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/** \file server/drivers/hd44780-ext8bit.c
* \c 8bit connection type of \c hd44780 driver for Hitachi HD44780 based LCD displays.
*
* The LCD is operated in its 8 bit-mode to be connected to a single PC parallel port.
*/
/* Copyright (c) 1999, 1995 Benjamin Tse <blt@Comports.com>
* 2001 Joris Robijn <joris@robijn.net>
*
* 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) RS (4)
* nLF (14) RW (5) (optional - pull all LCD RW low)
* INIT (16) EN (6)
*
* Backlight
* SEL (17) backlight (optional, see documentation)
*
* Keypad connection (optional):
* Some diodes and resistors are needed, see further documentation.
* printer port keypad
* D0 (2) Y1
* D1 (3) Y2
* D2 (4) Y3
* D3 (5) Y4
* D4 (6) Y5
* D5 (7) Y6
* D6 (8) Y7
* D7 (9) Y8
* nSTRB (1) Y9
* nSEL (17) Y10 (optional, only if no backlight is used)
* nACK (10) X1
* BUSY (11) X2
* PAPEREND (12) X3
* SELIN (13) X4
* nFAULT (15) X5
*
* 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 "hd44780-low.h"
#include "lpt-port.h"
#include "port.h"
#include "lcd_sem.h"
#include "report.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
// HD44780_readkeypad
void lcdtime_HD44780_senddata(PrivateData *p, unsigned char displayID, unsigned char flags, unsigned char ch);
void lcdtime_HD44780_backlight(PrivateData *p, unsigned char state);
unsigned char lcdtime_HD44780_readkeypad(PrivateData *p, unsigned int YData);
void lcdtime_HD44780_output(PrivateData *p, int data);
#define RS STRB
#define RW LF
#define EN1 INIT
#define BL SEL
#define LE SEL
static int semid;
/**
* Initialize the driver.
* \param drvthis Pointer to driver structure.
* \retval 0 Success.
* \retval -1 Error.
*/
int
hd_init_ext8bit(Driver *drvthis)
{
PrivateData *p = (PrivateData*) drvthis->private_data;
HD44780_functions *hd44780_functions = p->hd44780_functions;
semid = sem_get();
// Reserve the port registers
if (port_access_multiple(p->port,3)) {
report(RPT_ERR, "%s: cannot get IO-permission for 0x%03X: %s",
drvthis->name, p->port, strerror(errno));
return -1;
}
hd44780_functions->senddata = lcdtime_HD44780_senddata;
hd44780_functions->backlight = lcdtime_HD44780_backlight;
hd44780_functions->readkeypad = lcdtime_HD44780_readkeypad;
// setup the lcd in 8 bit mode
hd44780_functions->senddata(p, 0, RS_INSTR, FUNCSET | IF_8BIT);
hd44780_functions->uPause(p, 4100);
hd44780_functions->senddata(p, 0, RS_INSTR, FUNCSET | IF_8BIT);
hd44780_functions->uPause(p, 100);
hd44780_functions->senddata(p, 0, RS_INSTR, FUNCSET | IF_8BIT | TWOLINE | SMALLCHAR);
hd44780_functions->uPause(p, 40);
common_init (p, IF_8BIT);
if (p->have_keypad) {
// Remember which input lines are stuck
p->stuckinputs = lcdtime_HD44780_readkeypad(p, 0);
}
// Writes new value to the "bargraph" latches
hd44780_functions->output = lcdtime_HD44780_output;
return 0;
}
/**
* Send data or commands to the display.
* \param p Pointer to driver's private data structure.
* \param displayID ID of the display (or 0 for all) to send data to.
* \param flags Defines whether to end a command or data.
* \param ch The value to send.
*/
void
lcdtime_HD44780_senddata(PrivateData *p, unsigned char displayID, unsigned char flags, unsigned char ch)
{
unsigned char enableLines = 0, portControl;
// Only one controller is supported
enableLines = EN1;
if (flags == RS_INSTR)
portControl = 0;
else // RS_DATA
portControl = RS;
portControl |= p->backlight_bit;
sem_wait(semid);
port_out(p->port + 2, portControl ^ OUTMASK);
port_out(p->port, ch);
if (p->delayBus) p->hd44780_functions->uPause(p, 1);
port_out(p->port + 2, (enableLines|portControl) ^ OUTMASK);
if (p->delayBus) p->hd44780_functions->uPause(p, 1);
port_out(p->port + 2, portControl ^ OUTMASK);
sem_signal(semid);
}
/**
* Turn display backlight on or off.
* \param p Pointer to driver's private data structure.
* \param state New backlight status.
*/
void lcdtime_HD44780_backlight(PrivateData *p, unsigned char state)
{
p->backlight_bit = (state?0:BL);
// Semaphores not needed because backlight will not go together with
// the bargraph anyway...
port_out(p->port + 2, p->backlight_bit ^ OUTMASK);
}
/**
* Read keypress.
* \param p Pointer to driver's private data structure.
* \param YData Bitmap of rows / lines to enable.
* \return Bitmap of the pressed keys.
*/
unsigned char lcdtime_HD44780_readkeypad(PrivateData *p, unsigned int YData)
{
unsigned char readval;
sem_wait(semid);
// Convert the positive logic to the negative logic on the LPT port
port_out(p->port, ~YData & 0x00FF);
// 9 bits output if backlight is used, 10 bits otherwise
if (p->have_backlight)
port_out(p->port + 2, (((~YData & 0x0100) >> 8) | p->backlight_bit) ^ OUTMASK);
else
port_out(p->port + 2, (((~YData & 0x0100) >> 8) | ((~YData & 0x0200) >> 6)) ^ OUTMASK);
if (p->delayBus) p->hd44780_functions->uPause(p, 1);
// Read inputs
readval = ~ port_in(p->port + 1) ^ INMASK;
// Put port back into idle state
port_out(p->port, p->backlight_bit ^ OUTMASK);
sem_signal(semid);
// And convert value back (MSB first).
return (((readval & FAULT) / FAULT <<4) | /* pin 15 */
((readval & SELIN) / SELIN <<3) | /* pin 13 */
((readval & PAPEREND) / PAPEREND <<2) | /* pin 12 */
((readval & BUSY) / BUSY <<1) | /* pin 11 */
((readval & ACK) / ACK)) & ~p->stuckinputs; /* pin 10 */
}
/**
* Set output port.
* \param p Pointer to driver's private data structure.
* \param data Value the output port shall be set to.
*/
void lcdtime_HD44780_output(PrivateData *p, int data)
{
// Setup data bus
port_out(p->port, data);
// Strobe the latch (374 latches on rising edge, 3/574 on trailing. No matter)
port_out(p->port + 2, (LE | p->backlight_bit) ^ OUTMASK);
if (p->delayBus) p->hd44780_functions->uPause(p, 1);
port_out(p->port + 2, (p->backlight_bit) ^ OUTMASK);
if (p->delayBus) p->hd44780_functions->uPause(p, 1);
}
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