fbcon: add fbcon=margin:<color> command line option

This adds a new command line option to select the fbcon margin color.

The motivation for this is screens where black does not blend into the
physical surroundings of the screen. For example, using an LCD (not the
backlit kind), white text on a black background is hard to read, so
inverting the colors is preferred. However, when you do this, most of the
screen is filled with white but the margins are still filled with black.
This makes a big, black, backwards 'L' on the screen. By setting
fbcon=margin:7, the margins will be filled with white and the LCD looks as
expected.

Signed-off-by: David Lechner <david@lechnology.com>
[b.zolnierkie: ported over fbcon changes]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

8 files changed, 28 insertions, 11 deletions

diff --git a/Documentation/fb/fbcon.txt b/Documentation/fb/fbcon.txt
index 4a9739abc860..1822b190ccd6 100644
--- a/Documentation/fb/fbcon.txt
+++ b/Documentation/fb/fbcon.txt
@@ -148,6 +148,13 @@ C. Boot options
 	Actually, the underlying fb driver is totally ignorant of console
 	rotation.
 
+5. fbcon=margin:<color>
+
+	This option specifies the color of the margins. The margins are the
+	leftover area at the right and the bottom of the screen that are not
+	used by text. By default, this area will be black. The 'color' value
+	is 0 to 7 where 0 is black and 7 is white.
+
 C. Attaching, Detaching and Unloading
 
 Before going on how to attach, detach and unload the framebuffer console, an
diff --git a/drivers/video/fbdev/core/bitblit.c b/drivers/video/fbdev/core/bitblit.c
index 99f3a1c3d093..790900d646c0 100644
--- a/drivers/video/fbdev/core/bitblit.c
+++ b/drivers/video/fbdev/core/bitblit.c
@@ -203,7 +203,7 @@ static void bit_putcs(struct vc_data *vc, struct fb_info *info,
 }
 
 static void bit_clear_margins(struct vc_data *vc, struct fb_info *info,
-			      int bottom_only)
+			      int color, int bottom_only)
 {
 	unsigned int cw = vc->vc_font.width;
 	unsigned int ch = vc->vc_font.height;
@@ -213,7 +213,7 @@ static void bit_clear_margins(struct vc_data *vc, struct fb_info *info,
 	unsigned int bs = info->var.yres - bh;
 	struct fb_fillrect region;
 
-	region.color = 0;
+	region.color = color;
 	region.rop = ROP_COPY;
 
 	if (rw && !bottom_only) {
diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
index fcd5399949e0..4dd08b4af170 100644
--- a/drivers/video/fbdev/core/fbcon.c
+++ b/drivers/video/fbdev/core/fbcon.c
@@ -138,6 +138,7 @@ static int info_idx = -1;
 /* console rotation */
 static int initial_rotation = -1;
 static int fbcon_has_sysfs;
+static int margin_color;
 
 static const struct consw fb_con;
 
@@ -492,6 +493,15 @@ static int __init fb_console_setup(char *this_opt)
 				initial_rotation = 0;
 			continue;
 		}
+
+		if (!strncmp(options, "margin:", 7)) {
+			options += 7;
+			if (*options)
+				margin_color = simple_strtoul(options, &options, 0);
+			if (margin_color > 7)
+				margin_color = 0;
+			continue;
+		}
 	}
 	return 1;
 }
@@ -1306,7 +1316,7 @@ static void fbcon_clear_margins(struct vc_data *vc, int bottom_only)
 	struct fbcon_ops *ops = info->fbcon_par;
 
 	if (!fbcon_is_inactive(vc, info))
-		ops->clear_margins(vc, info, bottom_only);
+		ops->clear_margins(vc, info, margin_color, bottom_only);
 }
 
 static void fbcon_cursor(struct vc_data *vc, int mode)
diff --git a/drivers/video/fbdev/core/fbcon.h b/drivers/video/fbdev/core/fbcon.h
index 60e25e173fdb..18f3ac144237 100644
--- a/drivers/video/fbdev/core/fbcon.h
+++ b/drivers/video/fbdev/core/fbcon.h
@@ -60,7 +60,7 @@ struct fbcon_ops {
 		      const unsigned short *s, int count, int yy, int xx,
 		      int fg, int bg);
 	void (*clear_margins)(struct vc_data *vc, struct fb_info *info,
-			      int bottom_only);
+			      int color, int bottom_only);
 	void (*cursor)(struct vc_data *vc, struct fb_info *info, int mode,
 		       int softback_lines, int fg, int bg);
 	int  (*update_start)(struct fb_info *info);
diff --git a/drivers/video/fbdev/core/fbcon_ccw.c b/drivers/video/fbdev/core/fbcon_ccw.c
index 2eeefa97bd4a..37a8b0b22566 100644
--- a/drivers/video/fbdev/core/fbcon_ccw.c
+++ b/drivers/video/fbdev/core/fbcon_ccw.c
@@ -189,7 +189,7 @@ static void ccw_putcs(struct vc_data *vc, struct fb_info *info,
 }
 
 static void ccw_clear_margins(struct vc_data *vc, struct fb_info *info,
-			     int bottom_only)
+			      int color, int bottom_only)
 {
 	unsigned int cw = vc->vc_font.width;
 	unsigned int ch = vc->vc_font.height;
@@ -198,7 +198,7 @@ static void ccw_clear_margins(struct vc_data *vc, struct fb_info *info,
 	unsigned int bs = vc->vc_rows*ch;
 	struct fb_fillrect region;
 
-	region.color = 0;
+	region.color = color;
 	region.rop = ROP_COPY;
 
 	if (rw && !bottom_only) {
diff --git a/drivers/video/fbdev/core/fbcon_cw.c b/drivers/video/fbdev/core/fbcon_cw.c
index c321f7c59e5c..1888f8c866e8 100644
--- a/drivers/video/fbdev/core/fbcon_cw.c
+++ b/drivers/video/fbdev/core/fbcon_cw.c
@@ -172,7 +172,7 @@ static void cw_putcs(struct vc_data *vc, struct fb_info *info,
 }
 
 static void cw_clear_margins(struct vc_data *vc, struct fb_info *info,
-			     int bottom_only)
+			     int color, int bottom_only)
 {
 	unsigned int cw = vc->vc_font.width;
 	unsigned int ch = vc->vc_font.height;
@@ -181,7 +181,7 @@ static void cw_clear_margins(struct vc_data *vc, struct fb_info *info,
 	unsigned int rs = info->var.yres - rw;
 	struct fb_fillrect region;
 
-	region.color = 0;
+	region.color = color;
 	region.rop = ROP_COPY;
 
 	if (rw && !bottom_only) {
diff --git a/drivers/video/fbdev/core/fbcon_ud.c b/drivers/video/fbdev/core/fbcon_ud.c
index c0b605d49cb3..f98eee263597 100644
--- a/drivers/video/fbdev/core/fbcon_ud.c
+++ b/drivers/video/fbdev/core/fbcon_ud.c
@@ -220,7 +220,7 @@ static void ud_putcs(struct vc_data *vc, struct fb_info *info,
 }
 
 static void ud_clear_margins(struct vc_data *vc, struct fb_info *info,
-			     int bottom_only)
+			     int color, int bottom_only)
 {
 	unsigned int cw = vc->vc_font.width;
 	unsigned int ch = vc->vc_font.height;
@@ -228,7 +228,7 @@ static void ud_clear_margins(struct vc_data *vc, struct fb_info *info,
 	unsigned int bh = info->var.yres - (vc->vc_rows*ch);
 	struct fb_fillrect region;
 
-	region.color = 0;
+	region.color = color;
 	region.rop = ROP_COPY;
 
 	if (rw && !bottom_only) {
diff --git a/drivers/video/fbdev/core/tileblit.c b/drivers/video/fbdev/core/tileblit.c
index 4636a6110c27..93390312957f 100644
--- a/drivers/video/fbdev/core/tileblit.c
+++ b/drivers/video/fbdev/core/tileblit.c
@@ -74,7 +74,7 @@ static void tile_putcs(struct vc_data *vc, struct fb_info *info,
 }
 
 static void tile_clear_margins(struct vc_data *vc, struct fb_info *info,
-			       int bottom_only)
+			       int color, int bottom_only)
 {
 	return;
 }