arm64: dts: ti: iot2050: Add support for M.2 variant

The M.2 variant comes with 2 slots, one B-keyed and another one E-keyed.
They are configured by the firmware during startup. Also the device tree
will be adjusted according to the detect or manually configured
interface mode by the firmware. The kernel only carries a single
configuration as base device tree. It has to be built with a symbols
node so that the firmware can apply overlays for the connector modes.

Signed-off-by: chao zeng <[email protected]>
[Jan: refactored to a single DT]
Signed-off-by: Jan Kiszka <[email protected]>
Reviewed-by: Siddharth Vadapalli <[email protected]>
Link: https://lore.kernel.org/r/878e3a023767b5a6d9d2cff09015678aaba13fce.1674110442.git.jan.kiszka@siemens.com
Signed-off-by: Vignesh Raghavendra <[email protected]>

2 files changed, 124 insertions, 0 deletions

diff --git a/arch/arm64/boot/dts/ti/Makefile b/arch/arm64/boot/dts/ti/Makefile
index c94a877a8d03..0ac897800671 100644
--- a/arch/arm64/boot/dts/ti/Makefile
+++ b/arch/arm64/boot/dts/ti/Makefile
@@ -10,8 +10,11 @@ dtb-$(CONFIG_ARCH_K3) += k3-am654-base-board.dtb
 dtb-$(CONFIG_ARCH_K3) += k3-am6528-iot2050-basic.dtb
 dtb-$(CONFIG_ARCH_K3) += k3-am6528-iot2050-basic-pg2.dtb
 dtb-$(CONFIG_ARCH_K3) += k3-am6548-iot2050-advanced.dtb
+dtb-$(CONFIG_ARCH_K3) += k3-am6548-iot2050-advanced-m2.dtb
 dtb-$(CONFIG_ARCH_K3) += k3-am6548-iot2050-advanced-pg2.dtb
 
+DTC_FLAGS_k3-am6548-iot2050-advanced-m2 += -@
+
 dtb-$(CONFIG_ARCH_K3) += k3-am68-sk-base-board.dtb
 
 dtb-$(CONFIG_ARCH_K3) += k3-j721e-beagleboneai64.dtb
diff --git a/arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced-m2.dts b/arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced-m2.dts
new file mode 100644
index 000000000000..9400e35882a6
--- /dev/null
+++ b/arch/arm64/boot/dts/ti/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;
+};