/** \file server/drivers/hd44780-winamp.c * \c winamp 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 Andrew McMeikan * 1999-2000 Benjamin Tse * - modular driver * * 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 * * 2001 Joris Robijn * - Keypad support * * This file is released under the GNU General Public License. Refer to the * COPYING file distributed with this package. * * 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) * * Backlight * SEL (17) backlight (optional, see documentation) * * Additional output latch strobe * Not part of the hd44780 itself - addl '373/4, '574 chip or similar * (optional, see documentation (eventually)) * nLF (14) LE * * 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 * nACK (10) X1 * BUSY (11) X2 * PAPEREND (12) X3 * SELIN (13) X4 * nFAULT (15) X5 */ #include "hd44780-winamp.h" #include "hd44780-low.h" #include "lpt-port.h" #include "port.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 lcdwinamp_HD44780_senddata(PrivateData *p, unsigned char displayID, unsigned char flags, unsigned char ch); void lcdwinamp_HD44780_backlight(PrivateData *p, unsigned char state); unsigned char lcdwinamp_HD44780_readkeypad(PrivateData *p, unsigned int YData); void lcdwinamp_HD44780_output(PrivateData *p, int data); // Compile time mapping of control lines // For expert users only! #define EN1 STRB #define EN2 SEL #define EN3 LF #define RW LF #define RS INIT #define BL SEL #define LE LF static const unsigned char EnMask[] = { EN1, EN2, EN3 }; /** * Initialize the driver. * \param drvthis Pointer to driver structure. * \retval 0 Success. * \retval -1 Error. */ int hd_init_winamp(Driver *drvthis) { PrivateData *p = (PrivateData*) drvthis->private_data; HD44780_functions *hd44780_functions = p->hd44780_functions; // Safety check against common configuration errors if (p->numDisplays == 2) { if (p->have_backlight && (EnMask[1] == BL)) { report(RPT_ERR, "hd_init_winamp: backlight must be on different pin than 2nd controller"); report(RPT_ERR, "hd_init_winamp: please change connection mapping in hd44780-winamp.c"); return -1; } if (p->have_backlight && p->have_output) { report(RPT_ERR, "hd_init_winamp: backlight and output not possible with 2 controllers"); return -1; } } else if (p->numDisplays == 3 && (p->have_backlight || p->have_output)) { report(RPT_ERR, "hd_init_winamp: backlight or output not possible with 3 controllers"); return -1; } // 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 = lcdwinamp_HD44780_senddata; hd44780_functions->backlight = lcdwinamp_HD44780_backlight; hd44780_functions->readkeypad = lcdwinamp_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); common_init(p, IF_8BIT); if (p->have_keypad) { // Remember which input lines are stuck p->stuckinputs = lcdwinamp_HD44780_readkeypad(p, 0); } // Write new value to output port latches hd44780_functions->output = lcdwinamp_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 lcdwinamp_HD44780_senddata(PrivateData *p, unsigned char displayID, unsigned char flags, unsigned char ch) { unsigned char enableLines = 0, portControl; if (flags == RS_DATA) portControl = RS; else portControl = 0; portControl |= p->backlight_bit; if (displayID == 0) enableLines = EnMask[0] | ((p->numDisplays >= 2) ? EnMask[1] : 0) | ((p->numDisplays == 3) ? EnMask[2] : 0); else enableLines = EnMask[displayID - 1]; // 40 nS setup time for RS valid to EN high, so set RS port_out(p->port + 2, portControl ^ OUTMASK); // Output the actual data port_out(p->port, ch); if (p->delayBus) p->hd44780_functions->uPause(p, 1); // then set EN high port_out(p->port + 2, (enableLines|portControl) ^ OUTMASK); if (p->delayBus) p->hd44780_functions->uPause(p, 1); // 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... // ABOVE TEXT ignored now, using delays if delayBus is specified // Set EN low and we're done... port_out(p->port + 2, portControl ^ OUTMASK); // 10 nS data hold time provided by the length of ISA write for EN } /** * Turn display backlight on or off. * \param p Pointer to driver's private data structure. * \param state New backlight status. */ void lcdwinamp_HD44780_backlight(PrivateData *p, unsigned char state) { p->backlight_bit = (state ? 0 : BL); 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 lcdwinamp_HD44780_readkeypad(PrivateData *p, unsigned int YData) { unsigned char readval; // 8 bits output // Convert the positive logic to the negative logic on the LPT port port_out(p->port, ~YData & 0x00FF); if (p->delayBus) p->hd44780_functions->uPause(p, 1); // Read inputs readval = ~ port_in(p->port + 1) ^ INMASK; // 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 lcdwinamp_HD44780_output(PrivateData *p, int data) { // Setup data bus port_out(p->port, data); // Strobe the latch (374 latches on rising edge, 373 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); }