/*
 * "Winamp" 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 Andrew McMeikan <andrewm@engineer.com>
 *		  modular driver 1999-2000 Benjamin Tse <blt@Comports.com> 
 *
 *		  Modified July 2000 by Charles Steinkuehler for enhanced
 *		  performance and reduced CPU usage
 *		    - provided required setup time for RS valid to E high
 *		    - 1 uS call to uPause removed as it is unnecessary
 *
 * 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)
 * nSTRB (1)      EN (6)
 * nLF   (14)     nRW (5) (EN3 6 - LCD 3) (optional)
 * INIT  (16)     RS (4)
 * nSEL  (17)     EN2 (6 - LCD 2) (optional)
 *
 * Created modular driver Dec 1999, Benjamin Tse <blt@Comports.com>
 *
 * This file is released under the GNU General Public License. Refer to the
 * COPYING file distributed with this package.
 */

#include "hd44780-winamp.h"
#include "port.h"

#include "shared/str.h"
#include <stdio.h>
#include <string.h>
#include <errno.h>

void lcdwinamp_HD44780_senddata (unsigned char displayID, unsigned char flags, unsigned char ch);

#define EN1     STRB
#define EN2	SEL
#define EN3	LF
#define RS	INIT

static unsigned char EnMask[] = { EN1, EN2, EN3 };
static int EnMaskSize = sizeof (EnMask) / sizeof (unsigned char);

static unsigned int lptPort;
static int extIF = 0;			  // non-zero if extended interface

// initialise the driver
int
hd_init_winamp (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;

	hd44780_functions->senddata = lcdwinamp_HD44780_senddata;
	lptPort = port;

	// 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;

	if (port_access (lptPort + 2) || port_access (lptPort)) {
		fprintf (stderr, "HD44780_init: failed (%s)\n", strerror (errno));
		return -1;
	}

	common_init (IF_8bit);
	return 0;
}

// lcdwinamp_HD44780_senddata
void
lcdwinamp_HD44780_senddata (unsigned char displayID, unsigned char flags, unsigned char ch)
{
	unsigned char dispID = 0, portControl;

	if (flags == RS_DATA)
		portControl = RS;
	else
		portControl = 0;

	if (displayID == 0)
		dispID = EnMask[0] | EnMask[1] | ((extIF) ? EnMask[2] : 0);
	else
		dispID = EnMask[displayID - 1];

	// 40 nS setup time for RS valid to EN high, so set RS
	port_out (lptPort + 2, portControl ^ OUTMASK);

	// then set EN high
	port_out (lptPort + 2, (dispID | portControl) ^ OUTMASK);

	// Output the actual data
	port_out (lptPort, ch);

	// 80 nS setup from valid data to EN low will be met without any delay
	// unless you are running a REALLY FAST ISA bus (like 75 MHZ!)
	// 230 nS minimum E high time provided by ISA bus delays as well...

	// Set EN low and we're done...
	port_out (lptPort + 2, portControl ^ OUTMASK);

	// 10 nS data hold time provided by the length of ISA write for EN
}