path: root/drivers/net/phy/mdio_bus.c

// SPDX-License-Identifier: GPL-2.0+
/* MDIO Bus interface
 *
 * Author: Andy Fleming
 *
 * Copyright (c) 2004 Freescale Semiconductor, Inc.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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/mii.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/of_device.h>
#include <linux/of_mdio.h>
#include <linux/phy.h>
#include <linux/reset.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/uaccess.h>
#include <linux/unistd.h>
#include "mdio-private.h"

#define CREATE_TRACE_POINTS
#include <trace/events/mdio.h>

int mdiobus_register_device(struct mdio_device *mdiodev)
{
	int err;

	if (mdiodev->bus->mdio_map[mdiodev->addr])
		return -EBUSY;

	if (mdiodev->flags & MDIO_DEVICE_FLAG_PHY) {
		err = mdio_device_register_reset(mdiodev);
		if (err)
			return err;

		/* Assert the reset signal */
		mdio_device_reset(mdiodev, 1);
	}

	mdiodev->bus->mdio_map[mdiodev->addr] = mdiodev;

	return 0;
}
EXPORT_SYMBOL(mdiobus_register_device);

int mdiobus_unregister_device(struct mdio_device *mdiodev)
{
	if (mdiodev->bus->mdio_map[mdiodev->addr] != mdiodev)
		return -EINVAL;

	mdio_device_unregister_reset(mdiodev);

	mdiodev->bus->mdio_map[mdiodev->addr] = NULL;

	return 0;
}
EXPORT_SYMBOL(mdiobus_unregister_device);

static struct mdio_device *mdiobus_find_device(struct mii_bus *bus, int addr)
{
	bool addr_valid = addr >= 0 && addr < ARRAY_SIZE(bus->mdio_map);

	if (WARN_ONCE(!addr_valid, "addr %d out of range\n", addr))
		return NULL;

	return bus->mdio_map[addr];
}

struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr)
{
	struct mdio_device *mdiodev;

	mdiodev = mdiobus_find_device(bus, addr);
	if (!mdiodev)
		return NULL;

	if (!(mdiodev->flags & MDIO_DEVICE_FLAG_PHY))
		return NULL;

	return container_of(mdiodev, struct phy_device, mdio);
}
EXPORT_SYMBOL(mdiobus_get_phy);

bool mdiobus_is_registered_device(struct mii_bus *bus, int addr)
{
	return mdiobus_find_device(bus, addr) != NULL;
}
EXPORT_SYMBOL(mdiobus_is_registered_device);

/**
 * mdiobus_release - mii_bus device release callback
 * @d: the target struct device that contains the mii_bus
 *
 * Description: called when the last reference to an mii_bus is
 * dropped, to free the underlying memory.
 */
static void mdiobus_release(struct device *d)
{
	struct mii_bus *bus = to_mii_bus(d);

	WARN(bus->state != MDIOBUS_RELEASED &&
	     /* for compatibility with error handling in drivers */
	     bus->state != MDIOBUS_ALLOCATED,
	     "%s: not in RELEASED or ALLOCATED state\n",
	     bus->id);

	if (bus->state == MDIOBUS_RELEASED)
		fwnode_handle_put(dev_fwnode(d));

	kfree(bus);
}

struct mdio_bus_stat_attr {
	int addr;
	unsigned int field_offset;
};

static u64 mdio_bus_get_stat(struct mdio_bus_stats *s, unsigned int offset)
{
	const char *p = (const char *)s + offset;
	unsigned int start;
	u64 val = 0;

	do {
		start = u64_stats_fetch_begin(&s->syncp);
		val = u64_stats_read((const u64_stats_t *)p);
	} while (u64_stats_fetch_retry(&s->syncp, start));

	return val;
}

static u64 mdio_bus_get_global_stat(struct mii_bus *bus, unsigned int offset)
{
	unsigned int i;
	u64 val = 0;

	for (i = 0; i < PHY_MAX_ADDR; i