drm/modes: Parse overscan properties

Properly configuring the overscan properties might be needed for the
initial setup of the framebuffer for display that still have overscan.
Let's allow for more properties on the kernel command line to setup each
margin.

Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/e481f1628e3768ca49226ec2115cfa4dfcbd5e4c.1560783090.git-series.maxime.ripard@bootlin.com

1 files changed, 44 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index dc6d11292685..57e6408288c8 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -1609,6 +1609,50 @@ static int drm_mode_parse_cmdline_options(char *str, size_t len,
 		} else if (!strncmp(option, "reflect_y", delim - option)) {
 			rotation |= DRM_MODE_REFLECT_Y;
 			sep = delim;
+		} else if (!strncmp(option, "margin_right", delim - option)) {
+			const char *value = delim + 1;
+			unsigned int margin;
+
+			margin = simple_strtol(value, &sep, 10);
+
+			/* Make sure we have parsed something */
+			if (sep == value)
+				return -EINVAL;
+
+			mode->tv_margins.right = margin;
+		} else if (!strncmp(option, "margin_left", delim - option)) {
+			const char *value = delim + 1;
+			unsigned int margin;
+
+			margin = simple_strtol(value, &sep, 10);
+
+			/* Make sure we have parsed something */
+			if (sep == value)
+				return -EINVAL;
+
+			mode->tv_margins.left = margin;
+		} else if (!strncmp(option, "margin_top", delim - option)) {
+			const char *value = delim + 1;
+			unsigned int margin;
+
+			margin = simple_strtol(value, &sep, 10);
+
+			/* Make sure we have parsed something */
+			if (sep == value)
+				return -EINVAL;
+
+			mode->tv_margins.top = margin;
+		} else if (!strncmp(option, "margin_bottom", delim - option)) {
+			const char *value = delim + 1;
+			unsigned int margin;
+
+			margin = simple_strtol(value, &sep, 10);
+
+			/* Make sure we have parsed something */
+			if (sep == value)
+				return -EINVAL;
+
+			mode->tv_margins.bottom = margin;
 		} else {
 			return -EINVAL;
 		}