harmonize backingstroe name with other drivers; don't force connection type

drivers to define nop-like functions for features they don't support

server/drivers/hd44780-bwct-usb.c

@@ -50,8 +50,6 @@ hd_init_bwct_usb(Driver *drvthis)
   char serial[LCD_MAX_WIDTH+1] = DEFAULT_SERIALNO;
 
   p->hd44780_functions->senddata = bwct_usb_HD44780_senddata;
-  p->hd44780_functions->backlight = bwct_usb_HD44780_backlight;
-  p->hd44780_functions->scankeypad = bwct_usb_HD44780_scankeypad;
   p->hd44780_functions->close = bwct_usb_HD44780_close;
   drvthis->set_contrast = bwct_usb_set_contrast;
 
@@ -189,19 +187,6 @@ int type = (flags == RS_DATA) ? BWCT_LCD_DATA : BWCT_LCD_CMD;
 }
 
 
-void
-bwct_usb_HD44780_backlight(PrivateData *p, unsigned char state)
-{
-}
-
-
-unsigned char
-bwct_usb_HD44780_scankeypad(PrivateData *p)
-{
-  return '\0';
-}
-
-
 void
 bwct_usb_HD44780_close(PrivateData *p)
 {

server/drivers/hd44780-bwct-usb.h

@@ -19,9 +19,7 @@
 int hd_init_bwct_usb(Driver *drvthis);
 
 void bwct_usb_HD44780_senddata(PrivateData *p, unsigned char displayID, unsigned char flags, unsigned char ch);
-void bwct_usb_HD44780_backlight(PrivateData *p, unsigned char state);
 void bwct_usb_set_contrast(Driver *drvthis, int promille);
-unsigned char bwct_usb_HD44780_scankeypad(PrivateData *p);
 void bwct_usb_HD44780_close(PrivateData *p);
 
 #endif

server/drivers/hd44780-ftdi.c

@@ -1,3 +1,7 @@
+/** \file hd44780-ftdi.c
+ * \c ftdi connection type of \c hd44780 driver for Hitachi HD44780 based LCD displays.
+ */
+
 /*
  * FTDI/USB driver module for Hitachi HD44780 based LCD displays
  * connected to a FT2232C/D chip in 8 bit mode.
@@ -39,7 +43,6 @@ hd_init_ftdi(Driver *drvthis)
 
     p->hd44780_functions->senddata = ftdi_HD44780_senddata;
     p->hd44780_functions->backlight = ftdi_HD44780_backlight;
-    p->hd44780_functions->scankeypad = ftdi_HD44780_scankeypad;
     p->hd44780_functions->close = ftdi_HD44780_close;
 
     // Load config
@@ -93,7 +96,8 @@ ftdi_HD44780_senddata(PrivateData *p, unsigned char displayID, unsigned char fla
     // Output data on first channel
     int f = ftdi_write_data(&p->ftdic, &ch, 1);
     if (f < 0) {
-        p->hd44780_functions->drv_report(RPT_ERR, "failed to write: %d (%s). Exiting", f, ftdi_get_error_string(&p->ftdic));
+        p->hd44780_functions->drv_report(RPT_ERR, "failed to write: %d (%s). Exiting",
+					f, ftdi_get_error_string(&p->ftdic));
         exit (-1);
     }
 
@@ -104,7 +108,8 @@ ftdi_HD44780_senddata(PrivateData *p, unsigned char displayID, unsigned char fla
     }
     f = ftdi_write_data(&p->ftdic2, &ch, 1);
     if (f < 0) {
-        p->hd44780_functions->drv_report(RPT_ERR, "failed to write: %d (%s). Exiting", f, ftdi_get_error_string(&p->ftdic2));
+        p->hd44780_functions->drv_report(RPT_ERR, "failed to write: %d (%s). Exiting",
+					f, ftdi_get_error_string(&p->ftdic2));
         exit(-1);
     }
 
@@ -115,7 +120,8 @@ ftdi_HD44780_senddata(PrivateData *p, unsigned char displayID, unsigned char fla
     }
     f = ftdi_write_data(&p->ftdic2, &ch, 1);
     if (f < 0) {
-        p->hd44780_functions->drv_report(RPT_ERR, "failed to write: %d (%s). Exiting", f, ftdi_get_error_string(&p->ftdic2));
+        p->hd44780_functions->drv_report(RPT_ERR, "failed to write: %d (%s). Exiting",
+					f, ftdi_get_error_string(&p->ftdic2));
         exit(-1);
     }
 }
@@ -130,19 +136,13 @@ ftdi_HD44780_backlight(PrivateData *p, unsigned char state)
 
     f = ftdi_write_data(&p->ftdic2, &state, 1);
     if (f < 0) {
-        p->hd44780_functions->drv_report(RPT_ERR, "failed to write: %d (%s). Exiting", f, ftdi_get_error_string(&p->ftdic2));
+        p->hd44780_functions->drv_report(RPT_ERR, "failed to write: %d (%s). Exiting",
+					f, ftdi_get_error_string(&p->ftdic2));
         exit(-1);
     }
 }
 
 
-unsigned char
-ftdi_HD44780_scankeypad(PrivateData *p)
-{
-    return 0;
-}
-
-
 void
 ftdi_HD44780_close(PrivateData *p)
 {

server/drivers/hd44780-ftdi.h

@@ -9,7 +9,6 @@ int hd_init_ftdi(Driver *drvthis);
 
 void ftdi_HD44780_senddata(PrivateData *p, unsigned char displayID, unsigned char flags, unsigned char ch);
 void ftdi_HD44780_backlight(PrivateData *p, unsigned char state);
-unsigned char ftdi_HD44780_scankeypad(PrivateData *p);
 void ftdi_HD44780_close(PrivateData *p);
 
 #endif

server/drivers/hd44780-i2c.c

@@ -157,7 +157,6 @@ hd_init_i2c(Driver *drvthis)
 
 	hd44780_functions->senddata = i2c_HD44780_senddata;
 	hd44780_functions->backlight = i2c_HD44780_backlight;
-	hd44780_functions->scankeypad = NULL;
 
 	// powerup the lcd now
 	/* We'll now send 0x03 a couple of times,

server/drivers/hd44780-lis2.c

@@ -48,8 +48,6 @@ extern unsigned int **bitrate_conversion;
 extern int convert_bitrate(unsigned int conf_bitrate, size_t *bitrate);
 
 void lis2_HD44780_senddata(PrivateData *p, unsigned char displayID, unsigned char flags, unsigned char ch);
-void lis2_HD44780_backlight(PrivateData *p, unsigned char state);
-unsigned char lis2_HD44780_scankeypad(PrivateData *p);
 
 static void clearScreen(int fd);
 static void gotoXY(int fd, unsigned char x, unsigned char y);
@@ -122,8 +120,6 @@ int hd_init_lis2(Driver *drvthis)
 	tcsetattr(p->fd, TCSANOW, &portset);
 
 	p->hd44780_functions->senddata = lis2_HD44780_senddata;
-	p->hd44780_functions->backlight = lis2_HD44780_backlight;
-	p->hd44780_functions->scankeypad = lis2_HD44780_scankeypad;
 
 	common_init(p, IF_8BIT);
 
@@ -220,18 +216,6 @@ static unsigned char rowNum = 0;
 }
 
 
-void lis2_HD44780_backlight(PrivateData *p, unsigned char state)
-{
-	/* No backlight control */
-}
-
-
-unsigned char lis2_HD44780_scankeypad(PrivateData *p)
-{
-	return '\0';
-}
-
-
 // hardware specific functions common to all device types
 
 /**

server/drivers/hd44780-serial.c

@@ -171,8 +171,8 @@ hd_init_serial(Driver *drvthis)
 	size_t bitrate;
 
 	conf_bitrate = drvthis->config_get_int(drvthis->name, "Speed", 0, SERIAL_IF.default_bitrate);
-        if (conf_bitrate == 0)
+	if (conf_bitrate == 0)
-                conf_bitrate = SERIAL_IF.default_bitrate;
+		conf_bitrate = SERIAL_IF.default_bitrate;
 	if (convert_bitrate(conf_bitrate, &bitrate)) {
 		report(RPT_ERR, "HD44780: serial: invalid configured bitrate speed");
 		return -1;
@@ -215,14 +215,13 @@ hd_init_serial(Driver *drvthis)
 	/* Set TCSANOW mode of serial device */
 	tcsetattr(p->fd, TCSANOW, &portset);
 
-        lastdisplayID = -1;
+	lastdisplayID = -1;
 
 	/* Assign functions */
 	p->hd44780_functions->senddata = serial_HD44780_senddata;
 	p->hd44780_functions->backlight = serial_HD44780_backlight;
-	if (p->have_keypad)
+	p->hd44780_functions->scankeypad = serial_HD44780_scankeypad;
-		p->hd44780_functions->scankeypad = serial_HD44780_scankeypad;
+	p->hd44780_functions->close = serial_HD44780_close;
-        p->hd44780_functions->close = serial_HD44780_close;
 
 	/* Do initialization */
 	if (SERIAL_IF.if_bits == 8) {
@@ -248,8 +247,8 @@ serial_HD44780_senddata(PrivateData *p, unsigned char displayID, unsigned char f
 		/* Do we need a DATA indicator byte? */
 		if ((SERIAL_IF.data_escape != '\0') &&
 		    (((ch >= SERIAL_IF.data_escape_min) &&
-		    (ch < SERIAL_IF.data_escape_max)) ||
+		      (ch < SERIAL_IF.data_escape_max)) ||
-                    (SERIAL_IF.multiple_displays && displayID != lastdisplayID))) {
+		     (SERIAL_IF.multiple_displays && displayID != lastdisplayID))) {
 			write(p->fd, &SERIAL_IF.data_escape + displayID, 1);
 		}
 		write(p->fd, &ch, 1);
@@ -258,25 +257,25 @@ serial_HD44780_senddata(PrivateData *p, unsigned char displayID, unsigned char f
 		write(p->fd, &SERIAL_IF.instruction_escape, 1);
 		write(p->fd, &ch, 1);
 	}
-        lastdisplayID = displayID;
+	lastdisplayID = displayID;
 }
 
 void
 serial_HD44780_backlight(PrivateData *p, unsigned char state)
 {
-        unsigned char send[1];
+	unsigned char send[1];
 	if (p->have_backlight) {
 		if (SERIAL_IF.backlight_escape) {
 			send[0] = SERIAL_IF.backlight_escape;
 			write(p->fd, &send, 1);
-                }
+		}
-                if (SERIAL_IF.backlight_on && SERIAL_IF.backlight_off) {
+		if (SERIAL_IF.backlight_on && SERIAL_IF.backlight_off) {
 			send[0] = state ? SERIAL_IF.backlight_on : SERIAL_IF.backlight_off;
 		}
 		else {
 			send[0] = state ? 0 : 0xFF;
 		}
-                write(p->fd, &send, 1);
+		write(p->fd, &send, 1);
 	}
 }
 
@@ -302,7 +301,7 @@ serial_HD44780_scankeypad(PrivateData *p)
 void
 serial_HD44780_close(PrivateData *p)
 {
-        if (SERIAL_IF.end_code)
+	if (SERIAL_IF.end_code)
-                write(p->fd, &SERIAL_IF.end_code, 1);
+		write(p->fd, &SERIAL_IF.end_code, 1);
-        close(p->fd);
+	close(p->fd);
 }

server/drivers/hd44780.c

@@ -376,31 +376,38 @@ HD44780_init(Driver *drvthis)
 	p->hd44780_functions->set_contrast = NULL;
 	p->hd44780_functions->set_brightness = NULL;
 	p->hd44780_functions->readkeypad = NULL;
-	p->hd44780_functions->scankeypad = HD44780_scankeypad;
+	p->hd44780_functions->scankeypad = NULL;
 	p->hd44780_functions->output = NULL;
 	p->hd44780_functions->close = NULL;
 
-	// Do connection type specific display init
+	// Do local (=connection type specific) display init
 	if (init_fn(drvthis) != 0)
 		return -1;
 
-	// consistency check: local keypad functions missing => no keypad
+	// consistency check: fail if local senddata function was not defined
-	if ((p->hd44780_functions->readkeypad == NULL) &&
-	    (p->hd44780_functions->scankeypad == HD44780_scankeypad)) {
-		p->hd44780_functions->scankeypad = NULL;
-		p->have_keypad = 0;
-	}
-
-	// consistency check: no local output function => no output
-	if (p->hd44780_functions->output == NULL)
-		p->have_output = 0;
-
-	// fail if local senddata function was not defined
 	if (p->hd44780_functions->senddata == NULL) {
 		report(RPT_ERR, "%s: incomplete functions for connection type");
 		return -1;
 	}	
 
+	// set scankeypad function if local readkeypad function is defined
+	if ((p->hd44780_functions->readkeypad != NULL) &&
+	    (p->hd44780_functions->scankeypad == NULL)) {
+		p->hd44780_functions->scankeypad = HD44780_scankeypad;
+	}
+
+	// consistency check: no local keypad function => no keypad
+	if (p->hd44780_functions->scankeypad == NULL)
+		p->have_keypad = 0;
+
+	// consistency check: no local backlight function => no backlight
+	if (p->hd44780_functions->backlight == NULL)
+		p->have_backlight = 0;
+
+	// consistency check: no local output function => no output
+	if (p->hd44780_functions->output == NULL)
+		p->have_output = 0;
+
 
 	// Display startup parameters on the LCD
 	HD44780_clear(drvthis);