* [PATCH v6 0/2] drm/panel: Add support for the FocusLCDs E35GH-I-MW800CB
@ 2026-06-17 14:32 Igor Reznichenko
2026-06-17 14:32 ` [PATCH v6 1/2] dt-bindings: display: panel: Add Ilitek ILI9488 panel controller Igor Reznichenko
2026-06-17 14:32 ` [PATCH v6 2/2] drm/panel: Add Ilitek ILI9488 controller driver Igor Reznichenko
0 siblings, 2 replies; 4+ messages in thread
From: Igor Reznichenko @ 2026-06-17 14:32 UTC (permalink / raw)
To: Neil Armstrong, Jessica Zhang, Maarten Lankhorst, Maxime Ripard,
Thomas Zimmermann, David Airlie, Simona Vetter, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Heiko Stuebner, Lad Prabhakar,
Manivannan Sadhasivam, Kael D'Alcamo, Kever Yang
Cc: dri-devel, devicetree, linux-kernel
Add support for E35GH-I-MW800CB 320x480 MIPI DSI panel by FocusLCDs.
The panel uses Ilitek ILI9488 driver IC in DSI mode specifically.
ILI9488 also appears in DBI/SPI panels, but those require different bus drivers.
This panel driver has been tested on STM32MP157D-DK1 in addition to TI AM62P EVK.
The panel works in video mode on both platforms. Additional panels using
ILI9488 DSI can be added later with their own timings.
v6: Rebased
No functional changes
v5: Rebased
Switched to devm_drm_panel_add() and devm_mipi_dsi_attach()
Dropped not required anymore .remove callback
Added display_info.bpc=6 initialization
Changed 0x21 DCS command to send 0 arguments as per spec
https://lore.kernel.org/all/20260529062836.203990-1-igor@reznichenko.net/
v4: Rebased
Tested 7.1-rc5 on STM32MP157D-DK1
Adjusted E35GH-I-MW800CB mode timing to a 14.4 MHz pixel clock with
slightly increased blanking to make it more synthesizable across DSI hosts
https://lore.kernel.org/all/20260527062300.88928-1-igor@reznichenko.net/
v3: Fixed missing Reviewed-by tag
https://lore.kernel.org/all/20260204060114.345219-1-igor@reznichenko.net/
v2: Added comment explaining the "focuslcds" vendor prefix
https://lore.kernel.org/all/20260203054121.335441-1-igor@reznichenko.net/
v1:
https://lore.kernel.org/all/20260131034101.307486-1-igor@reznichenko.net/
Igor Reznichenko (2):
dt-bindings: display: panel: Add Ilitek ILI9488 panel controller
drm/panel: Add Ilitek ILI9488 controller driver
.../display/panel/ilitek,ili9488.yaml | 63 ++++
.../devicetree/bindings/vendor-prefixes.yaml | 2 +
MAINTAINERS | 6 +
drivers/gpu/drm/panel/Kconfig | 9 +
drivers/gpu/drm/panel/Makefile | 1 +
drivers/gpu/drm/panel/panel-ilitek-ili9488.c | 289 ++++++++++++++++++
6 files changed, 370 insertions(+)
create mode 100644 Documentation/devicetree/bindings/display/panel/ilitek,ili9488.yaml
create mode 100644 drivers/gpu/drm/panel/panel-ilitek-ili9488.c
base-commit: 4af021a977735420e8fe18d64bef18ad0608d981
--
2.43.0
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH v6 1/2] dt-bindings: display: panel: Add Ilitek ILI9488 panel controller
2026-06-17 14:32 [PATCH v6 0/2] drm/panel: Add support for the FocusLCDs E35GH-I-MW800CB Igor Reznichenko
@ 2026-06-17 14:32 ` Igor Reznichenko
2026-06-17 14:32 ` [PATCH v6 2/2] drm/panel: Add Ilitek ILI9488 controller driver Igor Reznichenko
1 sibling, 0 replies; 4+ messages in thread
From: Igor Reznichenko @ 2026-06-17 14:32 UTC (permalink / raw)
To: Neil Armstrong, Jessica Zhang, Maarten Lankhorst, Maxime Ripard,
Thomas Zimmermann, David Airlie, Simona Vetter, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Heiko Stuebner, Lad Prabhakar,
Manivannan Sadhasivam, Kael D'Alcamo, Kever Yang
Cc: dri-devel, devicetree, linux-kernel, Conor Dooley
Add binding for the Ilitek ILI9488 panel controller which is found on
the FocusLCDs E35GH-I-MW800-CB MIPI DSI panel. Add "focuslcds" to
vendor-prefixes.yaml as it's a brandname and a website
(https://focuslcds.com/) for Focus Display Solutions, Inc.
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Igor Reznichenko <igor@reznichenko.net>
---
.../display/panel/ilitek,ili9488.yaml | 63 +++++++++++++++++++
.../devicetree/bindings/vendor-prefixes.yaml | 2 +
2 files changed, 65 insertions(+)
create mode 100644 Documentation/devicetree/bindings/display/panel/ilitek,ili9488.yaml
diff --git a/Documentation/devicetree/bindings/display/panel/ilitek,ili9488.yaml b/Documentation/devicetree/bindings/display/panel/ilitek,ili9488.yaml
new file mode 100644
index 000000000000..ea7449273022
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/panel/ilitek,ili9488.yaml
@@ -0,0 +1,63 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/panel/ilitek,ili9488.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Ilitek ILI9488 based MIPI-DSI panels
+
+maintainers:
+ - Igor Reznichenko <igor@reznichenko.net>
+
+allOf:
+ - $ref: panel-common.yaml#
+
+properties:
+ compatible:
+ items:
+ - enum:
+ - focuslcds,e35gh-i-mw800cb
+ - const: ilitek,ili9488
+
+ reg:
+ maxItems: 1
+
+ vci-supply: true
+ iovcc-supply: true
+
+required:
+ - compatible
+ - reg
+ - vci-supply
+ - iovcc-supply
+ - reset-gpios
+ - backlight
+ - port
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+
+ dsi {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ panel@0 {
+ compatible = "focuslcds,e35gh-i-mw800cb", "ilitek,ili9488";
+ reg = <0>;
+ vci-supply = <®_vci_panel>;
+ iovcc-supply = <®_iovcc_panel>;
+ reset-gpios = <&gpio3 6 GPIO_ACTIVE_LOW>;
+ backlight = <&pwm_bl>;
+
+ port {
+ panel_in: endpoint {
+ remote-endpoint = <&dsi_out>;
+ };
+ };
+ };
+ };
+
+...
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
index 6d742a317642..db0dc4b44ed5 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
+++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
@@ -602,6 +602,8 @@ patternProperties:
description: Flipkart Inc.
"^focaltech,.*":
description: FocalTech Systems Co.,Ltd
+ "^focuslcds,.*":
+ description: Focus Display Solutions, Inc.
"^forlinx,.*":
description: Baoding Forlinx Embedded Technology Co., Ltd.
"^foursemi,.*":
--
2.43.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH v6 2/2] drm/panel: Add Ilitek ILI9488 controller driver
2026-06-17 14:32 [PATCH v6 0/2] drm/panel: Add support for the FocusLCDs E35GH-I-MW800CB Igor Reznichenko
2026-06-17 14:32 ` [PATCH v6 1/2] dt-bindings: display: panel: Add Ilitek ILI9488 panel controller Igor Reznichenko
@ 2026-06-17 14:32 ` Igor Reznichenko
2026-06-17 14:44 ` sashiko-bot
1 sibling, 1 reply; 4+ messages in thread
From: Igor Reznichenko @ 2026-06-17 14:32 UTC (permalink / raw)
To: Neil Armstrong, Jessica Zhang, Maarten Lankhorst, Maxime Ripard,
Thomas Zimmermann, David Airlie, Simona Vetter, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Heiko Stuebner, Lad Prabhakar,
Manivannan Sadhasivam, Kael D'Alcamo, Kever Yang
Cc: dri-devel, devicetree, linux-kernel
Add support for Ilitek ILI9488 DSI controller which is used in
FocusLCDs E35GH-I-MW800-CB 320x480 MIPI DSI panel. The mode timing
was adjusted after STM32MP157 testing. The previous 14.256 MHz mode
worked on AM62P, but was awkward for STM32 DSI/LTDC clock synthesis.
Signed-off-by: Igor Reznichenko <igor@reznichenko.net>
---
MAINTAINERS | 6 +
drivers/gpu/drm/panel/Kconfig | 9 +
drivers/gpu/drm/panel/Makefile | 1 +
drivers/gpu/drm/panel/panel-ilitek-ili9488.c | 289 +++++++++++++++++++
4 files changed, 305 insertions(+)
create mode 100644 drivers/gpu/drm/panel/panel-ilitek-ili9488.c
diff --git a/MAINTAINERS b/MAINTAINERS
index ac87c217ab1f..987635948cde 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8040,6 +8040,12 @@ T: git https://gitlab.freedesktop.org/drm/misc/kernel.git
F: Documentation/devicetree/bindings/display/ilitek,ili9486.yaml
F: drivers/gpu/drm/tiny/ili9486.c
+DRM DRIVER FOR ILITEK ILI9488 PANELS
+M: Igor Reznichenko <igor@reznichenko.net>
+S: Maintained
+F: Documentation/devicetree/bindings/display/panel/ilitek,ili9488.yaml
+F: drivers/gpu/drm/panel/panel-ilitek-ili9488.c
+
DRM DRIVER FOR ILITEK ILI9805 PANELS
M: Michael Trimarchi <michael@amarulasolutions.com>
S: Maintained
diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index 7450b27622a2..37987e47f3f7 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -284,6 +284,15 @@ config DRM_PANEL_ILITEK_ILI9341
QVGA (240x320) RGB panels. support serial & parallel rgb
interface.
+config DRM_PANEL_ILITEK_ILI9488
+ tristate "Ilitek ILI9488-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 ILI9488 controller.
+
config DRM_PANEL_ILITEK_ILI9805
tristate "Ilitek ILI9805-based panels"
depends on OF
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index c2c5cf817116..a1344a0a3fd0 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -28,6 +28,7 @@ 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_IL9322) += panel-ilitek-ili9322.o
obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9341) += panel-ilitek-ili9341.o
+obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9488) += panel-ilitek-ili9488.o
obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9805) += panel-ilitek-ili9805.o
obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9806E_CORE) += panel-ilitek-ili9806e-core.o
obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9806E_DSI) += panel-ilitek-ili9806e-dsi.o
diff --git a/drivers/gpu/drm/panel/panel-ilitek-ili9488.c b/drivers/gpu/drm/panel/panel-ilitek-ili9488.c
new file mode 100644
index 000000000000..7302766034fc
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-ilitek-ili9488.c
@@ -0,0 +1,289 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+
+#include <linux/gpio/consumer.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>
+
+#include <video/mipi_display.h>
+
+struct ili9488_desc {
+ const struct drm_display_mode *display_mode;
+ unsigned long mode_flags;
+ enum mipi_dsi_pixel_format format;
+ unsigned int lanes;
+ unsigned int bpc;
+ void (*init_sequence)(struct mipi_dsi_multi_context *ctx);
+};
+
+struct ili9488 {
+ struct drm_panel panel;
+ struct mipi_dsi_device *dsi;
+ struct gpio_desc *reset;
+ struct regulator_bulk_data supplies[2];
+ const struct ili9488_desc *desc;
+ enum drm_panel_orientation orientation;
+};
+
+static const char * const regulator_names[] = {
+ "vci",
+ "iovcc",
+};
+
+static void e35gh_i_mw800cb_init(struct mipi_dsi_multi_context *ctx)
+{
+ /* Gamma control 1,2 */
+ mipi_dsi_dcs_write_seq_multi(ctx, 0xE0, 0x00, 0x10, 0x14, 0x01, 0x0E, 0x04, 0x33,
+ 0x56, 0x48, 0x03, 0x0C, 0x0B, 0x2B, 0x34, 0x0F);
+ mipi_dsi_dcs_write_seq_multi(ctx, 0xE1, 0x00, 0x12, 0x18, 0x05, 0x12, 0x06, 0x40,
+ 0x34, 0x57, 0x06, 0x10, 0x0C, 0x3B, 0x3F, 0x0F);
+ /* Power control 1,2 */
+ mipi_dsi_dcs_write_seq_multi(ctx, 0xC0, 0x0F, 0x0C);
+ mipi_dsi_dcs_write_seq_multi(ctx, 0xC1, 0x41);
+ /* VCOM Control */
+ mipi_dsi_dcs_write_seq_multi(ctx, 0xC5, 0x00, 0x25, 0x80);
+ mipi_dsi_dcs_write_seq_multi(ctx, 0x36, 0x48);
+ /* Interface pixel format 18bpp */
+ mipi_dsi_dcs_write_seq_multi(ctx, 0x3A, 0x66);
+ mipi_dsi_dcs_write_seq_multi(ctx, 0xB0, 0x00);
+ mipi_dsi_dcs_write_seq_multi(ctx, 0xB1, 0xA0);
+ mipi_dsi_dcs_write_seq_multi(ctx, 0xB4, 0x02);
+ mipi_dsi_dcs_write_seq_multi(ctx, 0xB6, 0x02, 0x02, 0x3B);
+ mipi_dsi_dcs_write_seq_multi(ctx, 0xE9, 0x00);
+ mipi_dsi_dcs_write_seq_multi(ctx, 0xF7, 0xA9, 0x51, 0x2C, 0x82);
+ mipi_dsi_dcs_write_seq_multi(ctx, 0x21);
+}
+
+static const struct drm_display_mode e35gh_i_mw800cb_display_mode = {
+ .clock = 14400,
+
+ .hdisplay = 320,
+ .hsync_start = 320 + 60,
+ .hsync_end = 320 + 60 + 20,
+ .htotal = 320 + 60 + 20 + 42,
+
+ .vdisplay = 480,
+ .vsync_start = 480 + 20,
+ .vsync_end = 480 + 20 + 10,
+ .vtotal = 480 + 20 + 10 + 33,
+
+ .width_mm = 48,
+ .height_mm = 73,
+
+ .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
+ .type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
+};
+
+static inline struct ili9488 *panel_to_ili9488(struct drm_panel *panel)
+{
+ return container_of(panel, struct ili9488, panel);
+}
+
+static int ili9488_power_on(struct ili9488 *ili)
+{
+ struct mipi_dsi_device *dsi = ili->dsi;
+ int ret;
+
+ ret = regulator_bulk_enable(ARRAY_SIZE(ili->supplies), ili->supplies);
+ if (ret < 0) {
+ dev_err(&dsi->dev, "regulator bulk enable failed: %d\n", ret);
+ return ret;
+ }
+
+ gpiod_set_value_cansleep(ili->reset, 0);
+ usleep_range(1000, 5000);
+ gpiod_set_value_cansleep(ili->reset, 1);
+ usleep_range(1000, 5000);
+ gpiod_set_value_cansleep(ili->reset, 0);
+ usleep_range(5000, 10000);
+
+ return 0;
+}
+
+static int ili9488_power_off(struct ili9488 *ili)
+{
+ struct mipi_dsi_device *dsi = ili->dsi;
+ int ret;
+
+ gpiod_set_value_cansleep(ili->reset, 1);
+
+ ret = regulator_bulk_disable(ARRAY_SIZE(ili->supplies), ili->supplies);
+ if (ret)
+ dev_err(&dsi->dev, "regulator bulk disable failed: %d\n", ret);
+
+ return ret;
+}
+
+static int ili9488_activate(struct ili9488 *ili)
+{
+ struct mipi_dsi_multi_context ctx = { .dsi = ili->dsi };
+
+ if (ili->desc->init_sequence)
+ ili->desc->init_sequence(&ctx);
+
+ mipi_dsi_dcs_exit_sleep_mode_multi(&ctx);
+ mipi_dsi_msleep(&ctx, 120);
+ mipi_dsi_dcs_set_display_on_multi(&ctx);
+
+ return ctx.accum_err;
+}
+
+static int ili9488_prepare(struct drm_panel *panel)
+{
+ struct ili9488 *ili = panel_to_ili9488(panel);
+ int ret;
+
+ ret = ili9488_power_on(ili);
+ if (ret)
+ return ret;
+
+ ret = ili9488_activate(ili);
+ if (ret) {
+ ili9488_power_off(ili);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int ili9488_deactivate(struct ili9488 *ili)
+{
+ struct mipi_dsi_multi_context ctx = { .dsi = ili->dsi };
+
+ mipi_dsi_dcs_set_display_off_multi(&ctx);
+ mipi_dsi_dcs_enter_sleep_mode_multi(&ctx);
+ mipi_dsi_msleep(&ctx, 120);
+
+ return ctx.accum_err;
+}
+
+static int ili9488_unprepare(struct drm_panel *panel)
+{
+ struct ili9488 *ili = panel_to_ili9488(panel);
+ struct mipi_dsi_device *dsi = ili->dsi;
+ int ret;
+
+ ili9488_deactivate(ili);
+ ret = ili9488_power_off(ili);
+ if (ret < 0)
+ dev_err(&dsi->dev, "power off failed: %d\n", ret);
+
+ return ret;
+}
+
+static int ili9488_get_modes(struct drm_panel *panel, struct drm_connector *connector)
+{
+ struct ili9488 *ili = panel_to_ili9488(panel);
+ const struct drm_display_mode *mode = ili->desc->display_mode;
+
+ connector->display_info.bpc = ili->desc->bpc;
+
+ return drm_connector_helper_get_modes_fixed(connector, mode);
+}
+
+static enum drm_panel_orientation ili9488_get_orientation(struct drm_panel *panel)
+{
+ struct ili9488 *ili = panel_to_ili9488(panel);
+
+ return ili->orientation;
+}
+
+static const struct drm_panel_funcs ili9488_funcs = {
+ .prepare = ili9488_prepare,
+ .unprepare = ili9488_unprepare,
+ .get_modes = ili9488_get_modes,
+ .get_orientation = ili9488_get_orientation,
+};
+
+static int ili9488_dsi_probe(struct mipi_dsi_device *dsi)
+{
+ struct device *dev = &dsi->dev;
+ struct ili9488 *ili;
+ int i, ret;
+
+ ili = devm_drm_panel_alloc(dev, struct ili9488, panel, &ili9488_funcs,
+ DRM_MODE_CONNECTOR_DSI);
+ if (IS_ERR(ili))
+ return PTR_ERR(ili);
+
+ ili->desc = device_get_match_data(dev);
+ ili->dsi = dsi;
+
+ dsi->mode_flags = ili->desc->mode_flags;
+ dsi->format = ili->desc->format;
+ dsi->lanes = ili->desc->lanes;
+
+ ili->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+ if (IS_ERR(ili->reset))
+ return dev_err_probe(dev, PTR_ERR(ili->reset),
+ "failed to get reset-gpios\n");
+
+ for (i = 0; i < ARRAY_SIZE(ili->supplies); i++)
+ ili->supplies[i].supply = regulator_names[i];
+
+ ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ili->supplies),
+ ili->supplies);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "failed to get regulators\n");
+
+ ret = of_drm_get_panel_orientation(dev->of_node, &ili->orientation);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to get orientation\n");
+
+ ret = drm_panel_of_backlight(&ili->panel);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to get backlight\n");
+
+ ili->panel.prepare_prev_first = true;
+
+ ret = devm_drm_panel_add(dev, &ili->panel);
+ if (ret)
+ return ret;
+
+ ret = devm_mipi_dsi_attach(dev, dsi);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "failed to attach to DSI host\n");
+
+ return 0;
+}
+
+static const struct ili9488_desc e35gh_i_mw800cb_desc = {
+ .init_sequence = e35gh_i_mw800cb_init,
+ .display_mode = &e35gh_i_mw800cb_display_mode,
+ .mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
+ MIPI_DSI_MODE_LPM | MIPI_DSI_CLOCK_NON_CONTINUOUS,
+ .format = MIPI_DSI_FMT_RGB666_PACKED,
+ .lanes = 1,
+ .bpc = 6,
+};
+
+static const struct of_device_id ili9488_of_match[] = {
+ { .compatible = "focuslcds,e35gh-i-mw800cb", .data = &e35gh_i_mw800cb_desc },
+ { }
+};
+
+MODULE_DEVICE_TABLE(of, ili9488_of_match);
+
+static struct mipi_dsi_driver ili9488_dsi_driver = {
+ .probe = ili9488_dsi_probe,
+ .driver = {
+ .name = "ili9488-dsi",
+ .of_match_table = ili9488_of_match,
+ },
+};
+module_mipi_dsi_driver(ili9488_dsi_driver);
+
+MODULE_AUTHOR("Igor Reznichenko <igor@reznichenko.net>");
+MODULE_DESCRIPTION("Ilitek ILI9488 Controller Driver");
+MODULE_LICENSE("GPL");
--
2.43.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v6 2/2] drm/panel: Add Ilitek ILI9488 controller driver
2026-06-17 14:32 ` [PATCH v6 2/2] drm/panel: Add Ilitek ILI9488 controller driver Igor Reznichenko
@ 2026-06-17 14:44 ` sashiko-bot
0 siblings, 0 replies; 4+ messages in thread
From: sashiko-bot @ 2026-06-17 14:44 UTC (permalink / raw)
To: Igor Reznichenko; +Cc: dri-devel, devicetree, robh, conor+dt
Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [High] Missing NULL check for the result of device_get_match_data() leads to a kernel oops.
- [High] Undefined function call and missing DRM panel unregistration leading to Use-After-Free.
--
commit c22f05cd630ecc7dace66102729e2ea4cdfd93fc
Author: Igor Reznichenko <igor@reznichenko.net>
drm/panel: Add Ilitek ILI9488 controller driver
This commit adds support for the Ilitek ILI9488 DSI controller.
It introduces power sequencing and DSI initialization tailored
for the FocusLCDs E35GH-I-MW800-CB panel.
> diff --git a/drivers/gpu/drm/panel/panel-ilitek-ili9488.c b/drivers/gpu/drm/panel/panel-ilitek-ili9488.c
> new file mode 100644
> index 0000000000000..7302766034fc9
> --- /dev/null
> +++ b/drivers/gpu/drm/panel/panel-ilitek-ili9488.c
[ ... ]
> +static int ili9488_dsi_probe(struct mipi_dsi_device *dsi)
> +{
> + struct device *dev = &dsi->dev;
> + struct ili9488 *ili;
> + int i, ret;
> +
> + ili = devm_drm_panel_alloc(dev, struct ili9488, panel, &ili9488_funcs,
> + DRM_MODE_CONNECTOR_DSI);
> + if (IS_ERR(ili))
> + return PTR_ERR(ili);
> +
> + ili->desc = device_get_match_data(dev);
> + ili->dsi = dsi;
> +
> + dsi->mode_flags = ili->desc->mode_flags;
[Severity: High]
Can this dereference a NULL pointer if the device is instantiated without
matching firmware data?
The function device_get_match_data() can return NULL, for example via sysfs
or string-based matching. Verifying the return value before accessing
ili->desc->mode_flags would prevent a potential NULL pointer dereference.
[ ... ]
> + ret = drm_panel_of_backlight(&ili->panel);
> + if (ret)
> + return dev_err_probe(dev, ret, "failed to get backlight\n");
> +
> + ili->panel.prepare_prev_first = true;
> +
> + ret = devm_drm_panel_add(dev, &ili->panel);
[Severity: High]
Does the devm_drm_panel_add() function exist in the kernel, or will this
cause a build failure?
Additionally, if this call is replaced with drm_panel_add(), the driver
lacks a corresponding .remove() callback or a devres action to unregister
the panel with drm_panel_remove(). Since the panel structure is allocated
with devm_drm_panel_alloc() and freed on driver unbind, failing to unregister
the panel will leave it on the DRM core's global panel list, leading to a
Use-After-Free when the list is later accessed.
> + if (ret)
> + return ret;
> +
> + ret = devm_mipi_dsi_attach(dev, dsi);
> + if (ret < 0)
> + return dev_err_probe(dev, ret, "failed to attach to DSI host\n");
> +
> + return 0;
> +}
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260617143245.372182-1-igor@reznichenko.net?part=2
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2026-06-17 14:32 [PATCH v6 0/2] drm/panel: Add support for the FocusLCDs E35GH-I-MW800CB Igor Reznichenko
2026-06-17 14:32 ` [PATCH v6 1/2] dt-bindings: display: panel: Add Ilitek ILI9488 panel controller Igor Reznichenko
2026-06-17 14:32 ` [PATCH v6 2/2] drm/panel: Add Ilitek ILI9488 controller driver Igor Reznichenko
2026-06-17 14:44 ` sashiko-bot
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