DT properties dual-lvds-even-pixels and dual-lvds-odd-pixels
can be used to work out if the driver needs to swap even
and odd pixels around.
This patch makes use of the return value from function
drm_of_lvds_get_dual_link_pixel_order to determine if we
need to swap odd and even pixels around for things to work
properly.
Signed-off-by: Fabrizio Castro <fabrizio.castro@xxxxxxxxxxxxxx>
---
v3->v4:
* New patch extracted from patch:
"drm: rcar-du: lvds: Add dual-LVDS panels support"
---
drivers/gpu/drm/rcar-du/rcar_lvds.c | 46 +++++++++++++++++++++++++++++--------
1 file changed, 37 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/rcar-du/rcar_lvds.c b/drivers/gpu/drm/rcar-du/rcar_lvds.c
index 6c1f171..cb2147c 100644
--- a/drivers/gpu/drm/rcar-du/rcar_lvds.c
+++ b/drivers/gpu/drm/rcar-du/rcar_lvds.c
@@ -71,6 +71,7 @@ struct rcar_lvds {
struct drm_bridge *companion;
bool dual_link;
+ bool stripe_swap_data;
};
#define bridge_to_rcar_lvds(b) \
@@ -441,12 +442,20 @@ static void rcar_lvds_enable(struct drm_bridge *bridge)
rcar_lvds_write(lvds, LVDCHCR, lvdhcr);
if (lvds->info->quirks & RCAR_LVDS_QUIRK_DUAL_LINK) {
- /*
- * Configure vertical stripe based on the mode of operation of
- * the connected device.
- */
- rcar_lvds_write(lvds, LVDSTRIPE,
- lvds->dual_link ? LVDSTRIPE_ST_ON : 0);
+ u32 lvdstripe = 0;
+
+ if (lvds->dual_link)
+ /*
+ * Configure vertical stripe based on the mode of
+ * operation of the connected device.
+ *
+ * ST_SWAP from LVD1STRIPE is reserved, do not set
+ * in the companion LVDS
+ */
+ lvdstripe = LVDSTRIPE_ST_ON |
+ (lvds->companion && lvds->stripe_swap_data ?
+ LVDSTRIPE_ST_SWAP : 0);
+ rcar_lvds_write(lvds, LVDSTRIPE, lvdstripe);
}
/*
@@ -702,17 +711,33 @@ static int rcar_lvds_parse_dt_companion(struct rcar_lvds *lvds)
dual_link = drm_of_lvds_get_dual_link_pixel_order(p0, p1);
of_node_put(p0);
of_node_put(p1);
- if (dual_link >= DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS) {
+
+ switch (dual_link) {
+ case DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS:
+ /*
+ * By default we generate even pixels from this encoder and odd
+ * pixels from the companion encoder, but since p0 is connected
+ * to the port expecting ood pixels, and p1 is connected to the
+ * port expecting even pixels, we need to swap even and odd
+ * pixels around.
+ */
+ lvds->stripe_swap_data = true;
+ lvds->dual_link = true;
+ break;
+ case DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS:
lvds->dual_link = true;
- } else if (lvds->next_bridge && lvds->next_bridge->timings) {
+ break;
+ default:
/*
* Early dual-link bridge specific implementations populate the
* timings field of drm_bridge, read the dual_link flag off the
* bridge directly for backward compatibility.
*/
- lvds->dual_link = lvds->next_bridge->timings->dual_link;
+ if (lvds->next_bridge && lvds->next_bridge->timings)
+ lvds->dual_link = lvds->next_bridge->timings->dual_link;
}
+
if (!lvds->dual_link) {
dev_dbg(dev, "Single-link configuration detected\n");
goto done;
@@ -728,6 +753,9 @@ static int rcar_lvds_parse_dt_companion(struct rcar_lvds *lvds)
"Dual-link configuration detected (companion encoder %pOF)\n",
companion);
+ if (lvds->stripe_swap_data)
+ dev_dbg(dev, "Data swapping required\n");
+
companion_lvds = bridge_to_rcar_lvds(lvds->companion);
/*
--
2.7.4
