[PATCH v4 0/3] Add support for the Samsung S6E8FCO DSI and M1906F9 display panel

[PATCH v4 0/3] Add support for the Samsung S6E8FCO DSI and M1906F9 display panel

[Yedaya Katsman]

This adds a driver to support the Samsung S6E8FCO DSI controller with the
M1906F9 display panel found in Xiaomi Mi A3 (xiaomi-laurel). The driver is
generated using linux-mdss-dsi-panel-driver-generator[0].

The mdss reset dependency makes the screen work more reliably.

[0]: https://github.com/msm8916-mainline/linux-mdss-dsi-panel-driver-generator
Original tree with patches: https://gitlab.postmarketos.org/SzczurekYT/linux/-/tree/laurel

Signed-off-by: Yedaya Katsman <yedaya.ka@gmail.com>
---
Changes in v4:
- Use exisiting binding instead of creating a new one
- Mention dsi phy power source in commit message
- Mention only DSI controller, not panel where it makes sense
- Remove VIDEOMODE_HELPERS selection
- Collect trailers
- Link to v3: https://lore.kernel.org/r/20260312-panel-patches-v3-0-6ed8c006d0be@gmail.com

Changes in v3:
- Make driver, bindings, compatible specific to M1906F9 panel
- Adjust brightness scale and default
- de-mystify some dsi writes
- move pinctrl for mdss into panel node
- Rename regulator nodes and names according to schematic
- Treat vreg_l9a as input to vddi regulator
- Add myself to copyright header, remove years
- Link to v2: https://lore.kernel.org/r/20260223-panel-patches-v2-0-1b6ad471d540@gmail.com

Changes in v2:
- Changed commit title like Dmitry asked
- Fixed copyright header years
- Link to v1: https://lore.kernel.org/r/20260223-panel-patches-v1-0-7756209477f9@gmail.com

---
Yedaya Katsman (3):
      dt-bindings: display: panel: Add Samsung S6E8FCO-M1906F9
      drm: panel: Add Samsung S6E8FCO DSI controller for M1906F9 panel
      arm64: dts: qcom: sm6125-xiaomi-laurel-sprout: Enable MDSS and add panel

 .../panel/samsung,s6e8aa5x01-ams561ra01.yaml       |   5 +-
 MAINTAINERS                                        |   5 +
 .../boot/dts/qcom/sm6125-xiaomi-laurel-sprout.dts  |  94 +++++++
 drivers/gpu/drm/panel/Kconfig                      |  13 +
 drivers/gpu/drm/panel/Makefile                     |   1 +
 .../gpu/drm/panel/panel-samsung-s6e8fco-m1906f9.c  | 301 +++++++++++++++++++++
 6 files changed, 418 insertions(+), 1 deletion(-)
---
base-commit: d4906ae14a5f136ceb671bb14cedbf13fa560da6
change-id: 20260218-panel-patches-696df7e0d810
prerequisite-message-id: <20260303034847.13870-1-val@packett.cool>
prerequisite-patch-id: 3fba84f11111406e0d530013fd45ad0eb389786b
prerequisite-patch-id: 81440b7f28f9101d3dc5d4bad6dc86e39b81a026
prerequisite-patch-id: 53469d8c9810169d058f1bfd27ac8399038aae74
prerequisite-patch-id: 80809bee71eb6434f6699d5e5f8c7f9d4bcd1ca7
prerequisite-patch-id: 0269e01c9c54a37bb92983635cd516342189aee5
prerequisite-patch-id: e2bbf7c452d4da6d71b1a5194e0d7ce46584e113

Best regards,
-- 
Yedaya Katsman <yedaya.ka@gmail.com>

[PATCH v4 1/3] dt-bindings: display: panel: Add Samsung S6E8FCO-M1906F9

[Yedaya Katsman]

Add Samsung S6E8FCO DTS binding used with the M1906F9 6.09" 720x1560
panel found in the Xiaomi Mi A3 smartphone.

Co-developed-by: Kamil Gołda <kamil.golda@protonmail.com>
Signed-off-by: Kamil Gołda <kamil.golda@protonmail.com>
Signed-off-by: Yedaya Katsman <yedaya.ka@gmail.com>
---
 .../bindings/display/panel/samsung,s6e8aa5x01-ams561ra01.yaml        | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/display/panel/samsung,s6e8aa5x01-ams561ra01.yaml b/Documentation/devicetree/bindings/display/panel/samsung,s6e8aa5x01-ams561ra01.yaml
index eccfc66d7fe24fbe86e3c25f35beb0855c4fcee6..05451c1b00dbfee9034a05be7be50c3820d3787c 100644
--- a/Documentation/devicetree/bindings/display/panel/samsung,s6e8aa5x01-ams561ra01.yaml
+++ b/Documentation/devicetree/bindings/display/panel/samsung,s6e8aa5x01-ams561ra01.yaml
@@ -8,13 +8,16 @@ title: Samsung AMS561RA01 panel with S6E8AA5X01 controller
 
 maintainers:
   - Kaustabh Chakraborty <kauschluss@disroot.org>
+  - Yedaya Katsman <yedaya.ka@gmail.com>
 
 allOf:
   - $ref: panel-common.yaml#
 
 properties:
   compatible:
-    const: samsung,s6e8aa5x01-ams561ra01
+    enum:
+      - samsung,s6e8aa5x01-ams561ra01
+      - samsung,s6e8fco-m1906f9
 
   reg:
     maxItems: 1

-- 
2.53.0

Re: [PATCH v4 1/3] dt-bindings: display: panel: Add Samsung S6E8FCO-M1906F9

[Krzysztof Kozlowski]

On Sat, Mar 14, 2026 at 11:46:21PM +0200, Yedaya Katsman wrote:
> Add Samsung S6E8FCO DTS binding used with the M1906F9 6.09" 720x1560
> panel found in the Xiaomi Mi A3 smartphone.
> 
> Co-developed-by: Kamil Gołda <kamil.golda@protonmail.com>
> Signed-off-by: Kamil Gołda <kamil.golda@protonmail.com>
> Signed-off-by: Yedaya Katsman <yedaya.ka@gmail.com>
> ---
>  .../bindings/display/panel/samsung,s6e8aa5x01-ams561ra01.yaml        | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>

Best regards,
Krzysztof

Claude review: Re: [PATCH v4 1/3] dt-bindings: display: panel: Add Samsung S6E8FCO-M1906F9

[Claude Code Review Bot]

Patch Review

This patch extends the existing `samsung,s6e8aa5x01-ams561ra01.yaml` binding to add a new compatible `samsung,s6e8fco-m1906f9`.

**Concern: Are these panels similar enough to share a binding?** The S6E8AA5X01 and S6E8FCO are different DSI controllers. Sharing a binding YAML implies they have the same DT interface (same supplies, same properties). Looking at the existing binding, it requires `vdd-supply`, `vci-supply`, `reset-gpios`, which matches what the new driver uses — so the DT interface is compatible. However, the binding title says "Samsung AMS561RA01 panel with S6E8AA5X01 controller" which is now inaccurate for the new compatible. This was likely suggested during review to avoid a separate near-identical binding file, which is fine.

**Minor:** Adding yourself as a maintainer of this binding file is fine since you're adding a compatible, but the MAINTAINERS entry in patch 2 doesn't list this binding file — consider adding `F: Documentation/devicetree/bindings/display/panel/samsung,s6e8aa5x01-ams561ra01.yaml` to the MAINTAINERS block.

Otherwise looks fine.

---

---
Generated by Claude Code Patch Reviewer

[PATCH v4 2/3] drm: panel: Add Samsung S6E8FCO DSI controller for M1906F9 panel

[Yedaya Katsman]

Add driver for Samsung S6E8FCO DSI controller for M1906F9 video mode panel,
found in Xiaomi Mi A3 mobile phone.

Co-developed-by: Kamil Gołda <kamil.golda@protonmail.com>
Signed-off-by: Kamil Gołda <kamil.golda@protonmail.com>
Signed-off-by: Yedaya Katsman <yedaya.ka@gmail.com>

---

The downstream dts claims a max brightness of 2047, but seems to ignore the
MSB.
---
 MAINTAINERS                                        |   5 +
 drivers/gpu/drm/panel/Kconfig                      |  13 +
 drivers/gpu/drm/panel/Makefile                     |   1 +
 .../gpu/drm/panel/panel-samsung-s6e8fco-m1906f9.c  | 301 +++++++++++++++++++++
 4 files changed, 320 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index e087673237636268346979ddc270f8cf0905c722..0c835d432ced8cc1c8494596bc1c2a36eadd6fe8 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8183,6 +8183,11 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/display/panel/samsung,s6e3ha8.yaml
 F:	drivers/gpu/drm/panel/panel-samsung-s6e3ha8.c
 
+DRM DRIVER FOR SAMSUNG S6E8FCO PANELS
+M:	Yedaya Katsman <yedaya.ka@gmail.com>
+S:	Maintained
+F:	drivers/gpu/drm/panel/panel-samsung-s6e8fco-m1906f9.c
+
 DRM DRIVER FOR SAMSUNG SOFEF00 DDIC
 M:	David Heidelberg <david@ixit.cz>
 M:	Casey Connolly <casey.connolly@linaro.org>
diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index 7a83804fedca1b688ce6fbe4295ec9009007e693..47a8a2d2535f3fa46fc4545ae30f7e0b6b3d2e1d 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -893,6 +893,19 @@ config DRM_PANEL_SAMSUNG_S6E8AA5X01_AMS561RA01
 	  ~5.6 inch AMOLED display, and the controller is driven by the MIPI
 	  DSI protocol with 4 lanes.
 
+config DRM_PANEL_SAMSUNG_S6E8FCO
+	tristate "Samsung S6E8FCO DSI controller"
+	depends on OF
+	depends on BACKLIGHT_CLASS_DEVICE
+	select DRM_MIPI_DSI
+	help
+	  Say Y or M here if you want to enable support for the Samsung
+	  S6E8FCO DSI controller and connected panel.
+	  Currently supported panels:
+
+	    M1906F9 (M1906F9SH or M1906F9SI), 6.09 inch 720x1560, found
+	    in the Xiaomi Mi A3 smartphone (xiaomi-laurel).
+
 config DRM_PANEL_SAMSUNG_SOFEF00
 	tristate "Samsung SOFEF00 DSI panel controller"
 	depends on OF
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index b9562a6fdcb38bfd0dfee9e8c11e16149ada4386..0cf7f0fb4654eb3dc67b2f15294ea46015a9bcdc 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -91,6 +91,7 @@ obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E88A0_AMS427AP24) += panel-samsung-s6e88a0-ams4
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E88A0_AMS452EF01) += panel-samsung-s6e88a0-ams452ef01.o
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E8AA0) += panel-samsung-s6e8aa0.o
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E8AA5X01_AMS561RA01) += panel-samsung-s6e8aa5x01-ams561ra01.o
+obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E8FCO) += panel-samsung-s6e8fco-m1906f9.o
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_SOFEF00) += panel-samsung-sofef00.o
 obj-$(CONFIG_DRM_PANEL_SEIKO_43WVF1G) += panel-seiko-43wvf1g.o
 obj-$(CONFIG_DRM_PANEL_SHARP_LQ079L1SX01) += panel-sharp-lq079l1sx01.o
diff --git a/drivers/gpu/drm/panel/panel-samsung-s6e8fco-m1906f9.c b/drivers/gpu/drm/panel/panel-samsung-s6e8fco-m1906f9.c
new file mode 100644
index 0000000000000000000000000000000000000000..7fabfe19b5728612ab2a2518a8a100e7010b1d0c
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-samsung-s6e8fco-m1906f9.c
@@ -0,0 +1,301 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) Kamil Gołda <kamil.golda@protonmail.com>
+// Copyright (c) Yedaya Katsman <yedaya.ka@gmail.com>
+// Generated with linux-mdss-dsi-panel-driver-generator from vendor device tree:
+//   Copyright (c) The Linux Foundation. All rights reserved.
+
+#include <linux/backlight.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+
+#include <video/mipi_display.h>
+
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_probe_helper.h>
+
+struct s6e8fco_ctx {
+	struct drm_panel panel;
+	struct mipi_dsi_device *dsi;
+	struct regulator_bulk_data *supplies;
+	struct gpio_desc *reset_gpio;
+};
+
+static const struct regulator_bulk_data s6e8fco_m1906f9_supplies[] = {
+	{ .supply = "vdd" },
+	{ .supply = "vci" },
+};
+
+static inline
+struct s6e8fco_ctx *to_s6e8fco_ctx(struct drm_panel *panel)
+{
+	return container_of_const(panel, struct s6e8fco_ctx, panel);
+}
+
+static void s6e8fco_m1906f9_reset(struct s6e8fco_ctx *ctx)
+{
+	gpiod_set_value_cansleep(ctx->reset_gpio, 0);
+	usleep_range(12000, 13000);
+	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+	usleep_range(2000, 3000);
+	gpiod_set_value_cansleep(ctx->reset_gpio, 0);
+	usleep_range(10000, 11000);
+}
+
+#define s6e8fco_m1906f9_test_key_on_lvl2(ctx) \
+	mipi_dsi_dcs_write_seq_multi(ctx, 0xf0, 0x5a, 0x5a)
+#define s6e8fco_m1906f9_test_key_off_lvl2(ctx) \
+	mipi_dsi_dcs_write_seq_multi(ctx, 0xf0, 0xa5, 0xa5)
+#define s6e8fco_m1906f9_test_key_on_lvl3(ctx) \
+	mipi_dsi_dcs_write_seq_multi(ctx, 0xfc, 0x5a, 0x5a)
+#define s6e8fco_m1906f9_test_key_off_lvl3(ctx) \
+	mipi_dsi_dcs_write_seq_multi(ctx, 0xfc, 0xa5, 0xa5)
+
+static int s6e8fco_m1906f9_on(struct s6e8fco_ctx *ctx)
+{
+	struct mipi_dsi_multi_context dsi_ctx = { .dsi = ctx->dsi };
+
+	s6e8fco_m1906f9_test_key_on_lvl3(&dsi_ctx);
+
+	mipi_dsi_dcs_set_display_brightness_multi(&dsi_ctx, 0x0000);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, MIPI_DCS_WRITE_CONTROL_DISPLAY,
+				     0x20);
+	mipi_dsi_dcs_exit_sleep_mode_multi(&dsi_ctx);
+	mipi_dsi_msleep(&dsi_ctx, 50);
+	mipi_dsi_dcs_set_display_on_multi(&dsi_ctx);
+
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xb0, 0x04, 0xed);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xed,
+				     0xe4, 0x08, 0x96, 0xa4, 0x2a, 0x72, 0xe2,
+				     0xca, 0x00);
+	s6e8fco_m1906f9_test_key_off_lvl3(&dsi_ctx);
+	s6e8fco_m1906f9_test_key_on_lvl2(&dsi_ctx);
+	s6e8fco_m1906f9_test_key_on_lvl3(&dsi_ctx);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xe1, 0x93);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xb0, 0x05, 0xf4);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xf4, 0x03);
+	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xed, 0x01, 0x81, 0x04);
+	s6e8fco_m1906f9_test_key_off_lvl2(&dsi_ctx);
+	s6e8fco_m1906f9_test_key_off_lvl3(&dsi_ctx);
+
+	return dsi_ctx.accum_err;
+}
+
+static int s6e8fco_m1906f9_off(struct s6e8fco_ctx *ctx)
+{
+	struct mipi_dsi_multi_context dsi_ctx = { .dsi = ctx->dsi };
+
+	mipi_dsi_dcs_set_display_off_multi(&dsi_ctx);
+	mipi_dsi_msleep(&dsi_ctx, 20);
+	mipi_dsi_dcs_enter_sleep_mode_multi(&dsi_ctx);
+	mipi_dsi_msleep(&dsi_ctx, 120);
+
+	return dsi_ctx.accum_err;
+}
+
+static int s6e8fco_m1906f9_prepare(struct drm_panel *panel)
+{
+	struct s6e8fco_ctx *ctx = to_s6e8fco_ctx(panel);
+	struct device *dev = &ctx->dsi->dev;
+	int ret;
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(s6e8fco_m1906f9_supplies), ctx->supplies);
+	if (ret < 0) {
+		dev_err(dev, "Failed to enable regulators: %d\n", ret);
+		return ret;
+	}
+
+	s6e8fco_m1906f9_reset(ctx);
+
+	ret = s6e8fco_m1906f9_on(ctx);
+	if (ret < 0) {
+		dev_err(dev, "Failed to initialize panel: %d\n", ret);
+		gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+		regulator_bulk_disable(ARRAY_SIZE(s6e8fco_m1906f9_supplies), ctx->supplies);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int s6e8fco_m1906f9_unprepare(struct drm_panel *panel)
+{
+	struct s6e8fco_ctx *ctx = to_s6e8fco_ctx(panel);
+	struct device *dev = &ctx->dsi->dev;
+	int ret;
+
+	ret = s6e8fco_m1906f9_off(ctx);
+	if (ret < 0)
+		dev_err(dev, "Failed to un-initialize panel: %d\n", ret);
+
+	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+	regulator_bulk_disable(ARRAY_SIZE(s6e8fco_m1906f9_supplies), ctx->supplies);
+
+	return 0;
+}
+
+static const struct drm_display_mode s6e8fco_m1906f9_samsungp_mode = {
+	.clock = (720 + 350 + 40 + 294) * (1560 + 17 + 2 + 5) * 60 / 1000,
+	.hdisplay = 720,
+	.hsync_start = 720 + 350,
+	.hsync_end = 720 + 350 + 40,
+	.htotal = 720 + 350 + 40 + 294,
+	.vdisplay = 1560,
+	.vsync_start = 1560 + 17,
+	.vsync_end = 1560 + 17 + 2,
+	.vtotal = 1560 + 17 + 2 + 5,
+	.width_mm = 65,
+	.height_mm = 140,
+	.type = DRM_MODE_TYPE_DRIVER,
+};
+
+static int s6e8fco_m1906f9_get_modes(struct drm_panel *panel,
+				      struct drm_connector *connector)
+{
+	return drm_connector_helper_get_modes_fixed(connector, &s6e8fco_m1906f9_samsungp_mode);
+}
+
+static const struct drm_panel_funcs s6e8fco_m1906f9_panel_funcs = {
+	.prepare = s6e8fco_m1906f9_prepare,
+	.unprepare = s6e8fco_m1906f9_unprepare,
+	.get_modes = s6e8fco_m1906f9_get_modes,
+};
+
+static int s6e8fco_bl_update_status(struct backlight_device *bl)
+{
+	struct mipi_dsi_device *dsi = bl_get_data(bl);
+	u16 brightness = backlight_get_brightness(bl);
+	int ret;
+
+	dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
+
+	ret = mipi_dsi_dcs_set_display_brightness_large(dsi, brightness);
+	if (ret < 0)
+		return ret;
+
+	dsi->mode_flags |= MIPI_DSI_MODE_LPM;
+
+	return 0;
+}
+
+static int s6e8fco_bl_get_brightness(struct backlight_device *bl)
+{
+	struct mipi_dsi_device *dsi = bl_get_data(bl);
+	u16 brightness;
+	int ret;
+
+	dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
+
+	ret = mipi_dsi_dcs_get_display_brightness_large(dsi, &brightness);
+	if (ret < 0)
+		return ret;
+
+	dsi->mode_flags |= MIPI_DSI_MODE_LPM;
+
+	return brightness;
+}
+
+static const struct backlight_ops s6e8fco_bl_ops = {
+	.update_status = s6e8fco_bl_update_status,
+	.get_brightness = s6e8fco_bl_get_brightness,
+};
+
+static struct backlight_device *
+s6e8fco_m1906f9_create_backlight(struct mipi_dsi_device *dsi)
+{
+	struct device *dev = &dsi->dev;
+	const struct backlight_properties props = {
+		.type = BACKLIGHT_RAW,
+		.brightness = 512,
+		.max_brightness = 1023,
+	};
+
+	return devm_backlight_device_register(dev, dev_name(dev), dev, dsi,
+					      &s6e8fco_bl_ops, &props);
+}
+
+static int s6e8fco_m1906f9_probe(struct mipi_dsi_device *dsi)
+{
+	struct device *dev = &dsi->dev;
+	struct s6e8fco_ctx *ctx;
+	int ret;
+
+	ctx = devm_drm_panel_alloc(dev, struct s6e8fco_ctx, panel,
+				   &s6e8fco_m1906f9_panel_funcs,
+				   DRM_MODE_CONNECTOR_DSI);
+	if (IS_ERR(ctx))
+		return PTR_ERR(ctx);
+
+	ret = devm_regulator_bulk_get_const(dev,
+					    ARRAY_SIZE(s6e8fco_m1906f9_supplies),
+					    s6e8fco_m1906f9_supplies,
+					    &ctx->supplies);
+	if (ret < 0)
+		return ret;
+
+	ctx->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(ctx->reset_gpio))
+		return dev_err_probe(dev, PTR_ERR(ctx->reset_gpio),
+				     "Failed to get reset-gpios\n");
+
+	ctx->dsi = dsi;
+	mipi_dsi_set_drvdata(dsi, ctx);
+
+	dsi->lanes = 4;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
+			  MIPI_DSI_CLOCK_NON_CONTINUOUS;
+
+	ctx->panel.prepare_prev_first = true;
+
+	ctx->panel.backlight = s6e8fco_m1906f9_create_backlight(dsi);
+	if (IS_ERR(ctx->panel.backlight))
+		return dev_err_probe(dev, PTR_ERR(ctx->panel.backlight),
+				     "Failed to create backlight\n");
+
+	drm_panel_add(&ctx->panel);
+
+	ret = mipi_dsi_attach(dsi);
+	if (ret < 0) {
+		drm_panel_remove(&ctx->panel);
+		return dev_err_probe(dev, ret, "Failed to attach to DSI host\n");
+	}
+
+	return 0;
+}
+
+static void s6e8fco_remove(struct mipi_dsi_device *dsi)
+{
+	struct s6e8fco_ctx *ctx = mipi_dsi_get_drvdata(dsi);
+	int ret;
+
+	ret = mipi_dsi_detach(dsi);
+	if (ret < 0)
+		dev_err(&dsi->dev, "Failed to detach from DSI host: %d\n", ret);
+
+	drm_panel_remove(&ctx->panel);
+}
+
+static const struct of_device_id samsung_s6e8fco_m1906f9_of_match[] = {
+	{ .compatible = "samsung,s6e8fco-m1906f9" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, samsung_s6e8fco_m1906f9_of_match);
+
+static struct mipi_dsi_driver s6e8fco_m1906f9_driver = {
+	.probe = s6e8fco_m1906f9_probe,
+	.remove = s6e8fco_remove,
+	.driver = {
+		.name = "panel-samsung-s6e8fco-m1906f9",
+		.of_match_table = samsung_s6e8fco_m1906f9_of_match,
+	},
+};
+module_mipi_dsi_driver(s6e8fco_m1906f9_driver);
+
+MODULE_AUTHOR("Kamil Gołda <kamil.golda@protonmail.com>");
+MODULE_DESCRIPTION("DRM driver for Samsung s6e8fco DSI controller");
+MODULE_LICENSE("GPL");

-- 
2.53.0

Claude review: drm: panel: Add Samsung S6E8FCO DSI controller for M1906F9 panel

[Claude Code Review Bot]

Patch Review

The panel driver is well-structured and follows modern conventions.

**1. Reset GPIO polarity vs DTS mismatch.** The driver requests the GPIO as `GPIOD_OUT_HIGH` (line 1024 of the mbox / driver line 230):
```c
ctx->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
```
The reset sequence (driver lines 39-47) does:
```c
gpiod_set_value_cansleep(ctx->reset_gpio, 0); // deassert
usleep_range(12000, 13000);
gpiod_set_value_cansleep(ctx->reset_gpio, 1); // assert
usleep_range(2000, 3000);
gpiod_set_value_cansleep(ctx->reset_gpio, 0); // deassert
```
And in the DTS (patch 3), the reset GPIO is `GPIO_ACTIVE_LOW`:
```
reset-gpios = <&tlmm 90 GPIO_ACTIVE_LOW>;
```
With `GPIO_ACTIVE_LOW`, `gpiod_set_value(1)` drives the pin low (asserting reset), and `gpiod_set_value(0)` drives it high (deasserting). So initializing with `GPIOD_OUT_HIGH` means the panel starts with reset asserted, the sequence deasserts→asserts→deasserts, which is a standard reset pulse. This is consistent and correct.

**2. `_samsungp_mode` naming typo.** The mode struct has a stray "p" in the name (mbox line 925):
```c
static const struct drm_display_mode s6e8fco_m1906f9_samsungp_mode = {
```
Should probably be `s6e8fco_m1906f9_mode` — the `_samsungp_` looks like a leftover from the generator. Not a functional issue but worth cleaning up.

**3. LPM mode flag toggling in backlight ops.** The backlight update/get functions (mbox lines 952-984) toggle `MIPI_DSI_MODE_LPM` on `dsi->mode_flags`:
```c
dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
ret = mipi_dsi_dcs_set_display_brightness_large(dsi, brightness);
...
dsi->mode_flags |= MIPI_DSI_MODE_LPM;
```
But `MIPI_DSI_MODE_LPM` is never set in the probe function's `mode_flags` initialization (mbox line 1034):
```c
dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
                  MIPI_DSI_CLOCK_NON_CONTINUOUS;
```
So on the first call to `s6e8fco_bl_update_status`, clearing a flag that isn't set is a no-op, and then it unconditionally sets `MIPI_DSI_MODE_LPM` afterwards — which changes the DSI mode for all subsequent DSI traffic, not just the brightness command. If the panel truly needs HS mode for brightness and LPM for everything else, `MIPI_DSI_MODE_LPM` should be included in the initial `mode_flags`. If the panel doesn't need LPM at all, this toggling should be removed. Please verify the intended behavior.

**4. `drm_probe_helper.h` include appears unused.** The driver includes `<drm/drm_probe_helper.h>` but uses `drm_connector_helper_get_modes_fixed()` which is from `<drm/drm_probe_helper.h>` — actually this is correct, ignore this point.

**5. Missing `#include <linux/delay.h>` usage clarity.** The driver includes `<linux/delay.h>` for `usleep_range()` in the reset function — that's fine.

**6. Between-the-dashes comment.** The note between the `---` markers (mbox lines 718-719):
```
The downstream dts claims a max brightness of 2047, but seems to ignore the
MSB.
```
This is useful context for reviewers but won't appear in the final commit message, which is appropriate.

Overall this patch is good. The main actionable items are the mode name typo and the LPM flag question.

---

---
Generated by Claude Code Patch Reviewer

[PATCH v4 3/3] arm64: dts: qcom: sm6125-xiaomi-laurel-sprout: Enable MDSS and add panel

[Yedaya Katsman]

Enable the MDSS nodes and add supplies and bindings for the Samsung S6E8FCO
DSI controller for the M1906F9 panel.

The ldo and iovcc gpio pins boot up with a current of 16 mA, but they work
fine with 2mA, so I used that.

mdss_dsi0_phy is powered by VDD_MX, see power-domains in sm6125.dtsi

Co-developed-by: Kamil Gołda <kamil.golda@protonmail.com>
Signed-off-by: Kamil Gołda <kamil.golda@protonmail.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Yedaya Katsman <yedaya.ka@gmail.com>
---
 .../boot/dts/qcom/sm6125-xiaomi-laurel-sprout.dts  | 94 ++++++++++++++++++++++
 1 file changed, 94 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/sm6125-xiaomi-laurel-sprout.dts b/arch/arm64/boot/dts/qcom/sm6125-xiaomi-laurel-sprout.dts
index 994fb0412fcbdf5466f87a325c48b697a37b514b..9b046d21da1dc54bd851a94d0e209bf1763e865a 100644
--- a/arch/arm64/boot/dts/qcom/sm6125-xiaomi-laurel-sprout.dts
+++ b/arch/arm64/boot/dts/qcom/sm6125-xiaomi-laurel-sprout.dts
@@ -82,6 +82,33 @@ key-volume-up {
 		};
 	};
 
+	panel_vdd_1p8: regulator-panel-vdd {
+		compatible = "regulator-fixed";
+		regulator-name = "panel_vdd_1p8";
+		regulator-min-microvolt = <1800000>;
+		regulator-max-microvolt = <1800000>;
+		regulator-boot-on;
+		vin-supply = <&vreg_l9a>;
+
+		enable-active-high;
+		gpio = <&tlmm 26 GPIO_ACTIVE_HIGH>;
+		pinctrl-0 = <&panel_vdd_1p8_en>;
+		pinctrl-names = "default";
+	};
+
+	panel_vci_3p0: regulator-panel-vci {
+		compatible = "regulator-fixed";
+		regulator-name = "panel_vci_3p0";
+		regulator-min-microvolt = <1800000>;
+		regulator-max-microvolt = <1800000>;
+		regulator-boot-on;
+
+		enable-active-high;
+		gpio = <&tlmm 124 GPIO_ACTIVE_HIGH>;
+		pinctrl-0 = <&panel_vci_3p0_en>;
+		pinctrl-names = "default";
+	};
+
 	thermal-zones {
 		rf-pa0-thermal {
 			thermal-sensors = <&pm6125_adc_tm 0>;
@@ -128,6 +155,45 @@ &hsusb_phy1 {
 	status = "okay";
 };
 
+&mdss {
+	status = "okay";
+};
+
+&mdss_dsi0 {
+	vdda-supply = <&vreg_l18a>;
+	status = "okay";
+
+	panel@0 {
+		compatible = "samsung,s6e8fco-m1906f9";
+		reg = <0>;
+
+		reset-gpios = <&tlmm 90 GPIO_ACTIVE_LOW>;
+
+		pinctrl-0 = <&mdss_default>;
+		pinctrl-1 = <&mdss_sleep>;
+		pinctrl-names = "default", "sleep";
+
+		vdd-supply = <&panel_vdd_1p8>;
+		vci-supply = <&panel_vci_3p0>;
+
+		port {
+			panel_in: endpoint {
+				remote-endpoint = <&mdss_dsi0_out>;
+			};
+		};
+	};
+};
+
+&mdss_dsi0_out {
+	data-lanes = <0 1 2 3>;
+	remote-endpoint = <&panel_in>;
+};
+
+
+&mdss_dsi0_phy {
+	status = "okay";
+};
+
 &pm6125_adc {
 	pinctrl-names = "default";
 	pinctrl-0 = <&camera_flash_therm &emmc_ufs_therm>;
@@ -387,6 +453,34 @@ &sdhc_2 {
 
 &tlmm {
 	gpio-reserved-ranges = <22 2>, <28 6>;
+
+	panel_vdd_1p8_en: panel-vdd-default-state {
+		pins = "gpio26";
+		function = "gpio";
+		drive-strength = <2>;
+		bias-pull-up;
+	};
+
+	mdss_default: mdss-default-state {
+		pins = "gpio90";
+		function = "gpio";
+		drive-strength = <8>;
+		bias-disable;
+	};
+
+	mdss_sleep: mdss-sleep-state {
+		pins = "gpio90";
+		function = "gpio";
+		drive-strength = <2>;
+		bias-pull-down;
+	};
+
+	panel_vci_3p0_en: panel-vci-default-state {
+		pins = "gpio124";
+		function = "gpio";
+		drive-strength = <2>;
+		bias-pull-up;
+	};
 };
 
 &ufs_mem_hc {

-- 
2.53.0

Claude review: arm64: dts: qcom: sm6125-xiaomi-laurel-sprout: Enable MDSS and add panel

[Claude Code Review Bot]

Patch Review

**1. Regulator voltage mismatch for `panel_vci_3p0`.** This is the most significant issue. The regulator node is named `panel_vci_3p0` suggesting 3.0V, but the actual voltage specified is 1.8V (mbox lines 493-504):
```
panel_vci_3p0: regulator-panel-vci {
    ...
    regulator-name = "panel_vci_3p0";
    regulator-min-microvolt = <1800000>;
    regulator-max-microvolt = <1800000>;
```
Either the name is wrong (should reflect 1.8V), or the voltage is wrong (should be 3000000). VCI for OLED panels is typically 3.0V, so the name might be correct and the voltage should be `<3000000>`. Please verify against the hardware schematic. If 1.8V is actually correct, change the name to avoid confusion.

**2. Extra blank line.** There's a double blank line between `&mdss_dsi0_out` and `&mdss_dsi0_phy` blocks (mbox lines 547-548):
```

&mdss_dsi0_phy {
```
Should be a single blank line for consistency with the rest of the file.

**3. `regulator-boot-on` on `panel_vci_3p0`.** The `panel_vdd_1p8` regulator has `vin-supply = <&vreg_l9a>` but `panel_vci_3p0` does not specify a `vin-supply`. If this GPIO-controlled regulator is powered by a PMIC rail, the `vin-supply` should be specified for proper power sequencing. The commit message mentions "ldo and iovcc gpio pins" but doesn't fully explain the VCI supply chain.

**4. `regulator-boot-on` without `regulator-always-on`.** Both fixed regulators use `regulator-boot-on` which prevents them from being disabled at boot. This is common for panel regulators to avoid flicker, but worth noting that the driver does call `regulator_bulk_disable()` in unprepare, so these regulators will be disabled during runtime PM. This is fine.

The DTS changes have appropriate Reviewed-by tags from Dmitry and Konrad, which is good.

---
Generated by Claude Code Patch Reviewer

Claude review: Add support for the Samsung S6E8FCO DSI and M1906F9 display panel

[Claude Code Review Bot]

Overall Series Review

Subject: Add support for the Samsung S6E8FCO DSI and M1906F9 display panel
Author: Yedaya Katsman <yedaya.ka@gmail.com>
Patches: 5
Reviewed: 2026-03-16T11:54:45.138005

---

This is a v4 series adding support for the Samsung S6E8FCO DSI controller with the M1906F9 panel found in the Xiaomi Mi A3 (laurel-sprout). The series is 3 patches: a DT binding addition, a panel driver, and a DTS enablement patch. The code is largely auto-generated via `linux-mdss-dsi-panel-driver-generator` with manual refinements. Overall the series is in reasonable shape — it follows existing panel driver conventions, uses `devm_drm_panel_alloc()` and the multi-context DSI API. There are a few issues to address, mostly in the DTS patch.

---

---
Generated by Claude Code Patch Reviewer

[PATCH v3 0/3] Add support for the Samsung S6E8FCO DSI and M1906F9 display panel

[Yedaya Katsman]

This adds a driver to support the Samsung S6E8FCO DSI controller with the
M1906F9 display panel found in Xiaomi Mi A3 (xiaomi-laurel). The driver is
generated using linux-mdss-dsi-panel-driver-generator[0].

The mdss reset dependency makes the screen work more reliably.

[0]: https://github.com/msm8916-mainline/linux-mdss-dsi-panel-driver-generator
Original tree with patches: https://gitlab.postmarketos.org/SzczurekYT/linux/-/tree/laurel

Signed-off-by: Yedaya Katsman <yedaya.ka@gmail.com>
---
Changes in v3:
- Make driver, bindings, compatible specific to M1906F9 panel
- Adjust brightness scale and default
- de-mystify some dsi writes
- move pinctrl for mdss into panel node
- Rename regulator nodes and names according to schematic
- Treat vreg_l9a as input to vddi regulator
- Add myself to copyright header, remove years
- Link to v2: https://lore.kernel.org/r/20260223-panel-patches-v2-0-1b6ad471d540@gmail.com

Changes in v2:
- Changed commit title like Dmitry asked
- Fixed copyright header years
- Link to v1: https://lore.kernel.org/r/20260223-panel-patches-v1-0-7756209477f9@gmail.com

---
Yedaya Katsman (3):
      dt-bindings: display: panel: Add Samsung S6E8FCO-M1906F9
      drm: panel: Add Samsung S6E8FCO DSI controller for M1906F9 panel
      arm64: dts: qcom: sm6125-xiaomi-laurel-sprout: Enable MDSS and add panel

 .../display/panel/samsung,s6e8fco-m1906f9.yaml     |  63 +++++
 MAINTAINERS                                        |   6 +
 .../boot/dts/qcom/sm6125-xiaomi-laurel-sprout.dts  |  94 +++++++
 drivers/gpu/drm/panel/Kconfig                      |  13 +
 drivers/gpu/drm/panel/Makefile                     |   1 +
 .../gpu/drm/panel/panel-samsung-s6e8fco-m1906f9.c  | 302 +++++++++++++++++++++
 6 files changed, 479 insertions(+)
---
base-commit: d4906ae14a5f136ceb671bb14cedbf13fa560da6
change-id: 20260218-panel-patches-696df7e0d810
prerequisite-message-id: <20260303034847.13870-1-val@packett.cool>
prerequisite-patch-id: 3fba84f11111406e0d530013fd45ad0eb389786b
prerequisite-patch-id: 81440b7f28f9101d3dc5d4bad6dc86e39b81a026
prerequisite-patch-id: 53469d8c9810169d058f1bfd27ac8399038aae74
prerequisite-patch-id: 80809bee71eb6434f6699d5e5f8c7f9d4bcd1ca7
prerequisite-patch-id: 0269e01c9c54a37bb92983635cd516342189aee5
prerequisite-patch-id: e2bbf7c452d4da6d71b1a5194e0d7ce46584e113

Best regards,
-- 
Yedaya Katsman <yedaya.ka@gmail.com>

Claude review: Add support for the Samsung S6E8FCO DSI and M1906F9 display panel

[Claude Code Review Bot]

Overall Series Review

Subject: Add support for the Samsung S6E8FCO DSI and M1906F9 display panel
Author: Yedaya Katsman <yedaya.ka@gmail.com>
Patches: 7
Reviewed: 2026-03-13T14:15:08.071068

---

This is a 3-patch series adding support for the Samsung S6E8FCO DSI controller with the M1906F9 panel found in the Xiaomi Mi A3. The series is well-structured (bindings, driver, DTS) and follows modern panel driver conventions (uses `devm_drm_panel_alloc`, `mipi_dsi_multi_context`, `devm_regulator_bulk_get_const`). The code is largely auto-generated by `linux-mdss-dsi-panel-driver-generator` with manual refinements. There are a few issues that should be addressed, the most notable being a typo in MODULE_DESCRIPTION and a suspicious voltage mismatch in the DTS.

---
Generated by Claude Code Patch Reviewer