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/delay.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/init.h>
#include <linux/interrupt.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_gpio.h>
#include <linux/of_mdio.h>
#include <linux/phy.h>
#include <linux/reset.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/uaccess.h>
#include <linux/unistd.h>

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

#include "mdio-boardinfo.h"

static int mdiobus_register_gpiod(struct mdio_device *mdiodev)
{
	/* Deassert the optional reset signal */
	mdiodev->reset_gpio = gpiod_get_optional(&mdiodev->dev,
						 "reset", GPIOD_OUT_LOW);
	if (IS_ERR(mdiodev->reset_gpio))
		return PTR_ERR(mdiodev->reset_gpio);

	if (mdiodev->reset_gpio)
		gpiod_set_consumer_name(mdiodev->reset_gpio, "PHY reset");

	return 0;
}

static int mdiobus_register_reset(struct mdio_device *mdiodev)
{
	struct reset_control *reset;

	reset = reset_control_get_optional_exclusive(&mdiodev->dev, "phy");
	if (IS_ERR(reset))
		return PTR_ERR(reset);

	mdiodev->reset_ctrl = reset;

	return 0;
}

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 = mdiobus_register_gpiod(mdiodev);
		if (err)
			return err;

		err = mdiobus_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;

	reset_control_put(mdiodev->reset_ctrl);

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

	return 0;
}
EXPORT_SYMBOL(mdiobus_unregister_device);

struct phy_device *mdiobus_get_phy(struct mii_bus *bus, int addr)
{
	struct mdio_device *mdiodev = bus->mdio_map[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 bus->mdio_map[addr];
}
EXPORT_SYMBOL(mdiobus_is_registered_device);

/**
 * 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);

/**
 * 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);
	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