imx: imx6ul: Add support for Kontron Electronics SL/BL i.MX6UL/ULL boards (N63xx/N64xx)

This adds support for i.MX6UL/ULL-based evaluation kits with SoMs by
Kontron Electronics GmbH.

Currently there are the following SoM flavors (SoM-Line):
  * N6310: SOM with i.MX6UL-2, 256MB RAM, 256MB SPI NAND
  * N6311: SOM with i.MX6UL-2, 512MB RAM, 512MB SPI NAND
  * N6411: SOM with i.MX6ULL, 512MB RAM, 512MB SPI NAND

And the according evaluation boards (Board-Line):
  * N6310-S: Baseboard with SOM N6310, eMMC, display (optional), ...
  * N6311-S: Baseboard with SOM N6311, eMMC, display (optional), ...
  * N6411-S: Baseboard with SOM N6411, eMMC, display (optional), ...

Currently U-Boot describes i.MX6UL and i.MX6ULL through separate config
options at compile-time. Though the differences are so minor, that for
the scope of these SoMs we just use a single defconfig that is compatible
with both SoCs.

Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Reviewed-by: Stefano Babic <sbabic@denx.de>
diff --git a/arch/arm/dts/imx6ul-kontron-n6x1x-som-common.dtsi b/arch/arm/dts/imx6ul-kontron-n6x1x-som-common.dtsi
new file mode 100644
index 0000000..e9ec6b7
--- /dev/null
+++ b/arch/arm/dts/imx6ul-kontron-n6x1x-som-common.dtsi
@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2017 exceet electronics GmbH
+ * Copyright (C) 2018 Kontron Electronics GmbH
+ * Copyright (c) 2019 Krzysztof Kozlowski <krzk@kernel.org>
+ */
+
+#include <dt-bindings/gpio/gpio.h>
+
+/ {
+	chosen {
+		stdout-path = &uart4;
+	};
+
+	memory@80000000 {
+		reg = <0x80000000 0x10000000>;
+		device_type = "memory";
+	};
+};
+
+&ecspi2 {
+	cs-gpios = <&gpio4 22 GPIO_ACTIVE_HIGH>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_ecspi2>;
+	status = "okay";
+
+	spi-flash@0 {
+		compatible = "mxicy,mx25v8035f", "jedec,spi-nor";
+		spi-max-frequency = <50000000>;
+		reg = <0>;
+	};
+};
+
+&fec1 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_enet1 &pinctrl_enet1_mdio>;
+	phy-mode = "rmii";
+	phy-handle = <&ethphy1>;
+	status = "okay";
+
+	mdio {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		ethphy1: ethernet-phy@1 {
+			reg = <1>;
+			micrel,led-mode = <0>;
+			clocks = <&clks IMX6UL_CLK_ENET_REF>;
+			clock-names = "rmii-ref";
+		};
+	};
+};
+
+&fec2 {
+	phy-mode = "rmii";
+	status = "disabled";
+};
+
+&qspi {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_qspi>;
+	status = "okay";
+
+	spi-flash@0 {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "spi-nand";
+		spi-max-frequency = <104000000>;
+		spi-tx-bus-width = <4>;
+		spi-rx-bus-width = <4>;
+		reg = <0>;
+	};
+};
+
+&iomuxc {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pinctrl_reset_out>;
+
+	pinctrl_ecspi2: ecspi2grp {
+		fsl,pins = <
+			MX6UL_PAD_CSI_DATA03__ECSPI2_MISO      0x100b1
+			MX6UL_PAD_CSI_DATA02__ECSPI2_MOSI      0x100b1
+			MX6UL_PAD_CSI_DATA00__ECSPI2_SCLK      0x100b1
+			MX6UL_PAD_CSI_DATA01__GPIO4_IO22       0x100b1
+		>;
+	};
+
+	pinctrl_enet1: enet1grp {
+		fsl,pins = <
+			MX6UL_PAD_ENET1_RX_EN__ENET1_RX_EN      0x1b0b0
+			MX6UL_PAD_ENET1_RX_ER__ENET1_RX_ER      0x1b0b0
+			MX6UL_PAD_ENET1_RX_DATA0__ENET1_RDATA00 0x1b0b0
+			MX6UL_PAD_ENET1_RX_DATA1__ENET1_RDATA01 0x1b0b0
+			MX6UL_PAD_ENET1_TX_EN__ENET1_TX_EN      0x1b0b0
+			MX6UL_PAD_ENET1_TX_DATA0__ENET1_TDATA00 0x1b0b0
+			MX6UL_PAD_ENET1_TX_DATA1__ENET1_TDATA01 0x1b0b0
+			MX6UL_PAD_ENET1_TX_CLK__ENET1_REF_CLK1  0x4001b009
+		>;
+	};
+
+	pinctrl_enet1_mdio: enet1mdiogrp {
+		fsl,pins = <
+			MX6UL_PAD_GPIO1_IO07__ENET1_MDC         0x1b0b0
+			MX6UL_PAD_GPIO1_IO06__ENET1_MDIO        0x1b0b0
+		>;
+	};
+
+	pinctrl_qspi: qspigrp {
+		fsl,pins = <
+			MX6UL_PAD_NAND_WP_B__QSPI_A_SCLK        0x70a1
+			MX6UL_PAD_NAND_READY_B__QSPI_A_DATA00   0x70a1
+			MX6UL_PAD_NAND_CE0_B__QSPI_A_DATA01     0x70a1
+			MX6UL_PAD_NAND_CE1_B__QSPI_A_DATA02     0x70a1
+			MX6UL_PAD_NAND_CLE__QSPI_A_DATA03       0x70a1
+			MX6UL_PAD_NAND_DQS__QSPI_A_SS0_B        0x70a1
+		>;
+	};
+
+	pinctrl_reset_out: rstoutgrp {
+		fsl,pins = <
+			MX6UL_PAD_SNVS_TAMPER9__GPIO5_IO09      0x1b0b0
+		>;
+	};
+};