/** \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 * 2001 Joris Robijn * * 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 * * 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 #include #include // 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); }