a4m072: change 'display' command implementation

This patch changes implementation of 'display' command for a4m072
that uses 7-segment LED display as customer requested:

a) The "display" command shall _not_ turn on the decimal point.

b) Exception: "display ." shall turn on (only) the decimal point.

c) Hex digits (0-9, A-F, a-f) shall be displayed as usual.

d) Letters U, P, Y, L, S, T, H shall be displayed as usual (lower
   case letters identical to upper case letters)

e) 'I' (and 'i') shall be displayed like '1'

f) 'O' (and 'o') shall be displayed like '0'

g) all other Characters shall be displayed like ' ' (all segments off).

Signed-off-by: Ilya Yanok <yanok@emcraft.com>
diff --git a/board/a4m072/a4m072.c b/board/a4m072/a4m072.c
index ae7ccbb..09a5a51 100644
--- a/board/a4m072/a4m072.c
+++ b/board/a4m072/a4m072.c
@@ -270,8 +270,6 @@
 static u8 display_putc_pos;
 static u8 display_out_pos;
 
-static u8 display_dot_enable;
-
 void display_set(int cmd) {
 
 	if (cmd & DISPLAY_CLEAR) {
@@ -281,12 +279,6 @@
 	if (cmd & DISPLAY_HOME) {
 		display_putc_pos = 0;
 	}
-
-	if (cmd & DISPLAY_MARK) {
-		display_dot_enable = 1;
-	} else {
-		display_dot_enable = 0;
-	}
 }
 
 #define SEG_A    (1<<0)
@@ -314,10 +306,12 @@
  * A..Z		index 10..35
  * -		index 36
  * _		index 37
+ * .		index 38
  */
 
 #define SYMBOL_DASH		(36)
 #define SYMBOL_UNDERLINE	(37)
+#define SYMBOL_DOT		(38)
 
 static u8 display_char2seg7_tbl[]=
 {
@@ -337,28 +331,29 @@
 	SEG_B | SEG_C | SEG_D | SEG_E | SEG_G,			/* d */
 	SEG_A | SEG_D | SEG_E | SEG_F | SEG_G,			/* E */
 	SEG_A | SEG_E | SEG_F | SEG_G,				/* F */
-	SEG_A | SEG_B | SEG_C | SEG_D | SEG_F | SEG_G,		/* g */
+	0,					/* g - not displayed */
 	SEG_B | SEG_C | SEG_E | SEG_F | SEG_G,			/* H */
-	SEG_E | SEG_F,						/* I */
-	SEG_B | SEG_C | SEG_D | SEG_E,				/* J */
-	SEG_A,						/* K - special 1 */
+	SEG_B | SEG_C,						/* I */
+	0,					/* J - not displayed */
+	0,					/* K - not displayed */
 	SEG_D | SEG_E | SEG_F,					/* L */
-	SEG_B,						/* m - special 2 */
-	SEG_C | SEG_E | SEG_G,					/* n */
-	SEG_C | SEG_D | SEG_E | SEG_G,				/* o */
+	0,					/* m - not displayed */
+	0,					/* n - not displayed */
+	SEG_A | SEG_B | SEG_C | SEG_D | SEG_E | SEG_F,		/* O */
 	SEG_A | SEG_B | SEG_E | SEG_F | SEG_G,			/* P */
-	SEG_A | SEG_B | SEG_C | SEG_F | SEG_G,			/* q */
-	SEG_E | SEG_G,						/* r */
+	0,					/* q - not displayed */
+	0,					/* r - not displayed */
 	SEG_A | SEG_C | SEG_D | SEG_F | SEG_G,			/* S */
 	SEG_D | SEG_E | SEG_F | SEG_G,				/* t */
 	SEG_B | SEG_C | SEG_D | SEG_E | SEG_F,			/* U */
-	SEG_C | SEG_D | SEG_E | SEG_F,				/* V */
-	SEG_C,						/* w - special 3 */
-	SEG_B | SEG_C | SEG_E | SEG_F | SEG_G,			/* X */
+	0,					/* V - not displayed */
+	0,					/* w - not displayed */
+	0,					/* X - not displayed */
 	SEG_B | SEG_C | SEG_D | SEG_F | SEG_G,			/* Y */
-	SEG_A | SEG_B | SEG_D | SEG_E | SEG_G,			/* Z */
+	0,					/* Z - not displayed */
 	SEG_G,							/* - */
-	SEG_D							/* _ */
+	SEG_D,							/* _ */
+	SEG_P							/* . */
 };
 
 /* Convert char to the LED segments representation */
@@ -374,23 +369,20 @@
 		c -= 'A' - 10;
 	else if (c == '-')
 		c = SYMBOL_DASH;
-	else if ((c == '_') || (c == '.'))
+	else if (c == '_')
 		c = SYMBOL_UNDERLINE;
+	else if (c == '.')
+		c = SYMBOL_DOT;
 	else
 		c = ' ';	/* display unsupported symbols as space */
 
 	if (c != ' ')
 		val = display_char2seg7_tbl[(int)c];
 
-	/* Handle DP LED here */
-	if (display_dot_enable) {
-		val |= SEG_P;
-	}
-
 	return val;
 }
 
-static inline int display_putc_nomark(char c)
+int display_putc(char c)
 {
 	if (display_putc_pos >= DISPLAY_BUF_SIZE)
 		return -1;
@@ -403,13 +395,6 @@
 	return c;
 }
 
-int display_putc(char c)
-{
-	/* Mark the codes from the "display" command with the DP LED */
-	display_set(DISPLAY_MARK);
-	return display_putc_nomark(c);
-}
-
 /*
  * Flush current symbol to the LED display hardware
  */
@@ -493,9 +478,8 @@
 	if (a4m072_status2code(status, buf) < 0)
 		return;
 
-	display_set(0);	/* Clear DP Led */
-	display_putc_nomark(buf[0]);
-	display_putc_nomark(buf[1]);
+	display_putc(buf[0]);
+	display_putc(buf[1]);
 	display_set(DISPLAY_HOME);
 	display_out_pos = 0;	/* reset output position */