[PATCH v3 0/2] Add support for Renesas RZ/G3L LVDS encoder

[PATCH v3 0/2] Add support for Renesas RZ/G3L LVDS encoder

[Biju]

From: Biju Das <biju.das.jz@bp.renesas.com>

Add support for the RZ/G3L LVDS encoder driver. It operates in single-link
mode with 4 lanes (Data) + 1 lane (Clock) and supports pixel clock rates
from 25 to 87 MHz. The LVDS module cannot be used at the same time as
MIPI-DSI. However, LVDS and the DSI interface share a peripheral clock and
the MIPI_DSI_PRESET_N reset signal. Also, the MIPI_DSI_CMN_RSTB and
MIPI_DSI_ARESET_N reset signals must be asserted before using the LVDS
module.

v2->v3:
 * Collected tags.
v2->v2[1]:
 * Dropped patch#1 as it is accepted.
 * Replace drm_atomic_state with drm_atomic_commit in
   rzg3l_lvds_atomic_{en,dis}able().
 * Drop local variable ret and dev_err() messages in
   rzg3l_lvds_atomic_enable(); use WARN_ON() instead to
   capture unexpected failures since atomic_enable should not fail.
 * Drop local variable next_bridge from rzg3l_lvds_probe().
[1] https://lore.kernel.org/all/20260524194457.479681-1-biju.das.jz@bp.renesas.com/
v1->v2:
 * Collected the tags for binding patches.
 * Dropped unused function rzg3l_lvds_is_connected() and removed the 
   corresponding header file rzg3l_lvds.h
 * Dropped next_bridge from struct rzg3l_lvds instead using bridge's
   next_bridge.
 * Replaced pm_runtime_resume_and_get()->pm_runtime_get_sync() as
   atomic_enable doesn't fail and for each enable there always will be an
   atomic_disable() call.
 * Started using DEFINE_RUNTIME_DEV_PM_OPS for PM callback.
 * Replaced rzg3l_lvds_parse_dt() with devm_drm_of_get_bridge() in probe()
 * Started using reset_control_bulk_*() in rzg3l_lvds_pm_runtime_{suspend,
   resume}().

Biju Das (2):
  dt-bindings: display: bridge: Document Renesas RZ/G3L LVDS encoder
  drm: renesas: rz-du: Add support for RZ/G3L LVDS encoder

 .../bridge/renesas,r9a08g046-lvds.yaml        | 128 ++++++++
 drivers/gpu/drm/renesas/rz-du/Kconfig         |  13 +
 drivers/gpu/drm/renesas/rz-du/Makefile        |   1 +
 drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c    | 277 ++++++++++++++++++
 .../gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h   |  26 ++
 5 files changed, 445 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/bridge/renesas,r9a08g046-lvds.yaml
 create mode 100644 drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c
 create mode 100644 drivers/gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h

-- 
2.43.0

[PATCH v3 1/2] dt-bindings: display: bridge: Document Renesas RZ/G3L LVDS encoder

[Biju]

From: Biju Das <biju.das.jz@bp.renesas.com>

Document the LVDS encoder IP found on the RZ/G3L SoC. It supports
single-link mode. LVDS and the DSI interface share a peripheral clock and
the MIPI_DSI_PRESET_N reset signal. However, the LVDS module cannot be
used at the same time as MIPI-DSI.

Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
v2->v3:
 * Collected tag.
v2->v2[1]:
 * No change.
[1] https://lore.kernel.org/all/20260524195829.960401F000E9@smtp.kernel.org/
v1->v2:
 * Collected tag.
---
 .../bridge/renesas,r9a08g046-lvds.yaml        | 128 ++++++++++++++++++
 1 file changed, 128 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/bridge/renesas,r9a08g046-lvds.yaml

diff --git a/Documentation/devicetree/bindings/display/bridge/renesas,r9a08g046-lvds.yaml b/Documentation/devicetree/bindings/display/bridge/renesas,r9a08g046-lvds.yaml
new file mode 100644
index 000000000000..b1f6d020ae7b
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/bridge/renesas,r9a08g046-lvds.yaml
@@ -0,0 +1,128 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/bridge/renesas,r9a08g046-lvds.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas RZ/G3L LVDS Encoder
+
+maintainers:
+  - Biju Das <biju.das.jz@bp.renesas.com>
+  - Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
+
+description: |
+  This binding describe the LVDS encoder embedded in the Renesas RZ/G3L
+  SoC. The encoder can operate in LVDS Single-link mode with 4 lanes
+  (Data) + 1 lane (Clock).
+
+properties:
+  compatible:
+    const: renesas,r9a08g046-lvds
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    items:
+      - description: Peripheral clock
+      - description: PHY clock
+      - description: Dot clock
+
+  clock-names:
+    items:
+      - const: pclk
+      - const: phyclk
+      - const: dotclk
+
+  resets:
+    items:
+      - description: LVDS_RESET_N
+      - description: MIPI_DSI_PRESET_N
+      - description: MIPI_DSI_CMN_RSTB
+      - description: MIPI_DSI_ARESET_N
+
+  reset-names:
+    items:
+      - const: lvdrst
+      - const: prst
+      - const: rst
+      - const: arst
+
+  power-domains:
+    maxItems: 1
+
+  ports:
+    $ref: /schemas/graph.yaml#/properties/ports
+
+    properties:
+      port@0:
+        $ref: /schemas/graph.yaml#/properties/port
+        description: Input channel, directly connected to the Display Unit.
+
+      port@1:
+        $ref: /schemas/graph.yaml#/properties/port
+        description: |
+          Output channel, directly connected to the LVDS panel or bridge.
+
+    required:
+      - port@0
+      - port@1
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - resets
+  - reset-names
+  - power-domains
+  - ports
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/renesas,r9a08g046-cpg.h>
+
+    lvds-cmn@108a0000 {
+        compatible = "renesas,r9a08g046-lvds-cmn",
+                     "simple-mfd", "syscon";
+        reg = <0x108a0000 0x10000>;
+        #address-cells = <1>;
+        #size-cells = <1>;
+
+        lvds0: lvds@10 {
+            compatible = "renesas,r9a08g046-lvds";
+            reg = <0x10 0x8>;
+            clocks = <&cpg CPG_MOD R9A08G046_MIPI_DSI_PCLK>,
+                     <&cpg CPG_MOD R9A08G046_LVDS_PLLCLK>,
+                     <&cpg CPG_MOD R9A08G046_LVDS_CLK_DOT0>;
+            clock-names = "pclk", "phyclk", "dotclk";
+            resets = <&cpg R9A08G046_LVDS_RESET_N>,
+                     <&cpg R9A08G046_MIPI_DSI_PRESET_N>,
+                     <&cpg R9A08G046_MIPI_DSI_CMN_RSTB>,
+                     <&cpg R9A08G046_MIPI_DSI_ARESET_N>;
+            reset-names = "lvdrst", "prst", "rst", "arst";
+            power-domains = <&cpg>;
+
+            ports {
+                #address-cells = <1>;
+                #size-cells = <0>;
+
+                port@0 {
+                    reg = <0>;
+                    lvds0_in: endpoint {
+                        remote-endpoint = <&du_out_lvds0>;
+                    };
+                };
+
+                port@1 {
+                    reg = <1>;
+                    lvds0_out: endpoint {
+                        remote-endpoint = <&panel_in>;
+                    };
+                };
+            };
+        };
+    };
+...
-- 
2.43.0

Claude review: dt-bindings: display: bridge: Document Renesas RZ/G3L LVDS encoder

[Claude Code Review Bot]

Patch Review

This patch looks correct. The binding is well-structured, with clear property descriptions and a complete example.

**Minor nit (description text):**
```yaml
description: |
  This binding describe the LVDS encoder embedded in the Renesas RZ/G3L
```
Grammatically should be "describes" (third person singular).

**No functional issues.** The binding correctly documents the 3 clocks, 4 resets, power domain, and port graph with input (port@0 from DU) and output (port@1 to panel/bridge). The example is complete and self-consistent.

---

---
Generated by Claude Code Patch Reviewer

[PATCH v3 2/2] drm: renesas: rz-du: Add support for RZ/G3L LVDS encoder

[Biju]

From: Biju Das <biju.das.jz@bp.renesas.com>

Add support for the RZ/G3L LVDS encoder driver. It operates in single-link
mode with 4 lanes (Data) + 1 lane (Clock) and supports pixel clock rates
from 25 to 87 MHz. The LVDS module cannot be used at the same time as
MIPI-DSI. However, LVDS and the DSI interface share a peripheral clock and
the MIPI_DSI_PRESET_N reset signal. Also, the MIPI_DSI_CMN_RSTB and
MIPI_DSI_ARESET_N reset signals must be asserted before using the LVDS
module.

Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Tested-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Reviewed-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
v2->v3:
 * Collected tags.
v2->v2[1]:
 * Replace drm_atomic_state with drm_atomic_commit in
   rzg3l_lvds_atomic_{en,dis}able().
 * Drop local variable ret and dev_err() messages in
   rzg3l_lvds_atomic_enable(); use WARN_ON() instead to
   capture unexpected failures since atomic_enable should not fail.
 * Drop local variable next_bridge from rzg3l_lvds_probe().
[1] https://lore.kernel.org/all/20260524194457.479681-3-biju.das.jz@bp.renesas.com/
v1->v2:
 * Dropped unused function rzg3l_lvds_is_connected() and removed the 
   corresponding header file rzg3l_lvds.h
 * Dropped next_bridge from struct rzg3l_lvds instead using bridge's
   next_bridge.
 * Replaced pm_runtime_resume_and_get()->pm_runtime_get_sync() as
   atomic_enable doesn't fail and for each enable there always will be an
   atomic_disable() call.
 * Started using DEFINE_RUNTIME_DEV_PM_OPS for PM callback.
 * Replaced rzg3l_lvds_parse_dt() with devm_drm_of_get_bridge() in probe()
 * Started using reset_control_bulk_*() in rzg3l_lvds_pm_runtime_{suspend,
   resume}()
---
 drivers/gpu/drm/renesas/rz-du/Kconfig         |  13 +
 drivers/gpu/drm/renesas/rz-du/Makefile        |   1 +
 drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c    | 277 ++++++++++++++++++
 .../gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h   |  26 ++
 4 files changed, 317 insertions(+)
 create mode 100644 drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c
 create mode 100644 drivers/gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h

diff --git a/drivers/gpu/drm/renesas/rz-du/Kconfig b/drivers/gpu/drm/renesas/rz-du/Kconfig
index 7f2ef7137ae5..cbfc7b6bccb8 100644
--- a/drivers/gpu/drm/renesas/rz-du/Kconfig
+++ b/drivers/gpu/drm/renesas/rz-du/Kconfig
@@ -26,3 +26,16 @@ config DRM_RZG2L_MIPI_DSI
 	def_tristate DRM_RZG2L_DU
 	depends on DRM_RZG2L_USE_MIPI_DSI
 	select DRM_MIPI_DSI
+
+config DRM_RZG3L_USE_LVDS
+	bool "RZ/G3L DU LVDS Encoder Support"
+	depends on DRM_BRIDGE && OF
+	default DRM_RZG2L_DU
+	help
+	  Enable support for the RZ/G3L Display Unit embedded LVDS encoders.
+
+config DRM_RZG3L_LVDS
+	def_tristate DRM_RZG2L_DU
+	depends on DRM_RZG3L_USE_LVDS
+	select DRM_KMS_HELPER
+	select DRM_PANEL
diff --git a/drivers/gpu/drm/renesas/rz-du/Makefile b/drivers/gpu/drm/renesas/rz-du/Makefile
index 2987900ea6b6..46decb7ac4f1 100644
--- a/drivers/gpu/drm/renesas/rz-du/Makefile
+++ b/drivers/gpu/drm/renesas/rz-du/Makefile
@@ -8,3 +8,4 @@ rzg2l-du-drm-$(CONFIG_VIDEO_RENESAS_VSP1)	+= rzg2l_du_vsp.o
 obj-$(CONFIG_DRM_RZG2L_DU)		+= rzg2l-du-drm.o
 
 obj-$(CONFIG_DRM_RZG2L_MIPI_DSI)	+= rzg2l_mipi_dsi.o
+obj-$(CONFIG_DRM_RZG3L_LVDS)		+= rzg3l_lvds.o
diff --git a/drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c b/drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c
new file mode 100644
index 000000000000..a51c3e5a2efe
--- /dev/null
+++ b/drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c
@@ -0,0 +1,277 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * RZ/G3L LVDS Encoder Driver
+ *
+ * Copyright (C) 2026 Renesas Electronics Corporation
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/media-bus-format.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_graph.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+
+#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>
+
+#include "rzg3l_lvds_regs.h"
+
+enum rzg3l_lvds_mode {
+	RZG3L_LVDS_MODE_JEIDA = 0,
+	RZG3L_LVDS_MODE_JEIDA_MIRROR = 1,
+	RZG3L_LVDS_MODE_MODE2 = 2,
+	RZG3L_LVDS_MODE_MODE2_MIRROR = 3,
+	RZG3L_LVDS_MODE_VESA = 4,
+	RZG3L_LVDS_MODE_VESA_MIRROR = 5,
+	RZG3L_LVDS_MODE_MODE6 = 6,
+	RZG3L_LVDS_MODE_MODE6_MIRROR = 7,
+};
+
+struct rzg3l_lvds {
+	struct device *dev;
+	struct reset_control *prstc;
+	struct reset_control *lvd_rstc;
+	struct regmap *regmap;
+	struct drm_bridge bridge;
+};
+
+#define bridge_to_rzg3l_lvds(b) \
+	container_of(b, struct rzg3l_lvds, bridge)
+
+/* -----------------------------------------------------------------------------
+ * Bridge
+ */
+
+static void rzg3l_lvds_atomic_enable(struct drm_bridge *bridge,
+				     struct drm_atomic_commit *state)
+{
+	struct rzg3l_lvds *lvds = bridge_to_rzg3l_lvds(bridge);
+	const struct drm_bridge_state *bridge_state;
+	u32 fmt;
+
+	/* Get the LVDS format from the bridge state. */
+	bridge_state = drm_atomic_get_new_bridge_state(state, bridge);
+	if (WARN_ON(!bridge_state))
+		return;
+
+	switch (bridge_state->output_bus_cfg.format) {
+	case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
+		fmt = RZG3L_LVDS_MODE_JEIDA;
+		break;
+	case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
+		fmt = RZG3L_LVDS_MODE_VESA;
+		break;
+	default:
+		fmt = RZG3L_LVDS_MODE_VESA;
+		dev_warn(lvds->dev, "Unsupported bus fmt 0x%04x\n",
+			 bridge_state->output_bus_cfg.format);
+		break;
+	}
+
+	if (WARN_ON(pm_runtime_get_sync(lvds->dev) < 0))
+		return;
+
+	regmap_update_bits(lvds->regmap, LVDS_0_PHY_OFFSET,
+			   LVDS_0_PHY_CH_EN_BGR, LVDS_0_PHY_CH_EN_BGR);
+	fsleep(20);
+
+	regmap_update_bits(lvds->regmap, LVDS_0_PHY_OFFSET,
+			   LVDS_0_PHY_CH_EN_LDO, LVDS_0_PHY_CH_EN_LDO);
+	fsleep(10);
+
+	regmap_write(lvds->regmap, LVDS_CMN, LVDS_CMN_RST_PHY0_SEL);
+	regmap_update_bits(lvds->regmap, LVDS_0_CTL_OFFSET,
+			   LVDS_0_CTL_FMT_SEL_MSK,
+			   FIELD_PREP(LVDS_0_CTL_FMT_SEL_MSK, fmt));
+	regmap_update_bits(lvds->regmap, LVDS_0_PHY_OFFSET,
+			   LVDS_0_PHY_CH_IO_EN_MSK, LVDS_0_PHY_CH_IO_EN);
+	regmap_write(lvds->regmap, LVDS_CMN,
+		     LVDS_CMN_RST_PHY0_SEL | LVDS_CMN_PHY_RESET);
+	fsleep(100);
+}
+
+static void rzg3l_lvds_atomic_disable(struct drm_bridge *bridge,
+				      struct drm_atomic_commit *state)
+{
+	struct rzg3l_lvds *lvds = bridge_to_rzg3l_lvds(bridge);
+
+	regmap_update_bits(lvds->regmap, LVDS_CMN, LVDS_CMN_PHY_RESET, 0);
+	regmap_update_bits(lvds->regmap, LVDS_0_PHY_OFFSET,
+			   LVDS_0_PHY_CH_IO_EN_MSK, 0);
+	regmap_update_bits(lvds->regmap, LVDS_0_PHY_OFFSET,
+			   LVDS_0_PHY_CH_EN_LDO, 0);
+	regmap_update_bits(lvds->regmap, LVDS_0_PHY_OFFSET,
+			   LVDS_0_PHY_CH_EN_BGR, 0);
+
+	pm_runtime_put(lvds->dev);
+}
+
+static int rzg3l_lvds_attach(struct drm_bridge *bridge,
+			     struct drm_encoder *encoder,
+			     enum drm_bridge_attach_flags flags)
+{
+	struct rzg3l_lvds *lvds = bridge_to_rzg3l_lvds(bridge);
+
+	if (!lvds->bridge.next_bridge)
+		return 0;
+
+	return drm_bridge_attach(encoder, lvds->bridge.next_bridge, bridge, flags);
+}
+
+static enum drm_mode_status
+rzg3l_lvds_bridge_mode_valid(struct drm_bridge *bridge,
+			     const struct drm_display_info *info,
+			     const struct drm_display_mode *mode)
+{
+	if (mode->clock > 87000)
+		return MODE_CLOCK_HIGH;
+
+	if (mode->clock < 25000)
+		return MODE_CLOCK_LOW;
+
+	return MODE_OK;
+}
+
+static const struct drm_bridge_funcs rzg3l_lvds_bridge_ops = {
+	.attach = rzg3l_lvds_attach,
+	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
+	.atomic_reset = drm_atomic_helper_bridge_reset,
+	.atomic_enable = rzg3l_lvds_atomic_enable,
+	.atomic_disable = rzg3l_lvds_atomic_disable,
+	.mode_valid = rzg3l_lvds_bridge_mode_valid,
+};
+
+/* -----------------------------------------------------------------------------
+ * Power Management
+ */
+
+static int rzg3l_lvds_pm_runtime_suspend(struct device *dev)
+{
+	struct rzg3l_lvds *lvds = dev_get_drvdata(dev);
+	struct reset_control_bulk_data resets[] = {
+		{ .rstc = lvds->lvd_rstc },
+		{ .rstc = lvds->prstc },
+	};
+
+	return reset_control_bulk_assert(ARRAY_SIZE(resets), resets);
+}
+
+static int rzg3l_lvds_pm_runtime_resume(struct device *dev)
+{
+	struct rzg3l_lvds *lvds = dev_get_drvdata(dev);
+	struct reset_control_bulk_data resets[] = {
+		{ .rstc = lvds->lvd_rstc },
+		{ .rstc = lvds->prstc },
+	};
+
+	return reset_control_bulk_deassert(ARRAY_SIZE(resets), resets);
+}
+
+static DEFINE_RUNTIME_DEV_PM_OPS(rzg3l_lvds_pm_ops,
+				 rzg3l_lvds_pm_runtime_suspend,
+				 rzg3l_lvds_pm_runtime_resume, NULL);
+
+/* -----------------------------------------------------------------------------
+ * Probe & Remove
+ */
+
+static int rzg3l_lvds_probe(struct platform_device *pdev)
+{
+	struct reset_control *rstc, *arstc;
+	struct device *dev = &pdev->dev;
+	struct rzg3l_lvds *lvds;
+	int ret;
+
+	lvds = devm_drm_bridge_alloc(dev, struct rzg3l_lvds, bridge,
+				     &rzg3l_lvds_bridge_ops);
+	if (IS_ERR(lvds))
+		return PTR_ERR(lvds);
+
+	lvds->dev = dev;
+	lvds->bridge.of_node = pdev->dev.of_node;
+
+	lvds->regmap = syscon_node_to_regmap(dev->of_node->parent);
+	if (IS_ERR(lvds->regmap))
+		return PTR_ERR(lvds->regmap);
+
+	rstc = devm_reset_control_get_optional_exclusive(dev, "rst");
+	if (IS_ERR(rstc))
+		return dev_err_probe(dev, PTR_ERR(rstc), "failed to get rst\n");
+
+	arstc = devm_reset_control_get_optional_exclusive(dev, "arst");
+	if (IS_ERR(arstc))
+		return dev_err_probe(dev, PTR_ERR(arstc),
+				     "failed to get arst\n");
+
+	lvds->prstc = devm_reset_control_get_shared(dev, "prst");
+	if (IS_ERR(lvds->prstc))
+		return dev_err_probe(dev, PTR_ERR(lvds->prstc),
+				     "failed to get prst\n");
+
+	lvds->lvd_rstc = devm_reset_control_get_shared(dev, "lvdrst");
+	if (IS_ERR(lvds->lvd_rstc))
+		return dev_err_probe(dev, PTR_ERR(lvds->lvd_rstc),
+				     "failed to get core reset\n");
+
+	platform_set_drvdata(pdev, lvds);
+	ret = devm_pm_runtime_enable(dev);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to enable Runtime PM\n");
+
+	lvds->bridge.next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 1, 0);
+	if (IS_ERR(lvds->bridge.next_bridge))
+		return dev_err_probe(dev, PTR_ERR(lvds->bridge.next_bridge),
+				     "failed to get next bridge\n");
+
+	ret = reset_control_assert(rstc);
+	if (ret < 0)
+		return ret;
+
+	ret = reset_control_assert(arstc);
+	if (ret < 0)
+		return ret;
+
+	ret = devm_drm_bridge_add(dev, &lvds->bridge);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Failed to register drm bridge\n");
+
+	return ret;
+}
+
+static const struct of_device_id rzg3l_lvds_of_table[] = {
+	{ .compatible = "renesas,r9a08g046-lvds" },
+	{ /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, rzg3l_lvds_of_table);
+
+static struct platform_driver rzg3l_lvds_platform_driver = {
+	.probe		= rzg3l_lvds_probe,
+	.driver		= {
+		.name	= "rzg3l-lvds",
+		.pm	= pm_ptr(&rzg3l_lvds_pm_ops),
+		.of_match_table = rzg3l_lvds_of_table,
+	},
+};
+
+module_platform_driver(rzg3l_lvds_platform_driver);
+
+MODULE_AUTHOR("Biju Das <biju.das.jz@bp.renesas.com>");
+MODULE_AUTHOR("Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>");
+MODULE_DESCRIPTION("Renesas RZ/G3L LVDS Encoder Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h b/drivers/gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h
new file mode 100644
index 000000000000..281b7648f168
--- /dev/null
+++ b/drivers/gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * RZ/G3L LVDS Interface Registers Definitions
+ *
+ * Copyright (C) 2026 Renesas Electronics Corporation
+ *
+ */
+
+#ifndef __RZG3L_LVDS_REGS_H__
+#define __RZG3L_LVDS_REGS_H__
+
+#define LVDS_CMN			0x00
+#define LVDS_CMN_RST_PHY0_SEL		(1 << 24)
+#define LVDS_CMN_RST_PHY0_SEL_CH0	(1 << 24)
+#define LVDS_CMN_PHY_RESET		(1 << 0)
+
+#define LVDS_0_PHY_OFFSET		0x10
+#define LVDS_0_PHY_CH_IO_EN_MSK		(0x1f)
+#define LVDS_0_PHY_CH_IO_EN		(LVDS_0_PHY_CH_IO_EN_MSK << 0)
+#define LVDS_0_PHY_CH_EN_BGR		BIT(8)
+#define LVDS_0_PHY_CH_EN_LDO		BIT(9)
+
+#define LVDS_0_CTL_OFFSET		0x14
+#define LVDS_0_CTL_FMT_SEL_MSK		GENMASK(23, 20)
+
+#endif /* __RZG3L_LVDS_REGS_H__ */
-- 
2.43.0

Claude review: drm: renesas: rz-du: Add support for RZ/G3L LVDS encoder

[Claude Code Review Bot]

Patch Review

Overall a solid driver. A few items to flag:

**1. Potential refcount issue with `bridge.next_bridge` assignment (medium concern):**

```c
lvds->bridge.next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 1, 0);
```

The `next_bridge` field is documented as "automatically put when this bridge is freed" — i.e., `drm_bridge_put()` is called on it at destroy time. However, `devm_drm_of_get_bridge()` returns either a devm-managed panel bridge (refcount 1, also devm-cleaned) or an unrefcounted bridge pointer from `of_drm_find_bridge()`. Storing it directly into `next_bridge` without calling `drm_bridge_get()` risks a refcount mismatch — the auto-put at bridge destruction would underflow.

All existing in-tree drivers that store into `bridge.next_bridge` use `of_drm_find_and_get_bridge()`, `of_drm_get_bridge_by_endpoint()`, or `drm_bridge_get()` — functions that increment the refcount. Drivers that use `devm_drm_of_get_bridge()` store the result in a private struct field instead (like `rzg2l_mipi_dsi.c` does with `dsi->next_bridge`).

Consider either storing in a private `lvds->next_bridge` field (matching the pattern in `rzg2l_mipi_dsi.c`), or using `of_drm_get_bridge_by_endpoint()` with a `drm_bridge_get()` for the `bridge.next_bridge` assignment.

**2. Unnecessary include:**

```c
#include <linux/of_device.h>
```

This header is not needed — the driver doesn't use any `of_device_*` functions. The sibling `rzg2l_mipi_dsi.c` driver only includes `<linux/of.h>` and `<linux/of_graph.h>`. This include can be dropped.

**3. Register header: inconsistent bit-field style (`rzg3l_lvds_regs.h`):**

The header mixes `(1 << N)` with `BIT()`:

```c
#define LVDS_CMN_RST_PHY0_SEL		(1 << 24)
#define LVDS_CMN_RST_PHY0_SEL_CH0	(1 << 24)
#define LVDS_CMN_PHY_RESET		(1 << 0)
...
#define LVDS_0_PHY_CH_EN_BGR		BIT(8)
#define LVDS_0_PHY_CH_EN_LDO		BIT(9)
```

Prefer `BIT()` throughout for consistency with kernel style.

**4. Register header: redundant definitions:**

`LVDS_CMN_RST_PHY0_SEL` and `LVDS_CMN_RST_PHY0_SEL_CH0` are both defined as `(1 << 24)` — they are identical. Only `LVDS_CMN_RST_PHY0_SEL` is used in the driver; `LVDS_CMN_RST_PHY0_SEL_CH0` is dead code.

Similarly, `LVDS_0_PHY_CH_IO_EN` is defined as `(LVDS_0_PHY_CH_IO_EN_MSK << 0)` which equals `LVDS_0_PHY_CH_IO_EN_MSK` — the `<< 0` is a no-op and the two defines have the same value. This is confusing since one is used as a mask and the other as a value, but they're identical. Consider clarifying the intent or consolidating.

**5. Kconfig: `select DRM_PANEL` and `select DRM_KMS_HELPER`:**

```
config DRM_RZG3L_LVDS
	def_tristate DRM_RZG2L_DU
	depends on DRM_RZG3L_USE_LVDS
	select DRM_KMS_HELPER
	select DRM_PANEL
```

`DRM_KMS_HELPER` is already selected by `DRM_RZG2L_DU` (through `DRM_GEM_DMA_HELPER` dependencies). And `DRM_PANEL` — verify this is actually needed. The driver doesn't directly use `drm_panel_*` APIs; it uses `devm_drm_of_get_bridge()` which internally handles panels via panel-bridge. The `DRM_PANEL` select may be needed transitively for `devm_drm_of_get_bridge()` to find panels, but it would be worth confirming.

**6. Minor: `return ret` at end of probe:**

```c
ret = devm_drm_bridge_add(dev, &lvds->bridge);
if (ret)
    return dev_err_probe(dev, ret,
                 "Failed to register drm bridge\n");

return ret;
```

Since the error is already handled, `return ret` here is always `return 0`. Could be simplified to `return 0` for clarity, though functionally identical.

**7. The `attach` callback accesses `next_bridge` through the bridge struct:**

```c
static int rzg3l_lvds_attach(struct drm_bridge *bridge,
                 struct drm_encoder *encoder,
                 enum drm_bridge_attach_flags flags)
{
    struct rzg3l_lvds *lvds = bridge_to_rzg3l_lvds(bridge);

    if (!lvds->bridge.next_bridge)
        return 0;

    return drm_bridge_attach(encoder, lvds->bridge.next_bridge, bridge, flags);
}
```

This is correct for the `bridge.next_bridge` approach, but note that returning 0 when there's no next bridge means the encoder pipeline would be incomplete (no connector). This only works if the bridge connector infrastructure handles it. If you switch to a private `next_bridge` field per item 1 above, this would need adjustment too.

**No issues with:**
- The `drm_atomic_commit` type usage (matches current in-tree bridge callback signatures)
- The `pm_runtime_get_sync` + `WARN_ON` pattern (appropriate for atomic enable which shouldn't fail)
- The reset handling (optional `rst`/`arst` asserted-and-left, shared `prst`/`lvdrst` toggled via PM runtime)
- The `devm_drm_bridge_alloc` usage (correct modern API)
- The mode_valid clock range checking (25-87 MHz matching the binding description)

---
Generated by Claude Code Patch Reviewer

Claude review: Add support for Renesas RZ/G3L LVDS encoder

[Claude Code Review Bot]

Overall Series Review

Subject: Add support for Renesas RZ/G3L LVDS encoder
Author: Biju <biju.das.au@gmail.com>
Patches: 3
Reviewed: 2026-05-27T15:11:40.495706

---

This is a clean, well-structured 2-patch series adding LVDS encoder support for the Renesas RZ/G3L SoC. The driver follows established patterns from the existing `rzg2l_mipi_dsi.c` driver in the same directory and uses modern DRM bridge APIs (`devm_drm_bridge_alloc`, `devm_drm_bridge_add`). The DT binding is straightforward and already has Acked-by from a DT maintainer.

The series is in good shape overall for v3. There are a few minor issues worth flagging — one potential refcount concern with storing `devm_drm_of_get_bridge()` result directly into `bridge.next_bridge`, an unnecessary include, and some register header cleanup opportunities — but nothing that blocks merging.

---

---
Generated by Claude Code Patch Reviewer

[PATCH v2 0/2] Add support for Renesas RZ/G3L LVDS encoder

[Biju]

From: Biju Das <biju.das.jz@bp.renesas.com>

Add support for the RZ/G3L LVDS encoder driver. It operates in single-link
mode with 4 lanes (Data) + 1 lane (Clock) and supports pixel clock rates
from 25 to 87 MHz. The LVDS module cannot be used at the same time as
MIPI-DSI. However, LVDS and the DSI interface share a peripheral clock and
the MIPI_DSI_PRESET_N reset signal. Also, the MIPI_DSI_CMN_RSTB and
MIPI_DSI_ARESET_N reset signals must be asserted before using the LVDS
module.

v2->v3:
 * Dropped patch#1 as it is accepted.
 * Replace drm_atomic_state with drm_atomic_commit in
   rzg3l_lvds_atomic_{en,dis}able().
 * Drop local variable ret and dev_err() messages in
   rzg3l_lvds_atomic_enable(); use WARN_ON() instead to
   capture unexpected failures since atomic_enable should not fail.
 * Drop local variable next_bridge from rzg3l_lvds_probe().
v1->v2:
 * Collected the tags for binding patches.
 * Dropped unused function rzg3l_lvds_is_connected() and removed the 
   corresponding header file rzg3l_lvds.h
 * Dropped next_bridge from struct rzg3l_lvds instead using bridge's
   next_bridge.
 * Replaced pm_runtime_resume_and_get()->pm_runtime_get_sync() as
   atomic_enable doesn't fail and for each enable there always will be an
   atomic_disable() call.
 * Started using DEFINE_RUNTIME_DEV_PM_OPS for PM callback.
 * Replaced rzg3l_lvds_parse_dt() with devm_drm_of_get_bridge() in probe()
 * Started using reset_control_bulk_*() in rzg3l_lvds_pm_runtime_{suspend,
   resume}().

Biju Das (2):
  dt-bindings: display: bridge: Document Renesas RZ/G3L LVDS encoder
  drm: renesas: rz-du: Add support for RZ/G3L LVDS encoder

 .../bridge/renesas,r9a08g046-lvds.yaml        | 128 ++++++++
 drivers/gpu/drm/renesas/rz-du/Kconfig         |  13 +
 drivers/gpu/drm/renesas/rz-du/Makefile        |   1 +
 drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c    | 277 ++++++++++++++++++
 .../gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h   |  26 ++
 5 files changed, 445 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/bridge/renesas,r9a08g046-lvds.yaml
 create mode 100644 drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c
 create mode 100644 drivers/gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h

-- 
2.43.0

[PATCH v2 2/2] drm: renesas: rz-du: Add support for RZ/G3L LVDS encoder

[Biju]

From: Biju Das <biju.das.jz@bp.renesas.com>

Add support for the RZ/G3L LVDS encoder driver. It operates in single-link
mode with 4 lanes (Data) + 1 lane (Clock) and supports pixel clock rates
from 25 to 87 MHz. The LVDS module cannot be used at the same time as
MIPI-DSI. However, LVDS and the DSI interface share a peripheral clock and
the MIPI_DSI_PRESET_N reset signal. Also, the MIPI_DSI_CMN_RSTB and
MIPI_DSI_ARESET_N reset signals must be asserted before using the LVDS
module.

Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
v2->v3:
 * Replace drm_atomic_state with drm_atomic_commit in
   rzg3l_lvds_atomic_{en,dis}able().
 * Drop local variable ret and dev_err() messages in
   rzg3l_lvds_atomic_enable(); use WARN_ON() instead to
   capture unexpected failures since atomic_enable should not fail.
 * Drop local variable next_bridge from rzg3l_lvds_probe().
v1->v2:
 * Dropped unused function rzg3l_lvds_is_connected() and removed the 
   corresponding header file rzg3l_lvds.h
 * Dropped next_bridge from struct rzg3l_lvds instead using bridge's
   next_bridge.
 * Replaced pm_runtime_resume_and_get()->pm_runtime_get_sync() as
   atomic_enable doesn't fail and for each enable there always will be an
   atomic_disable() call.
 * Started using DEFINE_RUNTIME_DEV_PM_OPS for PM callback.
 * Replaced rzg3l_lvds_parse_dt() with devm_drm_of_get_bridge() in probe()
 * Started using reset_control_bulk_*() in rzg3l_lvds_pm_runtime_{suspend,
   resume}()
---
 drivers/gpu/drm/renesas/rz-du/Kconfig         |  13 +
 drivers/gpu/drm/renesas/rz-du/Makefile        |   1 +
 drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c    | 277 ++++++++++++++++++
 .../gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h   |  26 ++
 4 files changed, 317 insertions(+)
 create mode 100644 drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c
 create mode 100644 drivers/gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h

diff --git a/drivers/gpu/drm/renesas/rz-du/Kconfig b/drivers/gpu/drm/renesas/rz-du/Kconfig
index 7f2ef7137ae5..cbfc7b6bccb8 100644
--- a/drivers/gpu/drm/renesas/rz-du/Kconfig
+++ b/drivers/gpu/drm/renesas/rz-du/Kconfig
@@ -26,3 +26,16 @@ config DRM_RZG2L_MIPI_DSI
 	def_tristate DRM_RZG2L_DU
 	depends on DRM_RZG2L_USE_MIPI_DSI
 	select DRM_MIPI_DSI
+
+config DRM_RZG3L_USE_LVDS
+	bool "RZ/G3L DU LVDS Encoder Support"
+	depends on DRM_BRIDGE && OF
+	default DRM_RZG2L_DU
+	help
+	  Enable support for the RZ/G3L Display Unit embedded LVDS encoders.
+
+config DRM_RZG3L_LVDS
+	def_tristate DRM_RZG2L_DU
+	depends on DRM_RZG3L_USE_LVDS
+	select DRM_KMS_HELPER
+	select DRM_PANEL
diff --git a/drivers/gpu/drm/renesas/rz-du/Makefile b/drivers/gpu/drm/renesas/rz-du/Makefile
index 2987900ea6b6..46decb7ac4f1 100644
--- a/drivers/gpu/drm/renesas/rz-du/Makefile
+++ b/drivers/gpu/drm/renesas/rz-du/Makefile
@@ -8,3 +8,4 @@ rzg2l-du-drm-$(CONFIG_VIDEO_RENESAS_VSP1)	+= rzg2l_du_vsp.o
 obj-$(CONFIG_DRM_RZG2L_DU)		+= rzg2l-du-drm.o
 
 obj-$(CONFIG_DRM_RZG2L_MIPI_DSI)	+= rzg2l_mipi_dsi.o
+obj-$(CONFIG_DRM_RZG3L_LVDS)		+= rzg3l_lvds.o
diff --git a/drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c b/drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c
new file mode 100644
index 000000000000..a51c3e5a2efe
--- /dev/null
+++ b/drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c
@@ -0,0 +1,277 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * RZ/G3L LVDS Encoder Driver
+ *
+ * Copyright (C) 2026 Renesas Electronics Corporation
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/media-bus-format.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_graph.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+
+#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>
+
+#include "rzg3l_lvds_regs.h"
+
+enum rzg3l_lvds_mode {
+	RZG3L_LVDS_MODE_JEIDA = 0,
+	RZG3L_LVDS_MODE_JEIDA_MIRROR = 1,
+	RZG3L_LVDS_MODE_MODE2 = 2,
+	RZG3L_LVDS_MODE_MODE2_MIRROR = 3,
+	RZG3L_LVDS_MODE_VESA = 4,
+	RZG3L_LVDS_MODE_VESA_MIRROR = 5,
+	RZG3L_LVDS_MODE_MODE6 = 6,
+	RZG3L_LVDS_MODE_MODE6_MIRROR = 7,
+};
+
+struct rzg3l_lvds {
+	struct device *dev;
+	struct reset_control *prstc;
+	struct reset_control *lvd_rstc;
+	struct regmap *regmap;
+	struct drm_bridge bridge;
+};
+
+#define bridge_to_rzg3l_lvds(b) \
+	container_of(b, struct rzg3l_lvds, bridge)
+
+/* -----------------------------------------------------------------------------
+ * Bridge
+ */
+
+static void rzg3l_lvds_atomic_enable(struct drm_bridge *bridge,
+				     struct drm_atomic_commit *state)
+{
+	struct rzg3l_lvds *lvds = bridge_to_rzg3l_lvds(bridge);
+	const struct drm_bridge_state *bridge_state;
+	u32 fmt;
+
+	/* Get the LVDS format from the bridge state. */
+	bridge_state = drm_atomic_get_new_bridge_state(state, bridge);
+	if (WARN_ON(!bridge_state))
+		return;
+
+	switch (bridge_state->output_bus_cfg.format) {
+	case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
+		fmt = RZG3L_LVDS_MODE_JEIDA;
+		break;
+	case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
+		fmt = RZG3L_LVDS_MODE_VESA;
+		break;
+	default:
+		fmt = RZG3L_LVDS_MODE_VESA;
+		dev_warn(lvds->dev, "Unsupported bus fmt 0x%04x\n",
+			 bridge_state->output_bus_cfg.format);
+		break;
+	}
+
+	if (WARN_ON(pm_runtime_get_sync(lvds->dev) < 0))
+		return;
+
+	regmap_update_bits(lvds->regmap, LVDS_0_PHY_OFFSET,
+			   LVDS_0_PHY_CH_EN_BGR, LVDS_0_PHY_CH_EN_BGR);
+	fsleep(20);
+
+	regmap_update_bits(lvds->regmap, LVDS_0_PHY_OFFSET,
+			   LVDS_0_PHY_CH_EN_LDO, LVDS_0_PHY_CH_EN_LDO);
+	fsleep(10);
+
+	regmap_write(lvds->regmap, LVDS_CMN, LVDS_CMN_RST_PHY0_SEL);
+	regmap_update_bits(lvds->regmap, LVDS_0_CTL_OFFSET,
+			   LVDS_0_CTL_FMT_SEL_MSK,
+			   FIELD_PREP(LVDS_0_CTL_FMT_SEL_MSK, fmt));
+	regmap_update_bits(lvds->regmap, LVDS_0_PHY_OFFSET,
+			   LVDS_0_PHY_CH_IO_EN_MSK, LVDS_0_PHY_CH_IO_EN);
+	regmap_write(lvds->regmap, LVDS_CMN,
+		     LVDS_CMN_RST_PHY0_SEL | LVDS_CMN_PHY_RESET);
+	fsleep(100);
+}
+
+static void rzg3l_lvds_atomic_disable(struct drm_bridge *bridge,
+				      struct drm_atomic_commit *state)
+{
+	struct rzg3l_lvds *lvds = bridge_to_rzg3l_lvds(bridge);
+
+	regmap_update_bits(lvds->regmap, LVDS_CMN, LVDS_CMN_PHY_RESET, 0);
+	regmap_update_bits(lvds->regmap, LVDS_0_PHY_OFFSET,
+			   LVDS_0_PHY_CH_IO_EN_MSK, 0);
+	regmap_update_bits(lvds->regmap, LVDS_0_PHY_OFFSET,
+			   LVDS_0_PHY_CH_EN_LDO, 0);
+	regmap_update_bits(lvds->regmap, LVDS_0_PHY_OFFSET,
+			   LVDS_0_PHY_CH_EN_BGR, 0);
+
+	pm_runtime_put(lvds->dev);
+}
+
+static int rzg3l_lvds_attach(struct drm_bridge *bridge,
+			     struct drm_encoder *encoder,
+			     enum drm_bridge_attach_flags flags)
+{
+	struct rzg3l_lvds *lvds = bridge_to_rzg3l_lvds(bridge);
+
+	if (!lvds->bridge.next_bridge)
+		return 0;
+
+	return drm_bridge_attach(encoder, lvds->bridge.next_bridge, bridge, flags);
+}
+
+static enum drm_mode_status
+rzg3l_lvds_bridge_mode_valid(struct drm_bridge *bridge,
+			     const struct drm_display_info *info,
+			     const struct drm_display_mode *mode)
+{
+	if (mode->clock > 87000)
+		return MODE_CLOCK_HIGH;
+
+	if (mode->clock < 25000)
+		return MODE_CLOCK_LOW;
+
+	return MODE_OK;
+}
+
+static const struct drm_bridge_funcs rzg3l_lvds_bridge_ops = {
+	.attach = rzg3l_lvds_attach,
+	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
+	.atomic_reset = drm_atomic_helper_bridge_reset,
+	.atomic_enable = rzg3l_lvds_atomic_enable,
+	.atomic_disable = rzg3l_lvds_atomic_disable,
+	.mode_valid = rzg3l_lvds_bridge_mode_valid,
+};
+
+/* -----------------------------------------------------------------------------
+ * Power Management
+ */
+
+static int rzg3l_lvds_pm_runtime_suspend(struct device *dev)
+{
+	struct rzg3l_lvds *lvds = dev_get_drvdata(dev);
+	struct reset_control_bulk_data resets[] = {
+		{ .rstc = lvds->lvd_rstc },
+		{ .rstc = lvds->prstc },
+	};
+
+	return reset_control_bulk_assert(ARRAY_SIZE(resets), resets);
+}
+
+static int rzg3l_lvds_pm_runtime_resume(struct device *dev)
+{
+	struct rzg3l_lvds *lvds = dev_get_drvdata(dev);
+	struct reset_control_bulk_data resets[] = {
+		{ .rstc = lvds->lvd_rstc },
+		{ .rstc = lvds->prstc },
+	};
+
+	return reset_control_bulk_deassert(ARRAY_SIZE(resets), resets);
+}
+
+static DEFINE_RUNTIME_DEV_PM_OPS(rzg3l_lvds_pm_ops,
+				 rzg3l_lvds_pm_runtime_suspend,
+				 rzg3l_lvds_pm_runtime_resume, NULL);
+
+/* -----------------------------------------------------------------------------
+ * Probe & Remove
+ */
+
+static int rzg3l_lvds_probe(struct platform_device *pdev)
+{
+	struct reset_control *rstc, *arstc;
+	struct device *dev = &pdev->dev;
+	struct rzg3l_lvds *lvds;
+	int ret;
+
+	lvds = devm_drm_bridge_alloc(dev, struct rzg3l_lvds, bridge,
+				     &rzg3l_lvds_bridge_ops);
+	if (IS_ERR(lvds))
+		return PTR_ERR(lvds);
+
+	lvds->dev = dev;
+	lvds->bridge.of_node = pdev->dev.of_node;
+
+	lvds->regmap = syscon_node_to_regmap(dev->of_node->parent);
+	if (IS_ERR(lvds->regmap))
+		return PTR_ERR(lvds->regmap);
+
+	rstc = devm_reset_control_get_optional_exclusive(dev, "rst");
+	if (IS_ERR(rstc))
+		return dev_err_probe(dev, PTR_ERR(rstc), "failed to get rst\n");
+
+	arstc = devm_reset_control_get_optional_exclusive(dev, "arst");
+	if (IS_ERR(arstc))
+		return dev_err_probe(dev, PTR_ERR(arstc),
+				     "failed to get arst\n");
+
+	lvds->prstc = devm_reset_control_get_shared(dev, "prst");
+	if (IS_ERR(lvds->prstc))
+		return dev_err_probe(dev, PTR_ERR(lvds->prstc),
+				     "failed to get prst\n");
+
+	lvds->lvd_rstc = devm_reset_control_get_shared(dev, "lvdrst");
+	if (IS_ERR(lvds->lvd_rstc))
+		return dev_err_probe(dev, PTR_ERR(lvds->lvd_rstc),
+				     "failed to get core reset\n");
+
+	platform_set_drvdata(pdev, lvds);
+	ret = devm_pm_runtime_enable(dev);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to enable Runtime PM\n");
+
+	lvds->bridge.next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 1, 0);
+	if (IS_ERR(lvds->bridge.next_bridge))
+		return dev_err_probe(dev, PTR_ERR(lvds->bridge.next_bridge),
+				     "failed to get next bridge\n");
+
+	ret = reset_control_assert(rstc);
+	if (ret < 0)
+		return ret;
+
+	ret = reset_control_assert(arstc);
+	if (ret < 0)
+		return ret;
+
+	ret = devm_drm_bridge_add(dev, &lvds->bridge);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Failed to register drm bridge\n");
+
+	return ret;
+}
+
+static const struct of_device_id rzg3l_lvds_of_table[] = {
+	{ .compatible = "renesas,r9a08g046-lvds" },
+	{ /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, rzg3l_lvds_of_table);
+
+static struct platform_driver rzg3l_lvds_platform_driver = {
+	.probe		= rzg3l_lvds_probe,
+	.driver		= {
+		.name	= "rzg3l-lvds",
+		.pm	= pm_ptr(&rzg3l_lvds_pm_ops),
+		.of_match_table = rzg3l_lvds_of_table,
+	},
+};
+
+module_platform_driver(rzg3l_lvds_platform_driver);
+
+MODULE_AUTHOR("Biju Das <biju.das.jz@bp.renesas.com>");
+MODULE_AUTHOR("Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>");
+MODULE_DESCRIPTION("Renesas RZ/G3L LVDS Encoder Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h b/drivers/gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h
new file mode 100644
index 000000000000..281b7648f168
--- /dev/null
+++ b/drivers/gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * RZ/G3L LVDS Interface Registers Definitions
+ *
+ * Copyright (C) 2026 Renesas Electronics Corporation
+ *
+ */
+
+#ifndef __RZG3L_LVDS_REGS_H__
+#define __RZG3L_LVDS_REGS_H__
+
+#define LVDS_CMN			0x00
+#define LVDS_CMN_RST_PHY0_SEL		(1 << 24)
+#define LVDS_CMN_RST_PHY0_SEL_CH0	(1 << 24)
+#define LVDS_CMN_PHY_RESET		(1 << 0)
+
+#define LVDS_0_PHY_OFFSET		0x10
+#define LVDS_0_PHY_CH_IO_EN_MSK		(0x1f)
+#define LVDS_0_PHY_CH_IO_EN		(LVDS_0_PHY_CH_IO_EN_MSK << 0)
+#define LVDS_0_PHY_CH_EN_BGR		BIT(8)
+#define LVDS_0_PHY_CH_EN_LDO		BIT(9)
+
+#define LVDS_0_CTL_OFFSET		0x14
+#define LVDS_0_CTL_FMT_SEL_MSK		GENMASK(23, 20)
+
+#endif /* __RZG3L_LVDS_REGS_H__ */
-- 
2.43.0

Claude review: drm: renesas: rz-du: Add support for RZ/G3L LVDS encoder

[Claude Code Review Bot]

Patch Review

**Issues:**

**(1) `rst` and `arst` reset controls are fire-and-forget (medium severity)**

In `rzg3l_lvds_probe()`, the `rstc` and `arstc` resets are acquired, asserted, and then the local variables go out of scope. They are never stored in `struct rzg3l_lvds`, so they can never be deasserted:

```c
struct reset_control *rstc, *arstc;
...
rstc = devm_reset_control_get_optional_exclusive(dev, "rst");
...
arstc = devm_reset_control_get_optional_exclusive(dev, "arst");
...
ret = reset_control_assert(rstc);
...
ret = reset_control_assert(arstc);
```

Per the cover letter, these resets "must be asserted before using the LVDS module" and should stay asserted. If this is intentional (assert once, never deassert), it works because `devm_*` will release the reset control on driver remove, but a comment would clarify the intent. Additionally, using `_exclusive` reset controls that are only asserted and never deasserted is unusual — if they truly must stay asserted for the lifetime of the device, consider whether `_shared` would be more appropriate if the DSI driver also needs to manipulate them.

**(2) `pm_runtime_get_sync` error path leaks PM refcount (medium severity)**

In `rzg3l_lvds_atomic_enable()`:

```c
if (WARN_ON(pm_runtime_get_sync(lvds->dev) < 0))
    return;
```

`pm_runtime_get_sync()` increments the reference count even on failure. On error, you must call `pm_runtime_put_noidle()` or `pm_runtime_put()` to avoid a PM refcount leak. The matching `pm_runtime_put()` in `rzg3l_lvds_atomic_disable()` will never be called if enable bailed out. Consider:
```c
if (WARN_ON(pm_runtime_get_sync(lvds->dev) < 0)) {
    pm_runtime_put_noidle(lvds->dev);
    return;
}
```
Or alternatively, use `pm_runtime_resume_and_get()` which doesn't increment the refcount on failure.

**(3) Unused includes (minor)**

Several headers appear unnecessary:
- `linux/of_device.h` — nothing from this header is used (no `of_device_get_match_data()` etc.)
- `linux/of_graph.h` — no `of_graph_*` functions are called
- `linux/bitfield.h` — wait, `FIELD_PREP` is used, so this one is needed
- `linux/mfd/syscon.h` — `syscon_node_to_regmap()` is used, so needed
- `linux/regmap.h` — `regmap_*` functions used, needed
- `linux/media-bus-format.h` — `MEDIA_BUS_FMT_*` used, needed
- `drm/drm_panel.h` — no panel functions called directly, but `DRM_PANEL` is selected in Kconfig. This include is not needed in this source file.
- `drm/drm_probe_helper.h` — no probe helper functions called.

**(4) Register header mixes `BIT()` and raw shifts (minor style)**

In `rzg3l_lvds_regs.h`:

```c
#define LVDS_CMN_RST_PHY0_SEL		(1 << 24)
#define LVDS_CMN_RST_PHY0_SEL_CH0	(1 << 24)
#define LVDS_CMN_PHY_RESET		(1 << 0)
```

These should use `BIT()` for consistency with the rest of the file which uses `BIT(8)`, `BIT(9)`, `GENMASK()`:

```c
#define LVDS_0_PHY_CH_EN_BGR		BIT(8)
#define LVDS_0_PHY_CH_EN_LDO		BIT(9)
```

Also, `LVDS_CMN_RST_PHY0_SEL` and `LVDS_CMN_RST_PHY0_SEL_CH0` are defined to the same value `(1 << 24)` — one of them appears redundant.

**(5) `LVDS_0_PHY_CH_IO_EN` is redundant (minor)**

```c
#define LVDS_0_PHY_CH_IO_EN_MSK		(0x1f)
#define LVDS_0_PHY_CH_IO_EN		(LVDS_0_PHY_CH_IO_EN_MSK << 0)
```

`LVDS_0_PHY_CH_IO_EN` is just `LVDS_0_PHY_CH_IO_EN_MSK << 0`, which is the same value. Having both is confusing. This could be simplified, or at least the `<< 0` should be removed.

**(6) `select DRM_PANEL` in Kconfig may be unnecessary (minor)**

The driver doesn't use any panel API directly — it uses `devm_drm_of_get_bridge()` which handles panel wrapping via `drm_panel_bridge`. The `DRM_PANEL` symbol is typically pulled in transitively by the bridge infrastructure. Check whether `DRM_PANEL` is really needed here.

**(7) `select DRM_KMS_HELPER` — check necessity (minor)**

Similar to above, `DRM_KMS_HELPER` is often pulled in by `DRM_BRIDGE`. Verify it's needed as a direct dependency.

**(8) The `return ret;` at the end of probe could be `return 0;` (nitpick)**

```c
ret = devm_drm_bridge_add(dev, &lvds->bridge);
if (ret)
    return dev_err_probe(dev, ret,
                 "Failed to register drm bridge\n");

return ret;
```

At this point `ret` is always 0 (the error case already returned). Using `return 0;` is clearer.

**(9) Version numbering confusion (meta)**

The cover letter changelog says "v2->v3" but the subject lines say `[PATCH v2 0/2]`. This appears to actually be v3 based on the changelog content.

**(10) Bridge attach returns 0 when there's no next_bridge (needs verification)**

```c
static int rzg3l_lvds_attach(...)
{
    struct rzg3l_lvds *lvds = bridge_to_rzg3l_lvds(bridge);

    if (!lvds->bridge.next_bridge)
        return 0;

    return drm_bridge_attach(encoder, lvds->bridge.next_bridge, bridge, flags);
}
```

The `next_bridge` is set from `devm_drm_of_get_bridge()` in probe, which returns an error if not found. So `next_bridge` should always be non-NULL if probe succeeded. This NULL check is harmless defensive code but shouldn't be reachable. Not a bug, but the check is dead code given the current probe logic.

---
Generated by Claude Code Patch Reviewer

[PATCH v2 0/3] Add support for Renesas RZ/G3L LVDS encoder

[Biju]

From: Biju Das <biju.das.jz@bp.renesas.com>

Add support for the RZ/G3L LVDS encoder driver. It operates in single-link
mode with 4 lanes (Data) + 1 lane (Clock) and supports pixel clock rates
from 25 to 87 MHz. The LVDS module cannot be used at the same time as
MIPI-DSI. However, LVDS and the DSI interface share a peripheral clock and
the MIPI_DSI_PRESET_N reset signal. Also, the MIPI_DSI_CMN_RSTB and
MIPI_DSI_ARESET_N reset signals must be asserted before using the LVDS
module.

v1->v2:
 * Collected the tags for binding patches.
 * Dropped unused function rzg3l_lvds_is_connected() and removed the 
   corresponding header file rzg3l_lvds.h
 * Dropped next_bridge from struct rzg3l_lvds instead using bridge's
   next_bridge.
 * Replaced pm_runtime_resume_and_get()->pm_runtime_get_sync() as
   atomic_enable doesn't fail and for each enable there always will be an
   atomic_disable() call.
 * Started using DEFINE_RUNTIME_DEV_PM_OPS for PM callback.
 * Replaced rzg3l_lvds_parse_dt() with devm_drm_of_get_bridge() in probe()
 * Started using reset_control_bulk_*() in rzg3l_lvds_pm_runtime_{suspend,
   resume}().

Biju Das (3):
  dt-bindings: mfd: syscon: Document the LVDS_CMN syscon for the RZ/G3L
  dt-bindings: display: bridge: Document Renesas RZ/G3L LVDS encoder
  drm: renesas: rz-du: Add support for RZ/G3L LVDS encoder

 .../bridge/renesas,r9a08g046-lvds.yaml        | 128 ++++++++
 .../devicetree/bindings/mfd/syscon.yaml       |   1 +
 drivers/gpu/drm/renesas/rz-du/Kconfig         |  13 +
 drivers/gpu/drm/renesas/rz-du/Makefile        |   1 +
 drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c    | 285 ++++++++++++++++++
 .../gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h   |  26 ++
 6 files changed, 454 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/bridge/renesas,r9a08g046-lvds.yaml
 create mode 100644 drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c
 create mode 100644 drivers/gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h

-- 
2.43.0

[PATCH v2 3/3] drm: renesas: rz-du: Add support for RZ/G3L LVDS encoder

[Biju]

From: Biju Das <biju.das.jz@bp.renesas.com>

Add support for the RZ/G3L LVDS encoder driver. It operates in single-link
mode with 4 lanes (Data) + 1 lane (Clock) and supports pixel clock rates
from 25 to 87 MHz. The LVDS module cannot be used at the same time as
MIPI-DSI. However, LVDS and the DSI interface share a peripheral clock and
the MIPI_DSI_PRESET_N reset signal. Also, the MIPI_DSI_CMN_RSTB and
MIPI_DSI_ARESET_N reset signals must be asserted before using the LVDS
module.

Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
v1->v2:
 * Dropped unused function rzg3l_lvds_is_connected() and removed the 
   corresponding header file rzg3l_lvds.h
 * Dropped next_bridge from struct rzg3l_lvds instead using bridge's
   next_bridge.
 * Replaced pm_runtime_resume_and_get()->pm_runtime_get_sync() as
   atomic_enable doesn't fail and for each enable there always will be an
   atomic_disable() call.
 * Started using DEFINE_RUNTIME_DEV_PM_OPS for PM callback.
 * Replaced rzg3l_lvds_parse_dt() with devm_drm_of_get_bridge() in probe()
 * Started using reset_control_bulk_*() in rzg3l_lvds_pm_runtime_{suspend,
   resume}()
---
 drivers/gpu/drm/renesas/rz-du/Kconfig         |  13 +
 drivers/gpu/drm/renesas/rz-du/Makefile        |   1 +
 drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c    | 285 ++++++++++++++++++
 .../gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h   |  26 ++
 4 files changed, 325 insertions(+)
 create mode 100644 drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c
 create mode 100644 drivers/gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h

diff --git a/drivers/gpu/drm/renesas/rz-du/Kconfig b/drivers/gpu/drm/renesas/rz-du/Kconfig
index 7f2ef7137ae5..cbfc7b6bccb8 100644
--- a/drivers/gpu/drm/renesas/rz-du/Kconfig
+++ b/drivers/gpu/drm/renesas/rz-du/Kconfig
@@ -26,3 +26,16 @@ config DRM_RZG2L_MIPI_DSI
 	def_tristate DRM_RZG2L_DU
 	depends on DRM_RZG2L_USE_MIPI_DSI
 	select DRM_MIPI_DSI
+
+config DRM_RZG3L_USE_LVDS
+	bool "RZ/G3L DU LVDS Encoder Support"
+	depends on DRM_BRIDGE && OF
+	default DRM_RZG2L_DU
+	help
+	  Enable support for the RZ/G3L Display Unit embedded LVDS encoders.
+
+config DRM_RZG3L_LVDS
+	def_tristate DRM_RZG2L_DU
+	depends on DRM_RZG3L_USE_LVDS
+	select DRM_KMS_HELPER
+	select DRM_PANEL
diff --git a/drivers/gpu/drm/renesas/rz-du/Makefile b/drivers/gpu/drm/renesas/rz-du/Makefile
index 2987900ea6b6..46decb7ac4f1 100644
--- a/drivers/gpu/drm/renesas/rz-du/Makefile
+++ b/drivers/gpu/drm/renesas/rz-du/Makefile
@@ -8,3 +8,4 @@ rzg2l-du-drm-$(CONFIG_VIDEO_RENESAS_VSP1)	+= rzg2l_du_vsp.o
 obj-$(CONFIG_DRM_RZG2L_DU)		+= rzg2l-du-drm.o
 
 obj-$(CONFIG_DRM_RZG2L_MIPI_DSI)	+= rzg2l_mipi_dsi.o
+obj-$(CONFIG_DRM_RZG3L_LVDS)		+= rzg3l_lvds.o
diff --git a/drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c b/drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c
new file mode 100644
index 000000000000..60fd63b7be93
--- /dev/null
+++ b/drivers/gpu/drm/renesas/rz-du/rzg3l_lvds.c
@@ -0,0 +1,285 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * RZ/G3L LVDS Encoder Driver
+ *
+ * Copyright (C) 2026 Renesas Electronics Corporation
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/media-bus-format.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_graph.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+
+#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>
+
+#include "rzg3l_lvds_regs.h"
+
+enum rzg3l_lvds_mode {
+	RZG3L_LVDS_MODE_JEIDA = 0,
+	RZG3L_LVDS_MODE_JEIDA_MIRROR = 1,
+	RZG3L_LVDS_MODE_MODE2 = 2,
+	RZG3L_LVDS_MODE_MODE2_MIRROR = 3,
+	RZG3L_LVDS_MODE_VESA = 4,
+	RZG3L_LVDS_MODE_VESA_MIRROR = 5,
+	RZG3L_LVDS_MODE_MODE6 = 6,
+	RZG3L_LVDS_MODE_MODE6_MIRROR = 7,
+};
+
+struct rzg3l_lvds {
+	struct device *dev;
+	struct reset_control *prstc;
+	struct reset_control *lvd_rstc;
+	struct regmap *regmap;
+	struct drm_bridge bridge;
+};
+
+#define bridge_to_rzg3l_lvds(b) \
+	container_of(b, struct rzg3l_lvds, bridge)
+
+/* -----------------------------------------------------------------------------
+ * Bridge
+ */
+
+static void rzg3l_lvds_atomic_enable(struct drm_bridge *bridge,
+				     struct drm_atomic_state *state)
+{
+	struct rzg3l_lvds *lvds = bridge_to_rzg3l_lvds(bridge);
+	const struct drm_bridge_state *bridge_state;
+	int ret;
+	u32 fmt;
+
+	/* Get the LVDS format from the bridge state. */
+	bridge_state = drm_atomic_get_new_bridge_state(state, bridge);
+	if (!bridge_state) {
+		dev_err(lvds->dev, "failed to get bridge state\n");
+		return;
+	}
+
+	switch (bridge_state->output_bus_cfg.format) {
+	case MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA:
+		fmt = RZG3L_LVDS_MODE_JEIDA;
+		break;
+	case MEDIA_BUS_FMT_RGB888_1X7X4_SPWG:
+		fmt = RZG3L_LVDS_MODE_VESA;
+		break;
+	default:
+		fmt = RZG3L_LVDS_MODE_VESA;
+		dev_warn(lvds->dev, "Unsupported bus fmt 0x%04x\n",
+			 bridge_state->output_bus_cfg.format);
+		break;
+	}
+
+	ret = pm_runtime_get_sync(lvds->dev);
+	if (ret < 0) {
+		dev_err(lvds->dev, "pm_runtime_get_sync error\n");
+		return;
+	}
+
+	regmap_update_bits(lvds->regmap, LVDS_0_PHY_OFFSET,
+			   LVDS_0_PHY_CH_EN_BGR, LVDS_0_PHY_CH_EN_BGR);
+	fsleep(20);
+
+	regmap_update_bits(lvds->regmap, LVDS_0_PHY_OFFSET,
+			   LVDS_0_PHY_CH_EN_LDO, LVDS_0_PHY_CH_EN_LDO);
+	fsleep(10);
+
+	regmap_write(lvds->regmap, LVDS_CMN, LVDS_CMN_RST_PHY0_SEL);
+	regmap_update_bits(lvds->regmap, LVDS_0_CTL_OFFSET,
+			   LVDS_0_CTL_FMT_SEL_MSK,
+			   FIELD_PREP(LVDS_0_CTL_FMT_SEL_MSK, fmt));
+	regmap_update_bits(lvds->regmap, LVDS_0_PHY_OFFSET,
+			   LVDS_0_PHY_CH_IO_EN_MSK, LVDS_0_PHY_CH_IO_EN);
+	regmap_write(lvds->regmap, LVDS_CMN,
+		     LVDS_CMN_RST_PHY0_SEL | LVDS_CMN_PHY_RESET);
+	fsleep(100);
+}
+
+static void rzg3l_lvds_atomic_disable(struct drm_bridge *bridge,
+				      struct drm_atomic_state *state)
+{
+	struct rzg3l_lvds *lvds = bridge_to_rzg3l_lvds(bridge);
+
+	regmap_update_bits(lvds->regmap, LVDS_CMN, LVDS_CMN_PHY_RESET, 0);
+	regmap_update_bits(lvds->regmap, LVDS_0_PHY_OFFSET,
+			   LVDS_0_PHY_CH_IO_EN_MSK, 0);
+	regmap_update_bits(lvds->regmap, LVDS_0_PHY_OFFSET,
+			   LVDS_0_PHY_CH_EN_LDO, 0);
+	regmap_update_bits(lvds->regmap, LVDS_0_PHY_OFFSET,
+			   LVDS_0_PHY_CH_EN_BGR, 0);
+
+	pm_runtime_put(lvds->dev);
+}
+
+static int rzg3l_lvds_attach(struct drm_bridge *bridge,
+			     struct drm_encoder *encoder,
+			     enum drm_bridge_attach_flags flags)
+{
+	struct rzg3l_lvds *lvds = bridge_to_rzg3l_lvds(bridge);
+
+	if (!lvds->bridge.next_bridge)
+		return 0;
+
+	return drm_bridge_attach(encoder, lvds->bridge.next_bridge, bridge, flags);
+}
+
+static enum drm_mode_status
+rzg3l_lvds_bridge_mode_valid(struct drm_bridge *bridge,
+			     const struct drm_display_info *info,
+			     const struct drm_display_mode *mode)
+{
+	if (mode->clock > 87000)
+		return MODE_CLOCK_HIGH;
+
+	if (mode->clock < 25000)
+		return MODE_CLOCK_LOW;
+
+	return MODE_OK;
+}
+
+static const struct drm_bridge_funcs rzg3l_lvds_bridge_ops = {
+	.attach = rzg3l_lvds_attach,
+	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
+	.atomic_reset = drm_atomic_helper_bridge_reset,
+	.atomic_enable = rzg3l_lvds_atomic_enable,
+	.atomic_disable = rzg3l_lvds_atomic_disable,
+	.mode_valid = rzg3l_lvds_bridge_mode_valid,
+};
+
+/* -----------------------------------------------------------------------------
+ * Power Management
+ */
+
+static int rzg3l_lvds_pm_runtime_suspend(struct device *dev)
+{
+	struct rzg3l_lvds *lvds = dev_get_drvdata(dev);
+	struct reset_control_bulk_data resets[] = {
+		{ .rstc = lvds->lvd_rstc },
+		{ .rstc = lvds->prstc },
+	};
+
+	return reset_control_bulk_assert(ARRAY_SIZE(resets), resets);
+}
+
+static int rzg3l_lvds_pm_runtime_resume(struct device *dev)
+{
+	struct rzg3l_lvds *lvds = dev_get_drvdata(dev);
+	struct reset_control_bulk_data resets[] = {
+		{ .rstc = lvds->prstc },
+		{ .rstc = lvds->lvd_rstc },
+	};
+
+	return reset_control_bulk_deassert(ARRAY_SIZE(resets), resets);
+}
+
+static DEFINE_RUNTIME_DEV_PM_OPS(rzg3l_lvds_pm_ops,
+				 rzg3l_lvds_pm_runtime_suspend,
+				 rzg3l_lvds_pm_runtime_resume, NULL);
+
+/* -----------------------------------------------------------------------------
+ * Probe & Remove
+ */
+
+static int rzg3l_lvds_probe(struct platform_device *pdev)
+{
+	struct reset_control *rstc, *arstc;
+	struct device *dev = &pdev->dev;
+	struct drm_bridge *next_bridge;
+	struct rzg3l_lvds *lvds;
+	int ret;
+
+	lvds = devm_drm_bridge_alloc(dev, struct rzg3l_lvds, bridge,
+				     &rzg3l_lvds_bridge_ops);
+	if (IS_ERR(lvds))
+		return PTR_ERR(lvds);
+
+	lvds->dev = dev;
+	lvds->bridge.of_node = pdev->dev.of_node;
+
+	lvds->regmap = syscon_node_to_regmap(dev->of_node->parent);
+	if (IS_ERR(lvds->regmap))
+		return PTR_ERR(lvds->regmap);
+
+	rstc = devm_reset_control_get_optional_exclusive(dev, "rst");
+	if (IS_ERR(rstc))
+		return dev_err_probe(dev, PTR_ERR(rstc), "failed to get rst\n");
+
+	arstc = devm_reset_control_get_optional_exclusive(dev, "arst");
+	if (IS_ERR(arstc))
+		return dev_err_probe(dev, PTR_ERR(arstc),
+				     "failed to get arst\n");
+
+	lvds->prstc = devm_reset_control_get_shared(dev, "prst");
+	if (IS_ERR(lvds->prstc))
+		return dev_err_probe(dev, PTR_ERR(lvds->prstc),
+				     "failed to get prst\n");
+
+	lvds->lvd_rstc = devm_reset_control_get_shared(dev, "lvdrst");
+	if (IS_ERR(lvds->lvd_rstc))
+		return dev_err_probe(dev, PTR_ERR(lvds->lvd_rstc),
+				     "failed to get core reset\n");
+
+	platform_set_drvdata(pdev, lvds);
+	ret = devm_pm_runtime_enable(dev);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to enable Runtime PM\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");
+
+	lvds->bridge.next_bridge = next_bridge;
+	ret = reset_control_assert(rstc);
+	if (ret < 0)
+		return ret;
+
+	ret = reset_control_assert(arstc);
+	if (ret < 0)
+		return ret;
+
+	ret = devm_drm_bridge_add(dev, &lvds->bridge);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Failed to register drm bridge\n");
+
+	return ret;
+}
+
+static const struct of_device_id rzg3l_lvds_of_table[] = {
+	{ .compatible = "renesas,r9a08g046-lvds" },
+	{ /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, rzg3l_lvds_of_table);
+
+static struct platform_driver rzg3l_lvds_platform_driver = {
+	.probe		= rzg3l_lvds_probe,
+	.driver		= {
+		.name	= "rzg3l-lvds",
+		.pm	= pm_ptr(&rzg3l_lvds_pm_ops),
+		.of_match_table = rzg3l_lvds_of_table,
+	},
+};
+
+module_platform_driver(rzg3l_lvds_platform_driver);
+
+MODULE_AUTHOR("Biju Das <biju.das.jz@bp.renesas.com>");
+MODULE_AUTHOR("Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>");
+MODULE_DESCRIPTION("Renesas RZ/G3L LVDS Encoder Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h b/drivers/gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h
new file mode 100644
index 000000000000..281b7648f168
--- /dev/null
+++ b/drivers/gpu/drm/renesas/rz-du/rzg3l_lvds_regs.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * RZ/G3L LVDS Interface Registers Definitions
+ *
+ * Copyright (C) 2026 Renesas Electronics Corporation
+ *
+ */
+
+#ifndef __RZG3L_LVDS_REGS_H__
+#define __RZG3L_LVDS_REGS_H__
+
+#define LVDS_CMN			0x00
+#define LVDS_CMN_RST_PHY0_SEL		(1 << 24)
+#define LVDS_CMN_RST_PHY0_SEL_CH0	(1 << 24)
+#define LVDS_CMN_PHY_RESET		(1 << 0)
+
+#define LVDS_0_PHY_OFFSET		0x10
+#define LVDS_0_PHY_CH_IO_EN_MSK		(0x1f)
+#define LVDS_0_PHY_CH_IO_EN		(LVDS_0_PHY_CH_IO_EN_MSK << 0)
+#define LVDS_0_PHY_CH_EN_BGR		BIT(8)
+#define LVDS_0_PHY_CH_EN_LDO		BIT(9)
+
+#define LVDS_0_CTL_OFFSET		0x14
+#define LVDS_0_CTL_FMT_SEL_MSK		GENMASK(23, 20)
+
+#endif /* __RZG3L_LVDS_REGS_H__ */
-- 
2.43.0

Claude review: drm: renesas: rz-du: Add support for RZ/G3L LVDS encoder

[Claude Code Review Bot]

Patch Review

This is the main driver patch. Several items to address:

**1. Unnecessary includes** (`rzg3l_lvds.c` lines 9, 12, 16, 17, 27, 28):

```c
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/of_device.h>
#include <linux/of_graph.h>
...
#include <drm/drm_panel.h>
#include <drm/drm_probe_helper.h>
```

- `clk.h` — no `clk_*` calls anywhere in the driver (clocks managed by pm_runtime/syscon parent).
- `io.h` — no `ioread`/`iowrite`/`readl`/`writel` calls; registers accessed via regmap.
- `of_device.h` — no `of_match_device()` or other `of_device` APIs used. The sibling `rzg2l_mipi_dsi.c` doesn't include this.
- `of_graph.h` — no `of_graph_*` APIs called directly.
- `drm_panel.h` — no `drm_panel_*` functions called anywhere.
- `drm_probe_helper.h` — no probe helper functions called.

Please drop these unused includes.

**2. Register header: redundant and inconsistent definitions** (`rzg3l_lvds_regs.h`):

```c
#define LVDS_CMN_RST_PHY0_SEL       (1 << 24)
#define LVDS_CMN_RST_PHY0_SEL_CH0   (1 << 24)
#define LVDS_CMN_PHY_RESET           (1 << 0)
```

`LVDS_CMN_RST_PHY0_SEL` and `LVDS_CMN_RST_PHY0_SEL_CH0` have the same value and `_CH0` is never used. Drop `LVDS_CMN_RST_PHY0_SEL_CH0`.

Also, the file mixes `(1 << N)` with `BIT(N)` (used for bits 8 and 9). Use `BIT()` consistently throughout:
```c
#define LVDS_CMN_RST_PHY0_SEL   BIT(24)
#define LVDS_CMN_PHY_RESET       BIT(0)
```

Similarly:
```c
#define LVDS_0_PHY_CH_IO_EN_MSK     (0x1f)
#define LVDS_0_PHY_CH_IO_EN         (LVDS_0_PHY_CH_IO_EN_MSK << 0)
```

`LVDS_0_PHY_CH_IO_EN` is `0x1f << 0` which equals `LVDS_0_PHY_CH_IO_EN_MSK`. These are the same value, and the `<< 0` is a no-op. Should be `GENMASK(4, 0)` for the mask, and `LVDS_0_PHY_CH_IO_EN` can be dropped (just use the mask directly, since the value written is the mask itself).

**3. `pm_runtime_get_sync` error handling** (`rzg3l_lvds.c` lines 87-91):

```c
ret = pm_runtime_get_sync(lvds->dev);
if (ret < 0) {
    dev_err(lvds->dev, "pm_runtime_get_sync error\n");
    return;
}
```

The v2 changelog explains the switch from `pm_runtime_resume_and_get()` to `pm_runtime_get_sync()` because "atomic_enable doesn't fail and for each enable there always will be an atomic_disable() call." This rationale is valid — the DRM framework always pairs enable/disable. However, `pm_runtime_get_sync()` increments the usage count even on failure. If it fails and `atomic_disable` later calls `pm_runtime_put`, the count rebalances but the hardware was never properly initialized, and `atomic_disable` will write teardown register sequences to a device that never fully resumed.

Consider either:
- Using `pm_runtime_resume_and_get()` for cleaner semantics (the extra `pm_runtime_put` in disable on failure path is harmless since it just decrements to 0), or
- Dropping the error check entirely if this truly can't fail (since `atomic_enable` returns void and can't propagate errors anyway).

The current code is a hybrid that checks for errors but can't properly handle them.

**4. Probe ordering** (`rzg3l_lvds.c` lines 242-254):

```c
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");

lvds->bridge.next_bridge = next_bridge;
ret = reset_control_assert(rstc);
...
ret = reset_control_assert(arstc);
```

The `rst` and `arst` resets (MIPI_DSI_CMN_RSTB and MIPI_DSI_ARESET_N) must be asserted as a precondition for LVDS operation. Currently they're asserted *after* `devm_drm_of_get_bridge`, which can return `-EPROBE_DEFER`. Consider moving the reset assertions earlier (right after obtaining them), so they're asserted regardless of deferred probe. This avoids repeated assert/defer/assert cycles and ensures the hardware precondition is established as early as possible.

**5. Dead code in attach** (`rzg3l_lvds.c` lines 134-135):

```c
if (!lvds->bridge.next_bridge)
    return 0;
```

Since `probe()` returns an error if `devm_drm_of_get_bridge()` fails, `next_bridge` is always non-NULL by the time the bridge is registered and `attach` can be called. This check is dead code. It's a common defensive pattern and not harmful, but worth noting.

**6. Kconfig: `select DRM_PANEL` likely unnecessary**:

```
config DRM_RZG3L_LVDS
    def_tristate DRM_RZG2L_DU
    depends on DRM_RZG3L_USE_LVDS
    select DRM_KMS_HELPER
    select DRM_PANEL
```

The driver doesn't call any `drm_panel_*` functions. Panel support is handled transparently through the bridge chain (via `devm_drm_of_get_bridge` which wraps panels as bridges). `select DRM_PANEL` and the `drm_panel.h` include appear to be unnecessary. `select DRM_KMS_HELPER` is also already selected by `DRM_RZG2L_DU` (which this depends on transitively via `def_tristate DRM_RZG2L_DU`), though being explicit isn't wrong.

**7. Minor: `return ret` at end of probe** (`rzg3l_lvds.c` line 261):

```c
ret = devm_drm_bridge_add(dev, &lvds->bridge);
if (ret)
    return dev_err_probe(dev, ret,
                 "Failed to register drm bridge\n");

return ret;
```

At this point `ret` is always 0. Clearer to write `return 0;`.

**Summary for Patch 3:** The driver is functionally correct and follows established patterns. The main items to address are: cleaning up the unused includes, making the register definitions consistent (use `BIT()`/`GENMASK()`, drop redundant defs), and reconsidering the `pm_runtime_get_sync` error handling approach. The probe ordering of reset assertions could also be improved.

---
Generated by Claude Code Patch Reviewer