boards: riscv: longan_nano: add configuration for LCD

Add configuration for built-in display.
LCD has a Sitronix ST7735S controller that is connected to the SPI bus.
Using it with the ST7735R driver.

Signed-off-by: TOKITA Hiroshi <tokita.hiroshi@gmail.com>

Author: soburi

boards/riscv/longan_nano/longan_nano-common.dtsi

@@ -10,6 +10,7 @@
 		zephyr,shell-uart = &usart0;
 		zephyr,sram = &sram0;
 		zephyr,flash = &flash0;
+		zephyr,display = &lcd0;
 		sdhc0 = &sdhc0;
 	};
 
@@ -99,6 +100,49 @@
 	pinctrl-names = "default";
 };
 
+&spi0 {
+	status = "okay";
+	pinctrl-0 = <&spi0_default>;
+	pinctrl-names = "default";
+
+	cs-gpios = <&gpiob 2 GPIO_ACTIVE_LOW>;
+
+	/* longan nano has LCD with st7735s controller.
+	 * It can use with st7735r driver.
+	 */
+	lcd0: lcd@0 {
+		compatible = "sitronix,st7735r";
+		reg = <0>;
+		status = "okay";
+		reset-gpios = <&gpiob 1 GPIO_ACTIVE_LOW>;
+		cmd-data-gpios = <&gpiob 0 GPIO_ACTIVE_LOW>;
+		width = <160>;
+		height = <80>;
+		inversion-on;
+		rgb-is-inverted;
+		x-offset = <1>;
+		y-offset = <26>;
+		pwctr1 = [62 02 04];
+		pwctr2 = [C0];
+		pwctr3 = [0D 00];
+		pwctr4 = [8D 6A];
+		pwctr5 = [8D EE];
+		invctr = <3>;
+		frmctr1 = [05 3A 3A];
+		frmctr2 = [05 3A 3A];
+		frmctr3 = [05 3A 3A 05 3A 3A];
+		vmctr1 = <14>;
+		gamctrp1 = [10 0E 02 03 0E 07 02 07 0A 12 27 37 00 0D 0E 10];
+		gamctrn1 = [10 0E 03 03 0F 06 02 08 0A 13 26 36 00 0D 0E 10];
+		colmod = <5>;
+		madctl = <120>;
+		caset = [00 01 00 a0];
+		raset = [00 1a 00 69];
+
+		spi-max-frequency = <4000000>;
+	};
+};
+
 &spi1 {
 	status = "okay";
 	pinctrl-0 = <&spi1_default>;

boards/riscv/longan_nano/longan_nano-pinctrl.dtsi

@@ -24,6 +24,13 @@
 		};
 	};
 
+	spi0_default: spi0_default {
+		group1 {
+			pinmux = <SPI0_NSS_PA4_OUT_NORMP>, <SPI0_SCK_PA5_OUT_NORMP>,
+				 <SPI0_MISO_PA6_INP_NORMP>, <SPI0_MOSI_PA7_OUT_NORMP>;
+		};
+	};
+
 	spi1_default: spi1_default {
 		group1 {
 			pinmux = <SPI1_MISO_PB14_INP>, <SPI1_SCK_PB13_OUT>,