[U-Boot] [PATCH 3/8] video/console: Implement relative cursor movement ANSI handling

[Andre Przywara]

The ANSI terminal escapce sequence standard defines relative cursor
movement commands (ESC [ A-F). So far the DM_VIDEO console code was
ignoring them.

Interpret those sequences and move the cursor by the requested amount of
rows or columns in the right direction. This brings the code on par with
the legacy video console driver (cfb_console).

Signed-off-by: Andre Przywara <andre.przywara at arm.com>
---
 drivers/video/vidconsole-uclass.c | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/drivers/video/vidconsole-uclass.c b/drivers/video/vidconsole-uclass.c
index 87f43c2030..cbd63f0ce8 100644
--- a/drivers/video/vidconsole-uclass.c
+++ b/drivers/video/vidconsole-uclass.c
@@ -259,6 +259,43 @@ static void vidconsole_escape_char(struct udevice *dev, char ch)
 	priv->escape = 0;
 
 	switch (ch) {
+	case 'A':
+	case 'B':
+	case 'C':
+	case 'D':
+	case 'E':
+	case 'F': {
+		int row, col, num;
+		char *s = priv->escape_buf;
+
+		/*
+		 * Cursor up/down: [%dA, [%dB, [%dE, [%dF
+		 * Cursor left/right: [%dD, [%dC
+		 */
+		s++;    /* [ */
+		s = parsenum(s, &num);
+		if (num == 0)			/* No digit in sequence ... */
+			num = 1;		/* ... means "move by 1". */
+
+		get_cursor_position(priv, &row, &col);
+		if (ch == 'A' || ch == 'F')
+			row -= num;
+		if (ch == 'C')
+			col += num;
+		if (ch == 'D')
+			col -= num;
+		if (ch == 'B' || ch == 'E')
+			row += num;
+		if (ch == 'E' || ch == 'F')
+			col = 0;
+		if (col < 0)
+			col = 0;
+		if (row < 0)
+			row = 0;
+		/* Right and bottom overflows are handled in the callee. */
+		set_cursor_position(priv, row, col);
+		break;
+	}
 	case 'H':
 	case 'f': {
 		int row, col;
-- 
2.14.5