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: Darren Etheridge <detheridge@ti.com>
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Tested-by: Russell King <rmk_kernel@arm.linux.org.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This commit is contained in:
Sebastian Hesselbarth 2013-08-14 21:43:32 +02:00 committed by Dave Airlie
parent 088d61d1fd
commit 179f1aa407
1 changed files with 8 additions and 0 deletions

View File

@ -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;