The OnSemi FIN3385 Parallel-to-LVDS encoder has a dedicated input line to
select input pixel data sampling edge. Add DT property "pclk-sample", not
the same as the one used by display timings but rather the same as used by
media, and configure bus flags based on this DT property.
Signed-off-by: Marek Vasut <marex@xxxxxxx>
Cc: Alexandre Torgue <alexandre.torgue@xxxxxx>
Cc: Andrzej Hajda <a.hajda@xxxxxxxxxxx>
Cc: Antonio Borneo <antonio.borneo@xxxxxx>
Cc: Benjamin Gaignard <benjamin.gaignard@xxxxxx>
Cc: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Cc: Maxime Coquelin <mcoquelin.stm32@xxxxxxxxx>
Cc: Philippe Cornu <philippe.cornu@xxxxxx>
Cc: Sam Ravnborg <sam@xxxxxxxxxxxx>
Cc: Vincent Abriou <vincent.abriou@xxxxxx>
Cc: Yannick Fertre <yannick.fertre@xxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-stm32@xxxxxxxxxxxxxxxxxxxxxxxxxxxx
To: dri-devel@xxxxxxxxxxxxxxxxxxxxx
---
V2: - Limit the pixelclk-active to encoders only
- Update DT binding document
V3: - Determine whether this is encoder from connector, i.e.
lvds_codec->connector_type == DRM_MODE_CONNECTOR_LVDS
V4: - Switch to pclk-sample. Note that the value of this is inverted,
so all the existing users of pixelclk-active using previous
version of this patch must be reworked
V5: - Move pclk-sample to endpoint. Again, all existing users of the
bindings must be reworked
---
drivers/gpu/drm/bridge/lvds-codec.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/drivers/gpu/drm/bridge/lvds-codec.c b/drivers/gpu/drm/bridge/lvds-codec.c
index dcf579a4cf833..80ce6783d10a8 100644
--- a/drivers/gpu/drm/bridge/lvds-codec.c
+++ b/drivers/gpu/drm/bridge/lvds-codec.c
@@ -19,6 +19,7 @@ struct lvds_codec {
struct device *dev;
struct drm_bridge bridge;
struct drm_bridge *panel_bridge;
+ struct drm_bridge_timings timings;
struct regulator *vcc;
struct gpio_desc *powerdown_gpio;
u32 connector_type;
@@ -78,8 +79,10 @@ static int lvds_codec_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *panel_node;
+ struct device_node *bus_node;
struct drm_panel *panel;
struct lvds_codec *lvds_codec;
+ u32 val;
lvds_codec = devm_kzalloc(dev, sizeof(*lvds_codec), GFP_KERNEL);
if (!lvds_codec)
@@ -119,6 +122,27 @@ static int lvds_codec_probe(struct platform_device *pdev)
if (IS_ERR(lvds_codec->panel_bridge))
return PTR_ERR(lvds_codec->panel_bridge);
+ /*
+ * Encoder might sample data on different clock edge than the display,
+ * for example OnSemi FIN3385 has a dedicated strapping pin to select
+ * the sampling edge.
+ */
+ if (lvds_codec->connector_type == DRM_MODE_CONNECTOR_LVDS) {
+ bus_node = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
+ if (!bus_node) {
+ dev_dbg(dev, "bus DT node not found\n");
+ return -ENXIO;
+ }
+
+ if (!of_property_read_u32(dev->of_node, "pclk-sample", &val)) {
+ lvds_codec->timings.input_bus_flags = val ?
+ DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE :
+ DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE;
+ }
+
+ of_node_put(bus_node);
+ }
+
/*
* The panel_bridge bridge is attached to the panel's of_node,
* but we need a bridge attached to our of_node for our user
@@ -126,6 +150,7 @@ static int lvds_codec_probe(struct platform_device *pdev)
*/
lvds_codec->bridge.of_node = dev->of_node;
lvds_codec->bridge.funcs = &funcs;
+ lvds_codec->bridge.timings = &lvds_codec->timings;
drm_bridge_add(&lvds_codec->bridge);
platform_set_drvdata(pdev, lvds_codec);
--
2.30.2
