1 files changed, 98 insertions, 0 deletions
diff --git a/drivers/net/phy/phy_fixup.c b/drivers/net/phy/phy_fixup.c
new file mode 100644
index 000000000000..75ed9b142ccc
--- /dev/null
+++ b/drivers/net/phy/phy_fixup.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * PHY fixup support
+ */
+
+#include <linux/list.h>
+#include <linux/phy.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+#include "phylib-internal.h"
+
+static struct list_head phy_fixup_list __ro_after_init =
+	LIST_HEAD_INIT(phy_fixup_list);
+
+struct phy_fixup {
+	struct list_head list;
+	char bus_id[MII_BUS_ID_SIZE + 3];
+	u32 phy_uid;
+	u32 phy_uid_mask;
+	int (*run)(struct phy_device *phydev);
+};
+
+/**
+ * phy_register_fixup - creates a new phy_fixup and adds it to the list
+ * @bus_id: A string which matches phydev->mdio.dev.bus_id (or NULL)
+ * @phy_uid: Used to match against phydev->phy_id (the UID of the PHY)
+ * @phy_uid_mask: Applied to phydev->phy_id and fixup->phy_uid before
+ *	comparison (or 0 to disable id-based matching)
+ * @run: The actual code to be run when a matching PHY is found
+ */
+static void __init phy_register_fixup(const char *bus_id, u32 phy_uid,
+				      u32 phy_uid_mask,
+				      int (*run)(struct phy_device *))
+{
+	struct phy_fixup *fixup = kzalloc_obj(*fixup);
+
+	if (!fixup)
+		return;
+
+	if (bus_id)
+		strscpy(fixup->bus_id, bus_id);
+	fixup->phy_uid = phy_uid;
+	fixup->phy_uid_mask = phy_uid_mask;
+	fixup->run = run;
+
+	list_add_tail(&fixup->list, &phy_fixup_list);
+}
+
+/* Registers a fixup to be run on any PHY with the UID in phy_uid */
+void __init phy_register_fixup_for_uid(u32 phy_uid, u32 phy_uid_mask,
+				       int (*run)(struct phy_device *))
+{
+	phy_register_fixup(NULL, phy_uid, phy_uid_mask, run);
+}
+
+/* Registers a fixup to be run on the PHY with id string bus_id */
+void __init phy_register_fixup_for_id(const char *bus_id,
+				      int (*run)(struct phy_device *))
+{
+	phy_register_fixup(bus_id, 0, 0, run);
+}
+
+static bool phy_needs_fixup(struct phy_device *phydev, struct phy_fixup *fixup)
+{
+	if (!strcmp(fixup->bus_id, phydev_name(phydev)))
+		return true;
+
+	if (fixup->phy_uid_mask &&
+	    phy_id_compare(phydev->phy_id, fixup->phy_uid, fixup->phy_uid_mask))
+		return true;
+
+	return false;
+}
+
+/**
+ * phy_scan_fixups - runs any matching fixups for this phydev
+ * @phydev: the phydev to search and run fixups for
+ * Returns: 0 or an errno
+ */
+int phy_scan_fixups(struct phy_device *phydev)
+{
+	struct phy_fixup *fixup;
+
+	list_for_each_entry(fixup, &phy_fixup_list, list) {
+		if (phy_needs_fixup(phydev, fixup)) {
+			int err = fixup->run(phydev);
+
+			if (err < 0)
+				return err;
+
+			phydev->has_fixups = true;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(phy_scan_fixups);