v4.19.13 snapshot.
diff --git a/drivers/of/of_net.c b/drivers/of/of_net.c
new file mode 100644
index 0000000..53189d4
--- /dev/null
+++ b/drivers/of/of_net.c
@@ -0,0 +1,122 @@
+/*
+ * OF helpers for network devices.
+ *
+ * This file is released under the GPLv2
+ *
+ * Initially copied out of arch/powerpc/kernel/prom_parse.c
+ */
+#include <linux/etherdevice.h>
+#include <linux/kernel.h>
+#include <linux/nvmem-consumer.h>
+#include <linux/of_net.h>
+#include <linux/phy.h>
+#include <linux/export.h>
+
+/**
+ * of_get_phy_mode - Get phy mode for given device_node
+ * @np: Pointer to the given device_node
+ *
+ * The function gets phy interface string from property 'phy-mode' or
+ * 'phy-connection-type', and return its index in phy_modes table, or errno in
+ * error case.
+ */
+int of_get_phy_mode(struct device_node *np)
+{
+ const char *pm;
+ int err, i;
+
+ err = of_property_read_string(np, "phy-mode", &pm);
+ if (err < 0)
+ err = of_property_read_string(np, "phy-connection-type", &pm);
+ if (err < 0)
+ return err;
+
+ for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++)
+ if (!strcasecmp(pm, phy_modes(i)))
+ return i;
+
+ return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(of_get_phy_mode);
+
+static const void *of_get_mac_addr(struct device_node *np, const char *name)
+{
+ struct property *pp = of_find_property(np, name, NULL);
+
+ if (pp && pp->length == ETH_ALEN && is_valid_ether_addr(pp->value))
+ return pp->value;
+ return NULL;
+}
+
+/**
+ * Search the device tree for the best MAC address to use. 'mac-address' is
+ * checked first, because that is supposed to contain to "most recent" MAC
+ * address. If that isn't set, then 'local-mac-address' is checked next,
+ * because that is the default address. If that isn't set, then the obsolete
+ * 'address' is checked, just in case we're using an old device tree.
+ *
+ * Note that the 'address' property is supposed to contain a virtual address of
+ * the register set, but some DTS files have redefined that property to be the
+ * MAC address.
+ *
+ * All-zero MAC addresses are rejected, because those could be properties that
+ * exist in the device tree, but were not set by U-Boot. For example, the
+ * DTS could define 'mac-address' and 'local-mac-address', with zero MAC
+ * addresses. Some older U-Boots only initialized 'local-mac-address'. In
+ * this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
+ * but is all zeros.
+*/
+const void *of_get_mac_address(struct device_node *np)
+{
+ const void *addr;
+
+ addr = of_get_mac_addr(np, "mac-address");
+ if (addr)
+ return addr;
+
+ addr = of_get_mac_addr(np, "local-mac-address");
+ if (addr)
+ return addr;
+
+ return of_get_mac_addr(np, "address");
+}
+EXPORT_SYMBOL(of_get_mac_address);
+
+/**
+ * Obtain the MAC address from an nvmem provider named 'mac-address' through
+ * device tree.
+ * On success, copies the new address into memory pointed to by addr and
+ * returns 0. Returns a negative error code otherwise.
+ * @np: Device tree node containing the nvmem-cells phandle
+ * @addr: Pointer to receive the MAC address using ether_addr_copy()
+ */
+int of_get_nvmem_mac_address(struct device_node *np, void *addr)
+{
+ struct nvmem_cell *cell;
+ const void *mac;
+ size_t len;
+ int ret;
+
+ cell = of_nvmem_cell_get(np, "mac-address");
+ if (IS_ERR(cell))
+ return PTR_ERR(cell);
+
+ mac = nvmem_cell_read(cell, &len);
+
+ nvmem_cell_put(cell);
+
+ if (IS_ERR(mac))
+ return PTR_ERR(mac);
+
+ if (len < ETH_ALEN || !is_valid_ether_addr(mac)) {
+ ret = -EINVAL;
+ } else {
+ ether_addr_copy(addr, mac);
+ ret = 0;
+ }
+
+ kfree(mac);
+
+ return ret;
+}
+EXPORT_SYMBOL(of_get_nvmem_mac_address);