[PATCH v10 0/3] Add i.MX91/93 parallel display support

[PATCH v10 0/3] Add i.MX91/93 parallel display support

[Marco Felsch]

Hi,

this patchset adds the driver, dt-bindings and dt integration required
to drive a parallel display on the i.MX93.

Since the i.MX91 register layout equals the one from the i.MX93, I added
the support for both but tested only the i.MX93 case.

This patchset depends on:
 - https://lore.kernel.org/all/20251201-v6-18-topic-imx93-blkctrl-v1-0-b57a72e60105@pengutronix.de/

@Conor Dooley
I dropped your r-b tag since I added the 'bus-width' property.

Regards,
  Marco

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
Changes in v10:
- Link to v9: https://lore.kernel.org/r/20260115-v6-18-topic-imx93-parallel-display-v9-0-2c5051e4b144@pengutronix.de
- Add MEDIA_BUS_FMT_FIXED (Liu)
- Drop next_bridge from driver struct and use bridge.next_bridge (Liu)
- Drop linux/of_address.h include (Liu)
- imx93-pdfc: drop bridge.driver_private usage++ (Liu)
- Make use of kmalloc_obj() (Liu)

Changes in v9:
- Link to v8: https://lore.kernel.org/r/20260113-v6-18-topic-imx93-parallel-display-v8-0-4abccdc473a5@pengutronix.de
- dt-bindings: drop unncessary changes (Frank)
- imx93-pdfc: drop bridge.driver_private usage (Luca)
- Kconfig: Adapt Kconfig symbol and prompt (Luca)

Changes in v8:
- Link to v7: https://lore.kernel.org/r/20251202-v6-18-topic-imx93-parallel-display-v7-0-2cce31d64608@pengutronix.de
- dt-bindings: add nxp,imx91-pdfc compatible (Liu)
- dt-bindings: use video-interfaces.yaml# (Liu)
- dt-bindings: s/data lanes/data lines/ (Liu)
- dt-bindings: drop 'reg' poperty
- dt-bindings: drop #address-cells, #size-cells
- imx93-pdfc: drop drm/drm_print.h include (Liu)
- imx93-pdfc: s/exist/exists/ (Liu)
- imx93-pdfc: drop MEDIA_BUS_FMT_FIXED from imx93_pdfc_bus_output_fmts
- imx93-pdfc: imx93_pdfc_bus_output_fmt_supported: make fmt const
- imx93-pdfc: Rework input-fmt selection to always fallback to a sane
              default.
- imx93-pdfc: imx93_pdfc_bridge_atomic_check: make use of
	      imx93_pdfc_bus_output_fmt_supported() 
- imx93-pdfc: drop 'reg' dt-property usage
- imx93-pdfc: imx93_pdfc_bridge_probe: pass -1 for endpoint reg value (Liu)

Changes in v7:
- Link to v6: https://lore.kernel.org/r/20251201-v6-18-topic-imx93-parallel-display-v6-0-7b056e1e5b1e@pengutronix.de
- Add missing bits.h and bitfield.h headers (lkp)

Changes in v6:
- Link to v5: https://lore.kernel.org/all/20250304082434.834031-1-victor.liu@nxp.com/
- Add bus-width support
- rebase onto v6.18-rc1
- add review feedback (Alexander)
- driver license "GPL v2" -> "GPL" (checkpatch)
- make use of reg of-property
- fix to short Kconfig description (checkpath)
- add OF integration

---
Liu Ying (2):
      dt-bindings: soc: imx93-media-blk-ctrl: Add PDFC subnode to schema and example
      drm/bridge: imx: Add i.MX93 parallel display format configuration support

Marco Felsch (1):
      arm64: dts: imx93: Add parallel display output nodes

 .../bindings/soc/imx/fsl,imx93-media-blk-ctrl.yaml |  78 +++++++
 arch/arm64/boot/dts/freescale/imx91_93_common.dtsi |  54 +++++
 arch/arm64/boot/dts/freescale/imx93.dtsi           |  12 ++
 drivers/gpu/drm/bridge/imx/Kconfig                 |  11 +
 drivers/gpu/drm/bridge/imx/Makefile                |   1 +
 drivers/gpu/drm/bridge/imx/imx93-pdfc.c            | 225 +++++++++++++++++++++
 6 files changed, 381 insertions(+)
---
base-commit: 6de23f81a5e08be8fbf5e8d7e9febc72a5b5f27f
change-id: 20251201-v6-18-topic-imx93-parallel-display-95f9234bf6cc

Best regards,
-- 
Marco Felsch <m.felsch@pengutronix.de>

[PATCH v10 1/3] dt-bindings: soc: imx93-media-blk-ctrl: Add PDFC subnode to schema and example

[Marco Felsch]

From: Liu Ying <victor.liu@nxp.com>

i.MX93 SoC mediamix blk-ctrl contains one DISPLAY_MUX register which
configures parallel display format by using the "PARALLEL_DISP_FORMAT"
field. Document the Parallel Display Format Configuration(PDFC) subnode
and add the subnode to example.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Liu Ying <victor.liu@nxp.com>
[m.felsch@pengutronix.de: port to v7.0-rc1]
[m.felsch@pengutronix.de: add bus-width]
Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
 .../bindings/soc/imx/fsl,imx93-media-blk-ctrl.yaml | 78 ++++++++++++++++++++++
 1 file changed, 78 insertions(+)

diff --git a/Documentation/devicetree/bindings/soc/imx/fsl,imx93-media-blk-ctrl.yaml b/Documentation/devicetree/bindings/soc/imx/fsl,imx93-media-blk-ctrl.yaml
index 34aea58094e55365a2f9c86092f637e533f954ff..d828c2e82965c7a4cd69a67136047d83c96b0a35 100644
--- a/Documentation/devicetree/bindings/soc/imx/fsl,imx93-media-blk-ctrl.yaml
+++ b/Documentation/devicetree/bindings/soc/imx/fsl,imx93-media-blk-ctrl.yaml
@@ -40,6 +40,58 @@ properties:
     minItems: 8
     maxItems: 10
 
+  dpi-bridge:
+    type: object
+    additionalProperties: false
+
+    properties:
+      compatible:
+        enum:
+          - nxp,imx91-pdfc
+          - nxp,imx93-pdfc
+
+      ports:
+        $ref: /schemas/graph.yaml#/properties/ports
+
+        properties:
+          port@0:
+            $ref: /schemas/graph.yaml#/properties/port
+            description: Input port node to receive pixel data.
+
+          port@1:
+            $ref: /schemas/graph.yaml#/$defs/port-base
+            unevaluatedProperties: false
+            description: Output port node to downstream pixel data receivers.
+
+            properties:
+              endpoint:
+                $ref: /schemas/media/video-interfaces.yaml#
+                unevaluatedProperties: false
+
+                properties:
+                  bus-width:
+                    enum: [ 16, 18, 24 ]
+                    description:
+                      Specify the physical parallel bus width.
+
+                      This property is optional if the display bus-width
+                      matches the SoC bus-width, e.g. a 18-bit RGB666 (display)
+                      is connected and all 18-bit data lines are muxed to the
+                      parallel-output pads.
+
+                      This property must be set to 18 to cut only the LSBs
+                      instead of the MSBs in case a 24-bit RGB888 display is
+                      connected and only the lower 18-bit data lanes are muxed
+                      to the parallel-output pads.
+
+        required:
+          - port@0
+          - port@1
+
+    required:
+      - compatible
+      - ports
+
 allOf:
   - if:
       properties:
@@ -112,4 +164,30 @@ examples:
                clock-names = "apb", "axi", "nic", "disp", "cam",
                              "pxp", "lcdif", "isi", "csi", "dsi";
       #power-domain-cells = <1>;
+
+      dpi-bridge {
+        compatible = "nxp,imx93-pdfc";
+
+        ports {
+          #address-cells = <1>;
+          #size-cells = <0>;
+
+          port@0 {
+            reg = <0>;
+
+            pdfc_from_lcdif: endpoint {
+              remote-endpoint = <&lcdif_to_pdfc>;
+            };
+          };
+
+          port@1 {
+            reg = <1>;
+
+            pdfc_to_panel: endpoint {
+              remote-endpoint = <&panel_from_pdfc>;
+              bus-width = <18>;
+            };
+          };
+        };
+      };
     };

-- 
2.47.3

[PATCH v10 2/3] drm/bridge: imx: Add i.MX93 parallel display format configuration support

[Marco Felsch]

From: Liu Ying <victor.liu@nxp.com>

NXP i.MX93 mediamix blk-ctrl contains one DISPLAY_MUX register which
configures parallel display format by using the "PARALLEL_DISP_FORMAT"
field. Add a DRM bridge driver to support the display format configuration.

Signed-off-by: Liu Ying <victor.liu@nxp.com>
[m.felsch@pengutronix.de: port to v7.0-rc1]
[m.felsch@pengutronix.de: add review feedback (Alexander)]
[m.felsch@pengutronix.de: fix to short Kconfig description (checkpath)]
[m.felsch@pengutronix.de: use "GPL" instead of "GPL v2" (checkpatch)]
[m.felsch@pengutronix.de: add bus-width support]
Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
 drivers/gpu/drm/bridge/imx/Kconfig      |  11 ++
 drivers/gpu/drm/bridge/imx/Makefile     |   1 +
 drivers/gpu/drm/bridge/imx/imx93-pdfc.c | 225 ++++++++++++++++++++++++++++++++
 3 files changed, 237 insertions(+)

diff --git a/drivers/gpu/drm/bridge/imx/Kconfig b/drivers/gpu/drm/bridge/imx/Kconfig
index b9028a5e5a065c3237b404111d8df57e8e017f9d..47829300a4486a090514ebe914b7667a703039a9 100644
--- a/drivers/gpu/drm/bridge/imx/Kconfig
+++ b/drivers/gpu/drm/bridge/imx/Kconfig
@@ -99,4 +99,15 @@ config DRM_IMX93_MIPI_DSI
 	  Choose this to enable MIPI DSI controller found in Freescale i.MX93
 	  processor.
 
+config DRM_IMX93_PARALLEL_DISP_FMT_CONVERTER
+	tristate "NXP i.MX91/i.MX93 parallel display format converter"
+	depends on OF
+	select DRM_KMS_HELPER
+	help
+	  On i.MX93 and i.MX91 SoCs the parallel display format output is
+	  controlled via the MEDIAMIX BLK-CTRL DISPLAY_MUX.
+
+	  Say 'Y' or 'M' if you use the parallel display output path on a
+	  i.MX93 or i.MX91 SoC.
+
 endif # ARCH_MXC || COMPILE_TEST
diff --git a/drivers/gpu/drm/bridge/imx/Makefile b/drivers/gpu/drm/bridge/imx/Makefile
index 8d01fda25451aaa1bf51a068da18948094327116..da57fde2d813b88cdde89115ca801b4cfc69afbd 100644
--- a/drivers/gpu/drm/bridge/imx/Makefile
+++ b/drivers/gpu/drm/bridge/imx/Makefile
@@ -9,3 +9,4 @@ obj-$(CONFIG_DRM_IMX8QXP_PIXEL_COMBINER) += imx8qxp-pixel-combiner.o
 obj-$(CONFIG_DRM_IMX8QXP_PIXEL_LINK) += imx8qxp-pixel-link.o
 obj-$(CONFIG_DRM_IMX8QXP_PIXEL_LINK_TO_DPI) += imx8qxp-pxl2dpi.o
 obj-$(CONFIG_DRM_IMX93_MIPI_DSI) += imx93-mipi-dsi.o
+obj-$(CONFIG_DRM_IMX93_PARALLEL_DISP_FMT_CONVERTER) += imx93-pdfc.o
diff --git a/drivers/gpu/drm/bridge/imx/imx93-pdfc.c b/drivers/gpu/drm/bridge/imx/imx93-pdfc.c
new file mode 100644
index 0000000000000000000000000000000000000000..56698168a66bf716762a139b6fea318bf450f6b5
--- /dev/null
+++ b/drivers/gpu/drm/bridge/imx/imx93-pdfc.c
@@ -0,0 +1,225 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+/*
+ * Copyright 2022-2025 NXP
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/media-bus-format.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include <drm/drm_atomic_state_helper.h>
+#include <drm/drm_bridge.h>
+
+#define IMX93_DISPLAY_MUX_REG		0x60
+#define PARALLEL_DISP_FORMAT		GENMASK(10, 8)
+#define FORMAT_RGB888_TO_RGB888		FIELD_PREP(PARALLEL_DISP_FORMAT, 0)
+#define FORMAT_RGB888_TO_RGB666		FIELD_PREP(PARALLEL_DISP_FORMAT, 1)
+#define FORMAT_RGB565_TO_RGB565		FIELD_PREP(PARALLEL_DISP_FORMAT, 2)
+
+struct imx93_pdfc {
+	struct drm_bridge bridge;
+	struct device *dev;
+	struct regmap *regmap;
+	u32 phy_bus_width;
+};
+
+static struct imx93_pdfc *bridge_to_imx93_pdfc(struct drm_bridge *bridge)
+{
+	return container_of(bridge, struct imx93_pdfc, bridge);
+}
+
+static int
+imx93_pdfc_bridge_attach(struct drm_bridge *bridge, struct drm_encoder *encoder,
+			 enum drm_bridge_attach_flags flags)
+{
+	return drm_bridge_attach(bridge->encoder, bridge->next_bridge, bridge, flags);
+}
+
+static void imx93_pdfc_bridge_atomic_enable(struct drm_bridge *bridge,
+					    struct drm_atomic_state *state)
+{
+	struct imx93_pdfc *pdfc = bridge_to_imx93_pdfc(bridge);
+	const struct drm_bridge_state *bridge_state;
+	unsigned int mask = PARALLEL_DISP_FORMAT;
+	unsigned int val;
+
+	bridge_state = drm_atomic_get_new_bridge_state(state, bridge);
+
+	switch (bridge_state->output_bus_cfg.format) {
+	case MEDIA_BUS_FMT_RGB888_1X24:
+	case MEDIA_BUS_FMT_FIXED:
+		val = FORMAT_RGB888_TO_RGB888;
+		if (pdfc->phy_bus_width == 18) {
+			/*
+			 * Can be valid if physical bus limitation exists,
+			 * therefore use dev_dbg().
+			 */
+			dev_dbg(pdfc->dev, "Truncate two LSBs from each color\n");
+			val = FORMAT_RGB888_TO_RGB666;
+		}
+		break;
+	case MEDIA_BUS_FMT_RGB666_1X18:
+		val = FORMAT_RGB888_TO_RGB666;
+		break;
+	case MEDIA_BUS_FMT_RGB565_1X16:
+		val = FORMAT_RGB565_TO_RGB565;
+		break;
+	}
+
+	regmap_update_bits(pdfc->regmap, IMX93_DISPLAY_MUX_REG, mask, val);
+}
+
+/* TODO: Add YUV formats */
+static const u32 imx93_pdfc_bus_output_fmts[] = {
+	MEDIA_BUS_FMT_FIXED,
+	MEDIA_BUS_FMT_RGB888_1X24,
+	MEDIA_BUS_FMT_RGB666_1X18,
+	MEDIA_BUS_FMT_RGB565_1X16,
+};
+
+static bool imx93_pdfc_bus_output_fmt_supported(const  u32 fmt)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(imx93_pdfc_bus_output_fmts); i++) {
+		if (imx93_pdfc_bus_output_fmts[i] == fmt)
+			return true;
+	}
+
+	return false;
+}
+
+static u32 *
+imx93_pdfc_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
+					    struct drm_bridge_state *bridge_state,
+					    struct drm_crtc_state *crtc_state,
+					    struct drm_connector_state *conn_state,
+					    u32 output_fmt,
+					    unsigned int *num_input_fmts)
+{
+	struct imx93_pdfc *pdfc = bridge_to_imx93_pdfc(bridge);
+	u32 *input_fmts;
+
+	*num_input_fmts = 0;
+
+	input_fmts = kmalloc_obj(*input_fmts, GFP_KERNEL);
+	if (!input_fmts)
+		return NULL;
+
+	*num_input_fmts = 1;
+
+	if (!imx93_pdfc_bus_output_fmt_supported(output_fmt)) {
+		dev_dbg(pdfc->dev, "No valid output bus-fmt detected, fallback to MEDIA_BUS_FMT_RGB888_1X24\n");
+		input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24;
+		return input_fmts;
+	}
+
+	switch (output_fmt) {
+	case MEDIA_BUS_FMT_RGB888_1X24:
+	case MEDIA_BUS_FMT_RGB565_1X16:
+		input_fmts[0] = output_fmt;
+		break;
+	case MEDIA_BUS_FMT_RGB666_1X18:
+	case MEDIA_BUS_FMT_FIXED:
+		input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24;
+		break;
+	}
+
+	return input_fmts;
+}
+
+static int imx93_pdfc_bridge_atomic_check(struct drm_bridge *bridge,
+					  struct drm_bridge_state *bridge_state,
+					  struct drm_crtc_state *crtc_state,
+					  struct drm_connector_state *conn_state)
+{
+	struct imx93_pdfc *pdfc = bridge_to_imx93_pdfc(bridge);
+	const u32 format = bridge_state->output_bus_cfg.format;
+
+	if (imx93_pdfc_bus_output_fmt_supported(format))
+		return 0;
+
+	dev_warn(pdfc->dev, "Unsupported output bus format: 0x%x\n", format);
+
+	return -EINVAL;
+}
+
+static const struct drm_bridge_funcs funcs = {
+	.attach			= imx93_pdfc_bridge_attach,
+	.atomic_enable		= imx93_pdfc_bridge_atomic_enable,
+	.atomic_duplicate_state	= drm_atomic_helper_bridge_duplicate_state,
+	.atomic_destroy_state	= drm_atomic_helper_bridge_destroy_state,
+	.atomic_get_input_bus_fmts	= imx93_pdfc_bridge_atomic_get_input_bus_fmts,
+	.atomic_check		= imx93_pdfc_bridge_atomic_check,
+	.atomic_reset		= drm_atomic_helper_bridge_reset,
+};
+
+static int imx93_pdfc_bridge_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct drm_bridge *next_bridge;
+	struct imx93_pdfc *pdfc;
+	struct device_node *ep;
+	int err;
+
+	pdfc = devm_drm_bridge_alloc(dev, struct imx93_pdfc, bridge, &funcs);
+	if (IS_ERR(pdfc))
+		return PTR_ERR(pdfc);
+
+	pdfc->regmap = syscon_node_to_regmap(dev->of_node->parent);
+	if (IS_ERR(pdfc->regmap))
+		return dev_err_probe(dev, PTR_ERR(pdfc->regmap),
+				     "failed to get regmap\n");
+
+	/* No limits per default */
+	pdfc->phy_bus_width = 24;
+
+	/* Get output ep (port1/endpoint) */
+	ep = of_graph_get_endpoint_by_regs(dev->of_node, 1, -1);
+	if (ep) {
+		err = of_property_read_u32(ep, "bus-width", &pdfc->phy_bus_width);
+		of_node_put(ep);
+
+		/* bus-width is optional but it must have valid data if present */
+		if (err && err != -EINVAL)
+			return dev_err_probe(dev, err,
+					     "failed to query bus-width\n");
+	}
+
+	next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 1, 0);
+	if (IS_ERR(next_bridge))
+		return dev_err_probe(dev, PTR_ERR(next_bridge),
+				     "failed to get next bridge\n");
+	pdfc->dev = dev;
+	pdfc->bridge.of_node = dev->of_node;
+	pdfc->bridge.type = DRM_MODE_CONNECTOR_DPI;
+	pdfc->bridge.next_bridge = next_bridge;
+
+	return devm_drm_bridge_add(dev, &pdfc->bridge);
+}
+
+static const struct of_device_id imx93_pdfc_dt_ids[] = {
+	{ .compatible = "nxp,imx93-pdfc", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imx93_pdfc_dt_ids);
+
+static struct platform_driver imx93_pdfc_bridge_driver = {
+	.probe	= imx93_pdfc_bridge_probe,
+	.driver	= {
+		.of_match_table = imx93_pdfc_dt_ids,
+		.name = "imx93_pdfc",
+	},
+};
+module_platform_driver(imx93_pdfc_bridge_driver);
+
+MODULE_DESCRIPTION("NXP i.MX93 parallel display format configuration driver");
+MODULE_AUTHOR("Liu Ying <victor.liu@nxp.com>");
+MODULE_LICENSE("GPL");

-- 
2.47.3

[PATCH v10 3/3] arm64: dts: imx93: Add parallel display output nodes

[Marco Felsch]

Add required OF nodes to support the i.MX93 parallel output (DPI) path.

On the i.MX93 a single LCDIF is connected to three bridges: DPI, LVDS
LDB and the MIPI-DSI whereas the i.MX91 support only the DPI bridge.

Map endpoint@0 as DPI bridge output since the i.MX93 TRM (Figure 485.
MEDIAMIX block diagram) doesn't mention any port-number <-> bridge
combination.

Set the MEDIA-AXI and MEDIA-APB clocks to the overdrive (OD) values
since the i.MX93 and i.MX91 use the overdrive (OD) clk settings per
default.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
 arch/arm64/boot/dts/freescale/imx91_93_common.dtsi | 54 ++++++++++++++++++++++
 arch/arm64/boot/dts/freescale/imx93.dtsi           | 12 +++++
 2 files changed, 66 insertions(+)

diff --git a/arch/arm64/boot/dts/freescale/imx91_93_common.dtsi b/arch/arm64/boot/dts/freescale/imx91_93_common.dtsi
index 7958cef353766a430df5e626ff2403dc05a974b1..5a8813df6bc993d559fb0b20fc742a106bfe6315 100644
--- a/arch/arm64/boot/dts/freescale/imx91_93_common.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx91_93_common.dtsi
@@ -1122,8 +1122,62 @@ media_blk_ctrl: system-controller@4ac10000 {
 				 <&clk IMX93_CLK_MIPI_DSI_GATE>;
 			clock-names = "apb", "axi", "nic", "disp", "cam",
 				      "pxp", "lcdif", "isi", "csi", "dsi";
+			assigned-clocks = <&clk IMX93_CLK_MEDIA_AXI>,
+					  <&clk IMX93_CLK_MEDIA_APB>,
+					  <&clk IMX93_CLK_MEDIA_DISP_PIX>;
+			assigned-clock-parents = <&clk IMX93_CLK_SYS_PLL_PFD1>,
+						 <&clk IMX93_CLK_SYS_PLL_PFD1_DIV2>,
+						 <&clk IMX93_CLK_VIDEO_PLL>;
+			assigned-clock-rates = <400000000>, <133333333>;
 			#power-domain-cells = <1>;
 			status = "disabled";
+
+			dpi_bridge: dpi-bridge {
+				compatible = "nxp,imx93-pdfc";
+				status = "disabled";
+
+				ports {
+					#address-cells = <1>;
+					#size-cells = <0>;
+
+					port@0 {
+						reg = <0>;
+
+						dpi_from_lcdif: endpoint {
+							remote-endpoint = <&lcdif_to_dpi>;
+						};
+					};
+
+					port@1 {
+						reg = <1>;
+
+						dpi_to_panel: endpoint {
+						};
+					};
+				};
+			};
+		};
+
+		lcdif: display-controller@4ae30000 {
+			compatible = "fsl,imx93-lcdif";
+			reg = <0x4ae30000 0x23c>;
+			interrupts = <GIC_SPI 176 IRQ_TYPE_LEVEL_HIGH>;
+			clocks = <&clk IMX93_CLK_MEDIA_DISP_PIX>,
+				 <&clk IMX93_CLK_LCDIF_GATE>,
+				 <&clk IMX93_CLK_MEDIA_AXI>;
+			clock-names = "pix", "axi", "disp_axi";
+			power-domains = <&media_blk_ctrl IMX93_MEDIABLK_PD_LCDIF>;
+			status = "disabled";
+
+			port {
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				lcdif_to_dpi: endpoint@0 {
+					reg = <0>;
+					remote-endpoint = <&dpi_from_lcdif>;
+				};
+			};
 		};
 
 		usbotg1: usb@4c100000 {
diff --git a/arch/arm64/boot/dts/freescale/imx93.dtsi b/arch/arm64/boot/dts/freescale/imx93.dtsi
index 7b27012dfcb564650882dc8c40e836e797b2fda1..5436b48b30e89eb1f939b398ce1bf105abe7e34b 100644
--- a/arch/arm64/boot/dts/freescale/imx93.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx93.dtsi
@@ -150,6 +150,18 @@ l3_cache: l3-cache {
 	};
 };
 
+&lcdif {
+	port {
+		lcdif_to_ldb: endpoint@1 {
+			reg = <1>;
+		};
+
+		lcdif_to_dsi: endpoint@2 {
+			reg = <2>;
+		};
+	};
+};
+
 &src {
 	mlmix: power-domain@44461800 {
 		compatible = "fsl,imx93-src-slice";

-- 
2.47.3

Re: [PATCH v10 0/3] Add i.MX91/93 parallel display support

[Liu Ying]

On Mon, Mar 02, 2026 at 05:10:39PM +0100, Marco Felsch wrote:
> Hi,

Hi Marco,

Since Frank Li is a new "ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" maintainer,
you should copy him.  I'm Cc'ing him here.

> 
> this patchset adds the driver, dt-bindings and dt integration required
> to drive a parallel display on the i.MX93.
> 
> Since the i.MX91 register layout equals the one from the i.MX93, I added
> the support for both but tested only the i.MX93 case.
> 
> This patchset depends on:
>  - https://lore.kernel.org/all/20251201-v6-18-topic-imx93-blkctrl-v1-0-b57a72e60105@pengutronix.de/
> 
> @Conor Dooley
> I dropped your r-b tag since I added the 'bus-width' property.
> 
> Regards,
>   Marco
> 
> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> ---
> Changes in v10:
> - Link to v9: https://lore.kernel.org/r/20260115-v6-18-topic-imx93-parallel-display-v9-0-2c5051e4b144@pengutronix.de
> - Add MEDIA_BUS_FMT_FIXED (Liu)
> - Drop next_bridge from driver struct and use bridge.next_bridge (Liu)
> - Drop linux/of_address.h include (Liu)
> - imx93-pdfc: drop bridge.driver_private usage++ (Liu)
> - Make use of kmalloc_obj() (Liu)
> 
> Changes in v9:
> - Link to v8: https://lore.kernel.org/r/20260113-v6-18-topic-imx93-parallel-display-v8-0-4abccdc473a5@pengutronix.de
> - dt-bindings: drop unncessary changes (Frank)
> - imx93-pdfc: drop bridge.driver_private usage (Luca)
> - Kconfig: Adapt Kconfig symbol and prompt (Luca)
> 
> Changes in v8:
> - Link to v7: https://lore.kernel.org/r/20251202-v6-18-topic-imx93-parallel-display-v7-0-2cce31d64608@pengutronix.de
> - dt-bindings: add nxp,imx91-pdfc compatible (Liu)
> - dt-bindings: use video-interfaces.yaml# (Liu)
> - dt-bindings: s/data lanes/data lines/ (Liu)
> - dt-bindings: drop 'reg' poperty
> - dt-bindings: drop #address-cells, #size-cells
> - imx93-pdfc: drop drm/drm_print.h include (Liu)
> - imx93-pdfc: s/exist/exists/ (Liu)
> - imx93-pdfc: drop MEDIA_BUS_FMT_FIXED from imx93_pdfc_bus_output_fmts
> - imx93-pdfc: imx93_pdfc_bus_output_fmt_supported: make fmt const
> - imx93-pdfc: Rework input-fmt selection to always fallback to a sane
>               default.
> - imx93-pdfc: imx93_pdfc_bridge_atomic_check: make use of
> 	      imx93_pdfc_bus_output_fmt_supported() 
> - imx93-pdfc: drop 'reg' dt-property usage
> - imx93-pdfc: imx93_pdfc_bridge_probe: pass -1 for endpoint reg value (Liu)
> 
> Changes in v7:
> - Link to v6: https://lore.kernel.org/r/20251201-v6-18-topic-imx93-parallel-display-v6-0-7b056e1e5b1e@pengutronix.de
> - Add missing bits.h and bitfield.h headers (lkp)
> 
> Changes in v6:
> - Link to v5: https://lore.kernel.org/all/20250304082434.834031-1-victor.liu@nxp.com/
> - Add bus-width support
> - rebase onto v6.18-rc1
> - add review feedback (Alexander)
> - driver license "GPL v2" -> "GPL" (checkpatch)
> - make use of reg of-property
> - fix to short Kconfig description (checkpath)
> - add OF integration
> 
> ---
> Liu Ying (2):
>       dt-bindings: soc: imx93-media-blk-ctrl: Add PDFC subnode to schema and example

This one and ...

>       drm/bridge: imx: Add i.MX93 parallel display format configuration support
> 
> Marco Felsch (1):
>       arm64: dts: imx93: Add parallel display output nodes

... this one in v9 were applied by Frank, so you should no longer send them.

> 
>  .../bindings/soc/imx/fsl,imx93-media-blk-ctrl.yaml |  78 +++++++
>  arch/arm64/boot/dts/freescale/imx91_93_common.dtsi |  54 +++++
>  arch/arm64/boot/dts/freescale/imx93.dtsi           |  12 ++
>  drivers/gpu/drm/bridge/imx/Kconfig                 |  11 +
>  drivers/gpu/drm/bridge/imx/Makefile                |   1 +
>  drivers/gpu/drm/bridge/imx/imx93-pdfc.c            | 225 +++++++++++++++++++++
>  6 files changed, 381 insertions(+)
> ---
> base-commit: 6de23f81a5e08be8fbf5e8d7e9febc72a5b5f27f
> change-id: 20251201-v6-18-topic-imx93-parallel-display-95f9234bf6cc
> 
> Best regards,

-- 
Regards,
Liu Ying

Claude review: Add i.MX91/93 parallel display support

[Claude Code Review Bot]

Overall Series Review

Subject: Add i.MX91/93 parallel display support
Author: Marco Felsch <m.felsch@pengutronix.de>
Patches: 5
Reviewed: 2026-03-03T13:09:09.621913

---

This is a v10 patch series adding i.MX91/i.MX93 parallel display format configuration (PDFC) bridge driver support. The series is well-structured: DT binding (patch 1/3), bridge driver (patch 2/3), and DT integration (patch 3/3). It has been through extensive review cycles and is close to being mergeable. However, there are a few issues worth calling out, including one likely bug in the driver code and several minor concerns.

The series depends on an earlier blk-ctrl series. The patches did not apply cleanly, likely due to that dependency.

---
Generated by Claude Code Patch Reviewer

Claude review: dt-bindings: soc: imx93-media-blk-ctrl: Add PDFC subnode to schema and example

[Claude Code Review Bot]

Patch Review

**Subject:** `[PATCH v10 1/3] dt-bindings: soc: imx93-media-blk-ctrl: Add PDFC subnode to schema and example`

This patch adds the `dpi-bridge` subnode binding to the existing `fsl,imx93-media-blk-ctrl.yaml`. Looks reasonable.

**Minor observations:**

1. The binding only lists `nxp,imx91-pdfc` and `nxp,imx93-pdfc` in the compatible enum, but the driver in patch 2 only has a match for `nxp,imx93-pdfc`. If `nxp,imx91-pdfc` is a distinct compatible in the binding, the driver should also match it (or document a fallback). See patch 2 comments.

2. The `bus-width` enum is well-documented:
```yaml
                  bus-width:
                    enum: [ 16, 18, 24 ]
```
But the driver only acts on `bus-width == 18` (truncating LSBs). A `bus-width` of 16 at the physical level isn't handled differently in the driver. This is okay if `bus-width: 16` is only informational, but worth confirming intent.

3. No issues with the example node addition - it properly demonstrates `bus-width = <18>` in the output endpoint.

**Verdict:** Looks good. Already has Rob's Reviewed-by.

---

---
Generated by Claude Code Patch Reviewer

Claude review: drm/bridge: imx: Add i.MX93 parallel display format configuration support

[Claude Code Review Bot]

Patch Review

**Subject:** `[PATCH v10 2/3] drm/bridge: imx: Add i.MX93 parallel display format configuration support`

This is the main driver patch. Several issues:

**Bug: `kmalloc_obj` used with dereference of uninitialized pointer**

```c
input_fmts = kmalloc_obj(*input_fmts, GFP_KERNEL);
```

`kmalloc_obj` takes a `VAR_OR_TYPE` as its first argument and uses `typeof(VAR_OR_TYPE)` internally to determine the allocation size. Here `*input_fmts` is a dereference of the `u32 *input_fmts` pointer, which at this point is uninitialized. While `kmalloc_obj` uses only `typeof()` (so the value is never actually read at runtime - the compiler extracts the type at compile time), dereferencing an uninitialized pointer in the source expression is arguably UB by the letter of the C standard, even inside `typeof()`. More practically, this is confusing to read. The more idiomatic form would be:

```c
input_fmts = kmalloc_obj(u32, GFP_KERNEL);
```

or simply using `kmalloc(sizeof(*input_fmts), GFP_KERNEL)` / `kmalloc(sizeof(u32), GFP_KERNEL)` which is the traditional pattern used throughout the DRM bridge subsystem.

**Missing `default` in switch statement in `atomic_enable`:**

```c
	switch (bridge_state->output_bus_cfg.format) {
	case MEDIA_BUS_FMT_RGB888_1X24:
	case MEDIA_BUS_FMT_FIXED:
		val = FORMAT_RGB888_TO_RGB888;
		...
		break;
	case MEDIA_BUS_FMT_RGB666_1X18:
		val = FORMAT_RGB888_TO_RGB666;
		break;
	case MEDIA_BUS_FMT_RGB565_1X16:
		val = FORMAT_RGB565_TO_RGB565;
		break;
	}
```

If the format is something unexpected, `val` is used uninitialized in the `regmap_update_bits()` call below. The `atomic_check` should prevent this, but defensive programming would add a `default:` case (perhaps with a `dev_warn` + `return`). At minimum, initialize `val` to a sane default (e.g., `FORMAT_RGB888_TO_RGB888`).

**`imx93_pdfc_bridge_attach` uses `bridge->encoder` instead of the `encoder` parameter:**

```c
static int
imx93_pdfc_bridge_attach(struct drm_bridge *bridge, struct drm_encoder *encoder,
			 enum drm_bridge_attach_flags flags)
{
	return drm_bridge_attach(bridge->encoder, bridge->next_bridge, bridge, flags);
}
```

The function receives `encoder` as a parameter but passes `bridge->encoder` to `drm_bridge_attach()`. Looking at other drivers in the same directory (e.g., `imx8mp-hdmi-pvi.c`), the convention is to pass the `encoder` parameter directly:

```c
return drm_bridge_attach(encoder, pvi->bridge.next_bridge, bridge, flags);
```

While `bridge->encoder` should be set by the time `attach` is called, using the function parameter `encoder` is the correct and idiomatic pattern. This should be changed.

**Missing `nxp,imx91-pdfc` in the of_device_id table:**

The DT binding in patch 1 documents `nxp,imx91-pdfc` as a valid compatible string, but the driver only matches:
```c
static const struct of_device_id imx93_pdfc_dt_ids[] = {
	{ .compatible = "nxp,imx93-pdfc", },
	{ /* sentinel */ }
};
```

If i.MX91 uses the same register layout (as stated in the cover letter), a second entry `{ .compatible = "nxp,imx91-pdfc", }` should be added. Without it, the driver won't probe on i.MX91-based device trees using the `nxp,imx91-pdfc` compatible.

**Kconfig: Missing `COMPILE_TEST` dependency:**

```
config DRM_IMX93_PARALLEL_DISP_FMT_CONVERTER
	tristate "NXP i.MX91/i.MX93 parallel display format converter"
	depends on OF
```

Other entries in this Kconfig are inside an `if ARCH_MXC || COMPILE_TEST` block, so this inherits that guard. However, the `depends on OF` is redundant since `ARCH_MXC` already selects `OF`. Not a blocker, just a nit consistent with how other entries in the file are structured.

**Verdict:** Needs fixes for the `bridge->encoder` vs `encoder` parameter issue and the missing `nxp,imx91-pdfc` compatible. The `kmalloc_obj(*input_fmts, ...)` usage and missing `default` in the switch are worth addressing too.

---

---
Generated by Claude Code Patch Reviewer

Claude review: arm64: dts: imx93: Add parallel display output nodes

[Claude Code Review Bot]

Patch Review

**Subject:** `[PATCH v10 3/3] arm64: dts: imx93: Add parallel display output nodes`

This patch adds the DT nodes for the LCDIF display controller and wires it up to the PDFC bridge.

**`assigned-clock-rates` count mismatch:**

```dts
			assigned-clocks = <&clk IMX93_CLK_MEDIA_AXI>,
					  <&clk IMX93_CLK_MEDIA_APB>,
					  <&clk IMX93_CLK_MEDIA_DISP_PIX>;
			assigned-clock-parents = <&clk IMX93_CLK_SYS_PLL_PFD1>,
						 <&clk IMX93_CLK_SYS_PLL_PFD1_DIV2>,
						 <&clk IMX93_CLK_VIDEO_PLL>;
			assigned-clock-rates = <400000000>, <133333333>;
```

Three clocks are listed in `assigned-clocks` and `assigned-clock-parents`, but `assigned-clock-rates` only has two values. The third clock (`MEDIA_DISP_PIX`) has its parent set to `VIDEO_PLL` but no rate specified. This is intentionally leaving the pixel clock rate to be set at runtime (which is correct since the pixel clock rate depends on the display mode), but it would be clearer to explicitly pass `<0>` as the third rate to indicate "don't set a rate" (the standard DT convention). Some DT validation tools may warn about the length mismatch.

**The `dpi-bridge` compatible uses `nxp,imx93-pdfc` in the common dtsi:**

```dts
			dpi_bridge: dpi-bridge {
				compatible = "nxp,imx93-pdfc";
```

Since `imx91_93_common.dtsi` is shared between i.MX91 and i.MX93, using the `nxp,imx93-pdfc` compatible here means i.MX91-based boards would also use this compatible. If i.MX91 should use `nxp,imx91-pdfc` (as defined in the binding), then the compatible should be overridden in the i.MX91-specific dtsi file, or the common dtsi should use the i.MX91 compatible with a fallback. Currently there doesn't appear to be an i.MX91-specific override.

**LCDIF node looks correct:**

The `lcdif` node at `0x4ae30000` with appropriate clocks, power-domains, and port wiring to the PDFC bridge looks well-structured. The imx93.dtsi addition of `endpoint@1` (LDB) and `endpoint@2` (DSI) stubs for the other two bridge outputs is a clean forward-looking pattern.

**The patch closes the `media_blk_ctrl` node and adds `lcdif` as a sibling:**

```dts
+		};
+
+		lcdif: display-controller@4ae30000 {
```

This correctly makes `lcdif` a sibling of `media_blk_ctrl` in the SoC bus, not a child. This is the right approach since the LCDIF has its own register space.

**Verdict:** Mostly looks good. The `assigned-clock-rates` length mismatch is a minor DT style issue. The compatible string usage in the common dtsi should be considered in light of i.MX91 support.

---
Generated by Claude Code Patch Reviewer

Claude review: Add i.MX91/93 parallel display support

[Claude Code Review Bot]

Overall Series Review

Subject: Add i.MX91/93 parallel display support
Author: Marco Felsch <m.felsch@pengutronix.de>
Patches: 10
Reviewed: 2026-03-04T07:36:19.412812

---

This v11 series adds i.MX91/93 parallel display format configuration (PDFC) support via a DRM bridge driver, dt-bindings, and device tree nodes. The series is well-structured and clean after 11 revisions of community review. The driver is simple and correct in concept — it programs the `PARALLEL_DISP_FORMAT` field in the MEDIAMIX BLK-CTRL `DISPLAY_MUX` register to select the output pixel format (RGB888, RGB666, or RGB565).

The code follows established IMX bridge driver patterns and uses modern APIs (`devm_drm_bridge_alloc`, `kmalloc_obj`). I found a few minor issues worth noting but nothing that should block merging.

---
Generated by Claude Code Patch Reviewer