video/console: Implement reverse video ANSI sequence for DM_VIDEO

The video console for DM_VIDEO compliant drivers only understands a very
small number of ANSI sequences. First and foremost it misses the "reverse
video" command, which is used by our own bootmenu command to highlight
the selected entry.

To avoid forcing people to use their imagination when using the
bootmenu, let's just implement the rather simple reverse effect. We need
to store the background colour index for that, so that we can
recalculate both the foreground and background colour pixel values.
Signed-off-by: NAndre Przywara <andre.przywara@arm.com>
Reviewed-by: NSimon Glass <sjg@chromium.org>
[agust: merged BG color escape seq change to fix "ut dm video_ansi" test]
Signed-off-by: NAnatolij Gustschin <agust@denx.de>

drivers/video/vidconsole-uclass.c

@@ -360,6 +360,13 @@ static void vidconsole_escape_char(struct udevice *dev, char ch)
 				vid_priv->colour_fg = vid_console_color(
 						vid_priv, vid_priv->fg_col_idx);
 				break;
+			case 7:
+				/* reverse video */
+				vid_priv->colour_fg = vid_console_color(
+						vid_priv, vid_priv->bg_col_idx);
+				vid_priv->colour_bg = vid_console_color(
+						vid_priv, vid_priv->fg_col_idx);
+				break;
 			case 30 ... 37:
 				/* foreground color */
 				vid_priv->fg_col_idx &= ~7;
@@ -368,9 +375,11 @@ static void vidconsole_escape_char(struct udevice *dev, char ch)
 						vid_priv, vid_priv->fg_col_idx);
 				break;
 			case 40 ... 47:
-				/* background color */
+				/* background color, also mask the bold bit */
+				vid_priv->bg_col_idx &= ~0xf;
+				vid_priv->bg_col_idx |= val - 40;
 				vid_priv->colour_bg = vid_console_color(
-							vid_priv, val - 40);
+						vid_priv, vid_priv->bg_col_idx);
 				break;
 			default:
 				/* ignore unsupported SGR parameter */

drivers/video/video-uclass.c

@@ -136,6 +136,7 @@ void video_set_default_colors(struct udevice *dev, bool invert)
 		back = temp;
 	}
 	priv->fg_col_idx = fore;
+	priv->bg_col_idx = back;
 	priv->colour_fg = vid_console_color(priv, fore);
 	priv->colour_bg = vid_console_color(priv, back);
 }

include/video.h

@@ -70,6 +70,7 @@ enum video_log2_bpp {
  *		the LCD is updated
  * @cmap:	Colour map for 8-bit-per-pixel displays
  * @fg_col_idx:	Foreground color code (bit 3 = bold, bit 0-2 = color)
+ * @bg_col_idx:	Background color code (bit 3 = bold, bit 0-2 = color)
  */
 struct video_priv {
 	/* Things set up by the driver: */
@@ -92,6 +93,7 @@ struct video_priv {
 	bool flush_dcache;
 	ushort *cmap;
 	u8 fg_col_idx;
+	u8 bg_col_idx;
 };
 
 /* Placeholder - there are no video operations at present */