linux/drivers/net/phy/mdio_bus.c
Nate Case 35b5f6b1a8 PHYLIB: Locking fixes for PHY I/O potentially sleeping
PHY read/write functions can potentially sleep (e.g., a PHY accessed
via I2C).  The following changes were made to account for this:

    * Change spin locks to mutex locks
    * Add a BUG_ON() to phy_read() phy_write() to warn against
      calling them from an interrupt context.
    * Use work queue for PHY state machine handling since
      it can potentially sleep
    * Change phydev lock from spinlock to mutex

Signed-off-by: Nate Case <ncase@xes-inc.com>
Acked-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-02-03 04:28:41 -08:00

181 lines
3.8 KiB
C

/*
* drivers/net/phy/mdio_bus.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.
*
*/
#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/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 <asm/io.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
/**
* 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;
int err = 0;
mutex_init(&bus->mdio_lock);
if (NULL == bus || NULL == bus->name ||
NULL == bus->read ||
NULL == bus->write)
return -EINVAL;
if (bus->reset)
bus->reset(bus);
for (i = 0; i < PHY_MAX_ADDR; i++) {
struct phy_device *phydev;
if (bus->phy_mask & (1 << i)) {
bus->phy_map[i] = NULL;
continue;
}
phydev = get_phy_device(bus, i);
if (IS_ERR(phydev))
return PTR_ERR(phydev);
/* There's a PHY at this address
* We need to set:
* 1) IRQ
* 2) bus_id
* 3) parent
* 4) bus
* 5) mii_bus
* And, we need to register it */
if (phydev) {
phydev->irq = bus->irq[i];
phydev->dev.parent = bus->dev;
phydev->dev.bus = &mdio_bus_type;
snprintf(phydev->dev.bus_id, BUS_ID_SIZE, PHY_ID_FMT, bus->id, i);
phydev->bus = bus;
err = device_register(&phydev->dev);
if (err) {
printk(KERN_ERR "phy %d failed to register\n",
i);
phy_device_free(phydev);
phydev = NULL;
}
}
bus->phy_map[i] = phydev;
}
pr_info("%s: probed\n", bus->name);
return err;
}
EXPORT_SYMBOL(mdiobus_register);
void mdiobus_unregister(struct mii_bus *bus)
{
int i;
for (i = 0; i < PHY_MAX_ADDR; i++) {
if (bus->phy_map[i])
device_unregister(&bus->phy_map[i]->dev);
}
}
EXPORT_SYMBOL(mdiobus_unregister);
/**
* 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);
return ((phydrv->phy_id & phydrv->phy_id_mask) ==
(phydev->phy_id & phydrv->phy_id_mask));
}
/* Suspend and resume. Copied from platform_suspend and
* platform_resume
*/
static int mdio_bus_suspend(struct device * dev, pm_message_t state)
{
int ret = 0;
struct device_driver *drv = dev->driver;
if (drv && drv->suspend)
ret = drv->suspend(dev, state);
return ret;
}
static int mdio_bus_resume(struct device * dev)
{
int ret = 0;
struct device_driver *drv = dev->driver;
if (drv && drv->resume)
ret = drv->resume(dev);
return ret;
}
struct bus_type mdio_bus_type = {
.name = "mdio_bus",
.match = mdio_bus_match,
.suspend = mdio_bus_suspend,
.resume = mdio_bus_resume,
};
EXPORT_SYMBOL(mdio_bus_type);
int __init mdio_bus_init(void)
{
return bus_register(&mdio_bus_type);
}
void mdio_bus_exit(void)
{
bus_unregister(&mdio_bus_type);
}