[PATCH v2 0/2] drm/panel: Add Ilitek IL79900A controller and bindings

[PATCH v2 0/2] drm/panel: Add Ilitek IL79900A controller and bindings

[Langyan Ye]

This series adds device tree bindings and a DRM panel driver for
the Ilitek IL79900A MIPI-DSI LCD controller, which is used in the
Tianma TL121BVMS07-00 12.1-inch panel.

Changes in v2:
- PATCH 1/2: Address Rob Herring’s review comments and align with panel-common.yaml conventions.
- PATCH 2/2: Rename driver to panel-ilitek-il79900a and align naming and structure with existing Ilitek panel drivers.
- Link to v1: https://lore.kernel.org/all/20250930075044.1368134-1-yelangyan@huaqin.corp-partner.google.com/

Langyan Ye (2):
  dt-bindings: display: panel: Add Tianma TL121BVMS07-00 panel
  drm/panel: Add driver for Ilitek IL79900A-based panels

 .../display/panel/ilitek,il79900a.yaml        |  64 +++
 drivers/gpu/drm/panel/panel-ilitek-il79900a.c | 394 ++++++++++++++++++
 2 files changed, 458 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/panel/ilitek,il79900a.yaml
 create mode 100644 drivers/gpu/drm/panel/panel-ilitek-il79900a.c

-- 
2.34.1

[PATCH v2 1/2] dt-bindings: display: panel: Add Tianma TL121BVMS07-00 panel

[Langyan Ye]

Add device tree bindings for the Tianma TL121BVMS07-00 12.1-inch
MIPI-DSI TFT LCD panel. The panel is based on the Ilitek IL79900A
controller.

Signed-off-by: Langyan Ye <yelangyan@huaqin.corp-partner.google.com>
---
 .../display/panel/ilitek,il79900a.yaml        | 64 +++++++++++++++++++
 1 file changed, 64 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/panel/ilitek,il79900a.yaml

diff --git a/Documentation/devicetree/bindings/display/panel/ilitek,il79900a.yaml b/Documentation/devicetree/bindings/display/panel/ilitek,il79900a.yaml
new file mode 100644
index 000000000000..a723f179efdf
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/panel/ilitek,il79900a.yaml
@@ -0,0 +1,64 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/panel/ilitek,il79900a.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Ilitek IL79900a based MIPI-DSI panels
+
+maintainers:
+  - Langyan Ye <yelangyan@huaqin.corp-partner.google.com>
+
+allOf:
+  - $ref: panel-common.yaml#
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - tianma,il79900a
+      - const: ilitek,il79900a
+
+  reg: true
+
+  enable-gpios:
+    maxItems: 1
+    description: GPIO specifier for the enable pin
+
+  avdd-supply:
+    description: Positive analog voltage supply (AVDD)
+
+  avee-supply:
+    description: Negative analog voltage supply (AVEE)
+
+  pp1800-supply:
+    description: 1.8V logic voltage supply
+
+required:
+  - compatible
+  - reg
+  - enable-gpios
+  - avdd-supply
+  - avee-supply
+  - pp1800-supply
+
+additionalProperties: false
+
+examples:
+  - |
+    dsi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        panel@0 {
+            compatible = "tianma,il79900a", "ilitek,il79900a";
+            reg = <0>;
+            enable-gpios = <&pio 25 0>;
+            avdd-supply = <&reg_avdd>;
+            avee-supply = <&reg_avee>;
+            pp1800-supply = <&reg_pp1800>;
+            backlight = <&backlight>;
+        };
+    };
+
+...
-- 
2.34.1

[PATCH v2 2/2] drm/panel: Add driver for Ilitek IL79900A-based panels

[Langyan Ye]

Add a DRM panel driver for the Ilitek IL79900A MIPI-DSI LCD controller.

The controller is used in panels such as the Tianma TL121BVMS07-00.
It requires multiple power supplies (AVDD, AVEE, 1.8V logic), an enable
GPIO, and a backlight device.

Signed-off-by: Langyan Ye <yelangyan@huaqin.corp-partner.google.com>
---
 drivers/gpu/drm/panel/panel-ilitek-il79900a.c | 394 ++++++++++++++++++
 1 file changed, 394 insertions(+)
 create mode 100644 drivers/gpu/drm/panel/panel-ilitek-il79900a.c

diff --git a/drivers/gpu/drm/panel/panel-ilitek-il79900a.c b/drivers/gpu/drm/panel/panel-ilitek-il79900a.c
new file mode 100644
index 000000000000..2134f8af673e
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-ilitek-il79900a.c
@@ -0,0 +1,394 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Panels based on the Ilitek IL79900A display controller.
+ */
+#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_connector.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_panel.h>
+
+#include <video/mipi_display.h>
+
+struct il79900a;
+
+/*
+ * Use this descriptor struct to describe different panels using the
+ * Ilitek IL79900A display controller.
+ */
+struct panel_desc {
+	const struct drm_display_mode *modes;
+	unsigned int bpc;
+
+	/**
+	 * @width_mm: width of the panel's active display area
+	 * @height_mm: height of the panel's active display area
+	 */
+	struct {
+		unsigned int width_mm;
+		unsigned int height_mm;
+	} size;
+
+	unsigned long mode_flags;
+	enum mipi_dsi_pixel_format format;
+	int (*init)(struct il79900a *boe);
+	unsigned int lanes;
+};
+
+struct il79900a {
+	struct drm_panel base;
+	struct mipi_dsi_device *dsi;
+
+	const struct panel_desc *desc;
+
+	enum drm_panel_orientation orientation;
+	struct regulator *pp1800;
+	struct regulator *avee;
+	struct regulator *avdd;
+	struct gpio_desc *enable_gpio;
+};
+
+/* IL79900A-specific commands, add new commands as you decode them */
+#define IL79900A_DCS_SWITCH_PAGE	0xFF
+
+#define il79900a_switch_page(ctx, page) \
+	mipi_dsi_dcs_write_seq_multi(ctx, IL79900A_DCS_SWITCH_PAGE, \
+				     0x5a, 0xa5, (page))
+
+static int tianma_il79900a_init(struct il79900a *ili)
+{
+	struct mipi_dsi_multi_context ctx = { .dsi = ili->dsi };
+
+	usleep_range(5000, 5100);
+
+	il79900a_switch_page(&ctx, 0x06);
+	mipi_dsi_dcs_write_seq_multi(&ctx, 0x3e, 0x62);
+
+	il79900a_switch_page(&ctx, 0x02);
+	mipi_dsi_dcs_write_seq_multi(&ctx, 0x1b, 0x20);
+	mipi_dsi_dcs_write_seq_multi(&ctx, 0x5d, 0x00);
+	mipi_dsi_dcs_write_seq_multi(&ctx, 0x5e, 0x40);
+
+	il79900a_switch_page(&ctx, 0x07);
+	mipi_dsi_dcs_write_seq_multi(&ctx, 0X29, 0x00);
+
+	il79900a_switch_page(&ctx, 0x06);
+	mipi_dsi_dcs_write_seq_multi(&ctx, 0x92, 0x22);
+
+	il79900a_switch_page(&ctx, 0x00);
+	mipi_dsi_dcs_write_seq_multi(&ctx, MIPI_DCS_EXIT_SLEEP_MODE);
+	if (ctx.accum_err)
+		return ctx.accum_err;
+
+	msleep(120);
+
+	mipi_dsi_dcs_write_seq_multi(&ctx, MIPI_DCS_SET_DISPLAY_ON);
+	if (ctx.accum_err)
+		return ctx.accum_err;
+
+	msleep(80);
+
+	return 0;
+};
+
+static inline struct il79900a *to_il79900a(struct drm_panel *panel)
+{
+	return container_of(panel, struct il79900a, base);
+}
+
+static int il79900a_enter_sleep_mode(struct il79900a *ili)
+{
+	struct mipi_dsi_device *dsi = ili->dsi;
+	int ret;
+
+	dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
+
+	ret = mipi_dsi_dcs_set_display_off(dsi);
+	if (ret < 0)
+		return ret;
+
+	ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int il79900a_disable(struct drm_panel *panel)
+{
+	struct il79900a *ili = to_il79900a(panel);
+	struct mipi_dsi_multi_context ctx = { .dsi = ili->dsi };
+	int ret;
+
+	il79900a_switch_page(&ctx, 0x00);
+	if (ctx.accum_err)
+		return ctx.accum_err;
+
+	ret = il79900a_enter_sleep_mode(ili);
+	if (ret < 0) {
+		dev_err(panel->dev, "failed to set panel off: %d\n", ret);
+		return ret;
+	}
+
+	msleep(150);
+
+	return 0;
+}
+
+static int il79900a_unprepare(struct drm_panel *panel)
+{
+	struct il79900a *ili = to_il79900a(panel);
+
+	gpiod_set_value(ili->enable_gpio, 0);
+	usleep_range(1000, 2000);
+	regulator_disable(ili->avee);
+	regulator_disable(ili->avdd);
+	usleep_range(5000, 7000);
+	regulator_disable(ili->pp1800);
+
+	return 0;
+}
+
+static int il79900a_prepare(struct drm_panel *panel)
+{
+	struct il79900a *ili = to_il79900a(panel);
+	int ret;
+
+	gpiod_set_value(ili->enable_gpio, 0);
+	usleep_range(1000, 1500);
+
+	ret = regulator_enable(ili->pp1800);
+	if (ret < 0)
+		return ret;
+
+	usleep_range(3000, 5000);
+
+	ret = regulator_enable(ili->avdd);
+	if (ret < 0)
+		goto poweroff1v8;
+	ret = regulator_enable(ili->avee);
+	if (ret < 0)
+		goto poweroffavdd;
+
+	usleep_range(10000, 11000);
+
+	// MIPI needs to keep the LP11 state before the lcm_reset pin is pulled high
+	ret = mipi_dsi_dcs_nop(ili->dsi);
+	if (ret < 0) {
+		dev_err(&ili->dsi->dev, "Failed to send NOP: %d\n", ret);
+		goto poweroff;
+	}
+	usleep_range(1000, 2000);
+
+	gpiod_set_value(ili->enable_gpio, 1);
+	usleep_range(1000, 2000);
+	gpiod_set_value(ili->enable_gpio, 0);
+	usleep_range(10000, 11000);
+	gpiod_set_value(ili->enable_gpio, 1);
+	usleep_range(20000, 21000);
+
+	ret = ili->desc->init(ili);
+	if (ret < 0)
+		goto poweroff;
+
+	return 0;
+
+poweroff:
+	gpiod_set_value(ili->enable_gpio, 0);
+	regulator_disable(ili->avee);
+poweroffavdd:
+	regulator_disable(ili->avdd);
+poweroff1v8:
+	usleep_range(5000, 7000);
+	regulator_disable(ili->pp1800);
+
+	return ret;
+}
+
+static int il79900a_enable(struct drm_panel *panel)
+{
+	msleep(130);
+	return 0;
+}
+
+static const struct drm_display_mode tianma_il79900a_default_mode = {
+	.clock = 264355,
+	.hdisplay = 1600,
+	.hsync_start = 1600 + 20,
+	.hsync_end = 1600 + 20 + 4,
+	.htotal = 1600 + 20 + 4 + 20,
+	.vdisplay = 2560,
+	.vsync_start = 2560 + 82,
+	.vsync_end = 2560 + 82 + 2,
+	.vtotal = 2560 + 82 + 2 + 36,
+};
+
+static const struct panel_desc tianma_il79900a_desc = {
+	.modes = &tianma_il79900a_default_mode,
+	.bpc = 8,
+	.size = {
+		.width_mm = 163,
+		.height_mm = 260,
+	},
+	.lanes = 3,
+	.format = MIPI_DSI_FMT_RGB888,
+	.mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
+		      MIPI_DSI_MODE_LPM,
+	.init = tianma_il79900a_init,
+};
+
+static int il79900a_get_modes(struct drm_panel *panel,
+			      struct drm_connector *connector)
+{
+	struct il79900a *ili = to_il79900a(panel);
+	const struct drm_display_mode *m = ili->desc->modes;
+	struct drm_display_mode *mode;
+
+	mode = drm_mode_duplicate(connector->dev, m);
+	if (!mode) {
+		dev_err(panel->dev, "failed to add mode %ux%u@%u\n",
+			m->hdisplay, m->vdisplay, drm_mode_vrefresh(m));
+		return -ENOMEM;
+	}
+
+	mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
+	drm_mode_set_name(mode);
+	drm_mode_probed_add(connector, mode);
+
+	connector->display_info.width_mm = ili->desc->size.width_mm;
+	connector->display_info.height_mm = ili->desc->size.height_mm;
+	connector->display_info.bpc = ili->desc->bpc;
+
+	return 1;
+}
+
+static enum drm_panel_orientation il79900a_get_orientation(struct drm_panel *panel)
+{
+	struct il79900a *ili = to_il79900a(panel);
+
+	return ili->orientation;
+}
+
+static const struct drm_panel_funcs il79900a_funcs = {
+	.disable = il79900a_disable,
+	.unprepare = il79900a_unprepare,
+	.prepare = il79900a_prepare,
+	.enable = il79900a_enable,
+	.get_modes = il79900a_get_modes,
+	.get_orientation = il79900a_get_orientation,
+};
+
+static int il79900a_add(struct il79900a *ili)
+{
+	struct device *dev = &ili->dsi->dev;
+	int err;
+
+	ili->avdd = devm_regulator_get(dev, "avdd");
+	if (IS_ERR(ili->avdd))
+		return PTR_ERR(ili->avdd);
+
+	ili->avee = devm_regulator_get(dev, "avee");
+	if (IS_ERR(ili->avee))
+		return PTR_ERR(ili->avee);
+
+	ili->pp1800 = devm_regulator_get(dev, "pp1800");
+	if (IS_ERR(ili->pp1800))
+		return PTR_ERR(ili->pp1800);
+
+	ili->enable_gpio = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
+	if (IS_ERR(ili->enable_gpio)) {
+		dev_err(dev, "cannot get reset-gpios %ld\n",
+			PTR_ERR(ili->enable_gpio));
+		return PTR_ERR(ili->enable_gpio);
+	}
+
+	gpiod_set_value(ili->enable_gpio, 0);
+
+	drm_panel_init(&ili->base, dev, &il79900a_funcs,
+		       DRM_MODE_CONNECTOR_DSI);
+	err = of_drm_get_panel_orientation(dev->of_node, &ili->orientation);
+	if (err < 0) {
+		dev_err(dev, "%pOF: failed to get orientation %d\n", dev->of_node, err);
+		return err;
+	}
+
+	err = drm_panel_of_backlight(&ili->base);
+	if (err)
+		return err;
+
+	ili->base.funcs = &il79900a_funcs;
+	ili->base.dev = &ili->dsi->dev;
+
+	drm_panel_add(&ili->base);
+
+	return 0;
+}
+
+static int il79900a_probe(struct mipi_dsi_device *dsi)
+{
+	struct il79900a *ili;
+	int ret;
+	const struct panel_desc *desc;
+
+	ili = devm_kzalloc(&dsi->dev, sizeof(*ili), GFP_KERNEL);
+	if (!ili)
+		return -ENOMEM;
+
+	desc = of_device_get_match_data(&dsi->dev);
+	dsi->lanes = desc->lanes;
+	dsi->format = desc->format;
+	dsi->mode_flags = desc->mode_flags;
+	ili->desc = desc;
+	ili->dsi = dsi;
+	ret = il79900a_add(ili);
+	if (ret < 0)
+		return ret;
+
+	mipi_dsi_set_drvdata(dsi, ili);
+
+	ret = mipi_dsi_attach(dsi);
+	if (ret)
+		drm_panel_remove(&ili->base);
+
+	return ret;
+}
+
+static void il79900a_remove(struct mipi_dsi_device *dsi)
+{
+	struct il79900a *ili = 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);
+
+	if (ili->base.dev)
+		drm_panel_remove(&ili->base);
+}
+
+static const struct of_device_id il79900a_of_match[] = {
+	{ .compatible = "tianma,il79900a",
+	  .data = &tianma_il79900a_desc
+	},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, il79900a_of_match);
+
+static struct mipi_dsi_driver il79900a_driver = {
+	.driver = {
+		.name = "panel-il79900a",
+		.of_match_table = il79900a_of_match,
+	},
+	.probe = il79900a_probe,
+	.remove = il79900a_remove,
+};
+module_mipi_dsi_driver(il79900a_driver);
+
+MODULE_AUTHOR("Langyan Ye <yelangyan@huaqin.corp-partner.google.com>");
+MODULE_DESCRIPTION("Ilitek IL79900A-based panels driver");
+MODULE_LICENSE("GPL");
-- 
2.34.1

Re: [PATCH v2 1/2] dt-bindings: display: panel: Add Tianma TL121BVMS07-00 panel

[Rob Herring (Arm)]

On Fri, 10 Oct 2025 17:37:50 +0800, Langyan Ye wrote:
> Add device tree bindings for the Tianma TL121BVMS07-00 12.1-inch
> MIPI-DSI TFT LCD panel. The panel is based on the Ilitek IL79900A
> controller.
> 
> Signed-off-by: Langyan Ye <yelangyan@huaqin.corp-partner.google.com>
> ---
>  .../display/panel/ilitek,il79900a.yaml        | 64 +++++++++++++++++++
>  1 file changed, 64 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/display/panel/ilitek,il79900a.yaml
> 

My bot found errors running 'make dt_binding_check' on your patch:

yamllint warnings/errors:

dtschema/dtc warnings/errors:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/display/panel/ilitek,il79900a.example.dtb: panel@0 (tianma,il79900a): 'backlight' does not match any of the regexes: '^pinctrl-[0-9]+$'
	from schema $id: http://devicetree.org/schemas/display/panel/ilitek,il79900a.yaml#

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20251010093751.2793492-2-yelangyan@huaqin.corp-partner.google.com

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.

Re: [PATCH v2 2/2] drm/panel: Add driver for Ilitek IL79900A-based panels

[Dmitry Baryshkov]

On Fri, Oct 10, 2025 at 05:37:51PM +0800, Langyan Ye wrote:
> Add a DRM panel driver for the Ilitek IL79900A MIPI-DSI LCD controller.
> 
> The controller is used in panels such as the Tianma TL121BVMS07-00.
> It requires multiple power supplies (AVDD, AVEE, 1.8V logic), an enable
> GPIO, and a backlight device.
> 
> Signed-off-by: Langyan Ye <yelangyan@huaqin.corp-partner.google.com>
> ---
>  drivers/gpu/drm/panel/panel-ilitek-il79900a.c | 394 ++++++++++++++++++
>  1 file changed, 394 insertions(+)
>  create mode 100644 drivers/gpu/drm/panel/panel-ilitek-il79900a.c
> 
> diff --git a/drivers/gpu/drm/panel/panel-ilitek-il79900a.c b/drivers/gpu/drm/panel/panel-ilitek-il79900a.c
> new file mode 100644
> index 000000000000..2134f8af673e
> --- /dev/null
> +++ b/drivers/gpu/drm/panel/panel-ilitek-il79900a.c
> @@ -0,0 +1,394 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Panels based on the Ilitek IL79900A display controller.
> + */
> +#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_connector.h>
> +#include <drm/drm_crtc.h>
> +#include <drm/drm_mipi_dsi.h>
> +#include <drm/drm_panel.h>
> +
> +#include <video/mipi_display.h>
> +
> +struct il79900a;
> +
> +/*
> + * Use this descriptor struct to describe different panels using the
> + * Ilitek IL79900A display controller.
> + */
> +struct panel_desc {
> +	const struct drm_display_mode *modes;
> +	unsigned int bpc;
> +
> +	/**
> +	 * @width_mm: width of the panel's active display area
> +	 * @height_mm: height of the panel's active display area
> +	 */
> +	struct {
> +		unsigned int width_mm;
> +		unsigned int height_mm;
> +	} size;


Move these to the mode

> +
> +	unsigned long mode_flags;
> +	enum mipi_dsi_pixel_format format;
> +	int (*init)(struct il79900a *boe);
> +	unsigned int lanes;
> +};
> +
> +struct il79900a {
> +	struct drm_panel base;
> +	struct mipi_dsi_device *dsi;
> +
> +	const struct panel_desc *desc;
> +
> +	enum drm_panel_orientation orientation;
> +	struct regulator *pp1800;
> +	struct regulator *avee;
> +	struct regulator *avdd;
> +	struct gpio_desc *enable_gpio;
> +};
> +
> +/* IL79900A-specific commands, add new commands as you decode them */
> +#define IL79900A_DCS_SWITCH_PAGE	0xFF
> +
> +#define il79900a_switch_page(ctx, page) \
> +	mipi_dsi_dcs_write_seq_multi(ctx, IL79900A_DCS_SWITCH_PAGE, \
> +				     0x5a, 0xa5, (page))
> +
> +static int tianma_il79900a_init(struct il79900a *ili)
> +{
> +	struct mipi_dsi_multi_context ctx = { .dsi = ili->dsi };
> +
> +	usleep_range(5000, 5100);

mipi_dsi_usleep_range

> +
> +	il79900a_switch_page(&ctx, 0x06);
> +	mipi_dsi_dcs_write_seq_multi(&ctx, 0x3e, 0x62);
> +
> +	il79900a_switch_page(&ctx, 0x02);
> +	mipi_dsi_dcs_write_seq_multi(&ctx, 0x1b, 0x20);
> +	mipi_dsi_dcs_write_seq_multi(&ctx, 0x5d, 0x00);
> +	mipi_dsi_dcs_write_seq_multi(&ctx, 0x5e, 0x40);
> +
> +	il79900a_switch_page(&ctx, 0x07);
> +	mipi_dsi_dcs_write_seq_multi(&ctx, 0X29, 0x00);
> +
> +	il79900a_switch_page(&ctx, 0x06);
> +	mipi_dsi_dcs_write_seq_multi(&ctx, 0x92, 0x22);
> +
> +	il79900a_switch_page(&ctx, 0x00);
> +	mipi_dsi_dcs_write_seq_multi(&ctx, MIPI_DCS_EXIT_SLEEP_MODE);
> +	if (ctx.accum_err)
> +		return ctx.accum_err;

Drop

> +
> +	msleep(120);

mipi_dsi_msleep

> +
> +	mipi_dsi_dcs_write_seq_multi(&ctx, MIPI_DCS_SET_DISPLAY_ON);
> +	if (ctx.accum_err)
> +		return ctx.accum_err;

drop

> +
> +	msleep(80);

mipi_dsi_msleep
> +
> +	return 0;
> +};
> +
> +static inline struct il79900a *to_il79900a(struct drm_panel *panel)
> +{
> +	return container_of(panel, struct il79900a, base);
> +}
> +
> +static int il79900a_enter_sleep_mode(struct il79900a *ili)
> +{
> +	struct mipi_dsi_device *dsi = ili->dsi;
> +	int ret;
> +
> +	dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
> +
> +	ret = mipi_dsi_dcs_set_display_off(dsi);

_multi

> +	if (ret < 0)
> +		return ret;
> +
> +	ret = mipi_dsi_dcs_enter_sleep_mode(dsi);

_multi

> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int il79900a_disable(struct drm_panel *panel)
> +{
> +	struct il79900a *ili = to_il79900a(panel);
> +	struct mipi_dsi_multi_context ctx = { .dsi = ili->dsi };
> +	int ret;
> +
> +	il79900a_switch_page(&ctx, 0x00);
> +	if (ctx.accum_err)
> +		return ctx.accum_err;
> +
> +	ret = il79900a_enter_sleep_mode(ili);

Pass context to that function

> +	if (ret < 0) {
> +		dev_err(panel->dev, "failed to set panel off: %d\n", ret);
> +		return ret;
> +	}
> +
> +	msleep(150);

mipi_dsi_msleep

> +
> +	return 0;
> +}
> +
> +static int il79900a_unprepare(struct drm_panel *panel)
> +{
> +	struct il79900a *ili = to_il79900a(panel);
> +
> +	gpiod_set_value(ili->enable_gpio, 0);
> +	usleep_range(1000, 2000);
> +	regulator_disable(ili->avee);
> +	regulator_disable(ili->avdd);
> +	usleep_range(5000, 7000);
> +	regulator_disable(ili->pp1800);
> +
> +	return 0;
> +}
> +
> +static int il79900a_prepare(struct drm_panel *panel)
> +{
> +	struct il79900a *ili = to_il79900a(panel);
> +	int ret;
> +
> +	gpiod_set_value(ili->enable_gpio, 0);
> +	usleep_range(1000, 1500);
> +
> +	ret = regulator_enable(ili->pp1800);
> +	if (ret < 0)
> +		return ret;
> +
> +	usleep_range(3000, 5000);
> +
> +	ret = regulator_enable(ili->avdd);
> +	if (ret < 0)
> +		goto poweroff1v8;
> +	ret = regulator_enable(ili->avee);
> +	if (ret < 0)
> +		goto poweroffavdd;
> +
> +	usleep_range(10000, 11000);
> +
> +	// MIPI needs to keep the LP11 state before the lcm_reset pin is pulled high
> +	ret = mipi_dsi_dcs_nop(ili->dsi);
> +	if (ret < 0) {
> +		dev_err(&ili->dsi->dev, "Failed to send NOP: %d\n", ret);
> +		goto poweroff;
> +	}
> +	usleep_range(1000, 2000);
> +
> +	gpiod_set_value(ili->enable_gpio, 1);
> +	usleep_range(1000, 2000);
> +	gpiod_set_value(ili->enable_gpio, 0);
> +	usleep_range(10000, 11000);
> +	gpiod_set_value(ili->enable_gpio, 1);
> +	usleep_range(20000, 21000);
> +
> +	ret = ili->desc->init(ili);
> +	if (ret < 0)
> +		goto poweroff;
> +
> +	return 0;
> +
> +poweroff:
> +	gpiod_set_value(ili->enable_gpio, 0);
> +	regulator_disable(ili->avee);
> +poweroffavdd:
> +	regulator_disable(ili->avdd);
> +poweroff1v8:
> +	usleep_range(5000, 7000);
> +	regulator_disable(ili->pp1800);
> +
> +	return ret;
> +}
> +
> +static int il79900a_enable(struct drm_panel *panel)
> +{
> +	msleep(130);

Why?

> +	return 0;
> +}
> +
> +static const struct drm_display_mode tianma_il79900a_default_mode = {
> +	.clock = 264355,
> +	.hdisplay = 1600,
> +	.hsync_start = 1600 + 20,
> +	.hsync_end = 1600 + 20 + 4,
> +	.htotal = 1600 + 20 + 4 + 20,
> +	.vdisplay = 2560,
> +	.vsync_start = 2560 + 82,
> +	.vsync_end = 2560 + 82 + 2,
> +	.vtotal = 2560 + 82 + 2 + 36,
> +};
> +
> +static const struct panel_desc tianma_il79900a_desc = {
> +	.modes = &tianma_il79900a_default_mode,
> +	.bpc = 8,
> +	.size = {
> +		.width_mm = 163,
> +		.height_mm = 260,
> +	},
> +	.lanes = 3,
> +	.format = MIPI_DSI_FMT_RGB888,
> +	.mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
> +		      MIPI_DSI_MODE_LPM,
> +	.init = tianma_il79900a_init,
> +};
> +
> +static int il79900a_get_modes(struct drm_panel *panel,
> +			      struct drm_connector *connector)
> +{
> +	struct il79900a *ili = to_il79900a(panel);
> +	const struct drm_display_mode *m = ili->desc->modes;
> +	struct drm_display_mode *mode;
> +
> +	mode = drm_mode_duplicate(connector->dev, m);
> +	if (!mode) {
> +		dev_err(panel->dev, "failed to add mode %ux%u@%u\n",
> +			m->hdisplay, m->vdisplay, drm_mode_vrefresh(m));
> +		return -ENOMEM;
> +	}
> +
> +	mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
> +	drm_mode_set_name(mode);
> +	drm_mode_probed_add(connector, mode);
> +
> +	connector->display_info.width_mm = ili->desc->size.width_mm;
> +	connector->display_info.height_mm = ili->desc->size.height_mm;

drm_connector_helper_get_modes_fixed()

> +	connector->display_info.bpc = ili->desc->bpc;
> +
> +	return 1;
> +}
> +
> +static enum drm_panel_orientation il79900a_get_orientation(struct drm_panel *panel)
> +{
> +	struct il79900a *ili = to_il79900a(panel);
> +
> +	return ili->orientation;
> +}
> +
> +static const struct drm_panel_funcs il79900a_funcs = {
> +	.disable = il79900a_disable,
> +	.unprepare = il79900a_unprepare,
> +	.prepare = il79900a_prepare,
> +	.enable = il79900a_enable,
> +	.get_modes = il79900a_get_modes,
> +	.get_orientation = il79900a_get_orientation,
> +};
> +
> +static int il79900a_add(struct il79900a *ili)
> +{
> +	struct device *dev = &ili->dsi->dev;
> +	int err;
> +
> +	ili->avdd = devm_regulator_get(dev, "avdd");
> +	if (IS_ERR(ili->avdd))
> +		return PTR_ERR(ili->avdd);
> +
> +	ili->avee = devm_regulator_get(dev, "avee");
> +	if (IS_ERR(ili->avee))
> +		return PTR_ERR(ili->avee);
> +
> +	ili->pp1800 = devm_regulator_get(dev, "pp1800");
> +	if (IS_ERR(ili->pp1800))
> +		return PTR_ERR(ili->pp1800);
> +
> +	ili->enable_gpio = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
> +	if (IS_ERR(ili->enable_gpio)) {
> +		dev_err(dev, "cannot get reset-gpios %ld\n",
> +			PTR_ERR(ili->enable_gpio));
> +		return PTR_ERR(ili->enable_gpio);
> +	}
> +
> +	gpiod_set_value(ili->enable_gpio, 0);
> +
> +	drm_panel_init(&ili->base, dev, &il79900a_funcs,
> +		       DRM_MODE_CONNECTOR_DSI);
> +	err = of_drm_get_panel_orientation(dev->of_node, &ili->orientation);
> +	if (err < 0) {
> +		dev_err(dev, "%pOF: failed to get orientation %d\n", dev->of_node, err);
> +		return err;
> +	}
> +
> +	err = drm_panel_of_backlight(&ili->base);
> +	if (err)
> +		return err;
> +
> +	ili->base.funcs = &il79900a_funcs;
> +	ili->base.dev = &ili->dsi->dev;
> +
> +	drm_panel_add(&ili->base);
> +
> +	return 0;
> +}
> +
> +static int il79900a_probe(struct mipi_dsi_device *dsi)
> +{
> +	struct il79900a *ili;
> +	int ret;
> +	const struct panel_desc *desc;
> +
> +	ili = devm_kzalloc(&dsi->dev, sizeof(*ili), GFP_KERNEL);
> +	if (!ili)
> +		return -ENOMEM;
> +
> +	desc = of_device_get_match_data(&dsi->dev);
> +	dsi->lanes = desc->lanes;
> +	dsi->format = desc->format;
> +	dsi->mode_flags = desc->mode_flags;
> +	ili->desc = desc;
> +	ili->dsi = dsi;
> +	ret = il79900a_add(ili);
> +	if (ret < 0)
> +		return ret;
> +
> +	mipi_dsi_set_drvdata(dsi, ili);
> +
> +	ret = mipi_dsi_attach(dsi);
> +	if (ret)
> +		drm_panel_remove(&ili->base);
> +
> +	return ret;
> +}
> +
> +static void il79900a_remove(struct mipi_dsi_device *dsi)
> +{
> +	struct il79900a *ili = 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);
> +
> +	if (ili->base.dev)
> +		drm_panel_remove(&ili->base);
> +}
> +
> +static const struct of_device_id il79900a_of_match[] = {
> +	{ .compatible = "tianma,il79900a",
> +	  .data = &tianma_il79900a_desc
> +	},

Single line

> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, il79900a_of_match);
> +
> +static struct mipi_dsi_driver il79900a_driver = {
> +	.driver = {
> +		.name = "panel-il79900a",
> +		.of_match_table = il79900a_of_match,
> +	},
> +	.probe = il79900a_probe,
> +	.remove = il79900a_remove,
> +};
> +module_mipi_dsi_driver(il79900a_driver);
> +
> +MODULE_AUTHOR("Langyan Ye <yelangyan@huaqin.corp-partner.google.com>");
> +MODULE_DESCRIPTION("Ilitek IL79900A-based panels driver");
> +MODULE_LICENSE("GPL");
> -- 
> 2.34.1
> 

-- 
With best wishes
Dmitry