[PATCH V5 1/2] dt-bindings: display: bridge: lvds-codec: Document pixel data sampling edge select

[PATCH V5 1/2] dt-bindings: display: bridge: lvds-codec: Document pixel data sampling edge select

[Marek Vasut]

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, to define the pixel data sampling edge.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Antonio Borneo <antonio.borneo@st.com>
Cc: Benjamin Gaignard <benjamin.gaignard@st.com>
Cc: Biju Das <biju.das.jz@bp.renesas.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Philippe Cornu <philippe.cornu@st.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Vincent Abriou <vincent.abriou@st.com>
Cc: Yannick Fertre <yannick.fertre@st.com>
Cc: devicetree@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-stm32@st-md-mailman.stormreply.com
To: dri-devel@lists.freedesktop.org
---
V4: New patch split from combined V3
V5: Move the pclk-sample into port@0 endpoint
---
 .../bindings/display/bridge/lvds-codec.yaml   | 24 +++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/bridge/lvds-codec.yaml b/Documentation/devicetree/bindings/display/bridge/lvds-codec.yaml
index 304a1367faaa7..cacafa61e3f52 100644
--- a/Documentation/devicetree/bindings/display/bridge/lvds-codec.yaml
+++ b/Documentation/devicetree/bindings/display/bridge/lvds-codec.yaml
@@ -54,6 +54,14 @@ properties:
           For LVDS encoders, port 0 is the parallel input
           For LVDS decoders, port 0 is the LVDS input
 
+        properties:
+          endpoint:
+            $ref: /schemas/media/video-interfaces.yaml#
+            unevaluatedProperties: false
+
+            properties:
+              pclk-sample: true
+
       port@1:
         $ref: /schemas/graph.yaml#/properties/port
         description: |
@@ -71,6 +79,22 @@ properties:
 
   power-supply: true
 
+if:
+  not:
+    properties:
+      compatible:
+        contains:
+          const: lvds-encoder
+then:
+  properties:
+    ports:
+      properties:
+        port@0:
+          properties:
+            endpoint:
+              properties:
+                pclk-sample: false
+
 required:
   - compatible
   - ports
-- 
2.30.2


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[PATCH V5 2/2] drm/bridge: lvds-codec: Add support for pixel data sampling edge select

[Marek Vasut]

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@denx.de>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Antonio Borneo <antonio.borneo@st.com>
Cc: Benjamin Gaignard <benjamin.gaignard@st.com>
Cc: Biju Das <biju.das.jz@bp.renesas.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Philippe Cornu <philippe.cornu@st.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Vincent Abriou <vincent.abriou@st.com>
Cc: Yannick Fertre <yannick.fertre@st.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-stm32@st-md-mailman.stormreply.com
To: dri-devel@lists.freedesktop.org
---
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


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Re: [PATCH V5 1/2] dt-bindings: display: bridge: lvds-codec: Document pixel data sampling edge select

[Rob Herring]

On Wed, 02 Jun 2021 22:36:07 +0200, Marek Vasut wrote:
> 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, to define the pixel data sampling edge.
> 
> Signed-off-by: Marek Vasut <marex@denx.de>
> Cc: Alexandre Torgue <alexandre.torgue@st.com>
> Cc: Andrzej Hajda <a.hajda@samsung.com>
> Cc: Antonio Borneo <antonio.borneo@st.com>
> Cc: Benjamin Gaignard <benjamin.gaignard@st.com>
> Cc: Biju Das <biju.das.jz@bp.renesas.com>
> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
> Cc: Philippe Cornu <philippe.cornu@st.com>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Sam Ravnborg <sam@ravnborg.org>
> Cc: Vincent Abriou <vincent.abriou@st.com>
> Cc: Yannick Fertre <yannick.fertre@st.com>
> Cc: devicetree@vger.kernel.org
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-stm32@st-md-mailman.stormreply.com
> To: dri-devel@lists.freedesktop.org
> ---
> V4: New patch split from combined V3
> V5: Move the pclk-sample into port@0 endpoint
> ---
>  .../bindings/display/bridge/lvds-codec.yaml   | 24 +++++++++++++++++++
>  1 file changed, 24 insertions(+)
> 

Reviewed-by: Rob Herring <robh@kernel.org>

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