[PATCH v3 0/3] Add support for Waveshare DSI2DPI unit

[PATCH v3 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>
---
Changes in v3:
- Add Suggested-by tags
- s/R-b/A-b/ in patch 2
- Sort the config names alphabetically
- Add depends on BACKLIGHT_CLASS_DEVICE
- Drop disable_debugfs in regmap_config
- Sort the variables in reverse Christmas tree
- Drop inappropriate blank line
- Drop duplicate backlight variable
- Change API to upstream version
- Link to v2: https://lore.kernel.org/r/20250804-waveshare-v2-0-0a1b3ce92a95@nxp.com

Changes in v2:
- /s/i2c0/i2c/ in patch 1
- Add Review tags
- Link to v1: https://lore.kernel.org/r/20250716-waveshare-v1-0-81cb03fb25a3@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                     |  12 ++
 drivers/gpu/drm/bridge/Makefile                    |   1 +
 drivers/gpu/drm/bridge/waveshare-dsi.c             | 203 +++++++++++++++++++++
 5 files changed, 323 insertions(+)
---
base-commit: ade011daf9e9e0d0180d8bc85b9abc8a67a8d489
change-id: 20250715-waveshare-dad93ea9980f

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

[PATCH v3 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>
Suggested-by: Liu Ying <victor.liu@nxp.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
---
Change from v1 to v2
- /s/i2c0/i2c/
---
 .../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..5e8498c8303dd7415ecca97d12ac97362db73cf5
--- /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:
+  - |
+
+    i2c {
+      #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 v3 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>
Suggested-by: Liu Ying <victor.liu@nxp.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
---
 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 v3 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>
Suggested-by: Liu Ying <victor.liu@nxp.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
---
Change from v2 to v3
- Sort the config names alphabetically
- Add depends on BACKLIGHT_CLASS_DEVICE
- Drop disable_debugfs in regmap_config
- Sort the variables in reverse Christmas tree
- Drop inappropriate blank line
- Drop duplicate backlight variable
- Change API to upstream version
---
 drivers/gpu/drm/bridge/Kconfig         |  12 ++
 drivers/gpu/drm/bridge/Makefile        |   1 +
 drivers/gpu/drm/bridge/waveshare-dsi.c | 203 +++++++++++++++++++++++++++++++++
 3 files changed, 216 insertions(+)

diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index cb3b797fcea1c73e83c9187fef6582296b340305..0447967d125fe8c4cb7dccf3f55323086e7c6ef7 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -446,6 +446,18 @@ config DRM_TI_TPD12S015
 	  Texas Instruments TPD12S015 HDMI level shifter and ESD protection
 	  driver.
 
+config DRM_WAVESHARE_BRIDGE
+	tristate "Waveshare DSI bridge"
+	depends on OF
+	depends on BACKLIGHT_CLASS_DEVICE
+	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
+
 source "drivers/gpu/drm/bridge/analogix/Kconfig"
 
 source "drivers/gpu/drm/bridge/adv7511/Kconfig"
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
index 72185bfd87e4ff6e6ef367edb9d9f52d92bc75fa..fcec44cb273eb99fce08fc924d0d86eab67356ad 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -38,6 +38,7 @@ obj-$(CONFIG_DRM_TI_SN65DSI86) += ti-sn65dsi86.o
 obj-$(CONFIG_DRM_TI_TDP158) += ti-tdp158.o
 obj-$(CONFIG_DRM_TI_TFP410) += ti-tfp410.o
 obj-$(CONFIG_DRM_TI_TPD12S015) += ti-tpd12s015.o
+obj-$(CONFIG_DRM_WAVESHARE_BRIDGE) += waveshare-dsi.o
 obj-$(CONFIG_DRM_NWL_MIPI_DSI) += nwl-dsi.o
 obj-$(CONFIG_DRM_ITE_IT66121) += ite-it66121.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..01c70e7d3d3bd50b17b25396ed9507a2a7e96d18
--- /dev/null
+++ b/drivers/gpu/drm/bridge/waveshare-dsi.c
@@ -0,0 +1,203 @@
+// 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_bridge.h>
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_of.h>
+#include <drm/drm_panel.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,
+};
+
+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)
+{
+	const struct mipi_dsi_device_info info = {
+		.type = "ws-bridge",
+		.channel = 0,
+		.node = NULL,
+	};
+	struct device_node *dsi_host_node;
+	struct device *dev = ws->dev;
+	struct mipi_dsi_device *dsi;
+	struct mipi_dsi_host *host;
+	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,
+				   struct drm_encoder *encoder,
+				   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(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)
+{
+	const struct backlight_properties props = {
+		.type = BACKLIGHT_RAW,
+		.brightness = 255,
+		.max_brightness = 255,
+	};
+	struct device *dev = ws->dev;
+
+	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 drm_panel *panel;
+	struct ws_bridge *ws;
+	int ret;
+
+	ws = devm_drm_bridge_alloc(dev, struct ws_bridge, bridge, &ws_bridge_bridge_funcs);
+	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(ws->backlight)) {
+		ret = PTR_ERR(ws->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.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 v3 0/3] Add support for Waveshare DSI2DPI unit

[Neil Armstrong]

Hi,

On Wed, 06 Aug 2025 10:33:31 +0900, Joseph Guo wrote:
> This patchset add support for waveshare DSI2DPI unit.
> 
> 

Thanks, Applied to https://gitlab.freedesktop.org/drm/misc/kernel.git (drm-misc-next)

[1/3] dt-bindings: display: bridge: Add waveshare DSI2DPI unit support
      https://gitlab.freedesktop.org/drm/misc/kernel/-/commit/01048738d6b618fc1dba564b38b3df06b0937eb0
[2/3] dt-bindings: display: panel: Add waveshare DPI panel support
      https://gitlab.freedesktop.org/drm/misc/kernel/-/commit/80b0eb11f8e0a504078c3b405b54cddaf535ff97
[3/3] drm: bridge: Add waveshare DSI2DPI unit driver
      https://gitlab.freedesktop.org/drm/misc/kernel/-/commit/dbdea37add132a0f5d96006ea01fa73280984b88

-- 
Neil