boards: m5stack_cores3: add display support

boards/m5stack/m5stack_cores3/doc/index.rst

@@ -26,6 +26,24 @@ M5Stack CoreS3/CoreS3 SE features consist of:
 - Proximity sensor LTR-553ALS-WA (Not available for CoreS3 SE)
 - 6-Axis IMU BMI270 (Not available for CoreS3 SE)
 
+Display
+=======
+
+The integrated 2" SPI display is supported via the :dtcompatible:`ilitek,ili9342c`
+driver. Applications can access the panel through the
+:kconfig:option:`CONFIG_DISPLAY` API. For example, the following command builds
+the :zephyr:code-sample:`lvgl` sample for the primary CPU:
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/subsys/display/lvgl
+   :board: m5stack_cores3/esp32s3/procpu
+   :goals: build
+   :compact:
+
+The sample enables the LVGL GUI library by default. Once flashed, the graphical
+output is rendered on the CoreS3 screen and touch input is provided by the
+FT6336 controller.
+
 Start Application Development
 *****************************
 

boards/m5stack/m5stack_cores3/m5stack_cores3_procpu_common.dtsi

@@ -9,6 +9,7 @@
 #include "m5stack_cores3-pinctrl.dtsi"
 #include "m5stack_mbus_connectors.dtsi"
 #include "grove_connectors.dtsi"
+#include <zephyr/dt-bindings/display/ili9xxx.h>
 
 / {
 	chosen {
@@ -20,6 +21,7 @@
 		zephyr,rtc = &bm8563_rtc;
 		zephyr,bt-hci = &esp32_bt_hci;
 		zephyr,touch = &ft6336_touch;
+		zephyr,display = &ili9342c;
 	};
 
 	aliases {
@@ -39,6 +41,29 @@
 		compatible = "zephyr,lvgl-pointer-input";
 		input = <&ft6336_touch>;
 	};
+
+	mipi_dbi {
+		compatible = "zephyr,mipi-dbi-spi";
+		dc-gpios = <&gpio0 5 GPIO_ACTIVE_HIGH>;
+		reset-gpios = <&aw9523b_gpio 1 GPIO_ACTIVE_LOW>;
+		spi-dev = <&spi2>;
+		write-only;
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		ili9342c: ili9342c@0 {
+			compatible = "ilitek,ili9342c";
+			reg = <0>;
+			mipi-max-frequency = <30000000>;
+			vin-supply = <&vcc_bl>;
+			pixel-format = <ILI9XXX_PIXEL_FORMAT_RGB565>;
+			color-order = "rgb";
+			display-inversion;
+			width = <320>;
+			height = <240>;
+			rotation = <0>;
+		};
+	};
 };
 
 &usb_serial {

drivers/display/display_ili9xxx.c

@@ -324,7 +324,8 @@
 	struct ili9xxx_data *data = dev->data;
 
 	int r;
-	uint8_t tx_data = ILI9XXX_MADCTL_BGR;
+        uint8_t tx_data = (config->color_order == ILI9XXX_COLOR_ORDER_BGR) ?
+                                   ILI9XXX_MADCTL_BGR : 0U;
 	if (config->quirks->cmd_set == CMD_SET_1) {
 		if (orientation == DISPLAY_ORIENTATION_NORMAL) {
 			tx_data |= ILI9XXX_MADCTL_MX;
@@ -549,11 +550,13 @@
 		.rotation = DT_PROP(INST_DT_ILI9XXX(n, t), rotation),          \
 		.x_resolution = ILI##t##_X_RES,                                \
 		.y_resolution = ILI##t##_Y_RES,                                \
-		.inversion = DT_PROP(INST_DT_ILI9XXX(n, t), display_inversion),\
-		.te_mode = MIPI_DBI_TE_MODE_DT(INST_DT_ILI9XXX(n, t), te_mode),\
-		.regs = &ili##t##_regs_##n,                                    \
-		.regs_init_fn = ili##t##_regs_init,                            \
-	};                                                                     \
+                .inversion = DT_PROP(INST_DT_ILI9XXX(n, t), display_inversion),\
+                .te_mode = MIPI_DBI_TE_MODE_DT(INST_DT_ILI9XXX(n, t), te_mode),\
+                .regs = &ili##t##_regs_##n,                                    \
+                .regs_init_fn = ili##t##_regs_init,                            \
+                .color_order =                                                 \
+                        DT_ENUM_IDX(INST_DT_ILI9XXX(n, t), color_order),       \
+        };                                                                     \
 									       \
 	static struct ili9xxx_data ili9##t##_data_##n;                         \
 									       \

drivers/display/display_ili9xxx.h

@@ -62,6 +62,11 @@ enum madctl_cmd_set {
 	CMD_SET_2,	/* Used by ILI9342c */
 };
 
+enum ili9xxx_color_order {
+	ILI9XXX_COLOR_ORDER_RGB,
+	ILI9XXX_COLOR_ORDER_BGR,
+};
+
 struct ili9xxx_quirks {
 	enum madctl_cmd_set cmd_set;
 };
@@ -78,6 +83,7 @@ struct ili9xxx_config {
 	uint8_t te_mode;
 	const void *regs;
 	int (*regs_init_fn)(const struct device *dev);
+	enum ili9xxx_color_order color_order;
 };
 
 int ili9xxx_transmit(const struct device *dev, uint8_t cmd,

dts/bindings/display/ilitek,ili9xxx-common.yaml

@@ -42,3 +42,15 @@ properties:
     description:
       Display inversion mode. Every bit is inverted from the frame memory to
       the display.
+
+  color-order:
+    type: string
+    enum:
+      - "rgb"
+      - "bgr"
+    default: "bgr"
+    description: |
+      Define the byte order used when updating display memory. Some panels
+      require RGB ordering while others expect BGR ordering. The default value
+      keeps backwards compatibility with existing boards that rely on the
+      BGR order.