v4.19.13 snapshot.
diff --git a/drivers/net/phy/mdio_device.c b/drivers/net/phy/mdio_device.c
new file mode 100644
index 0000000..c924700
--- /dev/null
+++ b/drivers/net/phy/mdio_device.c
@@ -0,0 +1,212 @@
+/* Framework for MDIO devices, other than PHYs.
+ *
+ * Copyright (c) 2016 Andrew Lunn <andrew@lunn.ch>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/errno.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/mdio.h>
+#include <linux/mii.h>
+#include <linux/module.h>
+#include <linux/phy.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/unistd.h>
+#include <linux/delay.h>
+
+void mdio_device_free(struct mdio_device *mdiodev)
+{
+ put_device(&mdiodev->dev);
+}
+EXPORT_SYMBOL(mdio_device_free);
+
+static void mdio_device_release(struct device *dev)
+{
+ kfree(to_mdio_device(dev));
+}
+
+int mdio_device_bus_match(struct device *dev, struct device_driver *drv)
+{
+ struct mdio_device *mdiodev = to_mdio_device(dev);
+ struct mdio_driver *mdiodrv = to_mdio_driver(drv);
+
+ if (mdiodrv->mdiodrv.flags & MDIO_DEVICE_IS_PHY)
+ return 0;
+
+ return strcmp(mdiodev->modalias, drv->name) == 0;
+}
+
+struct mdio_device *mdio_device_create(struct mii_bus *bus, int addr)
+{
+ struct mdio_device *mdiodev;
+
+ /* We allocate the device, and initialize the default values */
+ mdiodev = kzalloc(sizeof(*mdiodev), GFP_KERNEL);
+ if (!mdiodev)
+ return ERR_PTR(-ENOMEM);
+
+ mdiodev->dev.release = mdio_device_release;
+ mdiodev->dev.parent = &bus->dev;
+ mdiodev->dev.bus = &mdio_bus_type;
+ mdiodev->device_free = mdio_device_free;
+ mdiodev->device_remove = mdio_device_remove;
+ mdiodev->bus = bus;
+ mdiodev->addr = addr;
+
+ dev_set_name(&mdiodev->dev, PHY_ID_FMT, bus->id, addr);
+
+ device_initialize(&mdiodev->dev);
+
+ return mdiodev;
+}
+EXPORT_SYMBOL(mdio_device_create);
+
+/**
+ * mdio_device_register - Register the mdio device on the MDIO bus
+ * @mdiodev: mdio_device structure to be added to the MDIO bus
+ */
+int mdio_device_register(struct mdio_device *mdiodev)
+{
+ int err;
+
+ dev_dbg(&mdiodev->dev, "mdio_device_register\n");
+
+ err = mdiobus_register_device(mdiodev);
+ if (err)
+ return err;
+
+ err = device_add(&mdiodev->dev);
+ if (err) {
+ pr_err("MDIO %d failed to add\n", mdiodev->addr);
+ goto out;
+ }
+
+ return 0;
+
+ out:
+ mdiobus_unregister_device(mdiodev);
+ return err;
+}
+EXPORT_SYMBOL(mdio_device_register);
+
+/**
+ * mdio_device_remove - Remove a previously registered mdio device from the
+ * MDIO bus
+ * @mdiodev: mdio_device structure to remove
+ *
+ * This doesn't free the mdio_device itself, it merely reverses the effects
+ * of mdio_device_register(). Use mdio_device_free() to free the device
+ * after calling this function.
+ */
+void mdio_device_remove(struct mdio_device *mdiodev)
+{
+ device_del(&mdiodev->dev);
+ mdiobus_unregister_device(mdiodev);
+}
+EXPORT_SYMBOL(mdio_device_remove);
+
+void mdio_device_reset(struct mdio_device *mdiodev, int value)
+{
+ unsigned int d;
+
+ if (!mdiodev->reset)
+ return;
+
+ gpiod_set_value(mdiodev->reset, value);
+
+ d = value ? mdiodev->reset_assert_delay : mdiodev->reset_deassert_delay;
+ if (d)
+ usleep_range(d, d + max_t(unsigned int, d / 10, 100));
+}
+EXPORT_SYMBOL(mdio_device_reset);
+
+/**
+ * mdio_probe - probe an MDIO device
+ * @dev: device to probe
+ *
+ * Description: Take care of setting up the mdio_device structure
+ * and calling the driver to probe the device.
+ */
+static int mdio_probe(struct device *dev)
+{
+ struct mdio_device *mdiodev = to_mdio_device(dev);
+ struct device_driver *drv = mdiodev->dev.driver;
+ struct mdio_driver *mdiodrv = to_mdio_driver(drv);
+ int err = 0;
+
+ if (mdiodrv->probe) {
+ /* Deassert the reset signal */
+ mdio_device_reset(mdiodev, 0);
+
+ err = mdiodrv->probe(mdiodev);
+ if (err) {
+ /* Assert the reset signal */
+ mdio_device_reset(mdiodev, 1);
+ }
+ }
+
+ return err;
+}
+
+static int mdio_remove(struct device *dev)
+{
+ struct mdio_device *mdiodev = to_mdio_device(dev);
+ struct device_driver *drv = mdiodev->dev.driver;
+ struct mdio_driver *mdiodrv = to_mdio_driver(drv);
+
+ if (mdiodrv->remove) {
+ mdiodrv->remove(mdiodev);
+
+ /* Assert the reset signal */
+ mdio_device_reset(mdiodev, 1);
+ }
+
+ return 0;
+}
+
+/**
+ * mdio_driver_register - register an mdio_driver with the MDIO layer
+ * @new_driver: new mdio_driver to register
+ */
+int mdio_driver_register(struct mdio_driver *drv)
+{
+ struct mdio_driver_common *mdiodrv = &drv->mdiodrv;
+ int retval;
+
+ pr_debug("mdio_driver_register: %s\n", mdiodrv->driver.name);
+
+ mdiodrv->driver.bus = &mdio_bus_type;
+ mdiodrv->driver.probe = mdio_probe;
+ mdiodrv->driver.remove = mdio_remove;
+
+ retval = driver_register(&mdiodrv->driver);
+ if (retval) {
+ pr_err("%s: Error %d in registering driver\n",
+ mdiodrv->driver.name, retval);
+
+ return retval;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(mdio_driver_register);
+
+void mdio_driver_unregister(struct mdio_driver *drv)
+{
+ struct mdio_driver_common *mdiodrv = &drv->mdiodrv;
+
+ driver_unregister(&mdiodrv->driver);
+}
+EXPORT_SYMBOL(mdio_driver_unregister);