linux_dsm_epyc7002/drivers/net/phy/mdio_bus.c
Roger Quadros 69226896ad mdio_bus: Issue GPIO RESET to PHYs.
Some boards [1] leave the PHYs at an invalid state
during system power-up or reset thus causing unreliability
issues with the PHY which manifests as PHY not being detected
or link not functional. To fix this, these PHYs need to be RESET
via a GPIO connected to the PHY's RESET pin.

Some boards have a single GPIO controlling the PHY RESET pin of all
PHYs on the bus whereas some others have separate GPIOs controlling
individual PHY RESETs.

In both cases, the RESET de-assertion cannot be done in the PHY driver
as the PHY will not probe till its reset is de-asserted.
So do the RESET de-assertion in the MDIO bus driver.

[1] - am572x-idk, am571x-idk, a437x-idk

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-24 12:40:24 -04:00

743 lines
18 KiB
C

/* 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/gpio.h>
#include <linux/gpio/consumer.h>
#include <linux/of_device.h>
#include <linux/of_mdio.h>
#include <linux/of_gpio.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>
#define CREATE_TRACE_POINTS
#include <trace/events/mdio.h>
#include "mdio-boardinfo.h"
int mdiobus_register_device(struct mdio_device *mdiodev)
{
if (mdiodev->bus->mdio_map[mdiodev->addr])
return -EBUSY;
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;
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 */
for (i = 0; i < PHY_MAX_ADDR; i++)
bus->irq[i] = PHY_POLL;
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_size);
/**
* 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 reference to the mii_bus, or NULL if none found. The
* embedded struct device will have its reference count incremented,
* and this must be put once the bus is finished with.
*
* 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);
/* 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.
*/
static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
struct mdio_device *mdiodev)
{
struct device *dev = &mdiodev->dev;
struct device_node *child;
if (dev->of_node || !bus->dev.of_node)
return;
for_each_available_child_of_node(bus->dev.of_node, child) {
int addr;
int ret;
ret = of_property_read_u32(child, "reg", &addr);
if (ret < 0) {
dev_err(dev, "%s has invalid MDIO address\n",
child->full_name);
continue;
}
/* A MDIO device must have a reg property in the range [0-31] */
if (addr >= PHY_MAX_ADDR) {
dev_err(dev, "%s MDIO address %i is too large\n",
child->full_name, addr);
continue;
}
if (addr == mdiodev->addr) {
dev->of_node = child;
return;
}
}
}
#else /* !IS_ENABLED(CONFIG_OF_MDIO) */
static inline void of_mdiobus_link_mdiodev(struct mii_bus *mdio,
struct mdio_device *mdiodev)
{
}
#endif
/**
* mdiobus_create_device_from_board_info - 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;
strncpy(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;
}
/**
* __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
* 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;
int i, err;
struct gpio_desc *gpiod;
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->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);
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);
/* de-assert bus level PHY GPIO resets */
if (bus->num_reset_gpios > 0) {
bus->reset_gpiod = devm_kcalloc(&bus->dev,
bus->num_reset_gpios,
sizeof(struct gpio_desc *),
GFP_KERNEL);
if (!bus->reset_gpiod)
return -ENOMEM;
}
for (i = 0; i < bus->num_reset_gpios; i++) {
gpiod = devm_gpiod_get_index(&bus->dev, "reset", i,
GPIOD_OUT_LOW);
if (IS_ERR(gpiod)) {
err = PTR_ERR(gpiod);
if (err != -ENOENT) {
dev_err(&bus->dev,
"mii_bus %s couldn't get reset GPIO\n",
bus->id);
return err;
}
} else {
bus->reset_gpiod[i] = gpiod;
gpiod_set_value_cansleep(gpiod, 1);
udelay(bus->reset_delay_us);
gpiod_set_value_cansleep(gpiod, 0);
}
}
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) && (PTR_ERR(phydev) != -ENODEV)) {
err = PTR_ERR(phydev);
goto error;
}
}
}
mdiobus_setup_mdiodev_from_board_info(bus, mdiobus_create_device);
bus->state = MDIOBUS_REGISTERED;
pr_info("%s: probed\n", bus->name);
return 0;
error:
while (--i >= 0) {
mdiodev = bus->mdio_map[i];
if (!mdiodev)
continue;
mdiodev->device_remove(mdiodev);
mdiodev->device_free(mdiodev);
}
/* Put PHYs in RESET to save power */
for (i = 0; i < bus->num_reset_gpios; i++) {
if (bus->reset_gpiod[i])
gpiod_set_value_cansleep(bus->reset_gpiod[i], 1);
}
device_del(&bus->dev);
return err;
}
EXPORT_SYMBOL(__mdiobus_register);
void mdiobus_unregister(struct mii_bus *bus)
{
struct mdio_device *mdiodev;
int i;
BUG_ON(bus->state != MDIOBUS_REGISTERED);
bus->state = MDIOBUS_UNREGISTERED;
for (i = 0; i < PHY_MAX_ADDR; i++) {
mdiodev = bus->mdio_map[i];
if (!mdiodev)
continue;
mdiodev->device_remove(mdiodev);
mdiodev->device_free(mdiodev);
}
/* Put PHYs in RESET to save power */
for (i = 0; i < bus->num_reset_gpios; i++) {
if (bus->reset_gpiod[i])
gpiod_set_value_cansleep(bus->reset_gpiod[i], 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;
}
BUG_ON(bus->state != MDIOBUS_UNREGISTERED);
bus->state = MDIOBUS_RELEASED;
put_device(&bus->dev);
}
EXPORT_SYMBOL(mdiobus_free);
/**
* mdiobus_scan - scan a bus for MDIO devices.
* @bus: mii_bus to scan
* @addr: address on bus to scan
*
* This function scans 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(struct mii_bus *bus, int addr)
{
struct phy_device *phydev;
int err;
phydev = get_phy_device(bus, addr, false);
if (IS_ERR(phydev))
return phydev;
/*
* For DT, see if the auto-probed phy has a correspoding child
* in the bus node, and set the of_node pointer in this case.
*/
of_mdiobus_link_mdiodev(bus, &phydev->mdio);
err = phy_device_register(phydev);
if (err) {
phy_device_free(phydev);
return ERR_PTR(-ENODEV);
}
return phydev;
}
EXPORT_SYMBOL(mdiobus_scan);
/**
* mdiobus_read_nested - Nested version of the mdiobus_read function
* @bus: the mii_bus struct
* @addr: the phy address
* @regnum: register number to read
*
* In case of nested MDIO bus access avoid lockdep false positives by
* using mutex_lock_nested().
*
* 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_nested(struct mii_bus *bus, int addr, u32 regnum)
{
int retval;
BUG_ON(in_interrupt());
mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
retval = bus->read(bus, addr, regnum);
mutex_unlock(&bus->mdio_lock);
trace_mdio_access(bus, 1, addr, regnum, retval, retval);
return retval;
}
EXPORT_SYMBOL(mdiobus_read_nested);
/**
* 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);
trace_mdio_access(bus, 1, addr, regnum, retval, retval);
return retval;
}
EXPORT_SYMBOL(mdiobus_read);
/**
* mdiobus_write_nested - Nested version of the mdiobus_write function
* @bus: the mii_bus struct
* @addr: the phy address
* @regnum: register number to write
* @val: value to write to @regnum
*
* In case of nested MDIO bus access avoid lockdep false positives by
* using mutex_lock_nested().
*
* 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_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
{
int err;
BUG_ON(in_interrupt());
mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
err = bus->write(bus, addr, regnum, val);
mutex_unlock(&bus->mdio_lock);
trace_mdio_access(bus, 0, addr, regnum, val, err);
return err;
}
EXPORT_SYMBOL(mdiobus_write_nested);
/**
* 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);
trace_mdio_access(bus, 0, addr, regnum, val, err);
return err;
}
EXPORT_SYMBOL(mdiobus_write);
/**
* mdio_bus_match - determine if given MDIO driver supports the given
* MDIO device
* @dev: target MDIO device
* @drv: given MDIO driver
*
* Description: Given a MDIO device, and a MDIO driver, return 1 if
* the driver supports the device. Otherwise, return 0. This may
* require calling the devices own match function, since different classes
* of MDIO devices have different match criteria.
*/
static int mdio_bus_match(struct device *dev, struct device_driver *drv)
{
struct mdio_device *mdio = to_mdio_device(dev);
if (of_driver_match_device(dev, drv))
return 1;
if (mdio->bus_match)
return mdio->bus_match(dev, drv);
return 0;
}
#ifdef CONFIG_PM
static int mdio_bus_suspend(struct device *dev)
{
struct mdio_device *mdio = to_mdio_device(dev);
if (mdio->pm_ops && mdio->pm_ops->suspend)
return mdio->pm_ops->suspend(dev);
return 0;
}
static int mdio_bus_resume(struct device *dev)
{
struct mdio_device *mdio = to_mdio_device(dev);
if (mdio->pm_ops && mdio->pm_ops->resume)
return mdio->pm_ops->resume(dev);
return 0;
}
static int mdio_bus_restore(struct device *dev)
{
struct mdio_device *mdio = to_mdio_device(dev);
if (mdio->pm_ops && mdio->pm_ops->restore)
return mdio->pm_ops->restore(dev);
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 */
struct bus_type mdio_bus_type = {
.name = "mdio_bus",
.match = mdio_bus_match,
.pm = MDIO_BUS_PM_OPS,
};
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;
}
EXPORT_SYMBOL_GPL(mdio_bus_init);
#if IS_ENABLED(CONFIG_PHYLIB)
void mdio_bus_exit(void)
{
class_unregister(&mdio_bus_class);
bus_unregister(&mdio_bus_type);
}
EXPORT_SYMBOL_GPL(mdio_bus_exit);
#else
module_init(mdio_bus_init);
/* no module_exit, intentional */
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("MDIO bus/device layer");
#endif