a4m072: led display support

This patch adds support for LED display on a4m072 board. Hardware is
capable of displaying only one symbol at any time. We support displaying
two symbols in software (via blinking).

Signed-off-by: Ilya Yanok <yanok@emcraft.com>

1 files changed, 174 insertions, 0 deletions

diff --git a/board/a4m072/a4m072.c b/board/a4m072/a4m072.c
index 3756975..9c272a0 100644
--- a/board/a4m072/a4m072.c
+++ b/board/a4m072/a4m072.c
@@ -34,6 +34,7 @@
 #include <asm/io.h>
 #include <libfdt.h>
 #include <netdev.h>
+#include <led-display.h>
 
 #include "mt46v32m16.h"
 
@@ -261,3 +262,176 @@ int eeprom_write_enable (unsigned dev_addr, int state)
 	return state;
 }
 #endif
+
+#ifdef CONFIG_CMD_DISPLAY
+#define DISPLAY_BUF_SIZE	2
+static u8 display_buf[DISPLAY_BUF_SIZE];
+static u8 display_putc_pos;
+static u8 display_out_pos;
+
+static u8 display_dot_enable;
+
+void display_set(int cmd) {
+
+	if (cmd & DISPLAY_CLEAR) {
+		display_buf[0] = display_buf[1] = 0;
+	}
+
+	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)
+#define SEG_B    (1<<1)
+#define SEG_C    (1<<2)
+#define SEG_D    (1<<3)
+#define SEG_E    (1<<4)
+#define SEG_F    (1<<5)
+#define SEG_G    (1<<6)
+#define SEG_P    (1<<7)
+#define SEG__    0
+
+/*
+ * +- A -+
+ * |     |
+ * F     B
+ * |     |
+ * +- G -+
+ * |     |
+ * E     C
+ * |     |
+ * +- D -+  P
+ *
+ * 0..9		index 0..9
+ * A..Z		index 10..35
+ * -		index 36
+ * _		index 37
+ */
+
+#define SYMBOL_DASH		(36)
+#define SYMBOL_UNDERLINE	(37)
+
+static u8 display_char2seg7_tbl[]=
+{
+	SEG_A | SEG_B | SEG_C | SEG_D | SEG_E | SEG_F,		/* 0 */
+	SEG_B | SEG_C,						/* 1 */
+	SEG_A | SEG_B | SEG_D | SEG_E | SEG_G,			/* 2 */
+	SEG_A | SEG_B | SEG_C | SEG_D | SEG_G,			/* 3 */
+	SEG_B | SEG_C | SEG_F | SEG_G,				/* 4 */
+	SEG_A | SEG_C | SEG_D | SEG_F | SEG_G,			/* 5 */
+	SEG_A | SEG_C | SEG_D | SEG_E | SEG_F | SEG_G,		/* 6 */
+	SEG_A | SEG_B | SEG_C,					/* 7 */
+	SEG_A | SEG_B | SEG_C | SEG_D | SEG_E | SEG_F | SEG_G,	/* 8 */
+	SEG_A | SEG_B | SEG_C | SEG_D | SEG_F | SEG_G,		/* 9 */
+	SEG_A | SEG_B | SEG_C | SEG_E | SEG_F | SEG_G,		/* A */
+	SEG_C | SEG_D | SEG_E | SEG_F | SEG_G,			/* b */
+	SEG_A | SEG_D | SEG_E | SEG_F,				/* C */
+	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 */
+	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_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 */
+	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 */
+	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 */
+	SEG_B | SEG_C | SEG_D | SEG_F | SEG_G,			/* Y */
+	SEG_A | SEG_B | SEG_D | SEG_E | SEG_G,			/* Z */
+	SEG_G,							/* - */
+	SEG_D							/* _ */
+};
+
+/* Convert char to the LED segments representation */
+static u8 display_char2seg7(char c)
+{
+	u8 val = 0;
+
+	if (c >= '0' && c <= '9')
+		c -= '0';
+	else if (c >= 'a' && c <= 'z')
+		c -= 'a' - 10;
+	else if (c >= 'A' && c <= 'Z')
+		c -= 'A' - 10;
+	else if (c == '-')
+		c = SYMBOL_DASH;
+	else if ((c == '_') || (c == '.'))
+		c = SYMBOL_UNDERLINE;
+	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)
+{
+	if (display_putc_pos >= DISPLAY_BUF_SIZE)
+		return -1;
+
+	display_buf[display_putc_pos++] = display_char2seg7(c);
+	/* one-symbol message should be steady */
+	if (display_putc_pos == 1)
+		display_buf[display_putc_pos] = display_char2seg7(c);
+
+	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);
+}
+
+/*
+ * Output content of the software display buffer to the LED display every 0.5s
+ */
+void board_show_activity(ulong timestamp)
+{
+	static ulong last;
+	static u8 once;
+	u32 val;
+
+	if (!once || (timestamp - last >= (CONFIG_SYS_HZ / 2))) {
+		val = display_buf[display_out_pos];
+		val |= (val << 8) | (val << 16) | (val << 24);
+		out_be32((void *)CONFIG_SYS_DISP_CHR_RAM, val);
+		display_out_pos ^= 1;
+		last = timestamp;
+		once = 1;
+	}
+}
+
+/*
+ * Empty fake function
+ */
+void show_activity(int arg)
+{
+}
+#endif