Portable and maintable HD44780 driver files.

2000-02-21 11:24:09 +00:00
parent 6cefefd52c
commit e481f1311e
12 changed files with 978 additions and 0 deletions
@@ -0,0 +1,109 @@
+/*
+ * 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, 1995 Benjamin Tse <blt@Comports.com>
+ *
+ * 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)
+ * nSEL  (17)     -
+ * nSTRB (1)      RS (4)
+ * nLF   (14)     RW (5) (LCD2 - 6) (optional - pull all LCD RW low)
+ * INIT  (16)     EN (6)
+ *
+ * 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 "port.h"
+
+#include "lcd_sem.h"
+#include <sys/perm.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
+
+void lcdtime_HD44780_senddata(unsigned char displayID, 
+			      unsigned char flags, 
+			      unsigned char ch);
+
+
+#define nRS 	nSTRB
+#define nRW 	nLF
+#define EN1     INIT
+#define METER_OFF nSEL
+
+#define SETUPLCD (METER_OFF | nRS)
+#define CTRL    (nRW | METER_OFF | nRS)
+#define CHAR    (nRW | METER_OFF)
+
+static unsigned int lptPort;
+static int semid;
+
+
+// initialise the driver
+int hd_init_ext8bit(HD44780_functions *hd44780_functions, 
+		    lcd_logical_driver *driver, 
+		    char *args, 
+		    unsigned int port)
+{
+  lptPort = port;
+  semid = sem_get();
+
+  hd44780_functions->senddata   = lcdtime_HD44780_senddata;
+
+  if ((ioperm(port + 2, 1, 255)) == -1) {
+    fprintf(stderr, "HD44780_init: failed (%s)\n", strerror(errno)); 
+    return -1;
+  }
+
+  common_init(IF_8bit);
+  return 0;
+}
+
+
+// lcdtime_HD44780_senddata
+void lcdtime_HD44780_senddata(unsigned char displayID, 
+			      unsigned char flags, 
+			      unsigned char ch)
+{
+  unsigned char dispID = 0, portControl;
+
+  if (displayID == 1)
+    dispID |= EN1;
+  else //if (displayID == 0)
+    dispID |= EN1;
+
+  if (flags == RS_DATA)
+    portControl = CHAR;
+  else
+    portControl = CTRL;
+
+  sem_wait(semid);
+  port_out(lptPort + 2, SETUPLCD);
+  port_out(lptPort, ch);
+  port_out(lptPort + 2, dispID | portControl);
+  hd44780_functions->uPause(1);
+  port_out(lptPort + 2, portControl);
+  sem_signal(semid);
+}