[PATCH 0/3] Add support for Waveshare DSI2DPI unit

[PATCH 0/3] Add support for Waveshare DSI2DPI unit

[Joseph Guo]

This patchset add support for waveshare DSI2DPI unit.

Signed-off-by: Joseph Guo <qijian.guo@nxp.com>
---
Joseph Guo (3):
      dt-bindings: display: bridge: Add waveshare DSI2DPI unit support
      dt-bindings: display: panel: Add waveshare DPI panel support
      drm: bridge: Add waveshare DSI2DPI unit driver

 .../bindings/display/bridge/waveshare,dsi2dpi.yaml | 103 ++++++++++
 .../bindings/display/panel/panel-simple.yaml       |   4 +
 drivers/gpu/drm/bridge/Kconfig                     |  11 ++
 drivers/gpu/drm/bridge/Makefile                    |   1 +
 drivers/gpu/drm/bridge/waveshare-dsi.c             | 210 +++++++++++++++++++++
 5 files changed, 329 insertions(+)
---
base-commit: 0952d89c3acf6590b89bcfb8505595d7c0e6f367
change-id: 20250715-waveshare-dad93ea9980f

Best regards,
-- 
Joseph Guo <qijian.guo@nxp.com>

[PATCH 1/3] dt-bindings: display: bridge: Add waveshare DSI2DPI unit support

[Joseph Guo]

Add dt-binding documentation for waveshare DSI2DPI unit

Signed-off-by: Joseph Guo <qijian.guo@nxp.com>
---
 .../bindings/display/bridge/waveshare,dsi2dpi.yaml | 103 +++++++++++++++++++++
 1 file changed, 103 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/bridge/waveshare,dsi2dpi.yaml b/Documentation/devicetree/bindings/display/bridge/waveshare,dsi2dpi.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..678922ebe138ec2fa7bd05902947a86ec73fc644
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/bridge/waveshare,dsi2dpi.yaml
@@ -0,0 +1,103 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/bridge/waveshare,dsi2dpi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Waveshare MIPI-DSI to DPI Converter bridge
+
+maintainers:
+  - Joseph Guo <qijian.guo@nxp.com>
+
+description:
+  Waveshare bridge board is part of Waveshare panel which converts DSI to DPI.
+
+properties:
+  compatible:
+    const: waveshare,dsi2dpi
+
+  reg:
+    maxItems: 1
+    description: base I2C address of the device
+
+  power-supply: true
+
+  ports:
+    $ref: /schemas/graph.yaml#/properties/ports
+
+    properties:
+      port@0:
+        $ref: /schemas/graph.yaml#/$defs/port-base
+        unevaluatedProperties: false
+        description:
+          Video port for MIPI DSI input
+
+        properties:
+          endpoint:
+            $ref: /schemas/media/video-interfaces.yaml#
+            unevaluatedProperties: false
+
+            properties:
+              data-lanes:
+                description: array of physical DSI data lane indexes.
+                items:
+                  - const: 1
+                  - const: 2
+
+            required:
+              - data-lanes
+
+      port@1:
+        $ref: /schemas/graph.yaml#/properties/port
+        description:
+          Video port for MIPI DPI output panel.
+
+    required:
+      - port@0
+      - port@1
+
+required:
+  - compatible
+  - reg
+  - ports
+  - power-supply
+
+additionalProperties: false
+
+examples:
+  - |
+
+    i2c0 {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      bridge@45 {
+        compatible = "waveshare,dsi2dpi";
+        reg = <0x45>;
+        power-supply = <&reg_3p3v>;
+
+        ports {
+          #address-cells = <1>;
+          #size-cells = <0>;
+
+          port@0 {
+            reg = <0>;
+
+            waveshare_from_dsim: endpoint {
+              data-lanes = <1 2>;
+              remote-endpoint = <&dsim_to_waveshare>;
+            };
+          };
+
+          port@1 {
+            reg = <1>;
+
+            waveshare_to_panel: endpoint {
+              remote-endpoint = <&panel_to_waveshare>;
+            };
+          };
+        };
+      };
+    };
+
+...

-- 
2.34.1

[PATCH 2/3] dt-bindings: display: panel: Add waveshare DPI panel support

[Joseph Guo]

Add dt-binding documentation for waveshare DPI panel

Signed-off-by: Joseph Guo <qijian.guo@nxp.com>
---
 Documentation/devicetree/bindings/display/panel/panel-simple.yaml | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/panel/panel-simple.yaml b/Documentation/devicetree/bindings/display/panel/panel-simple.yaml
index b89e3979057911ab9e669e97e71c16578d9e0150..16465fe3333948909c5d1fdc2a4ddf231bfbce70 100644
--- a/Documentation/devicetree/bindings/display/panel/panel-simple.yaml
+++ b/Documentation/devicetree/bindings/display/panel/panel-simple.yaml
@@ -301,6 +301,10 @@ properties:
       - vivax,tpc9150-panel
         # VXT 800x480 color TFT LCD panel
       - vxt,vl050-8048nt-c01
+        # Waveshare 13.3" FHD (1920x1080) LCD panel
+      - waveshare,13.3inch-panel
+        # Waveshare 7.0" WSVGA (1024x600) LCD panel
+      - waveshare,7.0inch-c-panel
         # Winstar Display Corporation 3.5" QVGA (320x240) TFT LCD panel
       - winstar,wf35ltiacd
         # Yes Optoelectronics YTC700TLAG-05-201C 7" TFT LCD panel

-- 
2.34.1

[PATCH 3/3] drm: bridge: Add waveshare DSI2DPI unit driver

[Joseph Guo]

Waveshare touchscreen consists of a DPI panel and a driver board.
The waveshare driver board consists of ICN6211 and a MCU to
convert DSI to DPI and control the backlight.
This driver treats the MCU and ICN6211 board as a whole unit.
It can support all resolution waveshare DSI2DPI based panel,
the timing table should come from 'panel-dpi' panel in the device tree.

Signed-off-by: Joseph Guo <qijian.guo@nxp.com>
---
 drivers/gpu/drm/bridge/Kconfig         |  11 ++
 drivers/gpu/drm/bridge/Makefile        |   1 +
 drivers/gpu/drm/bridge/waveshare-dsi.c | 210 +++++++++++++++++++++++++++++++++
 3 files changed, 222 insertions(+)

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index cb3b797fcea1c73e83c9187fef6582296b340305..26fec25c61ed7d950c094e0224f1196946079485 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -472,4 +472,15 @@ config DRM_ITE_IT6161
 	help
 	  ITE IT6161 bridge chip driver.
 
+config DRM_WAVESHARE_BRIDGE
+	tristate "Waveshare DSI bridge"
+	depends on OF
+	select DRM_PANEL_BRIDGE
+	select DRM_KMS_HELPER
+	select DRM_MIPI_DSI
+	select REGMAP_I2C
+	help
+	  Driver for waveshare DSI to DPI bridge board.
+	  Please say Y if you have such hardware
+
 endmenu
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
index d1db90688a150fdc3a5fd40acebe740798c452b0..3caa4d8f71675804328aa5a51ec67b2587938621 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -48,3 +48,4 @@ obj-$(CONFIG_DRM_ITE_IT6263) += it6263.o
 obj-$(CONFIG_DRM_ITE_IT6161) += it6161.o
 obj-$(CONFIG_DRM_SEC_MIPI_DSIM) += sec-dsim.o
 obj-$(CONFIG_DRM_NXP_SEIKO_43WVFIG) += nxp-seiko-43wvfig.o
+obj-$(CONFIG_DRM_WAVESHARE_BRIDGE) += waveshare-dsi.o
diff --git a/drivers/gpu/drm/bridge/waveshare-dsi.c b/drivers/gpu/drm/bridge/waveshare-dsi.c
new file mode 100644
index 0000000000000000000000000000000000000000..efb3a2fc501b5725b02f49862526d1704a3a4b7b
--- /dev/null
+++ b/drivers/gpu/drm/bridge/waveshare-dsi.c
@@ -0,0 +1,210 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright 2025 NXP
+ * Based on panel-raspberrypi-touchscreen by Broadcom
+ */
+
+#include <linux/backlight.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
+#include <linux/regmap.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_of.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_print.h>
+
+struct ws_bridge {
+	struct drm_bridge bridge;
+	struct drm_bridge *next_bridge;
+	struct backlight_device *backlight;
+	struct device *dev;
+	struct regmap *reg_map;
+};
+
+static const struct regmap_config ws_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0xff,
+	.disable_debugfs = true,
+};
+
+static struct ws_bridge *bridge_to_ws_bridge(struct drm_bridge *bridge)
+{
+	return container_of(bridge, struct ws_bridge, bridge);
+}
+
+static int ws_bridge_attach_dsi(struct ws_bridge *ws)
+{
+	struct device_node *dsi_host_node;
+	struct mipi_dsi_host *host;
+	struct mipi_dsi_device *dsi;
+	const struct mipi_dsi_device_info info = {
+		.type = "ws-bridge",
+		.channel = 0,
+		.node = NULL,
+	};
+	struct device *dev = ws->dev;
+	int ret;
+
+	dsi_host_node = of_graph_get_remote_node(dev->of_node, 0, 0);
+	if (!dsi_host_node) {
+		dev_err(dev, "Failed to get remote port\n");
+		return -ENODEV;
+	}
+
+	host = of_find_mipi_dsi_host_by_node(dsi_host_node);
+
+	of_node_put(dsi_host_node);
+	if (!host)
+		return dev_err_probe(dev, -EPROBE_DEFER, "Failed to find dsi_host\n");
+
+	dsi = devm_mipi_dsi_device_register_full(dev, host, &info);
+
+	if (IS_ERR(dsi))
+		return dev_err_probe(dev, PTR_ERR(dsi), "Failed to create dsi device\n");
+
+	dsi->mode_flags = MIPI_DSI_MODE_VIDEO_HSE | MIPI_DSI_MODE_VIDEO |
+			  MIPI_DSI_CLOCK_NON_CONTINUOUS;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->lanes = 2;
+
+	ret = devm_mipi_dsi_attach(dev, dsi);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Failed to attach dsi to host\n");
+
+	return 0;
+}
+
+static int ws_bridge_bridge_attach(struct drm_bridge *bridge,
+				   enum drm_bridge_attach_flags flags)
+{
+	struct ws_bridge *ws = bridge_to_ws_bridge(bridge);
+	int ret;
+
+	ret = ws_bridge_attach_dsi(ws);
+	if (ret)
+		return ret;
+
+	return drm_bridge_attach(ws->bridge.encoder, ws->next_bridge,
+				 &ws->bridge, flags);
+}
+
+static void ws_bridge_bridge_enable(struct drm_bridge *bridge)
+{
+	struct ws_bridge *ws = bridge_to_ws_bridge(bridge);
+
+	regmap_write(ws->reg_map, 0xad, 0x01);
+	backlight_enable(ws->backlight);
+}
+
+static void ws_bridge_bridge_disable(struct drm_bridge *bridge)
+{
+	struct ws_bridge *ws = bridge_to_ws_bridge(bridge);
+
+	backlight_disable(ws->backlight);
+	regmap_write(ws->reg_map, 0xad, 0x00);
+}
+
+static const struct drm_bridge_funcs ws_bridge_bridge_funcs = {
+	.enable = ws_bridge_bridge_enable,
+	.disable = ws_bridge_bridge_disable,
+	.attach = ws_bridge_bridge_attach,
+};
+
+static int ws_bridge_bl_update_status(struct backlight_device *bl)
+{
+	struct ws_bridge *ws = bl_get_data(bl);
+
+	regmap_write(ws->reg_map, 0xab, 0xff - backlight_get_brightness(bl));
+	regmap_write(ws->reg_map, 0xaa, 0x01);
+
+	return 0;
+}
+
+static const struct backlight_ops ws_bridge_bl_ops = {
+	.update_status = ws_bridge_bl_update_status,
+};
+
+static struct backlight_device *ws_bridge_create_backlight(struct ws_bridge *ws)
+{
+	struct device *dev = ws->dev;
+	const struct backlight_properties props = {
+		.type = BACKLIGHT_RAW,
+		.brightness = 255,
+		.max_brightness = 255,
+	};
+
+	return devm_backlight_device_register(dev, dev_name(dev), dev, ws,
+					      &ws_bridge_bl_ops, &props);
+}
+
+static int ws_bridge_probe(struct i2c_client *i2c)
+{
+	struct device *dev = &i2c->dev;
+	struct ws_bridge *ws;
+	struct drm_panel *panel;
+	int ret;
+	struct backlight_device *backlight;
+
+	ws = devm_kzalloc(dev, sizeof(*ws), GFP_KERNEL);
+	if (!ws)
+		return -ENOMEM;
+
+	ws->dev = dev;
+
+	ws->reg_map = devm_regmap_init_i2c(i2c, &ws_regmap_config);
+	if (IS_ERR(ws->reg_map))
+		return dev_err_probe(dev, PTR_ERR(ws->reg_map), "Failed to allocate regmap\n");
+
+	ret = drm_of_find_panel_or_bridge(dev->of_node, 1, -1, &panel, NULL);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to find remote panel\n");
+
+	ws->next_bridge = devm_drm_panel_bridge_add(dev, panel);
+	if (IS_ERR(ws->next_bridge))
+		return PTR_ERR(ws->next_bridge);
+
+	ws->backlight = ws_bridge_create_backlight(ws);
+	if (IS_ERR(backlight)) {
+		ret = PTR_ERR(backlight);
+		dev_err(dev, "Failed to create backlight: %d\n", ret);
+		return ret;
+	}
+
+	regmap_write(ws->reg_map, 0xc0, 0x01);
+	regmap_write(ws->reg_map, 0xc2, 0x01);
+	regmap_write(ws->reg_map, 0xac, 0x01);
+
+	ws->bridge.funcs = &ws_bridge_bridge_funcs;
+	ws->bridge.type = DRM_MODE_CONNECTOR_DPI;
+	ws->bridge.of_node = dev->of_node;
+	devm_drm_bridge_add(dev, &ws->bridge);
+
+	return 0;
+}
+
+static const struct of_device_id ws_bridge_of_ids[] = {
+	{.compatible = "waveshare,dsi2dpi",},
+	{ }
+};
+
+MODULE_DEVICE_TABLE(of, ws_bridge_of_ids);
+
+static struct i2c_driver ws_bridge_driver = {
+	.driver = {
+		.name = "ws_dsi2dpi",
+		.of_match_table = ws_bridge_of_ids,
+	},
+	.probe = ws_bridge_probe,
+};
+module_i2c_driver(ws_bridge_driver);
+
+MODULE_AUTHOR("Joseph Guo <qijian.guo@nxp.com>");
+MODULE_DESCRIPTION("Waveshare DSI2DPI bridge driver");
+MODULE_LICENSE("GPL");

-- 
2.34.1

Re: [PATCH 1/3] dt-bindings: display: bridge: Add waveshare DSI2DPI unit support

[Rob Herring]

On Wed, Jul 16, 2025 at 04:08:29PM +0900, Joseph Guo wrote:
> Add dt-binding documentation for waveshare DSI2DPI unit
> 
> Signed-off-by: Joseph Guo <qijian.guo@nxp.com>
> ---
>  .../bindings/display/bridge/waveshare,dsi2dpi.yaml | 103 +++++++++++++++++++++
>  1 file changed, 103 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/display/bridge/waveshare,dsi2dpi.yaml b/Documentation/devicetree/bindings/display/bridge/waveshare,dsi2dpi.yaml
> new file mode 100644
> index 0000000000000000000000000000000000000000..678922ebe138ec2fa7bd05902947a86ec73fc644
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/bridge/waveshare,dsi2dpi.yaml
> @@ -0,0 +1,103 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/display/bridge/waveshare,dsi2dpi.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Waveshare MIPI-DSI to DPI Converter bridge
> +
> +maintainers:
> +  - Joseph Guo <qijian.guo@nxp.com>
> +
> +description:
> +  Waveshare bridge board is part of Waveshare panel which converts DSI to DPI.
> +
> +properties:
> +  compatible:
> +    const: waveshare,dsi2dpi
> +
> +  reg:
> +    maxItems: 1
> +    description: base I2C address of the device
> +
> +  power-supply: true
> +
> +  ports:
> +    $ref: /schemas/graph.yaml#/properties/ports
> +
> +    properties:
> +      port@0:
> +        $ref: /schemas/graph.yaml#/$defs/port-base
> +        unevaluatedProperties: false
> +        description:
> +          Video port for MIPI DSI input
> +
> +        properties:
> +          endpoint:
> +            $ref: /schemas/media/video-interfaces.yaml#
> +            unevaluatedProperties: false
> +
> +            properties:
> +              data-lanes:
> +                description: array of physical DSI data lane indexes.
> +                items:
> +                  - const: 1
> +                  - const: 2
> +
> +            required:
> +              - data-lanes
> +
> +      port@1:
> +        $ref: /schemas/graph.yaml#/properties/port
> +        description:
> +          Video port for MIPI DPI output panel.
> +
> +    required:
> +      - port@0
> +      - port@1
> +
> +required:
> +  - compatible
> +  - reg
> +  - ports
> +  - power-supply
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +
> +    i2c0 {

i2c {

Otherwise,

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

Re: [PATCH 2/3] dt-bindings: display: panel: Add waveshare DPI panel support

[Rob Herring (Arm)]

On Wed, 16 Jul 2025 16:08:30 +0900, Joseph Guo wrote:
> Add dt-binding documentation for waveshare DPI panel
> 
> Signed-off-by: Joseph Guo <qijian.guo@nxp.com>
> ---
>  Documentation/devicetree/bindings/display/panel/panel-simple.yaml | 4 ++++
>  1 file changed, 4 insertions(+)
> 

Acked-by: Rob Herring (Arm) <robh@kernel.org>

RE: [EXT] Re: [PATCH 2/3] dt-bindings: display: panel: Add waveshare DPI panel support

[Joseph Guo]

HI,

> -----Original Message-----
> From: Rob Herring (Arm) <robh@kernel.org>
> Sent: Monday, July 21, 2025 6:53 AM
> To: Joseph Guo <qijian.guo@nxp.com>
> Cc: Robert Foss <rfoss@kernel.org>; Maxime Ripard <mripard@kernel.org>;
> Thomas Zimmermann <tzimmermann@suse.de>; dri-
> devel@lists.freedesktop.org; Maarten Lankhorst
> <maarten.lankhorst@linux.intel.com>; Simona Vetter <simona@ffwll.ch>;
> Laurent Pinchart <laurent.pinchart@ideasonboard.com>; Jonas Karlman
> <jonas@kwiboo.se>; David Airlie <airlied@gmail.com>; Andrzej Hajda
> <andrzej.hajda@intel.com>; linux-kernel@vger.kernel.org; Ying Liu
> <victor.liu@nxp.com>; Jessica Zhang <quic_jesszhan@quicinc.com>; Thierry
> Reding <thierry.reding@gmail.com>; Sam Ravnborg <sam@ravnborg.org>;
> Jernej Skrabec <jernej.skrabec@gmail.com>; Neil Armstrong
> <neil.armstrong@linaro.org>; devicetree@vger.kernel.org; Krzysztof
> Kozlowski <krzk+dt@kernel.org>; Conor Dooley <conor+dt@kernel.org>
> Subject: [EXT] Re: [PATCH 2/3] dt-bindings: display: panel: Add waveshare
> DPI panel support
> 
> Caution: This is an external email. Please take care when clicking links or
> opening attachments. When in doubt, report the message using the 'Report
> this email' button
> 
> 
> On Wed, 16 Jul 2025 16:08:30 +0900, Joseph Guo wrote:
> > Add dt-binding documentation for waveshare DPI panel
> >
> > Signed-off-by: Joseph Guo <qijian.guo@nxp.com>
> > ---
> >  Documentation/devicetree/bindings/display/panel/panel-simple.yaml | 4
> ++++
> >  1 file changed, 4 insertions(+)
> >
> 
> Acked-by: Rob Herring (Arm) <robh@kernel.org>
[Joseph] Thank you Rob. The PATCH 3/3 is not reviewed yet. Could you kindly take a look?

Re: [EXT] Re: [PATCH 2/3] dt-bindings: display: panel: Add waveshare DPI panel support

[Krzysztof Kozlowski]

On 24/07/2025 08:56, Joseph Guo wrote:
>>>
>>
>> Acked-by: Rob Herring (Arm) <robh@kernel.org>
> [Joseph] Thank you Rob. The PATCH 3/3 is not reviewed yet. Could you kindly take a look?

Why? It is not relevant to DT.

Anyway, contentless pings after a week are not helping.

Best regards,
Krzysztof