/* MDIO Bus interface
*
* Author: Andy Fleming
*
* Copyright (c) 2004 Freescale Semiconductor, Inc.
*
* 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/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/unistd.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/of_device.h>
#include <linux/of_mdio.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/mii.h>
#include <linux/ethtool.h>
#include <linux/phy.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <asm/irq.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;
/* 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) {
bus->state = MDIOBUS_ALLOCATED;
if (size)
bus->priv = (void *)bus + aligned_size;
}
return bus;
}
EXPORT_SYMBOL(mdiobus_alloc_size);
static void _devm_mdiobus_free(struct device *dev, void *res)
{
mdiobus_free(*(struct mii_bus **)res);
}
static int devm_mdiobus_match(struct device *dev, void *res, void *data)
{
struct mii_bus **r = res;
if (WARN_ON(!r || !*r))
return 0;
return *r == data;
}
/**
* devm_mdiobus_alloc_size - Resource-managed mdiobus_alloc_size()
* @dev: Device to allocate mii_bus for
* @sizeof_priv: Space to allocate for private structure.
*
* Managed mdiobus_alloc_size. mii_bus allocated with this function is
* automatically freed on driver detach.
*
* If an mii_bus allocated with this function needs to be freed separately,
* devm_mdiobus_free() must be used.
*
* RETURNS:
* Pointer to allocated mii_bus on success, NULL on failure.
*/
struct mii_bus *devm_mdiobus_alloc_size(struct device *dev, int sizeof_priv)
{
struct mii_bus **ptr, *bus;
ptr = devres_alloc(_devm_mdiobus_free, sizeof(*ptr), GFP_KERNEL);
if (!ptr)
return NULL;
/* use raw alloc_dr for kmalloc caller tracing */
bus = mdiobus_alloc_size(sizeof_priv);
if (bus) {
*ptr = bus;
devres_add(dev, ptr);
} else {
devres_free(ptr);
}
return bus;
}
EXPORT_SYMBOL_GPL(devm_mdiobus_alloc);
/**
* devm_mdiobus_free - Resource-managed mdiobus_free()
* @dev: Device this mii_bus belongs to
* @bus: the mii_bus associated with the device
*
* Free mii_bus allocated with devm_mdiobus_alloc_size().
*/
void devm_mdiobus_free(struct device *dev, struct mii_bus *bus)
{
int rc;
rc = devres_release(dev, _devm_mdiobus_free,
devm_mdiobus_match, bus);
WARN_ON(rc);
}
EXPORT_SYMBOL_GPL(devm_mdiobus_free);
/**
* 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);
BUG_ON(bus->state != MDIOBUS_RELEASED &&
/* for compatibility with error handling in drivers */
bus->state != MDIOBUS_ALLOCATED);
kfree(bus);
}
static struct class mdio_bus_class = {
.name = "mdio_bus",
.dev_release = mdiobus_release,
};
#if IS_ENABLED(CONFIG_OF_MDIO)
/* Helper function for of_mdio_find_bus */
static int of_mdio_bus_match(struct device *dev, const void *mdio_bus_np)
{
return dev->of_node == mdio_bus_np;
}
/**
* of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
* @mdio_bus_np: Pointer to the mii_bus.
*
* Returns a pointer to the mii_bus, or NULL if none found.
*
* Because the association of a device_node and mii_bus is made via
* of_mdiobus_register(), the mii_bus cannot be found before it is
* registered with of_mdiobus_register().
*
*/
struct mii_bus *of_mdio_find_bus(struct device_node *mdio_bus_np)
{
struct device *d;
if (!mdio_bus_np)
return NULL;
d = class_find_device(&mdio_bus_class, NULL, mdio_bus_np,
of_mdio_bus_match);
return d ? to_mii_bus(d) : NULL;
}
EXPORT_SYMBOL(of_mdio_find_bus);
#endif
/**
* mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
* @bus: target mii_bus
*
* Description: Called by a bus driver to bring up all the PHYs
* on a given bus, and attach them to the bus.
*
* Returns 0 on success or < 0 on error.
*/
int mdiobus_register(struct mii_bus *bus)
{
int i, err;
if (NULL == bus || NULL == bus->name ||
NULL == bus->read || NULL == bus->write)
return -EINVAL;
BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
bus->state != MDIOBUS_UNREGISTERED);
bus->dev.parent = bus->parent;
bus->dev.class = &mdio_bus_class;
bus->dev.groups = NULL;
dev_set_name(&bus->dev, "%s", bus->id);
err = device_register(&bus->dev);
if (err) {
pr_err("mii_bus %s failed to register\n", bus->id);
put_device(&bus->dev);
return -EINVAL;
}
mutex_init(&bus->mdio_lock);
if (bus->reset)
bus->reset(bus);
for (i = 0; i < PHY_MAX_ADDR; i++) {
if ((bus->phy_mask & (1 << i)) == 0) {
struct phy_device *phydev;
phydev = mdiobus_scan(bus, i);
if (IS_ERR(phydev)) {
err = PTR_ERR(phydev);
goto error;
}
}
}
bus->state = MDIOBUS_REGISTERED;
pr_info("%s: probed\n", bus->name);
return 0;
error:
while (--i >= 0) {
if (bus->phy_map[i])
device_unregister(&bus->phy_map[i]->dev);
}
device_del(&bus->dev);
return err;
}
EXPORT_SYMBOL(mdiobus_register);
void mdiobus_unregister(struct mii_bus *bus)
{
int i;
BUG_ON(bus->state != MDIOBUS_REGISTERED);
bus->state = MDIOBUS_UNREGISTERED;
device_del(&bus->dev);
for (i = 0; i < PHY_MAX_ADDR; i++) {
if (bus->phy_map[i])
device_unregister(&bus->phy_map[i]->dev);
bus->phy_map[i] = NULL;
}
}
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;
}
BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
bus->state = MDIOBUS_RELEASED;
put_device(&bus->dev);
}
EXPORT_SYMBOL(mdiobus_free);
struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
{
struct phy_device *phydev;
int err;
phydev = get_phy_device(bus, addr, false);
if (IS_ERR(phydev) || phydev == NULL)
return phydev;
err = phy_device_register(phydev);
if (err) {
phy_device_free(phydev);
return NULL;
}
return phydev;
}
EXPORT_SYMBOL(mdiobus_scan);
/**
* mdiobus_read - Convenience function for reading a given MII mgmt register
* @bus: the mii_bus struct
* @addr: the phy address
* @regnum: register number to read
*
* NOTE: MUST NOT be called from interrupt context,
* because the bus read/write functions may wait for an interrupt
* to conclude the operation.
*/
int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
{
int retval;
BUG_ON(in_interrupt());
mutex_lock(&bus->mdio_lock);
retval = bus->read(bus, addr, regnum);
mutex_unlock(&bus->mdio_lock);
return retval;
}
EXPORT_SYMBOL(mdiobus_read);
/**
* mdiobus_write - Convenience function for writing a given MII mgmt register
* @bus: the mii_bus struct
* @addr: the phy address
* @regnum: register number to write
* @val: value to write to @regnum
*
* NOTE: MUST NOT be called from interrupt context,
* because the bus read/write functions may wait for an interrupt
* to conclude the operation.
*/
int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
{
int err;
BUG_ON(in_interrupt());
mutex_lock(&bus->mdio_lock);
err = bus->write(bus, addr, regnum, val);
mutex_unlock(&bus->mdio_lock);
return err;
}
EXPORT_SYMBOL(mdiobus_write);
/**
* mdio_bus_match - determine if given PHY driver supports the given PHY device
* @dev: target PHY device
* @drv: given PHY driver
*
* Description: Given a PHY device, and a PHY driver, return 1 if
* the driver supports the device. Otherwise, return 0.
*/
static int mdio_bus_match(struct device *dev, struct device_driver *drv)
{
struct phy_device *phydev = to_phy_device(dev);
struct phy_driver *phydrv = to_phy_driver(drv);
if (of_driver_match_device(dev, drv))
return 1;
if (phydrv->match_phy_device)
return phydrv->match_phy_device(phydev);
return (phydrv->phy_id & phydrv->phy_id_mask) ==
(phydev->phy_id & phydrv->phy_id_mask);
}
#ifdef CONFIG_PM
static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
{
struct device_driver *drv = phydev->dev.driver;
struct phy_driver *phydrv = to_phy_driver(drv);
struct net_device *netdev = phydev->attached_dev;
if (!drv || !phydrv->suspend)
return false;
/* PHY not attached? May suspend. */
if (!netdev)
return true;
/* Don't suspend PHY if the attched netdev parent may wakeup.
* The parent may point to a PCI device, as in tg3 driver.
*/
if (netdev->dev.parent && device_may_wakeup(netdev->dev.parent))
return false;
/* Also don't suspend PHY if the netdev itself may wakeup. This
* is the case for devices w/o underlaying pwr. mgmt. aware bus,
* e.g. SoC devices.
*/
if (device_may_wakeup(&netdev->dev))
return false;
return true;
}
static int mdio_bus_suspend(struct device *dev)
{
struct phy_driver *phydrv = to_phy_driver(dev->driver);
struct phy_device *phydev = to_phy_device(dev);
/* We must stop the state machine manually, otherwise it stops out of
* control, possibly with the phydev->lock held. Upon resume, netdev
* may call phy routines that try to grab the same lock, and that may
* lead to a deadlock.
*/
if (phydev->attached_dev && phydev->adjust_link)
phy_stop_machine(phydev);
if (!mdio_bus_phy_may_suspend(phydev))
return 0;
return phydrv->suspend(phydev);
}
static int mdio_bus_resume(struct device *dev)
{
struct phy_driver *phydrv = to_phy_driver(dev->driver);
struct phy_device *phydev = to_phy_device(dev);
int ret;
if (!mdio_bus_phy_may_suspend(phydev))
goto no_resume;
ret = phydrv->resume(phydev);
if (ret < 0)
return ret;
no_resume:
if (phydev->attached_dev && phydev->adjust_link)
phy_start_machine(phydev);
return 0;
}
static int mdio_bus_restore(struct device *dev)
{
struct phy_device *phydev = to_phy_device(dev);
struct net_device *netdev = phydev->attached_dev;
int ret;
if (!netdev)
return 0;
ret = phy_init_hw(phydev);
if (ret < 0)
return ret;
/* The PHY needs to renegotiate. */
phydev->link = 0;
phydev->state = PHY_UP;
phy_start_machine(phydev);
return 0;
}
static const struct dev_pm_ops mdio_bus_pm_ops = {
.suspend = mdio_bus_suspend,
.resume = mdio_bus_resume,
.freeze = mdio_bus_suspend,
.thaw = mdio_bus_resume,
.restore = mdio_bus_restore,
};
#define MDIO_BUS_PM_OPS (&mdio_bus_pm_ops)
#else
#define MDIO_BUS_PM_OPS NULL
#endif /* CONFIG_PM */
static ssize_t
phy_id_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct phy_device *phydev = to_phy_device(dev);
return sprintf(buf, "0x%.8lx\n", (unsigned long)phydev->phy_id);
}
static DEVICE_ATTR_RO(phy_id);
static ssize_t
phy_interface_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct phy_device *phydev = to_phy_device(dev);
return sprintf(buf, "%s\n", phy_modes(phydev->interface));
}
static DEVICE_ATTR_RO(phy_interface);
static ssize_t
phy_has_fixups_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct phy_device *phydev = to_phy_device(dev);
return sprintf(buf, "%d\n", phydev->has_fixups);
}
static DEVICE_ATTR_RO(phy_has_fixups);
static struct attribute *mdio_dev_attrs[] = {
&dev_attr_phy_id.attr,
&dev_attr_phy_interface.attr,
&dev_attr_phy_has_fixups.attr,
NULL,
};
ATTRIBUTE_GROUPS(mdio_dev);
struct bus_type mdio_bus_type = {
.name = "mdio_bus",
.match = mdio_bus_match,
.pm = MDIO_BUS_PM_OPS,
.dev_groups = mdio_dev_groups,
};
EXPORT_SYMBOL(mdio_bus_type);
int __init mdio_bus_init(void)
{
int ret;
ret = class_register(&mdio_bus_class);
if (!ret) {
ret = bus_register(&mdio_bus_type);
if (ret)
class_unregister(&mdio_bus_class);
}
return ret;
}
void mdio_bus_exit(void)
{
class_unregister(&mdio_bus_class);
bus_unregister(&mdio_bus_type);
}
