arm: dts: iot2050: Add support for M.2 variant

Add support for the M.2 board based on the iot2050 advanced board.
The board has two m.2 connectors, one is B-keyed, the other E-keyed.
The B-key slot can connect 5G/SSD devices, and E-key can be used for
WIFI/BT devices.

This variant is covered by PG2 firmware image.

Signed-off-by: chao zeng <[email protected]>
[Jan: align DT to kernel, polish wording]
Signed-off-by: Jan Kiszka <[email protected]>

4 files changed, 128 insertions, 4 deletions

diff --git a/arch/arm/dts/Makefile b/arch/arm/dts/Makefile
index c160e884bf6..79ed4ac0825 100644
--- a/arch/arm/dts/Makefile
+++ b/arch/arm/dts/Makefile
@@ -1259,7 +1259,8 @@ dtb-$(CONFIG_SOC_K3_AM654) += \
 	k3-am6528-iot2050-basic.dtb \
 	k3-am6528-iot2050-basic-pg2.dtb \
 	k3-am6548-iot2050-advanced.dtb \
-	k3-am6548-iot2050-advanced-pg2.dtb
+	k3-am6548-iot2050-advanced-pg2.dtb \
+	k3-am6548-iot2050-advanced-m2.dtb
 dtb-$(CONFIG_SOC_K3_J721E) += k3-j721e-common-proc-board.dtb \
 			      k3-j721e-r5-common-proc-board.dtb \
 			      k3-j7200-common-proc-board.dtb \
diff --git a/arch/arm/dts/k3-am6548-iot2050-advanced-m2.dts b/arch/arm/dts/k3-am6548-iot2050-advanced-m2.dts
new file mode 100644
index 00000000000..9400e35882a
--- /dev/null
+++ b/arch/arm/dts/k3-am6548-iot2050-advanced-m2.dts
@@ -0,0 +1,121 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) Siemens AG, 2018-2023
+ *
+ * Authors:
+ *   Chao Zeng <[email protected]>
+ *   Jan Kiszka <[email protected]>
+ *
+ * AM6548-based (quad-core) IOT2050 M.2 variant (based on Advanced Product
+ * Generation 2), 2 GB RAM, 16 GB eMMC, USB-serial converter on connector X30
+ *
+ * Product homepage:
+ * https://new.siemens.com/global/en/products/automation/pc-based/iot-gateways/simatic-iot2050.html
+ */
+
+#include "k3-am6548-iot2050-advanced-common.dtsi"
+#include "k3-am65-iot2050-common-pg2.dtsi"
+
+/ {
+	compatible = "siemens,iot2050-advanced-m2", "ti,am654";
+	model = "SIMATIC IOT2050 Advanced M2";
+};
+
+&mcu_r5fss0 {
+	/* lock-step mode not supported on this board */
+	ti,cluster-mode = <0>;
+};
+
+&main_pmx0 {
+	main_m2_enable_pins_default: main-m2-enable-pins-default {
+		pinctrl-single,pins = <
+			AM65X_IOPAD(0x01c4, PIN_INPUT_PULLUP, 7)  /* (AH13) GPIO1_17 */
+		>;
+	};
+
+	main_bkey_pcie_reset: main-bkey-pcie-reset {
+		pinctrl-single,pins = <
+			AM65X_IOPAD(0x01bc, PIN_OUTPUT_PULLUP, 7)  /* (AG13) GPIO1_15 */
+		>;
+	};
+
+	main_pmx0_m2_config_pins_default: main-pmx0-m2-config-pins-default {
+		pinctrl-single,pins = <
+			AM65X_IOPAD(0x01c8, PIN_INPUT_PULLUP, 7)  /* (AE13) GPIO1_18 */
+			AM65X_IOPAD(0x01cc, PIN_INPUT_PULLUP, 7)  /* (AD13) GPIO1_19 */
+		>;
+	};
+
+	main_m2_pcie_mux_control: main-m2-pcie-mux-control {
+		pinctrl-single,pins = <
+			AM65X_IOPAD(0x0148, PIN_INPUT_PULLUP, 7)  /* (AG22) GPIO0_82 */
+			AM65X_IOPAD(0x0160, PIN_INPUT_PULLUP, 7)  /* (AE20) GPIO0_88 */
+			AM65X_IOPAD(0x0164, PIN_INPUT_PULLUP, 7)  /* (AF19) GPIO0_89 */
+		>;
+	};
+};
+
+&main_pmx1 {
+	main_pmx1_m2_config_pins_default: main-pmx1-m2-config-pins-default {
+		pinctrl-single,pins = <
+			AM65X_IOPAD(0x0018, PIN_INPUT_PULLUP, 7)  /* (B22) GPIO1_88 */
+			AM65X_IOPAD(0x001c, PIN_INPUT_PULLUP, 7)  /* (C23) GPIO1_89 */
+		>;
+	};
+};
+
+&main_gpio0 {
+	pinctrl-names = "default";
+	pinctrl-0 = <
+		&main_m2_pcie_mux_control
+		&arduino_io_d4_to_d9_pins_default
+	>;
+};
+
+&main_gpio1 {
+	pinctrl-names = "default";
+	pinctrl-0 = <
+		&main_m2_enable_pins_default
+		&main_pmx0_m2_config_pins_default
+		&main_pmx1_m2_config_pins_default
+		&cp2102n_reset_pin_default
+	>;
+};
+
+/*
+ * Base configuration for B-key slot with PCIe x2, E-key with USB 2.0 only.
+ * Firmware switches to other modes via device tree overlays.
+ */
+
+&serdes0 {
+	assigned-clocks = <&k3_clks 153 4>, <&serdes0 AM654_SERDES_CMU_REFCLK>;
+	assigned-clock-parents = <&k3_clks 153 8>, <&k3_clks 153 4>;
+};
+
+&pcie0_rc {
+	pinctrl-names = "default";
+	pinctrl-0 = <&main_bkey_pcie_reset>;
+
+	num-lanes = <2>;
+	phys = <&serdes0 PHY_TYPE_PCIE 1>, <&serdes1 PHY_TYPE_PCIE 1>;
+	phy-names = "pcie-phy0","pcie-phy1";
+	reset-gpios = <&main_gpio1 15 GPIO_ACTIVE_HIGH>;
+	status = "okay";
+};
+
+&pcie1_rc {
+	status = "disabled";
+};
+
+&dwc3_0 {
+	assigned-clock-parents = <&k3_clks 151 4>,  /* set REF_CLK to 20MHz i.e. PER0_PLL/48 */
+				 <&k3_clks 151 9>;  /* set PIPE3_TXB_CLK to CLK_12M_RC/256 (for HS only) */
+	/delete-property/ phys;
+	/delete-property/ phy-names;
+};
+
+&usb0 {
+	maximum-speed = "high-speed";
+	/delete-property/ snps,dis-u1-entry-quirk;
+	/delete-property/ snps,dis-u2-entry-quirk;
+};
diff --git a/configs/iot2050_pg2_defconfig b/configs/iot2050_pg2_defconfig
index d2bdeab593b..b20667780a3 100644
--- a/configs/iot2050_pg2_defconfig
+++ b/configs/iot2050_pg2_defconfig
@@ -69,7 +69,7 @@ CONFIG_CMD_TIME=y
 # CONFIG_ISO_PARTITION is not set
 CONFIG_OF_CONTROL=y
 CONFIG_SPL_OF_CONTROL=y
-CONFIG_OF_LIST="k3-am6528-iot2050-basic-pg2 k3-am6548-iot2050-advanced-pg2"
+CONFIG_OF_LIST="k3-am6528-iot2050-basic-pg2 k3-am6548-iot2050-advanced-pg2 k3-am6548-iot2050-advanced-m2"
 CONFIG_SPL_MULTI_DTB_FIT=y
 CONFIG_SPL_OF_LIST="k3-am65-iot2050-spl"
 CONFIG_SPL_MULTI_DTB_FIT_NO_COMPRESSION=y
diff --git a/doc/board/siemens/iot2050.rst b/doc/board/siemens/iot2050.rst
index efe94a448a9..442d2cac216 100644
--- a/doc/board/siemens/iot2050.rst
+++ b/doc/board/siemens/iot2050.rst
@@ -6,7 +6,9 @@ SIMATIC IOT2050 BASIC and ADVANCED
 
 The SIMATIC IOT2050 is an open industrial IoT gateway that is using the TI
 AM6528 GP (Basic variant) or the AM6548 HS (Advanced variant). The Advanced
-variant is prepared for secure boot.
+variant is prepared for secure boot. M.2 Variant also uses the AM6548 HS.
+Instead of a MiniPCI connector, it comes with two M.2 connectors and can
+support 5G/WIFI/BT applications or connect an SSD.
 
 The IOT2050 starts only from OSPI. It loads a Siemens-provided bootloader
 called SE-Boot for the MCU domain (R5F cores), then hands over to ATF and
@@ -70,7 +72,7 @@ U-Boot:
  # configure for PG1
  $ make iot2050_pg1_defconfig
 
- # or configure for PG2
+ # or configure for PG2 or the M.2 variant
  $ make iot2050_pg2_defconfig
 
  $ make