ARM: dts: bcm2711-rpi-4-b: Add SoC GPIO labels

This adds the labels for all the SoC GPIOs on the Raspberry Pi 4.
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/1581166975-22949-5-git-send-email-stefan.wahren@i2se.comSigned-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

arch/arm/boot/dts/bcm2711-rpi-4-b.dts

@@ -71,6 +71,79 @@ expgpio: gpio {
 	};
 };
 
+&gpio {
+	/*
+	 * Parts taken from rpi_SCH_4b_4p0_reduced.pdf and
+	 * the official GPU firmware DT blob.
+	 *
+	 * Legend:
+	 * "FOO" = GPIO line named "FOO" on the schematic
+	 * "FOO_N" = GPIO line named "FOO" on schematic, active low
+	 */
+	gpio-line-names = "ID_SDA",
+			  "ID_SCL",
+			  "SDA1",
+			  "SCL1",
+			  "GPIO_GCLK",
+			  "GPIO5",
+			  "GPIO6",
+			  "SPI_CE1_N",
+			  "SPI_CE0_N",
+			  "SPI_MISO",
+			  "SPI_MOSI",
+			  "SPI_SCLK",
+			  "GPIO12",
+			  "GPIO13",
+			  /* Serial port */
+			  "TXD1",
+			  "RXD1",
+			  "GPIO16",
+			  "GPIO17",
+			  "GPIO18",
+			  "GPIO19",
+			  "GPIO20",
+			  "GPIO21",
+			  "GPIO22",
+			  "GPIO23",
+			  "GPIO24",
+			  "GPIO25",
+			  "GPIO26",
+			  "GPIO27",
+			  "RGMII_MDIO",
+			  "RGMIO_MDC",
+			  /* Used by BT module */
+			  "CTS0",
+			  "RTS0",
+			  "TXD0",
+			  "RXD0",
+			  /* Used by Wifi */
+			  "SD1_CLK",
+			  "SD1_CMD",
+			  "SD1_DATA0",
+			  "SD1_DATA1",
+			  "SD1_DATA2",
+			  "SD1_DATA3",
+			  /* Shared with SPI flash */
+			  "PWM0_MISO",
+			  "PWM1_MOSI",
+			  "STATUS_LED_G_CLK",
+			  "SPIFLASH_CE_N",
+			  "SDA0",
+			  "SCL0",
+			  "RGMII_RXCLK",
+			  "RGMII_RXCTL",
+			  "RGMII_RXD0",
+			  "RGMII_RXD1",
+			  "RGMII_RXD2",
+			  "RGMII_RXD3",
+			  "RGMII_TXCLK",
+			  "RGMII_TXCTL",
+			  "RGMII_TXD0",
+			  "RGMII_TXD1",
+			  "RGMII_TXD2",
+			  "RGMII_TXD3";
+};
+
 &pwm1 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pwm1_0_gpio40 &pwm1_1_gpio41>;