drivers: display: display_mcux_elcdif: add backlight-gpios property

Add backlight gpios property to mcux display driver, so that the driver
can correctly initialize the backlight gpio control.

Signed-off-by: Daniel DeGrasse <daniel.degrasse@nxp.com>

boards/arm/mimxrt1050_evk/mimxrt1050_evk.dts

@@ -178,6 +178,7 @@ arduino_serial: &lpuart3 {
 	data-buswidth = "16-bit";
 	pinctrl-0 = <&pinmux_lcdif>;
 	pinctrl-names = "default";
+	backlight-gpios = <&gpio2 31 GPIO_ACTIVE_HIGH>;
 	port {
 		lcd_panel_out: endpoint {
 			remote-endpoint = <&lcd_panel_in>;

boards/arm/mimxrt1060_evk/mimxrt1060_evk.dts

@@ -163,6 +163,7 @@ arduino_serial: &lpuart3 {
 	data-buswidth = "16-bit";
 	pinctrl-0 = <&pinmux_lcdif>;
 	pinctrl-names = "default";
+	backlight-gpios = <&gpio2 31 GPIO_ACTIVE_HIGH>;
 	port {
 		lcd_panel_out: endpoint {
 			remote-endpoint = <&lcd_panel_in>;

boards/arm/mimxrt1064_evk/mimxrt1064_evk.dts

@@ -139,6 +139,7 @@ arduino_i2c: &lpi2c1 {};
 	data-buswidth = "16-bit";
 	pinctrl-0 = <&pinmux_lcdif>;
 	pinctrl-names = "default";
+	backlight-gpios = <&gpio2 31 GPIO_ACTIVE_HIGH>;
 	port {
 		lcd_panel_out: endpoint {
 			remote-endpoint = <&lcd_panel_in>;

drivers/display/display_mcux_elcdif.c

@@ -8,6 +8,7 @@
 
 #include <drivers/display.h>
 #include <drivers/pinctrl.h>
+#include <drivers/gpio.h>
 #include <fsl_elcdif.h>
 
 #ifdef CONFIG_HAS_MCUX_CACHE
@@ -32,6 +33,7 @@ struct mcux_elcdif_config {
 	elcdif_rgb_mode_config_t rgb_mode;
 	uint8_t pixel_format;
 	const struct pinctrl_dev_config *pincfg;
+	const struct gpio_dt_spec backlight_gpio;
 };
 
 struct mcux_mem_block {
@@ -196,6 +198,11 @@ static int mcux_elcdif_init(const struct device *dev)
 		return err;
 	}
 
+	err = gpio_pin_configure_dt(&config->backlight_gpio, GPIO_OUTPUT_ACTIVE);
+	if (err) {
+		return err;
+	}
+
 	elcdif_rgb_mode_config_t rgb_mode = config->rgb_mode;
 
 	/* Shift the polarity bits to the appropriate location in the register */
@@ -273,6 +280,7 @@ static const struct display_driver_api mcux_elcdif_api = {
 		},								\
 		.pixel_format = DT_INST_ENUM_IDX(id, pixel_format),		\
 		.pincfg = PINCTRL_DT_INST_DEV_CONFIG_GET(id),			\
+		.backlight_gpio = GPIO_DT_SPEC_INST_GET(id, backlight_gpios),	\
 	};									\
 	static struct mcux_elcdif_data mcux_elcdif_data_##id;			\
 	DEVICE_DT_INST_DEFINE(id,						\

dts/bindings/display/nxp,imx-elcdif.yaml

@@ -102,3 +102,9 @@ properties:
         - "24-bit"
       description:
         LCD data bus width. The default is set to the reset value of 16-bit
+
+    backlight-gpios:
+      type: phandle-array
+      required: true
+      description:
+        LCB backlight control gpio. Driver will initialize this GPIO to active high