Commit 179f1aa4 authored by Sebastian Hesselbarth's avatar Sebastian Hesselbarth Committed by Dave Airlie

drm/i2c: tda998x: prepare for broken sync workaround

Some LCD controller cannot provide valid VESA style sync, i.e. coincident
HS/VS edges. First, this patch adds hskew passed from the adjusted_mode to
reference pixel calculation to allow those controllers to add an offset
relative to the expected reference pixel.
Signed-off-by: default avatarDarren Etheridge <detheridge@ti.com>
Signed-off-by: default avatarSebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Tested-by: default avatarRussell King <rmk_kernel@arm.linux.org.uk>
Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
parent 088d61d1
......@@ -782,6 +782,14 @@ tda998x_encoder_mode_set(struct drm_encoder *encoder,
de_pix_s = mode->htotal - mode->hdisplay;
ref_pix = 3 + hs_pix_s;
/*
* Attached LCD controllers may generate broken sync. Allow
* those to adjust the position of the rising VS edge by adding
* HSKEW to ref_pix.
*/
if (adjusted_mode->flags & DRM_MODE_FLAG_HSKEW)
ref_pix += adjusted_mode->hskew;
if ((mode->flags & DRM_MODE_FLAG_INTERLACE) == 0) {
ref_line = 1 + mode->vsync_start - mode->vdisplay;
vwin1_line_s = mode->vtotal - mode->vdisplay - 1;
......
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