[PATCH v5 0/6] Add dual-LVDS panel support to EK874

[PATCH v5 0/6] Add dual-LVDS panel support to EK874

[Fabrizio Castro]

Dear All,

this series adds support for dual-LVDS panel IDK-2121WR
from Advantech:
https://buy.advantech.eu/Displays/Embedded-LCD-Kits-High-Brightness/model-IDK-2121WR-K2FHA2E.htm

V5 incorporates the comments from Laurent on v4, including rebasing
the series on top of patch:
https://patchwork.kernel.org/patch/11290969/
As a result, patch "drm: rcar-du: lvds: Fix mode for companion encoder"
has been dropped.

Thanks,
Fab

Fabrizio Castro (6):
  drm: of: Add drm_of_lvds_get_dual_link_pixel_order
  drm: rcar-du: lvds: Improve identification of panels
  drm: rcar-du: lvds: Get dual link configuration from DT
  drm: rcar-du: lvds: Allow for even and odd pixels swap
  dt-bindings: display: Add idk-2121wr binding
  arm64: dts: renesas: Add EK874 board with idk-2121wr display support

 .../display/panel/advantech,idk-2121wr.yaml        | 128 +++++++++++++++
 arch/arm64/boot/dts/renesas/Makefile               |   3 +-
 .../boot/dts/renesas/r8a774c0-ek874-idk-2121wr.dts | 116 ++++++++++++++
 drivers/gpu/drm/drm_of.c                           | 116 ++++++++++++++
 drivers/gpu/drm/rcar-du/rcar_lvds.c                | 172 ++++++++++++---------
 include/drm/drm_of.h                               |  20 +++
 6 files changed, 479 insertions(+), 76 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/display/panel/advantech,idk-2121wr.yaml
 create mode 100644 arch/arm64/boot/dts/renesas/r8a774c0-ek874-idk-2121wr.dts

-- 
2.7.4

[PATCH v5 1/6] drm: of: Add drm_of_lvds_get_dual_link_pixel_order

[Fabrizio Castro]

An LVDS dual-link connection is made of two links, with even
pixels transitting on one link, and odd pixels on the other
link. The device tree can be used to fully describe dual-link
LVDS connections between encoders and bridges/panels.
The sink of an LVDS dual-link connection is made of two ports,
the corresponding OF graph port nodes can be marked
with either dual-lvds-even-pixels or dual-lvds-odd-pixels,
and that fully describes an LVDS dual-link connection,
including pixel order.

drm_of_lvds_get_dual_link_pixel_order is a new helper
added by this patch, given the source port nodes it
returns DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS if the source
port nodes belong to an LVDS dual-link connection, with even
pixels expected to be generated from the first port, and odd
pixels expected to be generated from the second port.
If the new helper returns DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS,
odd pixels are expected to be generated from the first port,
and even pixels from the other port.

Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

---
v4->v5:
* Addressed comments from Laurent's review

v3->v4:
* New patch extracted from patch:
  "drm: rcar-du: lvds: Add dual-LVDS panels support"
---
 drivers/gpu/drm/drm_of.c | 116 +++++++++++++++++++++++++++++++++++++++++++++++
 include/drm/drm_of.h     |  20 ++++++++
 2 files changed, 136 insertions(+)

diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c
index 0ca5880..b50b44e 100644
--- a/drivers/gpu/drm/drm_of.c
+++ b/drivers/gpu/drm/drm_of.c
@@ -274,3 +274,119 @@ int drm_of_find_panel_or_bridge(const struct device_node *np,
 	return ret;
 }
 EXPORT_SYMBOL_GPL(drm_of_find_panel_or_bridge);
+
+enum drm_of_lvds_pixels {
+	DRM_OF_LVDS_EVEN = BIT(0),
+	DRM_OF_LVDS_ODD = BIT(1),
+};
+
+static int drm_of_lvds_get_port_pixels_type(struct device_node *port_node)
+{
+	bool even_pixels =
+		of_property_read_bool(port_node, "dual-lvds-even-pixels");
+	bool odd_pixels =
+		of_property_read_bool(port_node, "dual-lvds-odd-pixels");
+
+	return (even_pixels ? DRM_OF_LVDS_EVEN : 0) |
+	       (odd_pixels ? DRM_OF_LVDS_ODD : 0);
+}
+
+static int drm_of_lvds_get_remote_pixels_type(
+			const struct device_node *port_node)
+{
+	struct device_node *endpoint = NULL;
+	int pixels_type = -EPIPE;
+
+	for_each_child_of_node(port_node, endpoint) {
+		struct device_node *remote_port;
+		int current_pt;
+
+		if (!of_node_name_eq(endpoint, "endpoint"))
+			continue;
+
+		remote_port = of_graph_get_remote_port(endpoint);
+		if (!remote_port) {
+			of_node_put(remote_port);
+			return -EPIPE;
+		}
+
+		current_pt = drm_of_lvds_get_port_pixels_type(remote_port);
+		of_node_put(remote_port);
+		if (pixels_type < 0)
+			pixels_type = current_pt;
+
+		/*
+		 * Sanity check, ensure that all remote endpoints have the same
+		 * pixel type. We may lift this restriction later if we need to
+		 * support multiple sinks with different dual-link
+		 * configurations by passing the endpoints explicitly to
+		 * drm_of_lvds_get_dual_link_pixel_order().
+		 */
+		if (!current_pt || pixels_type != current_pt) {
+			of_node_put(remote_port);
+			return -EINVAL;
+		}
+	}
+
+	return pixels_type;
+}
+
+/**
+ * drm_of_lvds_get_dual_link_pixel_order - Get LVDS dual-link pixel order
+ * @port1: First DT port node of the Dual-link LVDS source
+ * @port2: Second DT port node of the Dual-link LVDS source
+ *
+ * An LVDS dual-link connection is made of two links, with even pixels
+ * transitting on one link, and odd pixels on the other link. This function
+ * returns, for two ports of an LVDS dual-link source, which port shall transmit
+ * the even and odd pixels, based on the requirements of the connected sink.
+ *
+ * The pixel order is determined from the dual-lvds-even-pixels and
+ * dual-lvds-odd-pixels properties in the sink's DT port nodes. If those
+ * properties are not present, or if their usage is not valid, this function
+ * returns -EINVAL.
+ *
+ * If either port is not connected, this function returns -EPIPE.
+ *
+ * @port1 and @port2 are typically DT sibling nodes, but may have different
+ * parents when, for instance, two separate LVDS encoders carry the even and odd
+ * pixels.
+ *
+ * Return:
+ * * DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS - @port1 carries even pixels and @port2
+ *   carries odd pixels
+ * * DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS - @port1 carries odd pixels and @port2
+ *   carries even pixels
+ * * -EINVAL - @port1 and @port2 are not connected to a dual-link LVDS sink, or
+ *   the sink configuration is invalid
+ * * -EPIPE - when @port1 or @port2 are not connected
+ */
+int drm_of_lvds_get_dual_link_pixel_order(const struct device_node *port1,
+					  const struct device_node *port2)
+{
+	int remote_p1_pt, remote_p2_pt;
+
+	if (!port1 || !port2)
+		return -EINVAL;
+
+	remote_p1_pt = drm_of_lvds_get_remote_pixels_type(port1);
+	if (remote_p1_pt < 0)
+		return remote_p1_pt;
+
+	remote_p2_pt = drm_of_lvds_get_remote_pixels_type(port2);
+	if (remote_p2_pt < 0)
+		return remote_p2_pt;
+
+	/*
+	 * A valid dual-lVDS bus is found when one remote port is marked with
+	 * "dual-lvds-even-pixels", and the other remote port is marked with
+	 * "dual-lvds-odd-pixels", bail out if the markers are not right.
+	 */
+	if (remote_p1_pt + remote_p2_pt != DRM_OF_LVDS_EVEN + DRM_OF_LVDS_ODD)
+		return -EINVAL;
+
+	return remote_p1_pt == DRM_OF_LVDS_EVEN ?
+		DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS :
+		DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS;
+}
+EXPORT_SYMBOL_GPL(drm_of_lvds_get_dual_link_pixel_order);
diff --git a/include/drm/drm_of.h b/include/drm/drm_of.h
index ead34ab..8ec7ca6 100644
--- a/include/drm/drm_of.h
+++ b/include/drm/drm_of.h
@@ -16,6 +16,18 @@ struct drm_panel;
 struct drm_bridge;
 struct device_node;
 
+/**
+ * enum drm_lvds_dual_link_pixels - Pixel order of an LVDS dual-link connection
+ * @DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS: Even pixels are expected to be generated
+ *    from the first port, odd pixels from the second port
+ * @DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS: Odd pixels are expected to be generated
+ *    from the first port, even pixels from the second port
+ */
+enum drm_lvds_dual_link_pixels {
+	DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS = 0,
+	DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS = 1,
+};
+
 #ifdef CONFIG_OF
 uint32_t drm_of_crtc_port_mask(struct drm_device *dev,
 			    struct device_node *port);
@@ -35,6 +47,8 @@ int drm_of_find_panel_or_bridge(const struct device_node *np,
 				int port, int endpoint,
 				struct drm_panel **panel,
 				struct drm_bridge **bridge);
+int drm_of_lvds_get_dual_link_pixel_order(const struct device_node *port1,
+					  const struct device_node *port2);
 #else
 static inline uint32_t drm_of_crtc_port_mask(struct drm_device *dev,
 					  struct device_node *port)
@@ -77,6 +91,12 @@ static inline int drm_of_find_panel_or_bridge(const struct device_node *np,
 {
 	return -EINVAL;
 }
+
+int drm_of_lvds_get_dual_link_pixel_order(const struct device_node *port1,
+					  const struct device_node *port2)
+{
+	return -EINVAL;
+}
 #endif
 
 /*
-- 
2.7.4

[PATCH v5 2/6] drm: rcar-du: lvds: Improve identification of panels

[Fabrizio Castro]

Dual-LVDS panels are mistakenly identified as bridges, this
commit replaces the current logic with a call to
drm_of_find_panel_or_bridge to sort that out.

Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>

---
v4->v5:
* Addressed comments from Laurent's review

v3->v4:
* New patch extracted from patch:
  "drm: rcar-du: lvds: Add dual-LVDS panels support"
---
 drivers/gpu/drm/rcar-du/rcar_lvds.c | 75 +++++--------------------------------
 1 file changed, 10 insertions(+), 65 deletions(-)

diff --git a/drivers/gpu/drm/rcar-du/rcar_lvds.c b/drivers/gpu/drm/rcar-du/rcar_lvds.c
index b03b7cd..4d038bd 100644
--- a/drivers/gpu/drm/rcar-du/rcar_lvds.c
+++ b/drivers/gpu/drm/rcar-du/rcar_lvds.c
@@ -21,6 +21,7 @@
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_bridge.h>
+#include <drm/drm_of.h>
 #include <drm/drm_panel.h>
 #include <drm/drm_probe_helper.h>
 
@@ -716,79 +717,23 @@ static int rcar_lvds_parse_dt_companion(struct rcar_lvds *lvds)
 
 static int rcar_lvds_parse_dt(struct rcar_lvds *lvds)
 {
-	struct device_node *local_output = NULL;
-	struct device_node *remote_input = NULL;
-	struct device_node *remote = NULL;
-	struct device_node *node;
-	bool is_bridge = false;
-	int ret = 0;
-
-	local_output = of_graph_get_endpoint_by_regs(lvds->dev->of_node, 1, 0);
-	if (!local_output) {
-		dev_dbg(lvds->dev, "unconnected port@1\n");
-		ret = -ENODEV;
-		goto done;
-	}
-
-	/*
-	 * Locate the connected entity and infer its type from the number of
-	 * endpoints.
-	 */
-	remote = of_graph_get_remote_port_parent(local_output);
-	if (!remote) {
-		dev_dbg(lvds->dev, "unconnected endpoint %pOF\n", local_output);
-		ret = -ENODEV;
-		goto done;
-	}
+	int ret;
 
-	if (!of_device_is_available(remote)) {
-		dev_dbg(lvds->dev, "connected entity %pOF is disabled\n",
-			remote);
-		ret = -ENODEV;
+	ret = drm_of_find_panel_or_bridge(lvds->dev->of_node, 1, 0,
+					  &lvds->panel, &lvds->next_bridge);
+	if (ret)
 		goto done;
-	}
 
-	remote_input = of_graph_get_remote_endpoint(local_output);
-
-	for_each_endpoint_of_node(remote, node) {
-		if (node != remote_input) {
-			/*
-			 * We've found one endpoint other than the input, this
-			 * must be a bridge.
-			 */
-			is_bridge = true;
-			of_node_put(node);
-			break;
-		}
-	}
-
-	if (is_bridge) {
-		lvds->next_bridge = of_drm_find_bridge(remote);
-		if (!lvds->next_bridge) {
-			ret = -EPROBE_DEFER;
-			goto done;
-		}
-
-		if (lvds->info->quirks & RCAR_LVDS_QUIRK_DUAL_LINK)
-			lvds->dual_link = lvds->next_bridge->timings
-					? lvds->next_bridge->timings->dual_link
-					: false;
-	} else {
-		lvds->panel = of_drm_find_panel(remote);
-		if (IS_ERR(lvds->panel)) {
-			ret = PTR_ERR(lvds->panel);
-			goto done;
-		}
-	}
+	if ((lvds->info->quirks & RCAR_LVDS_QUIRK_DUAL_LINK) &&
+	    lvds->next_bridge)
+		lvds->dual_link = lvds->next_bridge->timings
+				? lvds->next_bridge->timings->dual_link
+				: false;
 
 	if (lvds->dual_link)
 		ret = rcar_lvds_parse_dt_companion(lvds);
 
 done:
-	of_node_put(local_output);
-	of_node_put(remote_input);
-	of_node_put(remote);
-
 	/*
 	 * On D3/E3 the LVDS encoder provides a clock to the DU, which can be
 	 * used for the DPAD output even when the LVDS output is not connected.
-- 
2.7.4

Re: [PATCH v5 2/6] drm: rcar-du: lvds: Improve identification of panels

[Laurent Pinchart]

Hi Fabrizio,

Thank you for the patch.

On Mon, Dec 16, 2019 at 08:12:30PM +0000, Fabrizio Castro wrote:
> Dual-LVDS panels are mistakenly identified as bridges, this
> commit replaces the current logic with a call to
> drm_of_find_panel_or_bridge to sort that out.
> 
> Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> ---
> v4->v5:
> * Addressed comments from Laurent's review
> 
> v3->v4:
> * New patch extracted from patch:
>   "drm: rcar-du: lvds: Add dual-LVDS panels support"
> ---
>  drivers/gpu/drm/rcar-du/rcar_lvds.c | 75 +++++--------------------------------
>  1 file changed, 10 insertions(+), 65 deletions(-)
> 
> diff --git a/drivers/gpu/drm/rcar-du/rcar_lvds.c b/drivers/gpu/drm/rcar-du/rcar_lvds.c
> index b03b7cd..4d038bd 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_lvds.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_lvds.c
> @@ -21,6 +21,7 @@
>  #include <drm/drm_atomic.h>
>  #include <drm/drm_atomic_helper.h>
>  #include <drm/drm_bridge.h>
> +#include <drm/drm_of.h>
>  #include <drm/drm_panel.h>
>  #include <drm/drm_probe_helper.h>
>  
> @@ -716,79 +717,23 @@ static int rcar_lvds_parse_dt_companion(struct rcar_lvds *lvds)
>  
>  static int rcar_lvds_parse_dt(struct rcar_lvds *lvds)
>  {
> -	struct device_node *local_output = NULL;
> -	struct device_node *remote_input = NULL;
> -	struct device_node *remote = NULL;
> -	struct device_node *node;
> -	bool is_bridge = false;
> -	int ret = 0;
> -
> -	local_output = of_graph_get_endpoint_by_regs(lvds->dev->of_node, 1, 0);
> -	if (!local_output) {
> -		dev_dbg(lvds->dev, "unconnected port@1\n");
> -		ret = -ENODEV;
> -		goto done;
> -	}
> -
> -	/*
> -	 * Locate the connected entity and infer its type from the number of
> -	 * endpoints.
> -	 */
> -	remote = of_graph_get_remote_port_parent(local_output);
> -	if (!remote) {
> -		dev_dbg(lvds->dev, "unconnected endpoint %pOF\n", local_output);
> -		ret = -ENODEV;
> -		goto done;
> -	}
> +	int ret;
>  
> -	if (!of_device_is_available(remote)) {
> -		dev_dbg(lvds->dev, "connected entity %pOF is disabled\n",
> -			remote);
> -		ret = -ENODEV;
> +	ret = drm_of_find_panel_or_bridge(lvds->dev->of_node, 1, 0,
> +					  &lvds->panel, &lvds->next_bridge);
> +	if (ret)
>  		goto done;
> -	}
>  
> -	remote_input = of_graph_get_remote_endpoint(local_output);
> -
> -	for_each_endpoint_of_node(remote, node) {
> -		if (node != remote_input) {
> -			/*
> -			 * We've found one endpoint other than the input, this
> -			 * must be a bridge.
> -			 */
> -			is_bridge = true;
> -			of_node_put(node);
> -			break;
> -		}
> -	}
> -
> -	if (is_bridge) {
> -		lvds->next_bridge = of_drm_find_bridge(remote);
> -		if (!lvds->next_bridge) {
> -			ret = -EPROBE_DEFER;
> -			goto done;
> -		}
> -
> -		if (lvds->info->quirks & RCAR_LVDS_QUIRK_DUAL_LINK)
> -			lvds->dual_link = lvds->next_bridge->timings
> -					? lvds->next_bridge->timings->dual_link
> -					: false;
> -	} else {
> -		lvds->panel = of_drm_find_panel(remote);
> -		if (IS_ERR(lvds->panel)) {
> -			ret = PTR_ERR(lvds->panel);
> -			goto done;
> -		}
> -	}
> +	if ((lvds->info->quirks & RCAR_LVDS_QUIRK_DUAL_LINK) &&
> +	    lvds->next_bridge)
> +		lvds->dual_link = lvds->next_bridge->timings
> +				? lvds->next_bridge->timings->dual_link
> +				: false;
>  
>  	if (lvds->dual_link)
>  		ret = rcar_lvds_parse_dt_companion(lvds);
>  
>  done:
> -	of_node_put(local_output);
> -	of_node_put(remote_input);
> -	of_node_put(remote);
> -
>  	/*
>  	 * On D3/E3 the LVDS encoder provides a clock to the DU, which can be
>  	 * used for the DPAD output even when the LVDS output is not connected.

-- 
Regards,

Laurent Pinchart

[PATCH v5 3/6] drm: rcar-du: lvds: Get dual link configuration from DT

[Fabrizio Castro]

For dual-LVDS configurations, it is now possible to mark the
DT port nodes for the sink with boolean properties (like
dual-lvds-even-pixels and dual-lvds-odd-pixels) to let drivers
know the encoders need to be configured in dual-LVDS mode.

Rework the implementation of rcar_lvds_parse_dt_companion
to make use of the DT markers while keeping backward
compatibility.

Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

---
v4->v5:
* Addressed comments from Laurent's review

v3->v4:
* New patch extracted from patch:
  "drm: rcar-du: lvds: Add dual-LVDS panels support"
---
 drivers/gpu/drm/rcar-du/rcar_lvds.c | 54 +++++++++++++++++++++++++++++++------
 1 file changed, 46 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/rcar-du/rcar_lvds.c b/drivers/gpu/drm/rcar-du/rcar_lvds.c
index 4d038bd..3eb208e 100644
--- a/drivers/gpu/drm/rcar-du/rcar_lvds.c
+++ b/drivers/gpu/drm/rcar-du/rcar_lvds.c
@@ -682,7 +682,10 @@ static int rcar_lvds_parse_dt_companion(struct rcar_lvds *lvds)
 {
 	const struct of_device_id *match;
 	struct device_node *companion;
+	struct device_node *port0, *port1;
+	struct rcar_lvds *companion_lvds;
 	struct device *dev = lvds->dev;
+	int dual_link;
 	int ret = 0;
 
 	/* Locate the companion LVDS encoder for dual-link operation, if any. */
@@ -701,13 +704,54 @@ static int rcar_lvds_parse_dt_companion(struct rcar_lvds *lvds)
 		goto done;
 	}
 
+	/*
+	 * We need to work out if the sink is expecting us to function in
+	 * dual-link mode. We do this by looking at the DT port nodes we are
+	 * connected to, if they are marked as expecting even pixels and
+	 * odd pixels than we need to enable vertical stripe output.
+	 */
+	port0 = of_graph_get_port_by_id(dev->of_node, 1);
+	port1 = of_graph_get_port_by_id(companion, 1);
+	dual_link = drm_of_lvds_get_dual_link_pixel_order(port0, port1);
+	of_node_put(port0);
+	of_node_put(port1);
+
+	if (dual_link >= DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS)
+		lvds->dual_link = true;
+	else if (lvds->next_bridge && lvds->next_bridge->timings)
+		/*
+		 * 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->dual_link) {
+		dev_dbg(dev, "Single-link configuration detected\n");
+		goto done;
+	}
+
 	lvds->companion = of_drm_find_bridge(companion);
 	if (!lvds->companion) {
 		ret = -EPROBE_DEFER;
 		goto done;
 	}
 
-	dev_dbg(dev, "Found companion encoder %pOF\n", companion);
+	dev_dbg(dev,
+		"Dual-link configuration detected (companion encoder %pOF)\n",
+		companion);
+
+	/*
+	 * FIXME: We should not be messing with the companion encoder private
+	 * data from the primary encoder, we should rather let the companion
+	 * encoder work things out on its own. However, the companion encoder
+	 * doesn't hold a reference to the primary encoder, and
+	 * drm_of_lvds_get_dual_link_pixel_order needs to be given references
+	 * to the output ports of both encoders, therefore leave it like this
+	 * for the time being.
+	 */
+	companion_lvds = bridge_to_rcar_lvds(lvds->companion);
+	companion_lvds->dual_link = true;
 
 done:
 	of_node_put(companion);
@@ -724,13 +768,7 @@ static int rcar_lvds_parse_dt(struct rcar_lvds *lvds)
 	if (ret)
 		goto done;
 
-	if ((lvds->info->quirks & RCAR_LVDS_QUIRK_DUAL_LINK) &&
-	    lvds->next_bridge)
-		lvds->dual_link = lvds->next_bridge->timings
-				? lvds->next_bridge->timings->dual_link
-				: false;
-
-	if (lvds->dual_link)
+	if (lvds->info->quirks & RCAR_LVDS_QUIRK_DUAL_LINK)
 		ret = rcar_lvds_parse_dt_companion(lvds);
 
 done:
-- 
2.7.4

[PATCH v5 4/6] drm: rcar-du: lvds: Allow for even and odd pixels swap

[Fabrizio Castro]

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@bp.renesas.com>

---
v4->v5:
* Addressed comments from Laurent's review

v3->v4:
* New patch extracted from patch:
  "drm: rcar-du: lvds: Add dual-LVDS panels support"
---
 drivers/gpu/drm/rcar-du/rcar_lvds.c | 67 +++++++++++++++++++++++++++++--------
 1 file changed, 53 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/rcar-du/rcar_lvds.c b/drivers/gpu/drm/rcar-du/rcar_lvds.c
index 3eb208e..c6a38c3 100644
--- a/drivers/gpu/drm/rcar-du/rcar_lvds.c
+++ b/drivers/gpu/drm/rcar-du/rcar_lvds.c
@@ -37,6 +37,12 @@ enum rcar_lvds_mode {
 	RCAR_LVDS_MODE_VESA = 4,
 };
 
+enum rcar_lvds_link_type {
+	RCAR_LVDS_SINGLE_LINK = 0,
+	RCAR_LVDS_DUAL_LINK_EVEN_ODD_PIXELS = 1,
+	RCAR_LVDS_DUAL_LINK_ODD_EVEN_PIXELS = 2,
+};
+
 #define RCAR_LVDS_QUIRK_LANES		BIT(0)	/* LVDS lanes 1 and 3 inverted */
 #define RCAR_LVDS_QUIRK_GEN3_LVEN	BIT(1)	/* LVEN bit needs to be set on R8A77970/R8A7799x */
 #define RCAR_LVDS_QUIRK_PWD		BIT(2)	/* PWD bit available (all of Gen3 but E3) */
@@ -67,7 +73,7 @@ struct rcar_lvds {
 	} clocks;
 
 	struct drm_bridge *companion;
-	bool dual_link;
+	enum rcar_lvds_link_type dual_link;
 };
 
 #define bridge_to_rcar_lvds(b) \
@@ -484,12 +490,31 @@ static void rcar_lvds_atomic_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) {
+			/*
+			 * By default we generate even pixels from the primary
+			 * encoder and odd pixels from the companion encoder.
+			 * Swap pixels around if the sink requires odd pixels
+			 * from the primary encoder and even pixels from the
+			 * companion encoder.
+			 */
+			bool swap_pixels = lvds->dual_link ==
+				RCAR_LVDS_DUAL_LINK_ODD_EVEN_PIXELS;
+
+			/*
+			 * Configure vertical stripe since we are dealing with
+			 * an LVDS dual-link connection.
+			 *
+			 * ST_SWAP is reserved for the companion encoder, only
+			 * set it in the primary encoder.
+			 */
+			lvdstripe = LVDSTRIPE_ST_ON
+				  | (lvds->companion && swap_pixels ?
+				     LVDSTRIPE_ST_SWAP : 0);
+		}
+		rcar_lvds_write(lvds, LVDSTRIPE, lvdstripe);
 	}
 
 	/*
@@ -716,15 +741,26 @@ static int rcar_lvds_parse_dt_companion(struct rcar_lvds *lvds)
 	of_node_put(port0);
 	of_node_put(port1);
 
-	if (dual_link >= DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS)
-		lvds->dual_link = true;
-	else if (lvds->next_bridge && lvds->next_bridge->timings)
+	switch (dual_link) {
+	case DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS:
+		lvds->dual_link = RCAR_LVDS_DUAL_LINK_ODD_EVEN_PIXELS;
+		break;
+	case DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS:
+		lvds->dual_link = RCAR_LVDS_DUAL_LINK_EVEN_ODD_PIXELS;
+		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.
+		 * timings field of drm_bridge. If the flag is set, we assume
+		 * that we are expected to generate even pixels from the primary
+		 * encoder, and odd pixels from the companion encoder.
 		 */
-		lvds->dual_link = lvds->next_bridge->timings->dual_link;
+		if (lvds->next_bridge && lvds->next_bridge->timings &&
+		    lvds->next_bridge->timings->dual_link)
+			lvds->dual_link = RCAR_LVDS_DUAL_LINK_EVEN_ODD_PIXELS;
+		else
+			lvds->dual_link = RCAR_LVDS_SINGLE_LINK;
+	}
 
 	if (!lvds->dual_link) {
 		dev_dbg(dev, "Single-link configuration detected\n");
@@ -741,6 +777,9 @@ static int rcar_lvds_parse_dt_companion(struct rcar_lvds *lvds)
 		"Dual-link configuration detected (companion encoder %pOF)\n",
 		companion);
 
+	if (lvds->dual_link == RCAR_LVDS_DUAL_LINK_ODD_EVEN_PIXELS)
+		dev_dbg(dev, "Data swapping required\n");
+
 	/*
 	 * FIXME: We should not be messing with the companion encoder private
 	 * data from the primary encoder, we should rather let the companion
@@ -751,7 +790,7 @@ static int rcar_lvds_parse_dt_companion(struct rcar_lvds *lvds)
 	 * for the time being.
 	 */
 	companion_lvds = bridge_to_rcar_lvds(lvds->companion);
-	companion_lvds->dual_link = true;
+	companion_lvds->dual_link = lvds->dual_link;
 
 done:
 	of_node_put(companion);
-- 
2.7.4

Re: [PATCH v5 4/6] drm: rcar-du: lvds: Allow for even and odd pixels swap

[Laurent Pinchart]

Hi Fabrizio,

Thank you for the patch.

On Mon, Dec 16, 2019 at 08:12:32PM +0000, Fabrizio Castro wrote:
> 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@bp.renesas.com>
> 
> ---
> v4->v5:
> * Addressed comments from Laurent's review
> 
> v3->v4:
> * New patch extracted from patch:
>   "drm: rcar-du: lvds: Add dual-LVDS panels support"
> ---
>  drivers/gpu/drm/rcar-du/rcar_lvds.c | 67 +++++++++++++++++++++++++++++--------
>  1 file changed, 53 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/gpu/drm/rcar-du/rcar_lvds.c b/drivers/gpu/drm/rcar-du/rcar_lvds.c
> index 3eb208e..c6a38c3 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_lvds.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_lvds.c
> @@ -37,6 +37,12 @@ enum rcar_lvds_mode {
>  	RCAR_LVDS_MODE_VESA = 4,
>  };
>  
> +enum rcar_lvds_link_type {
> +	RCAR_LVDS_SINGLE_LINK = 0,
> +	RCAR_LVDS_DUAL_LINK_EVEN_ODD_PIXELS = 1,
> +	RCAR_LVDS_DUAL_LINK_ODD_EVEN_PIXELS = 2,
> +};
> +
>  #define RCAR_LVDS_QUIRK_LANES		BIT(0)	/* LVDS lanes 1 and 3 inverted */
>  #define RCAR_LVDS_QUIRK_GEN3_LVEN	BIT(1)	/* LVEN bit needs to be set on R8A77970/R8A7799x */
>  #define RCAR_LVDS_QUIRK_PWD		BIT(2)	/* PWD bit available (all of Gen3 but E3) */
> @@ -67,7 +73,7 @@ struct rcar_lvds {
>  	} clocks;
>  
>  	struct drm_bridge *companion;
> -	bool dual_link;
> +	enum rcar_lvds_link_type dual_link;

Do you think we should rename this to link_type (and test for
lvds->link_type != RCAR_LVDS_SINGLE_LINK) instead of lvds->dual_link) ?
Apart from that,

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

>  };
>  
>  #define bridge_to_rcar_lvds(b) \
> @@ -484,12 +490,31 @@ static void rcar_lvds_atomic_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) {
> +			/*
> +			 * By default we generate even pixels from the primary
> +			 * encoder and odd pixels from the companion encoder.
> +			 * Swap pixels around if the sink requires odd pixels
> +			 * from the primary encoder and even pixels from the
> +			 * companion encoder.
> +			 */
> +			bool swap_pixels = lvds->dual_link ==
> +				RCAR_LVDS_DUAL_LINK_ODD_EVEN_PIXELS;
> +
> +			/*
> +			 * Configure vertical stripe since we are dealing with
> +			 * an LVDS dual-link connection.
> +			 *
> +			 * ST_SWAP is reserved for the companion encoder, only
> +			 * set it in the primary encoder.
> +			 */
> +			lvdstripe = LVDSTRIPE_ST_ON
> +				  | (lvds->companion && swap_pixels ?
> +				     LVDSTRIPE_ST_SWAP : 0);
> +		}
> +		rcar_lvds_write(lvds, LVDSTRIPE, lvdstripe);
>  	}
>  
>  	/*
> @@ -716,15 +741,26 @@ static int rcar_lvds_parse_dt_companion(struct rcar_lvds *lvds)
>  	of_node_put(port0);
>  	of_node_put(port1);
>  
> -	if (dual_link >= DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS)
> -		lvds->dual_link = true;
> -	else if (lvds->next_bridge && lvds->next_bridge->timings)
> +	switch (dual_link) {
> +	case DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS:
> +		lvds->dual_link = RCAR_LVDS_DUAL_LINK_ODD_EVEN_PIXELS;
> +		break;
> +	case DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS:
> +		lvds->dual_link = RCAR_LVDS_DUAL_LINK_EVEN_ODD_PIXELS;
> +		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.
> +		 * timings field of drm_bridge. If the flag is set, we assume
> +		 * that we are expected to generate even pixels from the primary
> +		 * encoder, and odd pixels from the companion encoder.
>  		 */
> -		lvds->dual_link = lvds->next_bridge->timings->dual_link;
> +		if (lvds->next_bridge && lvds->next_bridge->timings &&
> +		    lvds->next_bridge->timings->dual_link)
> +			lvds->dual_link = RCAR_LVDS_DUAL_LINK_EVEN_ODD_PIXELS;
> +		else
> +			lvds->dual_link = RCAR_LVDS_SINGLE_LINK;
> +	}
>  
>  	if (!lvds->dual_link) {
>  		dev_dbg(dev, "Single-link configuration detected\n");
> @@ -741,6 +777,9 @@ static int rcar_lvds_parse_dt_companion(struct rcar_lvds *lvds)
>  		"Dual-link configuration detected (companion encoder %pOF)\n",
>  		companion);
>  
> +	if (lvds->dual_link == RCAR_LVDS_DUAL_LINK_ODD_EVEN_PIXELS)
> +		dev_dbg(dev, "Data swapping required\n");
> +
>  	/*
>  	 * FIXME: We should not be messing with the companion encoder private
>  	 * data from the primary encoder, we should rather let the companion
> @@ -751,7 +790,7 @@ static int rcar_lvds_parse_dt_companion(struct rcar_lvds *lvds)
>  	 * for the time being.
>  	 */
>  	companion_lvds = bridge_to_rcar_lvds(lvds->companion);
> -	companion_lvds->dual_link = true;
> +	companion_lvds->dual_link = lvds->dual_link;
>  
>  done:
>  	of_node_put(companion);

-- 
Regards,

Laurent Pinchart

RE: [PATCH v5 4/6] drm: rcar-du: lvds: Allow for even and odd pixels swap

[Fabrizio Castro]

Hi Laurent,

Thank you for your feedback!

> From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Sent: 16 December 2019 21:35
> Subject: Re: [PATCH v5 4/6] drm: rcar-du: lvds: Allow for even and odd pixels swap
> 
> Hi Fabrizio,
> 
> Thank you for the patch.
> 
> On Mon, Dec 16, 2019 at 08:12:32PM +0000, Fabrizio Castro wrote:
> > 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@bp.renesas.com>
> >
> > ---
> > v4->v5:
> > * Addressed comments from Laurent's review
> >
> > v3->v4:
> > * New patch extracted from patch:
> >   "drm: rcar-du: lvds: Add dual-LVDS panels support"
> > ---
> >  drivers/gpu/drm/rcar-du/rcar_lvds.c | 67 +++++++++++++++++++++++++++++--------
> >  1 file changed, 53 insertions(+), 14 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/rcar-du/rcar_lvds.c b/drivers/gpu/drm/rcar-du/rcar_lvds.c
> > index 3eb208e..c6a38c3 100644
> > --- a/drivers/gpu/drm/rcar-du/rcar_lvds.c
> > +++ b/drivers/gpu/drm/rcar-du/rcar_lvds.c
> > @@ -37,6 +37,12 @@ enum rcar_lvds_mode {
> >  	RCAR_LVDS_MODE_VESA = 4,
> >  };
> >
> > +enum rcar_lvds_link_type {
> > +	RCAR_LVDS_SINGLE_LINK = 0,
> > +	RCAR_LVDS_DUAL_LINK_EVEN_ODD_PIXELS = 1,
> > +	RCAR_LVDS_DUAL_LINK_ODD_EVEN_PIXELS = 2,
> > +};
> > +
> >  #define RCAR_LVDS_QUIRK_LANES		BIT(0)	/* LVDS lanes 1 and 3 inverted */
> >  #define RCAR_LVDS_QUIRK_GEN3_LVEN	BIT(1)	/* LVEN bit needs to be set on R8A77970/R8A7799x */
> >  #define RCAR_LVDS_QUIRK_PWD		BIT(2)	/* PWD bit available (all of Gen3 but E3) */
> > @@ -67,7 +73,7 @@ struct rcar_lvds {
> >  	} clocks;
> >
> >  	struct drm_bridge *companion;
> > -	bool dual_link;
> > +	enum rcar_lvds_link_type dual_link;
> 
> Do you think we should rename this to link_type (and test for
> lvds->link_type != RCAR_LVDS_SINGLE_LINK) instead of lvds->dual_link) ?
> Apart from that,

I'll send v6 to address that. I will also rebase on top of:
https://patchwork.kernel.org/patch/11295991/
and will use that as a dependency for v6

Cheers,
Fab

> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> 
> >  };
> >
> >  #define bridge_to_rcar_lvds(b) \
> > @@ -484,12 +490,31 @@ static void rcar_lvds_atomic_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) {
> > +			/*
> > +			 * By default we generate even pixels from the primary
> > +			 * encoder and odd pixels from the companion encoder.
> > +			 * Swap pixels around if the sink requires odd pixels
> > +			 * from the primary encoder and even pixels from the
> > +			 * companion encoder.
> > +			 */
> > +			bool swap_pixels = lvds->dual_link ==
> > +				RCAR_LVDS_DUAL_LINK_ODD_EVEN_PIXELS;
> > +
> > +			/*
> > +			 * Configure vertical stripe since we are dealing with
> > +			 * an LVDS dual-link connection.
> > +			 *
> > +			 * ST_SWAP is reserved for the companion encoder, only
> > +			 * set it in the primary encoder.
> > +			 */
> > +			lvdstripe = LVDSTRIPE_ST_ON
> > +				  | (lvds->companion && swap_pixels ?
> > +				     LVDSTRIPE_ST_SWAP : 0);
> > +		}
> > +		rcar_lvds_write(lvds, LVDSTRIPE, lvdstripe);
> >  	}
> >
> >  	/*
> > @@ -716,15 +741,26 @@ static int rcar_lvds_parse_dt_companion(struct rcar_lvds *lvds)
> >  	of_node_put(port0);
> >  	of_node_put(port1);
> >
> > -	if (dual_link >= DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS)
> > -		lvds->dual_link = true;
> > -	else if (lvds->next_bridge && lvds->next_bridge->timings)
> > +	switch (dual_link) {
> > +	case DRM_LVDS_DUAL_LINK_ODD_EVEN_PIXELS:
> > +		lvds->dual_link = RCAR_LVDS_DUAL_LINK_ODD_EVEN_PIXELS;
> > +		break;
> > +	case DRM_LVDS_DUAL_LINK_EVEN_ODD_PIXELS:
> > +		lvds->dual_link = RCAR_LVDS_DUAL_LINK_EVEN_ODD_PIXELS;
> > +		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.
> > +		 * timings field of drm_bridge. If the flag is set, we assume
> > +		 * that we are expected to generate even pixels from the primary
> > +		 * encoder, and odd pixels from the companion encoder.
> >  		 */
> > -		lvds->dual_link = lvds->next_bridge->timings->dual_link;
> > +		if (lvds->next_bridge && lvds->next_bridge->timings &&
> > +		    lvds->next_bridge->timings->dual_link)
> > +			lvds->dual_link = RCAR_LVDS_DUAL_LINK_EVEN_ODD_PIXELS;
> > +		else
> > +			lvds->dual_link = RCAR_LVDS_SINGLE_LINK;
> > +	}
> >
> >  	if (!lvds->dual_link) {
> >  		dev_dbg(dev, "Single-link configuration detected\n");
> > @@ -741,6 +777,9 @@ static int rcar_lvds_parse_dt_companion(struct rcar_lvds *lvds)
> >  		"Dual-link configuration detected (companion encoder %pOF)\n",
> >  		companion);
> >
> > +	if (lvds->dual_link == RCAR_LVDS_DUAL_LINK_ODD_EVEN_PIXELS)
> > +		dev_dbg(dev, "Data swapping required\n");
> > +
> >  	/*
> >  	 * FIXME: We should not be messing with the companion encoder private
> >  	 * data from the primary encoder, we should rather let the companion
> > @@ -751,7 +790,7 @@ static int rcar_lvds_parse_dt_companion(struct rcar_lvds *lvds)
> >  	 * for the time being.
> >  	 */
> >  	companion_lvds = bridge_to_rcar_lvds(lvds->companion);
> > -	companion_lvds->dual_link = true;
> > +	companion_lvds->dual_link = lvds->dual_link;
> >
> >  done:
> >  	of_node_put(companion);
> 
> --
> Regards,
> 
> Laurent Pinchart

[PATCH v5 5/6] dt-bindings: display: Add idk-2121wr binding

[Fabrizio Castro]

Add binding for the idk-2121wr LVDS panel from Advantech.

Some panel-specific documentation can be found here:
https://buy.advantech.eu/Displays/Embedded-LCD-Kits-High-Brightness/model-IDK-2121WR-K2FHA2E.htm

Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

---
v4->v5:
* No change

v3->v4:
* Absorbed patch "dt-bindings: display: Add bindings for LVDS
  bus-timings"
* Big restructuring after Rob's and Laurent's comments

v2->v3:
* new patch
---
 .../display/panel/advantech,idk-2121wr.yaml        | 128 +++++++++++++++++++++
 1 file changed, 128 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/panel/advantech,idk-2121wr.yaml

diff --git a/Documentation/devicetree/bindings/display/panel/advantech,idk-2121wr.yaml b/Documentation/devicetree/bindings/display/panel/advantech,idk-2121wr.yaml
new file mode 100644
index 0000000..24cd38b
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/panel/advantech,idk-2121wr.yaml
@@ -0,0 +1,128 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/panel/advantech,idk-2121wr.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Advantech IDK-2121WR 21.5" Full-HD dual-LVDS panel
+
+maintainers:
+  - Fabrizio Castro <fabrizio.castro@bp.renesas.com>
+  - Thierry Reding <thierry.reding@gmail.com>
+
+description: |
+  The IDK-2121WR from Advantech is a Full-HD dual-LVDS panel.
+  A dual-LVDS interface is a dual-link connection with even pixels traveling
+  on one link, and with odd pixels traveling on the other link.
+
+  The panel expects odd pixels on the first port, and even pixels on the
+  second port, therefore the ports must be marked accordingly (with either
+  dual-lvds-odd-pixels or dual-lvds-even-pixels).
+
+properties:
+  compatible:
+    items:
+      - const: advantech,idk-2121wr
+      - {} # panel-lvds, but not listed here to avoid false select
+
+  width-mm:
+    const: 476
+
+  height-mm:
+    const: 268
+
+  data-mapping:
+    const: vesa-24
+
+  ports:
+    type: object
+    properties:
+      "#address-cells":
+        const: 1
+
+      "#size-cells":
+        const: 0
+
+      port@0:
+        type: object
+        description: The sink for odd pixels.
+        properties:
+          reg:
+            const: 0
+
+          dual-lvds-odd-pixels: true
+
+        required:
+          - reg
+          - dual-lvds-odd-pixels
+
+      port@1:
+        type: object
+        description: The sink for even pixels.
+        properties:
+          reg:
+            const: 1
+
+          dual-lvds-even-pixels: true
+
+        required:
+          - reg
+          - dual-lvds-even-pixels
+
+  panel-timing: true
+
+additionalProperties: false
+
+required:
+  - compatible
+  - width-mm
+  - height-mm
+  - data-mapping
+  - panel-timing
+  - ports
+
+examples:
+  - |+
+    panel-lvds {
+      compatible = "advantech,idk-2121wr", "panel-lvds";
+
+      width-mm = <476>;
+      height-mm = <268>;
+
+      data-mapping = "vesa-24";
+
+      panel-timing {
+        clock-frequency = <148500000>;
+        hactive = <1920>;
+        vactive = <1080>;
+        hsync-len = <44>;
+        hfront-porch = <88>;
+        hback-porch = <148>;
+        vfront-porch = <4>;
+        vback-porch = <36>;
+        vsync-len = <5>;
+      };
+
+      ports {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        port@0 {
+          reg = <0>;
+          dual-lvds-odd-pixels;
+          panel_in0: endpoint {
+            remote-endpoint = <&lvds0_out>;
+          };
+        };
+
+        port@1 {
+          reg = <1>;
+          dual-lvds-even-pixels;
+          panel_in1: endpoint {
+            remote-endpoint = <&lvds1_out>;
+          };
+        };
+      };
+    };
+
+...
-- 
2.7.4

[PATCH v5 6/6] arm64: dts: renesas: Add EK874 board with idk-2121wr display support

[Fabrizio Castro]

The EK874 is advertised as compatible with panel IDK-2121WR from
Advantech, however the panel isn't sold alongside the board.
A new dts, adding everything that's required to get the panel to
to work with the EK874, is the most convenient way to support the
EK874 when it's connected to the IDK-2121WR.

Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

---
Hi Geert,

I think it is now safe for you to have a look at this patch.

Thanks,
Fab

v4->v5:
* no change

v3->v4:
* no change

v2->v3:
* removed renesas,swap-data property
* added dual-lvds-odd-pixels and dual-lvds-even-pixels properties

v1->v2:
* Added comment for lvds-connector-en-gpio
* Renamed &lvds0_panel_in to panel_in0
* Renamed &lvds1_panel_in to panel_in1
---
 arch/arm64/boot/dts/renesas/Makefile               |   3 +-
 .../boot/dts/renesas/r8a774c0-ek874-idk-2121wr.dts | 116 +++++++++++++++++++++
 2 files changed, 118 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm64/boot/dts/renesas/r8a774c0-ek874-idk-2121wr.dts

diff --git a/arch/arm64/boot/dts/renesas/Makefile b/arch/arm64/boot/dts/renesas/Makefile
index d4cc332..ab2c799 100644
--- a/arch/arm64/boot/dts/renesas/Makefile
+++ b/arch/arm64/boot/dts/renesas/Makefile
@@ -3,7 +3,8 @@ dtb-$(CONFIG_ARCH_R8A774A1) += r8a774a1-hihope-rzg2m.dtb
 dtb-$(CONFIG_ARCH_R8A774A1) += r8a774a1-hihope-rzg2m-ex.dtb
 dtb-$(CONFIG_ARCH_R8A774B1) += r8a774b1-hihope-rzg2n.dtb
 dtb-$(CONFIG_ARCH_R8A774B1) += r8a774b1-hihope-rzg2n-ex.dtb
-dtb-$(CONFIG_ARCH_R8A774C0) += r8a774c0-cat874.dtb r8a774c0-ek874.dtb
+dtb-$(CONFIG_ARCH_R8A774C0) += r8a774c0-cat874.dtb r8a774c0-ek874.dtb \
+			       r8a774c0-ek874-idk-2121wr.dtb
 dtb-$(CONFIG_ARCH_R8A7795) += r8a7795-salvator-x.dtb r8a7795-h3ulcb.dtb
 dtb-$(CONFIG_ARCH_R8A7795) += r8a7795-h3ulcb-kf.dtb
 dtb-$(CONFIG_ARCH_R8A7795) += r8a7795-salvator-xs.dtb
diff --git a/arch/arm64/boot/dts/renesas/r8a774c0-ek874-idk-2121wr.dts b/arch/arm64/boot/dts/renesas/r8a774c0-ek874-idk-2121wr.dts
new file mode 100644
index 0000000..a7b27d0
--- /dev/null
+++ b/arch/arm64/boot/dts/renesas/r8a774c0-ek874-idk-2121wr.dts
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Device Tree Source for the Silicon Linux RZ/G2E evaluation kit (EK874),
+ * connected to an Advantech IDK-2121WR 21.5" LVDS panel
+ *
+ * Copyright (C) 2019 Renesas Electronics Corp.
+ */
+
+#include "r8a774c0-ek874.dts"
+
+/ {
+	backlight: backlight {
+		compatible = "pwm-backlight";
+		pwms = <&pwm5 0 50000>;
+
+		brightness-levels = <0 4 8 16 32 64 128 255>;
+		default-brightness-level = <6>;
+
+		power-supply = <&reg_12p0v>;
+		enable-gpios = <&gpio6 12 GPIO_ACTIVE_HIGH>;
+	};
+
+	panel-lvds {
+		compatible = "advantech,idk-2121wr", "panel-lvds";
+
+		width-mm = <476>;
+		height-mm = <268>;
+
+		data-mapping = "vesa-24";
+
+		panel-timing {
+			clock-frequency = <148500000>;
+			hactive = <1920>;
+			vactive = <1080>;
+			hsync-len = <44>;
+			hfront-porch = <88>;
+			hback-porch = <148>;
+			vfront-porch = <4>;
+			vback-porch = <36>;
+			vsync-len = <5>;
+		};
+
+		ports {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			port@0 {
+				reg = <0>;
+				dual-lvds-odd-pixels;
+				panel_in0: endpoint {
+					remote-endpoint = <&lvds0_out>;
+				};
+			};
+
+			port@1 {
+				reg = <1>;
+				dual-lvds-even-pixels;
+				panel_in1: endpoint {
+					remote-endpoint = <&lvds1_out>;
+				};
+			};
+		};
+	};
+};
+
+&gpio0 {
+	/*
+	 * When GP0_17 is low LVDS[01] are connected to the LVDS connector
+	 * When GP0_17 is high LVDS[01] are connected to the LT8918L
+	 */
+	lvds-connector-en-gpio{
+		gpio-hog;
+		gpios = <17 GPIO_ACTIVE_HIGH>;
+		output-low;
+		line-name = "lvds-connector-en-gpio";
+	};
+};
+
+&lvds0 {
+	ports {
+		port@1 {
+			lvds0_out: endpoint {
+				remote-endpoint = <&panel_in0>;
+			};
+		};
+	};
+};
+
+&lvds1 {
+	status = "okay";
+
+	clocks = <&cpg CPG_MOD 727>, <&x13_clk>, <&extal_clk>;
+	clock-names = "fck", "dclkin.0", "extal";
+
+	ports {
+		port@1 {
+			lvds1_out: endpoint {
+				remote-endpoint = <&panel_in1>;
+			};
+		};
+	};
+};
+
+&pfc {
+	pwm5_pins: pwm5 {
+		groups = "pwm5_a";
+		function = "pwm5";
+	};
+};
+
+&pwm5 {
+	pinctrl-0 = <&pwm5_pins>;
+	pinctrl-names = "default";
+
+	status = "okay";
+};
-- 
2.7.4