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ppilcd.c
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Editing: ppilcd.c
/* * Control LCD module hung off parallel port using the * ppi 'geek port' interface. * * $FreeBSD$ */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <ctype.h> #include <fcntl.h> #include <unistd.h> #include <err.h> #include <sysexits.h> #include <dev/ppbus/ppbconf.h> #include <dev/ppbus/ppi.h> #define debug(lev, fmt, args...) if (debuglevel >= lev) fprintf(stderr, fmt "\n" , ## args); static void usage(void); static char *progname; #define DEFAULT_DEVICE "/dev/ppi0" /* Driver functions */ static void hd44780_prepare(char *devname, char *options); static void hd44780_finish(void); static void hd44780_command(int cmd); static void hd44780_putc(int c); /* * Commands * Note that unrecognised command escapes are passed through with * the command value set to the ASCII value of the escaped character. */ #define CMD_RESET 0 #define CMD_BKSP 1 #define CMD_CLR 2 #define CMD_NL 3 #define CMD_CR 4 #define CMD_HOME 5 #define MAX_DRVOPT 10 /* maximum driver-specific options */ struct lcd_driver { char *l_code; char *l_name; char *l_options[MAX_DRVOPT]; void (* l_prepare)(char *name, char *options); void (* l_finish)(void); void (* l_command)(int cmd); void (* l_putc)(int c); }; static struct lcd_driver lcd_drivertab[] = { { "hd44780", "Hitachi HD44780 and compatibles", { "Reset options:", " 1 1-line display (default 2)", " B Cursor blink enable", " C Cursor enable", " F Large font select", NULL }, hd44780_prepare, hd44780_finish, hd44780_command, hd44780_putc }, { NULL, NULL, { NULL }, NULL, NULL } }; static void do_char(struct lcd_driver *driver, char ch); int debuglevel = 0; int vflag = 0; int main(int argc, char *argv[]) { extern char *optarg; extern int optind; struct lcd_driver *driver = &lcd_drivertab[0]; char *drivertype, *cp; char *devname = DEFAULT_DEVICE; char *drvopts = NULL; int ch, i; if ((progname = strrchr(argv[0], '/'))) { progname++; } else { progname = argv[0]; } drivertype = getenv("LCD_TYPE"); while ((ch = getopt(argc, argv, "Dd:f:o:v")) != -1) { switch(ch) { case 'D': debuglevel++; break; case 'd': drivertype = optarg; break; case 'f': devname = optarg; break; case 'o': drvopts = optarg; break; case 'v': vflag = 1; break; default: usage(); } } argc -= optind; argv += optind; /* If an LCD type was specified, look it up */ if (drivertype != NULL) { driver = NULL; for (i = 0; lcd_drivertab[i].l_code != NULL; i++) { if (!strcmp(drivertype, lcd_drivertab[i].l_code)) { driver = &lcd_drivertab[i]; break; } } if (driver == NULL) { warnx("LCD driver '%s' not known", drivertype); usage(); } } debug(1, "Driver selected for %s", driver->l_name); driver->l_prepare(devname, drvopts); atexit(driver->l_finish); if (argc > 0) { debug(2, "reading input from %d argument%s", argc, (argc > 1) ? "s" : ""); for (i = 0; i < argc; i++) for (cp = argv[i]; *cp; cp++) do_char(driver, *cp); } else { debug(2, "reading input from stdin"); setvbuf(stdin, NULL, _IONBF, 0); while ((ch = fgetc(stdin)) != EOF) do_char(driver, (char)ch); } exit(EX_OK); } static void usage(void) { int i, j; fprintf(stderr, "usage: %s [-v] [-d drivername] [-f device] [-o options] [args...]\n", progname); fprintf(stderr, " -D Increase debugging\n"); fprintf(stderr, " -f Specify device, default is '%s'\n", DEFAULT_DEVICE); fprintf(stderr, " -d Specify driver, one of:\n"); for (i = 0; lcd_drivertab[i].l_code != NULL; i++) { fprintf(stderr, " %-10s (%s)%s\n", lcd_drivertab[i].l_code, lcd_drivertab[i].l_name, (i == 0) ? " *default*" : ""); if (lcd_drivertab[i].l_options[0] != NULL) { for (j = 0; lcd_drivertab[i].l_options[j] != NULL; j++) fprintf(stderr, " %s\n", lcd_drivertab[i].l_options[j]); } } fprintf(stderr, " -o Specify driver option string\n"); fprintf(stderr, " args Message strings. Embedded escapes supported:\n"); fprintf(stderr, " \\b Backspace\n"); fprintf(stderr, " \\f Clear display, home cursor\n"); fprintf(stderr, " \\n Newline\n"); fprintf(stderr, " \\r Carriage return\n"); fprintf(stderr, " \\R Reset display\n"); fprintf(stderr, " \\v Home cursor\n"); fprintf(stderr, " \\\\ Literal \\\n"); fprintf(stderr, " If args not supplied, strings are read from standard input\n"); exit(EX_USAGE); } static void do_char(struct lcd_driver *driver, char ch) { static int esc = 0; if (esc) { switch(ch) { case 'b': driver->l_command(CMD_BKSP); break; case 'f': driver->l_command(CMD_CLR); break; case 'n': driver->l_command(CMD_NL); break; case 'r': driver->l_command(CMD_CR); break; case 'R': driver->l_command(CMD_RESET); break; case 'v': driver->l_command(CMD_HOME); break; case '\\': driver->l_putc('\\'); break; default: driver->l_command(ch); break; } esc = 0; } else { if (ch == '\\') { esc = 1; } else { if (vflag || isprint(ch)) driver->l_putc(ch); } } } /****************************************************************************** * Driver for the Hitachi HD44780. This is probably *the* most common driver * to be found on one- and two-line alphanumeric LCDs. * * This driver assumes the following connections : * * Parallel Port LCD Module * -------------------------------- * Strobe (1) Enable (6) * Data (2-9) Data (7-14) * Select In (17) RS (4) * Auto Feed (14) R/W (5) * * In addition, power must be supplied to the module, normally with * a circuit similar to this: * * VCC (+5V) O------o-------o--------O Module pin 2 * | | + * / --- * \ --- 1uF * / | - * \ <-----o--------O Module pin 3 * / * \ * | * GND O------o----------------O Module pin 1 * * The ground line should also be connected to the parallel port, on * one of the ground pins (eg. pin 25). * * Note that the pinning on some LCD modules has the odd and even pins * arranged as though reversed; check carefully before connecting a module * as it is possible to toast the HD44780 if the power is reversed. */ static int hd_fd; static u_int8_t hd_cbits; static int hd_lines = 2; static int hd_blink = 0; static int hd_cursor = 0; static int hd_font = 0; #define HD_COMMAND SELECTIN #define HD_DATA 0 #define HD_READ 0 #define HD_WRITE AUTOFEED #define HD_BF 0x80 /* internal busy flag */ #define HD_ADDRMASK 0x7f /* DDRAM address mask */ #define hd_sctrl(v) {u_int8_t _val; _val = hd_cbits | v; ioctl(hd_fd, PPISCTRL, &_val);} #define hd_sdata(v) {u_int8_t _val; _val = v; ioctl(hd_fd, PPISDATA, &_val);} #define hd_gdata(v) ioctl(hd_fd, PPIGDATA, &v) static void hd44780_output(int type, int data) { debug(3, "%s -> 0x%02x", (type == HD_COMMAND) ? "cmd " : "data", data); hd_sctrl(type | HD_WRITE | STROBE); /* set direction, address */ hd_sctrl(type | HD_WRITE); /* raise E */ hd_sdata((u_int8_t) data); /* drive data */ hd_sctrl(type | HD_WRITE | STROBE); /* lower E */ } static int hd44780_input(int type) { u_int8_t val; hd_sctrl(type | HD_READ | STROBE); /* set direction, address */ hd_sctrl(type | HD_READ); /* raise E */ hd_gdata(val); /* read data */ hd_sctrl(type | HD_READ | STROBE); /* lower E */ debug(3, "0x%02x -> %s", val, (type == HD_COMMAND) ? "cmd " : "data"); return(val); } static void hd44780_prepare(char *devname, char *options) { char *cp = options; if ((hd_fd = open(devname, O_RDWR, 0)) == -1) err(EX_OSFILE, "can't open '%s'", devname); /* parse options */ while (cp && *cp) { switch (*cp++) { case '1': hd_lines = 1; break; case 'B': hd_blink = 1; break; case 'C': hd_cursor = 1; break; case 'F': hd_font = 1; break; default: errx(EX_USAGE, "hd44780: unknown option code '%c'", *(cp-1)); } } /* Put LCD in idle state */ if (ioctl(hd_fd, PPIGCTRL, &hd_cbits)) /* save other control bits */ err(EX_IOERR, "ioctl PPIGCTRL failed (not a ppi device?)"); hd_cbits &= ~(STROBE | SELECTIN | AUTOFEED); /* set strobe, RS, R/W low */ debug(2, "static control bits 0x%x", hd_cbits); hd_sctrl(STROBE); hd_sdata(0); } static void hd44780_finish(void) { close(hd_fd); } static void hd44780_command(int cmd) { u_int8_t val; switch (cmd) { case CMD_RESET: /* full manual reset and reconfigure as per datasheet */ debug(1, "hd44780: reset to %d lines, %s font,%s%s cursor", hd_lines, hd_font ? "5x10" : "5x7", hd_cursor ? "" : " no", hd_blink ? " blinking" : ""); val = 0x30; if (hd_lines == 2) val |= 0x08; if (hd_font) val |= 0x04; hd44780_output(HD_COMMAND, val); usleep(10000); hd44780_output(HD_COMMAND, val); usleep(1000); hd44780_output(HD_COMMAND, val); usleep(1000); val = 0x08; /* display off */ hd44780_output(HD_COMMAND, val); usleep(1000); val |= 0x04; /* display on */ if (hd_cursor) val |= 0x02; if (hd_blink) val |= 0x01; hd44780_output(HD_COMMAND, val); usleep(1000); hd44780_output(HD_COMMAND, 0x06); /* shift cursor by increment */ usleep(1000); /* FALLTHROUGH */ case CMD_CLR: hd44780_output(HD_COMMAND, 0x01); usleep(2000); break; case CMD_BKSP: hd44780_output(HD_DATA, 0x10); /* shift cursor left one */ break; case CMD_NL: if (hd_lines == 2) hd44780_output(HD_COMMAND, 0xc0); /* beginning of second line */ break; case CMD_CR: /* XXX will not work in 4-line mode, or where readback fails */ val = hd44780_input(HD_COMMAND) & 0x3f; /* mask character position, save line pos */ hd44780_output(HD_COMMAND, 0x80 | val); break; case CMD_HOME: hd44780_output(HD_COMMAND, 0x02); usleep(2000); break; default: if (isprint(cmd)) { warnx("unknown command %c", cmd); } else { warnx("unknown command 0x%x", cmd); } } usleep(40); } static void hd44780_putc(int c) { hd44780_output(HD_DATA, c); usleep(40); }
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