As the TC358768 is a DPI to DSI bridge, the DSI side does not need to
define h/v sync polarities. This means that sometimes we have a mode
without defined sync polarities, which does not work on the DPI side.
Add a mode_fixup hook to default to positive sync polarities.
Reviewed-by: Peter Ujfalusi <peter.ujfalusi@xxxxxxxxx>
Tested-by: Maxim Schwalm <maxim.schwalm@xxxxxxxxx> # Asus TF700T
Tested-by: Marcel Ziswiler <marcel.ziswiler@xxxxxxxxxxx>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/bridge/tc358768.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/drivers/gpu/drm/bridge/tc358768.c b/drivers/gpu/drm/bridge/tc358768.c
index bc97a837955b..963ac550509b 100644
--- a/drivers/gpu/drm/bridge/tc358768.c
+++ b/drivers/gpu/drm/bridge/tc358768.c
@@ -963,9 +963,27 @@ tc358768_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
return input_fmts;
}
+static bool tc358768_mode_fixup(struct drm_bridge *bridge,
+ const struct drm_display_mode *mode,
+ struct drm_display_mode *adjusted_mode)
+{
+ /* Default to positive sync */
+
+ if (!(adjusted_mode->flags &
+ (DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_NHSYNC)))
+ adjusted_mode->flags |= DRM_MODE_FLAG_PHSYNC;
+
+ if (!(adjusted_mode->flags &
+ (DRM_MODE_FLAG_PVSYNC | DRM_MODE_FLAG_NVSYNC)))
+ adjusted_mode->flags |= DRM_MODE_FLAG_PVSYNC;
+
+ return true;
+}
+
static const struct drm_bridge_funcs tc358768_bridge_funcs = {
.attach = tc358768_bridge_attach,
.mode_valid = tc358768_bridge_mode_valid,
+ .mode_fixup = tc358768_mode_fixup,
.pre_enable = tc358768_bridge_pre_enable,
.enable = tc358768_bridge_enable,
.disable = tc358768_bridge_disable,
--
2.34.1
