1 files changed, 484 insertions, 0 deletions
diff --git a/drivers/net/phy/mdio_bus_provider.c b/drivers/net/phy/mdio_bus_provider.c
new file mode 100644
index 000000000000..65850e36284d
--- /dev/null
+++ b/drivers/net/phy/mdio_bus_provider.c
@@ -0,0 +1,484 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* MDIO Bus provider interface
+ *
+ * Author: Andy Fleming
+ *
+ * Copyright (c) 2004 Freescale Semiconductor, Inc.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/etherdevice.h>
+#include <linux/ethtool.h>
+#include <linux/gpio/consumer.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/micrel_phy.h>
+#include <linux/mii.h>
+#include <linux/mm.h>
+#include <linux/netdevice.h>
+#include <linux/of_device.h>
+#include <linux/of_mdio.h>
+#include <linux/phy.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/uaccess.h>
+#include <linux/unistd.h>
+
+#include "mdio-boardinfo.h"
+
+/**
+ * mdiobus_alloc_size - allocate a mii_bus structure
+ * @size: extra amount of memory to allocate for private storage.
+ * If non-zero, then bus->priv is points to that memory.
+ *
+ * Description: called by a bus driver to allocate an mii_bus
+ * structure to fill in.
+ */
+struct mii_bus *mdiobus_alloc_size(size_t size)
+{
+	struct mii_bus *bus;
+	size_t aligned_size = ALIGN(sizeof(*bus), NETDEV_ALIGN);
+	size_t alloc_size;
+	int i;
+
+	/* If we alloc extra space, it should be aligned */
+	if (size)
+		alloc_size = aligned_size + size;
+	else
+		alloc_size = sizeof(*bus);
+
+	bus = kzalloc(alloc_size, GFP_KERNEL);
+	if (!bus)
+		return NULL;
+
+	bus->state = MDIOBUS_ALLOCATED;
+	if (size)
+		bus->priv = (void *)bus + aligned_size;
+
+	/* Initialise the interrupts to polling and 64-bit seqcounts */
+	for (i = 0; i < PHY_MAX_ADDR; i++) {
+		bus->irq[i] = PHY_POLL;
+		u64_stats_init(&bus->stats[i].syncp);
+	}
+
+	return bus;
+}
+EXPORT_SYMBOL(mdiobus_alloc_size);
+
+#if IS_ENABLED(CONFIG_OF_MDIO)
+/* Walk the list of subnodes of a mdio bus and look for a node that
+ * matches the mdio device's address with its 'reg' property. If
+ * found, set the of_node pointer for the mdio device. This allows
+ * auto-probed phy devices to be supplied with information passed in
+ * via DT.
+ * If a PHY package is found, PHY is searched also there.
+ */
+static int of_mdiobus_find_phy(struct device *dev, struct mdio_device *mdiodev,
+			       struct device_node *np)
+{
+	struct device_node *child;
+
+	for_each_available_child_of_node(np, child) {
+		int addr;
+
+		if (of_node_name_eq(child, "ethernet-phy-package")) {
+			/* Validate PHY package reg presence */
+			if (!of_property_present(child, "reg")) {
+				of_node_put(child);
+				return -EINVAL;
+			}
+
+			if (!of_mdiobus_find_phy(dev, mdiodev, child)) {
+				/* The refcount for the PHY package will be
+				 * incremented later when PHY join the Package.
+				 */
+				of_node_put(child);
+				return 0;
+			}
+
+			continue;
+		}
+
+		addr = of_mdio_parse_addr(dev, child);
+		if (addr < 0)
+			continue;
+
+		if (addr == mdiodev->addr) {
+			device_set_node(dev, of_fwnode_handle(child));
+			/* The refcount on "child" is passed to the mdio
+			 * device. Do _not_ use of_node_put(child) here.
+			 */
+			return 0;
+		}
+	}
+
+	return -ENODEV;
+}
+
+static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
+				    struct mdio_device *mdiodev)
+{
+	struct device *dev = &mdiodev->dev;
+
+	if (dev->of_node || !bus->dev.of_node)
+		return;
+
+	of_mdiobus_find_phy(dev, mdiodev, bus->dev.of_node);
+}
+#endif
+
+/**
+ * mdiobus_create_device - create a full MDIO device given
+ * a mdio_board_info structure
+ * @bus: MDIO bus to create the devices on
+ * @bi: mdio_board_info structure describing the devices
+ *
+ * Returns 0 on success or < 0 on error.
+ */
+static int mdiobus_create_device(struct mii_bus *bus,
+				 struct mdio_board_info *bi)
+{
+	struct mdio_device *mdiodev;
+	int ret = 0;
+
+	mdiodev = mdio_device_create(bus, bi->mdio_addr);
+	if (IS_ERR(mdiodev))
+		return -ENODEV;
+
+	strscpy(mdiodev->modalias, bi->modalias,
+		sizeof(mdiodev->modalias));
+	mdiodev->bus_match = mdio_device_bus_match;
+	mdiodev->dev.platform_data = (void *)bi->platform_data;
+
+	ret = mdio_device_register(mdiodev);
+	if (ret)
+		mdio_device_free(mdiodev);
+
+	return ret;
+}
+
+static struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr, bool c45)
+{
+	struct phy_device *phydev = ERR_PTR(-ENODEV);
+	struct fwnode_handle *fwnode;
+	char node_name[16];
+	int err;
+
+	phydev = get_phy_device(bus, addr, c45);
+	if (IS_ERR(phydev))
+		return phydev;
+
+#if IS_ENABLED(CONFIG_OF_MDIO)
+	/* For DT, see if the auto-probed phy has a corresponding child
+	 * in the bus node, and set the of_node pointer in this case.
+	 */
+	of_mdiobus_link_mdiodev(bus, &phydev->mdio);
+#endif
+
+	/* Search for a swnode for the phy in the swnode hierarchy of the bus.
+	 * If there is no swnode for the phy provided, just ignore it.
+	 */
+	if (dev_fwnode(&bus->dev) && !dev_fwnode(&phydev->mdio.dev)) {
+		snprintf(node_name, sizeof(node_name), "ethernet-phy@%d",
+			 addr);
+		fwnode = fwnode_get_named_child_node(dev_fwnode(&bus->dev),
+						     node_name);
+		if (fwnode)
+			device_set_node(&phydev->mdio.dev, fwnode);
+	}
+
+	err = phy_device_register(phydev);
+	if (err) {
+		phy_device_free(phydev);
+		return ERR_PTR(-ENODEV);
+	}
+
+	return phydev;
+}
+
+/**
+ * mdiobus_scan_c22 - scan one address on a bus for C22 MDIO devices.
+ * @bus: mii_bus to scan
+ * @addr: address on bus to scan
+ *
+ * This function scans one address on the MDIO bus, looking for
+ * devices which can be identified using a vendor/product ID in
+ * registers 2 and 3. Not all MDIO devices have such registers, but
+ * PHY devices typically do. Hence this function assumes anything
+ * found is a PHY, or can be treated as a PHY. Other MDIO devices,
+ * such as switches, will probably not be found during the scan.
+ */
+struct phy_device *mdiobus_scan_c22(struct mii_bus *bus, int addr)
+{
+	return mdiobus_scan(bus, addr, false);
+}
+EXPORT_SYMBOL(mdiobus_scan_c22);
+
+/**
+ * mdiobus_scan_c45 - scan one address on a bus for C45 MDIO devices.
+ * @bus: mii_bus to scan
+ * @addr: address on bus to scan
+ *
+ * This function scans one address on the MDIO bus, looking for
+ * devices which can be identified using a vendor/product ID in
+ * registers 2 and 3. Not all MDIO devices have such registers, but
+ * PHY devices typically do. Hence this function assumes anything
+ * found is a PHY, or can be treated as a PHY. Other MDIO devices,
+ * such as switches, will probably not be found during the scan.
+ */
+static struct phy_device *mdiobus_scan_c45(struct mii_bus *bus, int addr)
+{
+	return mdiobus_scan(bus, addr, true);
+}
+
+static int mdiobus_scan_bus_c22(struct mii_bus *bus)
+{
+	int i;
+
+	for (i = 0; i < PHY_MAX_ADDR; i++) {
+		if ((bus->phy_mask & BIT(i)) == 0) {
+			struct phy_device *phydev;
+
+			phydev = mdiobus_scan_c22(bus, i);
+			if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV))
+				return PTR_ERR(phydev);
+		}
+	}
+	return 0;
+}
+
+static int mdiobus_scan_bus_c45(struct mii_bus *bus)
+{
+	int i;
+
+	for (i = 0; i < PHY_MAX_ADDR; i++) {
+		if ((bus->phy_mask & BIT(i)) == 0) {
+			struct phy_device *phydev;
+
+			/* Don't scan C45 if we already have a C22 device */
+			if (bus->mdio_map[i])
+				continue;
+
+			phydev = mdiobus_scan_c45(bus, i);
+			if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV))
+				return PTR_ERR(phydev);
+		}
+	}
+	return 0;
+}
+
+/* There are some C22 PHYs which do bad things when where is a C45
+ * transaction on the bus, like accepting a read themselves, and
+ * stomping over the true devices reply, to performing a write to
+ * themselves which was intended for another device. Now that C22
+ * devices have been found, see if any of them are bad for C45, and if we
+ * should skip the C45 scan.
+ */
+static bool mdiobus_prevent_c45_scan(struct mii_bus *bus)
+{
+	int i;
+
+	for (i = 0; i < PHY_MAX_ADDR; i++) {
+		struct phy_device *phydev;
+		u32 oui;
+
+		phydev = mdiobus_get_phy(bus, i);
+		if (!phydev)
+			continue;
+		oui = phydev->phy_id >> 10;
+
+		if (oui == MICREL_OUI)
+			return true;
+	}
+	return false;
+}
+
+/**
+ * __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
+ * @bus: target mii_bus
+ * @owner: module containing bus accessor functions
+ *
+ * Description: Called by a bus driver to bring up all the PHYs
+ *   on a given bus, and attach them to the bus. Drivers should use
+ *   mdiobus_register() rather than __mdiobus_register() unless they
+ *   need to pass a specific owner module. MDIO devices which are not
+ *   PHYs will not be brought up by this function. They are expected
+ *   to be explicitly listed in DT and instantiated by of_mdiobus_register().
+ *
+ * Returns 0 on success or < 0 on error.
+ */
+int __mdiobus_register(struct mii_bus *bus, struct module *owner)
+{
+	struct mdio_device *mdiodev;
+	struct gpio_desc *gpiod;
+	bool prevent_c45_scan;
+	int i, err;
+
+	if (!bus || !bus->name)
+		return -EINVAL;
+
+	/* An access method always needs both read and write operations */
+	if (!!bus->read != !!bus->write || !!bus->read_c45 != !!bus->write_c45)
+		return -EINVAL;
+
+	/* At least one method is mandatory */
+	if (!bus->read && !bus->read_c45)
+		return -EINVAL;
+
+	if (bus->parent && bus->parent->of_node)
+		bus->parent->of_node->fwnode.flags |=
+					FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD;
+
+	WARN(bus->state != MDIOBUS_ALLOCATED &&
+	     bus->state != MDIOBUS_UNREGISTERED,
+	     "%s: not in ALLOCATED or UNREGISTERED state\n", bus->id);
+
+	bus->owner = owner;
+	bus->dev.parent = bus->parent;
+	bus->dev.class = &mdio_bus_class;
+	bus->dev.groups = NULL;
+	dev_set_name(&bus->dev, "%s", bus->id);
+
+	/* If the bus state is allocated, we're registering a fresh bus
+	 * that may have a fwnode associated with it. Grab a reference
+	 * to the fwnode. This will be dropped when the bus is released.
+	 * If the bus was set to unregistered, it means that the bus was
+	 * previously registered, and we've already grabbed a reference.
+	 */
+	if (bus->state == MDIOBUS_ALLOCATED)
+		fwnode_handle_get(dev_fwnode(&bus->dev));
+
+	/* We need to set state to MDIOBUS_UNREGISTERED to correctly release
+	 * the device in mdiobus_free()
+	 *
+	 * State will be updated later in this function in case of success
+	 */
+	bus->state = MDIOBUS_UNREGISTERED;
+
+	err = device_register(&bus->dev);
+	if (err) {
+		pr_err("mii_bus %s failed to register\n", bus->id);
+		return -EINVAL;
+	}
+
+	mutex_init(&bus->mdio_lock);
+	mutex_init(&bus->shared_lock);
+
+	/* assert bus level PHY GPIO reset */
+	gpiod = devm_gpiod_get_optional(&bus->dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(gpiod)) {
+		err = dev_err_probe(&bus->dev, PTR_ERR(gpiod),
+				    "mii_bus %s couldn't get reset GPIO\n",
+				    bus->id);
+		device_del(&bus->dev);
+		return err;
+	} else	if (gpiod) {
+		bus->reset_gpiod = gpiod;
+		fsleep(bus->reset_delay_us);
+		gpiod_set_value_cansleep(gpiod, 0);
+		if (bus->reset_post_delay_us > 0)
+			fsleep(bus->reset_post_delay_us);
+	}
+
+	if (bus->reset) {
+		err = bus->reset(bus);
+		if (err)
+			goto error_reset_gpiod;
+	}
+
+	if (bus->read) {
+		err = mdiobus_scan_bus_c22(bus);
+		if (err)
+			goto error;
+	}
+
+	prevent_c45_scan = mdiobus_prevent_c45_scan(bus);
+
+	if (!prevent_c45_scan && bus->read_c45) {
+		err = mdiobus_scan_bus_c45(bus);
+		if (err)
+			goto error;
+	}
+
+	mdiobus_setup_mdiodev_from_board_info(bus, mdiobus_create_device);
+
+	bus->state = MDIOBUS_REGISTERED;
+	dev_dbg(&bus->dev, "probed\n");
+	return 0;
+
+error:
+	for (i = 0; i < PHY_MAX_ADDR; i++) {
+		mdiodev = bus->mdio_map[i];
+		if (!mdiodev)
+			continue;
+
+		mdiodev->device_remove(mdiodev);
+		mdiodev->device_free(mdiodev);
+	}
+error_reset_gpiod:
+	/* Put PHYs in RESET to save power */
+	if (bus->reset_gpiod)
+		gpiod_set_value_cansleep(bus->reset_gpiod, 1);
+
+	device_del(&bus->dev);
+	return err;
+}
+EXPORT_SYMBOL(__mdiobus_register);
+
+void mdiobus_unregister(struct mii_bus *bus)
+{
+	struct mdio_device *mdiodev;
+	int i;
+
+	if (WARN_ON_ONCE(bus->state != MDIOBUS_REGISTERED))
+		return;
+	bus->state = MDIOBUS_UNREGISTERED;
+
+	for (i = 0; i < PHY_MAX_ADDR; i++) {
+		mdiodev = bus->mdio_map[i];
+		if (!mdiodev)
+			continue;
+
+		if (mdiodev->reset_gpio)
+			gpiod_put(mdiodev->reset_gpio);
+
+		mdiodev->device_remove(mdiodev);
+		mdiodev->device_free(mdiodev);
+	}
+
+	/* Put PHYs in RESET to save power */
+	if (bus->reset_gpiod)
+		gpiod_set_value_cansleep(bus->reset_gpiod, 1);
+
+	device_del(&bus->dev);
+}
+EXPORT_SYMBOL(mdiobus_unregister);
+
+/**
+ * mdiobus_free - free a struct mii_bus
+ * @bus: mii_bus to free
+ *
+ * This function releases the reference to the underlying device
+ * object in the mii_bus.  If this is the last reference, the mii_bus
+ * will be freed.
+ */
+void mdiobus_free(struct mii_bus *bus)
+{
+	/* For compatibility with error handling in drivers. */
+	if (bus->state == MDIOBUS_ALLOCATED) {
+		kfree(bus);
+		return;
+	}
+
+	WARN(bus->state != MDIOBUS_UNREGISTERED,
+	     "%s: not in UNREGISTERED state\n", bus->id);
+	bus->state = MDIOBUS_RELEASED;
+
+	put_device(&bus->dev);
+}
+EXPORT_SYMBOL(mdiobus_free);