mdio: Add support for mdio drivers.

Not all devices on an MDIO bus are PHYs. Meaning not all MDIO drivers
are PHY drivers. Add support for generic MDIO drivers.

Change-Id: I65c7c8a497bbac9ef67b3d21c869818a09378e3c
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Git-Commit: a9049e0c513c4521dbfaa302af8ed08b3366b41f
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Anthony Mah <amah@codeaurora.org>

drivers/net/phy/mdio_device.c

@@ -0,0 +1,171 @@
+/* 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/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>
+
+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));
+}
+
+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_info(&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);
+
+/**
+ * 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)
+		err = mdiodrv->probe(mdiodev);
+
+	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);
+
+	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_info("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);

include/linux/mdio.h

@@ -11,6 +11,53 @@
 
 #include <uapi/linux/mdio.h>
 
+struct mdio_device {
+	struct device dev;
+
+	const struct dev_pm_ops *pm_ops;
+	struct mii_bus *bus;
+
+	int (*bus_match)(struct device *dev, struct device_driver *drv);
+	void (*device_free)(struct mdio_device *mdiodev);
+	void (*device_remove)(struct mdio_device *mdiodev);
+
+	/* Bus address of the MDIO device (0-31) */
+	int addr;
+	int flags;
+};
+#define to_mdio_device(d) container_of(d, struct mdio_device, dev)
+
+/* struct mdio_driver_common: Common to all MDIO drivers */
+struct mdio_driver_common {
+	struct device_driver driver;
+	int flags;
+};
+#define MDIO_DEVICE_FLAG_PHY		1
+#define to_mdio_common_driver(d) \
+	container_of(d, struct mdio_driver_common, driver)
+
+/* struct mdio_driver: Generic MDIO driver */
+struct mdio_driver {
+	struct mdio_driver_common mdiodrv;
+
+	/*
+	 * Called during discovery.  Used to set
+	 * up device-specific structures, if any
+	 */
+	int (*probe)(struct mdio_device *mdiodev);
+
+	/* Clears up any memory if needed */
+	void (*remove)(struct mdio_device *mdiodev);
+};
+#define to_mdio_driver(d)						\
+	container_of(to_mdio_common_driver(d), struct mdio_driver, mdiodrv)
+
+void mdio_device_free(struct mdio_device *mdiodev);
+struct mdio_device *mdio_device_create(struct mii_bus *bus, int addr);
+int mdio_device_register(struct mdio_device *mdiodev);
+void mdio_device_remove(struct mdio_device *mdiodev);
+int mdio_driver_register(struct mdio_driver *drv);
+void mdio_driver_unregister(struct mdio_driver *drv);
 
 static inline bool mdio_phy_id_is_c45(int phy_id)
 {

include/linux/phy.h

@@ -18,6 +18,7 @@
 
 #include <linux/spinlock.h>
 #include <linux/ethtool.h>
+#include <linux/mdio.h>
 #include <linux/mii.h>
 #include <linux/module.h>
 #include <linux/timer.h>
@@ -357,6 +358,8 @@ struct phy_c45_device_ids {
  * handling, as well as handling shifts in PHY hardware state
  */
 struct phy_device {
+	struct mdio_device mdio;
+
 	/* Information about the PHY type */
 	/* And management functions */
 	struct phy_driver *drv;