[PATCH v3 0/2] drm/panel: add support for Ilitek ILI7807S DSI panels

[PATCH v3 0/2] drm/panel: add support for Ilitek ILI7807S DSI panels

[Arpit Saini]

Add DT bindings and a DRM panel driver for panels based on the Ilitek
ILI7807S display controller. The first supported panel is the DLC
DLC0697 1080x1920@60Hz MIPI DSI panel.

Changes in v3:
- Return devm_mipi_dsi_attach() directly (Neil Armstrong)
- Link to v2: https://lore.kernel.org/all/20260618-ili7807s-v2-0-b3f0c109b102@oss.qualcomm.com/

Changes in v2:
- Drop MAINTAINERS entry (Dmitry Baryshkov)
- Use devm_drm_panel_add() instead of drm_panel_add() to avoid
  manual drm_panel_remove() in the error path (Dmitry Baryshkov)
- Rework backlight: call drm_panel_of_backlight() first and fall back
  to creating a DCS backlight device if panel->backlight is still NULL
  (Dmitry Baryshkov)
- Remove backlight-en-gpios from the binding (Dmitry Baryshkov)
- Fix mode_flags LPM not restored on backlight update error path
- Link to v1 : https://lore.kernel.org/all/20260518-ili7807s-panel-v1-0-d7b048163b1c@oss.qualcomm.com/

---
Arpit Saini (2):
      dt-bindings: display: panel: add Ilitek ILI7807S panel controller
      drm/panel: add Ilitek ILI7807S panel driver

 .../bindings/display/panel/ilitek,ili7807s.yaml    |  71 +++++
 drivers/gpu/drm/panel/Kconfig                      |  12 +
 drivers/gpu/drm/panel/Makefile                     |   1 +
 drivers/gpu/drm/panel/panel-ilitek-ili7807s.c      | 293 +++++++++++++++++++++
 4 files changed, 377 insertions(+)
---
base-commit: 4e5dfb7c84012007c3c7061126491bbc92d71bf1
change-id: 20260615-ili7807s-panel

Best regards,
-- 
Arpit Saini <arpit.saini@oss.qualcomm.com>

[PATCH v3 1/2] dt-bindings: display: panel: add Ilitek ILI7807S panel controller

[Arpit Saini]

ILI7807S is a DSI display controller used to drive MIPI-DSI panels.
The DLC DLC0697 1080x1920 LCD panel is based on this controller.

The panel requires a reset GPIO, I/O voltage supply (vddi), positive
LCD bias supply (avdd) and negative LCD bias supply (avee). The panel
operates in video burst mode with four data lanes using RGB888 pixel
format.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Arpit Saini <arpit.saini@oss.qualcomm.com>
---
 .../bindings/display/panel/ilitek,ili7807s.yaml    | 71 ++++++++++++++++++++++
 1 file changed, 71 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/panel/ilitek,ili7807s.yaml b/Documentation/devicetree/bindings/display/panel/ilitek,ili7807s.yaml
new file mode 100644
index 000000000000..ba8c5bbf8ffc
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/panel/ilitek,ili7807s.yaml
@@ -0,0 +1,71 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/panel/ilitek,ili7807s.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Ilitek ILI7807S-based DSI panels
+
+maintainers:
+  - Arpit Saini <arpit.saini@oss.qualcomm.com>
+
+allOf:
+  - $ref: panel-common.yaml#
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - dlc,dlc0697
+      - const: ilitek,ili7807s
+
+  reg:
+    maxItems: 1
+    description: DSI virtual channel
+
+  vddi-supply:
+    description: I/O voltage supply (1.8V)
+
+  avdd-supply:
+    description: Positive LCD bias supply (AVDD), typically +5.5V
+      (range 4.5V to 6.3V)
+
+  avee-supply:
+    description: Negative LCD bias supply (AVEE), typically -5.5V
+      (range -6.3V to -4.5V)
+
+required:
+  - compatible
+  - reg
+  - reset-gpios
+  - vddi-supply
+  - avdd-supply
+  - avee-supply
+  - port
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    dsi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        panel@0 {
+            compatible = "dlc,dlc0697", "ilitek,ili7807s";
+            reg = <0>;
+
+            reset-gpios = <&tlmm 3 GPIO_ACTIVE_LOW>;
+            vddi-supply = <&pm4125_l15>;
+            avdd-supply = <&avdd>;
+            avee-supply = <&avee>;
+
+            port {
+                panel_in: endpoint {
+                    remote-endpoint = <&dsi0_out>;
+                };
+            };
+        };
+    };

-- 
2.34.1

[PATCH v3 2/2] drm/panel: add Ilitek ILI7807S panel driver

[Arpit Saini]

Add a DRM panel driver for the DLC DLC0697 1080x1920@60Hz MIPI DSI
panel based on the Ilitek ILI7807S display controller.

The panel operates in video burst mode with four data lanes using
RGB888 pixel format.

Signed-off-by: Arpit Saini <arpit.saini@oss.qualcomm.com>
---
 drivers/gpu/drm/panel/Kconfig                 |  12 ++
 drivers/gpu/drm/panel/Makefile                |   1 +
 drivers/gpu/drm/panel/panel-ilitek-ili7807s.c | 293 ++++++++++++++++++++++++++
 3 files changed, 306 insertions(+)

diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index 7450b27622a2..1cbaac1bf545 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -264,6 +264,18 @@ config DRM_PANEL_HYDIS_HV101HD1
 
 	  If M is selected the module will be called panel-hydis-hv101hd1
 
+config DRM_PANEL_ILITEK_ILI7807S
+	tristate "Ilitek ILI7807S-based panels"
+	depends on OF
+	depends on DRM_MIPI_DSI
+	depends on BACKLIGHT_CLASS_DEVICE
+	help
+	  Say Y if you want to enable support for panels based on the
+	  Ilitek ILI7807S display controller, such as the DLC DLC0697
+	  1080x1920 MIPI DSI panel.
+
+	  If M is selected the module will be called panel-ilitek-ili7807s.
+
 config DRM_PANEL_ILITEK_IL9322
 	tristate "Ilitek ILI9322 320x240 QVGA panels"
 	depends on OF && SPI
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index c2c5cf817116..c3002b351cb8 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_DRM_PANEL_HIMAX_HX83112B) += panel-himax-hx83112b.o
 obj-$(CONFIG_DRM_PANEL_HIMAX_HX83121A) += panel-himax-hx83121a.o
 obj-$(CONFIG_DRM_PANEL_HIMAX_HX8394) += panel-himax-hx8394.o
 obj-$(CONFIG_DRM_PANEL_HYDIS_HV101HD1) += panel-hydis-hv101hd1.o
+obj-$(CONFIG_DRM_PANEL_ILITEK_ILI7807S) += panel-ilitek-ili7807s.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_IL9322) += panel-ilitek-ili9322.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9341) += panel-ilitek-ili9341.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9805) += panel-ilitek-ili9805.o
diff --git a/drivers/gpu/drm/panel/panel-ilitek-ili7807s.c b/drivers/gpu/drm/panel/panel-ilitek-ili7807s.c
new file mode 100644
index 000000000000..8ddfab2693ec
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-ilitek-ili7807s.c
@@ -0,0 +1,293 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
+ */
+
+#include <linux/backlight.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regulator/consumer.h>
+
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_probe_helper.h>
+
+struct panel_desc {
+	const struct drm_display_mode *mode;
+	unsigned int lanes;
+	enum mipi_dsi_pixel_format format;
+	unsigned long mode_flags;
+	void (*init)(struct mipi_dsi_multi_context *dsi_ctx);
+};
+
+struct ili7807s {
+	struct drm_panel panel;
+	struct mipi_dsi_device *dsi;
+	const struct panel_desc *desc;
+
+	struct regulator_bulk_data *supplies;
+	struct gpio_desc *reset_gpio;
+};
+
+static const struct regulator_bulk_data ili7807s_supplies[] = {
+	{ .supply = "vddi" },
+	{ .supply = "avdd" },
+	{ .supply = "avee" },
+};
+
+static inline struct ili7807s *to_ili7807s(struct drm_panel *panel)
+{
+	return container_of(panel, struct ili7807s, panel);
+}
+
+static void ili7807s_reset(struct ili7807s *ctx)
+{
+	gpiod_set_value_cansleep(ctx->reset_gpio, 0);
+	usleep_range(10000, 11000);
+	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+	usleep_range(10000, 11000);
+	gpiod_set_value_cansleep(ctx->reset_gpio, 0);
+	usleep_range(10000, 11000);
+}
+
+static void dlc0697_init_sequence(struct mipi_dsi_multi_context *dsi_ctx)
+{
+	mipi_dsi_dcs_soft_reset_multi(dsi_ctx);
+	mipi_dsi_msleep(dsi_ctx, 120);
+
+	mipi_dsi_dcs_write_seq_multi(dsi_ctx, 0xff, 0x78, 0x07, 0x00);
+	mipi_dsi_dcs_write_seq_multi(dsi_ctx, 0x35, 0x00);
+	mipi_dsi_dcs_write_seq_multi(dsi_ctx, 0x5e, 0x09, 0x99);
+	mipi_dsi_dcs_write_seq_multi(dsi_ctx, 0x53, 0x24);
+	mipi_dsi_dcs_write_seq_multi(dsi_ctx, 0x55, 0x01);
+	mipi_dsi_dcs_write_seq_multi(dsi_ctx, 0x51, 0x3f, 0xff);
+
+	mipi_dsi_dcs_exit_sleep_mode_multi(dsi_ctx);
+	mipi_dsi_msleep(dsi_ctx, 120);
+
+	mipi_dsi_dcs_set_display_on_multi(dsi_ctx);
+	mipi_dsi_msleep(dsi_ctx, 20);
+}
+
+static int ili7807s_on(struct ili7807s *ctx)
+{
+	struct mipi_dsi_multi_context dsi_ctx = { .dsi = ctx->dsi };
+
+	ctx->dsi->mode_flags |= MIPI_DSI_MODE_LPM;
+
+	ctx->desc->init(&dsi_ctx);
+
+	ctx->dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
+
+	return dsi_ctx.accum_err;
+}
+
+static int ili7807s_off(struct ili7807s *ctx)
+{
+	struct mipi_dsi_multi_context dsi_ctx = { .dsi = ctx->dsi };
+
+	ctx->dsi->mode_flags |= MIPI_DSI_MODE_LPM;
+
+	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);
+
+	ctx->dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
+
+	return dsi_ctx.accum_err;
+}
+
+static int ili7807s_prepare(struct drm_panel *panel)
+{
+	struct ili7807s *ctx = to_ili7807s(panel);
+	int ret;
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(ili7807s_supplies), ctx->supplies);
+	if (ret < 0) {
+		dev_err(ctx->panel.dev, "failed to enable regulators: %d\n", ret);
+		return ret;
+	}
+
+	msleep(20);
+
+	ili7807s_reset(ctx);
+
+	ret = ili7807s_on(ctx);
+	if (ret < 0) {
+		dev_err(ctx->panel.dev, "failed to initialise panel: %d\n", ret);
+		goto err;
+	}
+
+	return 0;
+
+err:
+	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+
+	regulator_bulk_disable(ARRAY_SIZE(ili7807s_supplies), ctx->supplies);
+	return ret;
+}
+
+static int ili7807s_unprepare(struct drm_panel *panel)
+{
+	struct ili7807s *ctx = to_ili7807s(panel);
+	int ret;
+
+	ret = ili7807s_off(ctx);
+	if (ret < 0)
+		dev_err(ctx->panel.dev, "failed to disable panel: %d\n", ret);
+
+	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+
+	regulator_bulk_disable(ARRAY_SIZE(ili7807s_supplies), ctx->supplies);
+
+	return 0;
+}
+
+static int ili7807s_get_modes(struct drm_panel *panel,
+			      struct drm_connector *connector)
+{
+	struct ili7807s *ctx = to_ili7807s(panel);
+
+	return drm_connector_helper_get_modes_fixed(connector, ctx->desc->mode);
+}
+
+static const struct drm_panel_funcs ili7807s_panel_funcs = {
+	.prepare = ili7807s_prepare,
+	.unprepare = ili7807s_unprepare,
+	.get_modes = ili7807s_get_modes,
+};
+
+static int ili7807s_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);
+
+	dsi->mode_flags |= MIPI_DSI_MODE_LPM;
+
+	return ret;
+}
+
+static const struct backlight_ops ili7807s_bl_ops = {
+	.update_status = ili7807s_bl_update_status,
+};
+
+static struct backlight_device *ili7807s_create_backlight(struct mipi_dsi_device *dsi)
+{
+	struct device *dev = &dsi->dev;
+	const struct backlight_properties props = {
+		.type           = BACKLIGHT_RAW,
+		.brightness     = 0x3fff,
+		.max_brightness = 0x3fff,
+	};
+
+	return devm_backlight_device_register(dev, dev_name(dev), dev, dsi,
+					      &ili7807s_bl_ops, &props);
+}
+
+static const struct drm_display_mode dlc0697_mode = {
+	.clock = 131911,
+
+	.hdisplay    = 1080,
+	.hsync_start = 1080 + 18,
+	.hsync_end   = 1080 + 18 + 2,
+	.htotal      = 1080 + 18 + 2 + 16,
+
+	.vdisplay    = 1920,
+	.vsync_start = 1920 + 26,
+	.vsync_end   = 1920 + 26 + 4,
+	.vtotal      = 1920 + 26 + 4 + 20,
+
+	.width_mm  = 0,
+	.height_mm = 0,
+	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
+};
+
+static const struct panel_desc dlc0697_desc = {
+	.mode       = &dlc0697_mode,
+	.lanes      = 4,
+	.format     = MIPI_DSI_FMT_RGB888,
+	.mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST,
+	.init       = dlc0697_init_sequence,
+};
+
+static int ili7807s_probe(struct mipi_dsi_device *dsi)
+{
+	struct device *dev = &dsi->dev;
+	const struct panel_desc *desc;
+	struct ili7807s *ctx;
+	int ret;
+
+	ctx = devm_drm_panel_alloc(dev, struct ili7807s, panel,
+				   &ili7807s_panel_funcs,
+				   DRM_MODE_CONNECTOR_DSI);
+	if (IS_ERR(ctx))
+		return PTR_ERR(ctx);
+
+	desc = of_device_get_match_data(dev);
+	ctx->desc = desc;
+
+	ret = devm_regulator_bulk_get_const(dev, ARRAY_SIZE(ili7807s_supplies),
+					    ili7807s_supplies, &ctx->supplies);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "failed to get regulators\n");
+
+	ctx->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(ctx->reset_gpio))
+		return dev_err_probe(dev, PTR_ERR(ctx->reset_gpio),
+				     "failed to get reset gpio\n");
+
+	ctx->dsi = dsi;
+	mipi_dsi_set_drvdata(dsi, ctx);
+
+	dsi->lanes      = desc->lanes;
+	dsi->format     = desc->format;
+	dsi->mode_flags = desc->mode_flags;
+
+	ctx->panel.prepare_prev_first = true;
+
+	ret = drm_panel_of_backlight(&ctx->panel);
+	if (ret)
+		return ret;
+
+	if (!ctx->panel.backlight) {
+		ctx->panel.backlight = ili7807s_create_backlight(dsi);
+		if (IS_ERR(ctx->panel.backlight))
+			return dev_err_probe(dev, PTR_ERR(ctx->panel.backlight),
+					     "failed to create backlight\n");
+	}
+
+	ret = devm_drm_panel_add(dev, &ctx->panel);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "failed to add panel\n");
+
+	return devm_mipi_dsi_attach(dev, dsi);
+}
+
+static const struct of_device_id ili7807s_of_match[] = {
+	{ .compatible = "dlc,dlc0697", .data = &dlc0697_desc },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ili7807s_of_match);
+
+static struct mipi_dsi_driver ili7807s_dsi_driver = {
+	.probe  = ili7807s_probe,
+	.driver = {
+		.name           = "panel-ilitek-ili7807s",
+		.of_match_table = ili7807s_of_match,
+	},
+};
+module_mipi_dsi_driver(ili7807s_dsi_driver);
+
+MODULE_AUTHOR("Arpit Saini <arpit.saini@oss.qualcomm.com>");
+MODULE_DESCRIPTION("Panel driver for Ilitek ILI7807S LCD DSI panel");
+MODULE_LICENSE("GPL");

-- 
2.34.1

Re: [PATCH v3 2/2] drm/panel: add Ilitek ILI7807S panel driver

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [High] Incorrect and non-atomic modification of `dsi->mode_flags` permanently enables Low Power Mode and introduces a data race.
- [High] Backlight `update_status` sends DSI commands without verifying that the panel is powered on, risking DSI host timeouts.
--

commit 2f966f15c21adb82ce5699cdffad22cac6628b98
Author: Arpit Saini <arpit.saini@oss.qualcomm.com>

drm/panel: add Ilitek ILI7807S panel driver
    
Add a DRM panel driver for the DLC DLC0697 1080x1920@60Hz MIPI DSI
panel based on the Ilitek ILI7807S display controller.

> diff --git a/drivers/gpu/drm/panel/panel-ilitek-ili7807s.c b/drivers/gpu/drm/panel/panel-ilitek-ili7807s.c
> new file mode 100644
> index 0000000000000..8ddfab2693ec8
> --- /dev/null
> +++ b/drivers/gpu/drm/panel/panel-ilitek-ili7807s.c

[ ... ]

> +static int ili7807s_bl_update_status(struct backlight_device *bl)
> +{
> +	struct mipi_dsi_device *dsi = bl_get_data(bl);
> +	u16 brightness = backlight_get_brightness(bl);
> +	int ret;
> +

[Severity: High]
Does this code send DSI commands without verifying if the panel is powered on?

If the panel regulators are disabled and reset is asserted via
ili7807s_unprepare(), attempting to communicate with it here during a sysfs
backlight update could result in DSI host bus timeouts or hardware lockups.

Should there be a check against a power state tracking flag before
sending the DCS command?

> +	dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
> +
> +	ret = mipi_dsi_dcs_set_display_brightness_large(dsi, brightness);
> +
> +	dsi->mode_flags |= MIPI_DSI_MODE_LPM;

[Severity: High]
Does unconditionally setting MIPI_DSI_MODE_LPM here permanently alter the
panel's base operating state?

Since the mode_flags are modified without synchronization with DRM modeset
paths (like ili7807s_on() and ili7807s_off()), could this create a data
race?

Also, the logic clears the flag before the transaction and unconditionally
sets it afterwards, leaving Low Power Mode permanently enabled for
subsequent DSI transmissions.

> +
> +	return ret;
> +}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260624-ili7807s-v3-0-ddf37052a289@oss.qualcomm.com?part=2