lkml.org 
[lkml]   [2013]   [Aug]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 7/8] drm/i2c: tda998x: prepare for broken sync workaround
Date
From: Darren Etheridge <detheridge@ti.com>

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>
---
Changelog:
for v1:
- reword comment

Cc: David Airlie <airlied@linux.ie>
Cc: Darren Etheridge <detheridge@ti.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
---
drivers/gpu/drm/i2c/tda998x_drv.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/i2c/tda998x_drv.c b/drivers/gpu/drm/i2c/tda998x_drv.c
index 7bf227a..7dc5650 100644
--- a/drivers/gpu/drm/i2c/tda998x_drv.c
+++ b/drivers/gpu/drm/i2c/tda998x_drv.c
@@ -784,6 +784,15 @@ tda998x_encoder_mode_set(struct drm_encoder *encoder,
n_line = mode->vtotal;

ref_pix = 3 + mode->hsync_start - mode->hdisplay;
+
+ /*
+ * 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;
+
de_pix_s = mode->htotal - mode->hdisplay;
de_pix_e = de_pix_s + mode->hdisplay;
hs_pix_s = mode->hsync_start - mode->hdisplay;
--
1.7.10.4


\
 
 \ /
  Last update: 2013-08-06 00:41    [W:0.141 / U:0.328 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site