; // 10 bits output or 6 bits if >=3 displays // Convert the positive logic to the negative logic on the LPT port port_out (lptPort, ~YData & 0x003F ); if (!extIF) { port_out (lptPort + 2, ( ((~YData & 0x03C0) << 6 )) ^ OUTMASK); } // And convert it back. readval = ~ port_in (lptPort + 1) ^ INMASK; return ( (readval >> 4 & 0x03) | (readval >> 5 & 0x04) | (readval >> 3 & 0x08) | (readval << 1 & 0x10) ) & ~stuckinputs; }