boards: shields: Add support for WIZnet WIZ550io Ethernet shield

Add support for WIZnet WIZ550io Ethernet shield

Signed-off-by: Grant Ramsay <gramsay@enphaseenergy.com>

boards/shields/wiznet_eth_wiz550io/Kconfig.defconfig

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+# Copyright (c) 2024 Grant Ramsay
+# SPDX-License-Identifier: Apache-2.0
+
+if SHIELD_WIZNET_ETH_WIZ550IO
+
+if NETWORKING
+
+config NET_L2_ETHERNET
+	default y
+
+endif # NETWORKING
+
+endif # SHIELD_WIZNET_ETH_WIZ550IO

boards/shields/wiznet_eth_wiz550io/Kconfig.shield

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+# Copyright (c) 2024 Grant Ramsay
+# SPDX-License-Identifier: Apache-2.0
+
+config SHIELD_WIZNET_ETH_WIZ550IO
+	def_bool $(shields_list_contains,wiznet_eth_wiz550io)

boards/shields/wiznet_eth_wiz550io/doc/index.rst

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+.. _wiznet_eth_wiz550io:
+
+WIZnet WIZ550io ETH
+###################
+
+Overview
+********
+
+WIZnet WIZ550io Ethernet is breakout board with SPI bus access.
+`WIZ550io`_ contains a W5500 Ethernet controller with an extra PIC12F519 MCU.
+The PIC12F519 MCU initialises the W5500 with a unique MAC address after a GPIO
+reset.
+
+`W5500`_  is 10/100 MBPS stand alone Ethernet controller with on-board MAC & PHY,
+16 KiloBytes for FIFO buffer and SPI serial interface.
+
+Pins Assignment of the WIZ550io Shield
+======================================
+
++-----------------------+---------------------------------------------+
+| Shield Connector Pin  | Function                                    |
++=======================+=============================================+
+| RST#                  | Ethernet Controller's Reset                 |
++-----------------------+---------------------------------------------+
+| CS#                   | SPI's Chip Select                           |
++-----------------------+---------------------------------------------+
+| SCK                   | SPI's ClocK                                 |
++-----------------------+---------------------------------------------+
+| SDO                   | SPI's Slave Data Output  (MISO)             |
++-----------------------+---------------------------------------------+
+| SDI                   | SPI's Slave Data Input   (MISO)             |
++-----------------------+---------------------------------------------+
+| INT                   | Ethernet Controller's Interrupt Output      |
++-----------------------+---------------------------------------------+
+| RDY                   | WIZ550io Ready Output                       |
++-----------------------+---------------------------------------------+
+
+Requirements
+************
+
+This shield/breakout board can be used with any board with SPI interfaces in
+Arduino header or custom header (by adjusting the overlay).
+
+Programming
+***********
+
+Set ``-DSHIELD=wiznet_eth_wiz550io`` when you invoke ``west build``. For example:
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/net/dhcpv4_client
+   :board: nrf52840dk/nrf52840
+   :shield: wiznet_eth_wiz550io
+   :goals: build
+
+References
+**********
+
+.. target-notes::
+
+.. _WIZ550io:
+   https://wiznet.io/products/network-modules/wiz550io
+
+.. _W5500:
+   https://wiznet.io/products/iethernet-chips/w5500

boards/shields/wiznet_eth_wiz550io/wiznet_eth_wiz550io.overlay

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+/* Copyright (c) 2024 Grant Ramsay
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+&arduino_spi {
+	status = "okay";
+
+	eth_w5500: eth_w5500@0 {
+		compatible = "wiznet,w5500";
+		reg = <0x0>;
+		/* Note: Reducing spi-max-frequency may help with errors/stability */
+		spi-max-frequency = <DT_FREQ_M(80)>;
+		int-gpios = <&arduino_header 15 GPIO_ACTIVE_LOW>;    /* D9 */
+		/* Do not put the reset-gpios property here */
+	};
+};
+
+/ {
+	wiz550io {
+		compatible = "wiznet,wiz550io";
+		wiznet,w5500 = <&eth_w5500>;
+		reset-gpios = <&arduino_header 14 GPIO_ACTIVE_LOW>;  /* D8 */
+		ready-gpios = <&arduino_header 13 GPIO_ACTIVE_HIGH>; /* D7 */
+	};
+};