7 files changed, 53 insertions, 0 deletions
diff --git a/src/device/Makefile.inc b/src/device/Makefile.inc
index 28acd73879..3018ef9626 100644
--- a/src/device/Makefile.inc
+++ b/src/device/Makefile.inc
@@ -64,3 +64,4 @@ ramstage-y += resource_allocator_v4.c
 ramstage-$(CONFIG_XHCI_UTILS) += xhci.c
 
 ramstage-y += gpio.c
+ramstage-y += mdio.c
diff --git a/src/device/device_const.c b/src/device/device_const.c
index a40d0b05b9..a63a629344 100644
--- a/src/device/device_const.c
+++ b/src/device/device_const.c
@@ -147,6 +147,10 @@ static int path_eq(const struct device_path *path1,
 	case DEVICE_PATH_GPIO:
 		equal = (path1->gpio.id == path2->gpio.id);
 		break;
+	case DEVICE_PATH_MDIO:
+		equal = (path1->mdio.addr == path2->mdio.addr);
+		break;
+
 	default:
 		printk(BIOS_ERR, "Unknown device type: %d\n", path1->type);
 		break;
diff --git a/src/device/device_util.c b/src/device/device_util.c
index 9beb2ce8e2..c5e03f2079 100644
--- a/src/device/device_util.c
+++ b/src/device/device_util.c
@@ -135,6 +135,9 @@ u32 dev_path_encode(const struct device *dev)
 	case DEVICE_PATH_GPIO:
 		ret |= dev->path.gpio.id;
 		break;
+	case DEVICE_PATH_MDIO:
+		ret |= dev->path.mdio.addr;
+		break;
 	case DEVICE_PATH_NONE:
 	case DEVICE_PATH_MMIO:  /* don't care */
 	default:
@@ -223,6 +226,9 @@ const char *dev_path(const struct device *dev)
 		case DEVICE_PATH_GPIO:
 			snprintf(buffer, sizeof(buffer), "GPIO: %d", dev->path.gpio.id);
 			break;
+		case DEVICE_PATH_MDIO:
+			snprintf(buffer, sizeof(buffer), "MDIO: %02x", dev->path.mdio.addr);
+			break;
 		default:
 			printk(BIOS_ERR, "Unknown device path type: %d\n",
 			       dev->path.type);
diff --git a/src/device/mdio.c b/src/device/mdio.c
new file mode 100644
index 0000000000..9f560e6bdf
--- /dev/null
+++ b/src/device/mdio.c
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <console/console.h>
+#include <device/device.h>
+#include <device/mdio.h>
+#include <stddef.h>
+
+const struct mdio_bus_operations *dev_get_mdio_ops(struct device *dev)
+{
+	if (!dev || !dev->ops || !dev->ops->ops_mdio) {
+		printk(BIOS_ERR, "Could not get MDIO operations.\n");
+		return NULL;
+	}
+
+	return dev->ops->ops_mdio;
+}
diff --git a/src/include/device/device.h b/src/include/device/device.h
index 0f9c39f17e..8b1dde1109 100644
--- a/src/include/device/device.h
+++ b/src/include/device/device.h
@@ -20,6 +20,7 @@ struct pnp_mode_ops;
 struct spi_bus_operations;
 struct usb_bus_operations;
 struct gpio_operations;
+struct mdio_bus_operations;
 
 /* Chip operations */
 struct chip_operations {
@@ -67,6 +68,7 @@ struct device_operations {
 	const struct smbus_bus_operations *ops_smbus_bus;
 	const struct pnp_mode_ops *ops_pnp_mode;
 	const struct gpio_operations *ops_gpio;
+	const struct mdio_bus_operations *ops_mdio;
 };
 
 /**
diff --git a/src/include/device/mdio.h b/src/include/device/mdio.h
new file mode 100644
index 0000000000..39e60f582d
--- /dev/null
+++ b/src/include/device/mdio.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __DEVICE_MDIO_H__
+#define __DEVICE_MDIO_H__
+
+#include <device/device.h>
+#include <types.h>
+
+struct mdio_bus_operations {
+	uint16_t (*read)(struct device *dev, uint8_t phy_adr, uint8_t reg_adr);
+	void (*write)(struct device *dev, uint8_t phy_adr, uint8_t reg_adr, uint16_t data);
+};
+
+/* Helper for getting mdio operations from a device */
+const struct mdio_bus_operations *dev_get_mdio_ops(struct device *dev);
+
+#endif	/* __DEVICE_MDIO_H__ */
diff --git a/src/include/device/path.h b/src/include/device/path.h
index 1be7e7299f..28c932ad8e 100644
--- a/src/include/device/path.h
+++ b/src/include/device/path.h
@@ -22,6 +22,7 @@ enum device_path_type {
 	DEVICE_PATH_USB,
 	DEVICE_PATH_MMIO,
 	DEVICE_PATH_GPIO,
+	DEVICE_PATH_MDIO,
 
 	/*
 	 * When adding path types to this table, please also update the
@@ -46,6 +47,7 @@ enum device_path_type {
 		"DEVICE_PATH_USB",		\
 		"DEVICE_PATH_MMIO",		\
 		"DEVICE_PATH_GPIO",		\
+		"DEVICE_PATH_MDIO",		\
 }
 
 struct domain_path {
@@ -112,6 +114,10 @@ struct gpio_path {
 	unsigned int id;
 };
 
+struct mdio_path {
+	unsigned int addr;
+};
+
 struct device_path {
 	enum device_path_type type;
 	union {
@@ -129,6 +135,7 @@ struct device_path {
 		struct usb_path		usb;
 		struct mmio_path	mmio;
 		struct gpio_path	gpio;
+		struct mdio_path	mdio;
 	};
 };