linux/drivers/net/phy/phy_device.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

766 lines
18 KiB
C

/*
* drivers/net/phy/phy_device.c
*
* Framework for finding and configuring PHYs.
* Also contains generic PHY driver
*
* 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/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>
MODULE_DESCRIPTION("PHY library");
MODULE_AUTHOR("Andy Fleming");
MODULE_LICENSE("GPL");
static struct phy_driver genphy_driver;
extern int mdio_bus_init(void);
extern void mdio_bus_exit(void);
void phy_device_free(struct phy_device *phydev)
{
kfree(phydev);
}
static void phy_device_release(struct device *dev)
{
phy_device_free(to_phy_device(dev));
}
struct phy_device* phy_device_create(struct mii_bus *bus, int addr, int phy_id)
{
struct phy_device *dev;
/* We allocate the device, and initialize the
* default values */
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (NULL == dev)
return (struct phy_device*) PTR_ERR((void*)-ENOMEM);
dev->dev.release = phy_device_release;
dev->speed = 0;
dev->duplex = -1;
dev->pause = dev->asym_pause = 0;
dev->link = 1;
dev->interface = PHY_INTERFACE_MODE_GMII;
dev->autoneg = AUTONEG_ENABLE;
dev->addr = addr;
dev->phy_id = phy_id;
dev->bus = bus;
dev->state = PHY_DOWN;
mutex_init(&dev->lock);
return dev;
}
EXPORT_SYMBOL(phy_device_create);
/**
* get_phy_device - reads the specified PHY device and returns its @phy_device struct
* @bus: the target MII bus
* @addr: PHY address on the MII bus
*
* Description: Reads the ID registers of the PHY at @addr on the
* @bus, then allocates and returns the phy_device to represent it.
*/
struct phy_device * get_phy_device(struct mii_bus *bus, int addr)
{
int phy_reg;
u32 phy_id;
struct phy_device *dev = NULL;
/* Grab the bits from PHYIR1, and put them
* in the upper half */
phy_reg = bus->read(bus, addr, MII_PHYSID1);
if (phy_reg < 0)
return ERR_PTR(phy_reg);
phy_id = (phy_reg & 0xffff) << 16;
/* Grab the bits from PHYIR2, and put them in the lower half */
phy_reg = bus->read(bus, addr, MII_PHYSID2);
if (phy_reg < 0)
return ERR_PTR(phy_reg);
phy_id |= (phy_reg & 0xffff);
/* If the phy_id is all Fs, there is no device there */
if (0xffffffff == phy_id)
return NULL;
dev = phy_device_create(bus, addr, phy_id);
return dev;
}
/**
* phy_prepare_link - prepares the PHY layer to monitor link status
* @phydev: target phy_device struct
* @handler: callback function for link status change notifications
*
* Description: Tells the PHY infrastructure to handle the
* gory details on monitoring link status (whether through
* polling or an interrupt), and to call back to the
* connected device driver when the link status changes.
* If you want to monitor your own link state, don't call
* this function.
*/
void phy_prepare_link(struct phy_device *phydev,
void (*handler)(struct net_device *))
{
phydev->adjust_link = handler;
}
/**
* phy_connect - connect an ethernet device to a PHY device
* @dev: the network device to connect
* @phy_id: the PHY device to connect
* @handler: callback function for state change notifications
* @flags: PHY device's dev_flags
* @interface: PHY device's interface
*
* Description: Convenience function for connecting ethernet
* devices to PHY devices. The default behavior is for
* the PHY infrastructure to handle everything, and only notify
* the connected driver when the link status changes. If you
* don't want, or can't use the provided functionality, you may
* choose to call only the subset of functions which provide
* the desired functionality.
*/
struct phy_device * phy_connect(struct net_device *dev, const char *phy_id,
void (*handler)(struct net_device *), u32 flags,
phy_interface_t interface)
{
struct phy_device *phydev;
phydev = phy_attach(dev, phy_id, flags, interface);
if (IS_ERR(phydev))
return phydev;
phy_prepare_link(phydev, handler);
phy_start_machine(phydev, NULL);
if (phydev->irq > 0)
phy_start_interrupts(phydev);
return phydev;
}
EXPORT_SYMBOL(phy_connect);
/**
* phy_disconnect - disable interrupts, stop state machine, and detach a PHY device
* @phydev: target phy_device struct
*/
void phy_disconnect(struct phy_device *phydev)
{
if (phydev->irq > 0)
phy_stop_interrupts(phydev);
phy_stop_machine(phydev);
phydev->adjust_link = NULL;
phy_detach(phydev);
}
EXPORT_SYMBOL(phy_disconnect);
static int phy_compare_id(struct device *dev, void *data)
{
return strcmp((char *)data, dev->bus_id) ? 0 : 1;
}
/**
* phy_attach - attach a network device to a particular PHY device
* @dev: network device to attach
* @phy_id: PHY device to attach
* @flags: PHY device's dev_flags
* @interface: PHY device's interface
*
* Description: Called by drivers to attach to a particular PHY
* device. The phy_device is found, and properly hooked up
* to the phy_driver. If no driver is attached, then the
* genphy_driver is used. The phy_device is given a ptr to
* the attaching device, and given a callback for link status
* change. The phy_device is returned to the attaching driver.
*/
struct phy_device *phy_attach(struct net_device *dev,
const char *phy_id, u32 flags, phy_interface_t interface)
{
struct bus_type *bus = &mdio_bus_type;
struct phy_device *phydev;
struct device *d;
/* Search the list of PHY devices on the mdio bus for the
* PHY with the requested name */
d = bus_find_device(bus, NULL, (void *)phy_id, phy_compare_id);
if (d) {
phydev = to_phy_device(d);
} else {
printk(KERN_ERR "%s not found\n", phy_id);
return ERR_PTR(-ENODEV);
}
/* Assume that if there is no driver, that it doesn't
* exist, and we should use the genphy driver. */
if (NULL == d->driver) {
int err;
d->driver = &genphy_driver.driver;
err = d->driver->probe(d);
if (err >= 0)
err = device_bind_driver(d);
if (err)
return ERR_PTR(err);
}
if (phydev->attached_dev) {
printk(KERN_ERR "%s: %s already attached\n",
dev->name, phy_id);
return ERR_PTR(-EBUSY);
}
phydev->attached_dev = dev;
phydev->dev_flags = flags;
phydev->interface = interface;
/* Do initial configuration here, now that
* we have certain key parameters
* (dev_flags and interface) */
if (phydev->drv->config_init) {
int err;
err = phydev->drv->config_init(phydev);
if (err < 0)
return ERR_PTR(err);
}
return phydev;
}
EXPORT_SYMBOL(phy_attach);
/**
* phy_detach - detach a PHY device from its network device
* @phydev: target phy_device struct
*/
void phy_detach(struct phy_device *phydev)
{
phydev->attached_dev = NULL;
/* If the device had no specific driver before (i.e. - it
* was using the generic driver), we unbind the device
* from the generic driver so that there's a chance a
* real driver could be loaded */
if (phydev->dev.driver == &genphy_driver.driver)
device_release_driver(&phydev->dev);
}
EXPORT_SYMBOL(phy_detach);
/* Generic PHY support and helper functions */
/**
* genphy_config_advert - sanitize and advertise auto-negotation parameters
* @phydev: target phy_device struct
*
* Description: Writes MII_ADVERTISE with the appropriate values,
* after sanitizing the values to make sure we only advertise
* what is supported.
*/
int genphy_config_advert(struct phy_device *phydev)
{
u32 advertise;
int adv;
int err;
/* Only allow advertising what
* this PHY supports */
phydev->advertising &= phydev->supported;
advertise = phydev->advertising;
/* Setup standard advertisement */
adv = phy_read(phydev, MII_ADVERTISE);
if (adv < 0)
return adv;
adv &= ~(ADVERTISE_ALL | ADVERTISE_100BASE4 | ADVERTISE_PAUSE_CAP |
ADVERTISE_PAUSE_ASYM);
if (advertise & ADVERTISED_10baseT_Half)
adv |= ADVERTISE_10HALF;
if (advertise & ADVERTISED_10baseT_Full)
adv |= ADVERTISE_10FULL;
if (advertise & ADVERTISED_100baseT_Half)
adv |= ADVERTISE_100HALF;
if (advertise & ADVERTISED_100baseT_Full)
adv |= ADVERTISE_100FULL;
if (advertise & ADVERTISED_Pause)
adv |= ADVERTISE_PAUSE_CAP;
if (advertise & ADVERTISED_Asym_Pause)
adv |= ADVERTISE_PAUSE_ASYM;
err = phy_write(phydev, MII_ADVERTISE, adv);
if (err < 0)
return err;
/* Configure gigabit if it's supported */
if (phydev->supported & (SUPPORTED_1000baseT_Half |
SUPPORTED_1000baseT_Full)) {
adv = phy_read(phydev, MII_CTRL1000);
if (adv < 0)
return adv;
adv &= ~(ADVERTISE_1000FULL | ADVERTISE_1000HALF);
if (advertise & SUPPORTED_1000baseT_Half)
adv |= ADVERTISE_1000HALF;
if (advertise & SUPPORTED_1000baseT_Full)
adv |= ADVERTISE_1000FULL;
err = phy_write(phydev, MII_CTRL1000, adv);
if (err < 0)
return err;
}
return adv;
}
EXPORT_SYMBOL(genphy_config_advert);
/**
* genphy_setup_forced - configures/forces speed/duplex from @phydev
* @phydev: target phy_device struct
*
* Description: Configures MII_BMCR to force speed/duplex
* to the values in phydev. Assumes that the values are valid.
* Please see phy_sanitize_settings().
*/
int genphy_setup_forced(struct phy_device *phydev)
{
int ctl = 0;
phydev->pause = phydev->asym_pause = 0;
if (SPEED_1000 == phydev->speed)
ctl |= BMCR_SPEED1000;
else if (SPEED_100 == phydev->speed)
ctl |= BMCR_SPEED100;
if (DUPLEX_FULL == phydev->duplex)
ctl |= BMCR_FULLDPLX;
ctl = phy_write(phydev, MII_BMCR, ctl);
if (ctl < 0)
return ctl;
/* We just reset the device, so we'd better configure any
* settings the PHY requires to operate */
if (phydev->drv->config_init)
ctl = phydev->drv->config_init(phydev);
return ctl;
}
/**
* genphy_restart_aneg - Enable and Restart Autonegotiation
* @phydev: target phy_device struct
*/
int genphy_restart_aneg(struct phy_device *phydev)
{
int ctl;
ctl = phy_read(phydev, MII_BMCR);
if (ctl < 0)
return ctl;
ctl |= (BMCR_ANENABLE | BMCR_ANRESTART);
/* Don't isolate the PHY if we're negotiating */
ctl &= ~(BMCR_ISOLATE);
ctl = phy_write(phydev, MII_BMCR, ctl);
return ctl;
}
/**
* genphy_config_aneg - restart auto-negotiation or write BMCR
* @phydev: target phy_device struct
*
* Description: If auto-negotiation is enabled, we configure the
* advertising, and then restart auto-negotiation. If it is not
* enabled, then we write the BMCR.
*/
int genphy_config_aneg(struct phy_device *phydev)
{
int err = 0;
if (AUTONEG_ENABLE == phydev->autoneg) {
err = genphy_config_advert(phydev);
if (err < 0)
return err;
err = genphy_restart_aneg(phydev);
} else
err = genphy_setup_forced(phydev);
return err;
}
EXPORT_SYMBOL(genphy_config_aneg);
/**
* genphy_update_link - update link status in @phydev
* @phydev: target phy_device struct
*
* Description: Update the value in phydev->link to reflect the
* current link value. In order to do this, we need to read
* the status register twice, keeping the second value.
*/
int genphy_update_link(struct phy_device *phydev)
{
int status;
/* Do a fake read */
status = phy_read(phydev, MII_BMSR);
if (status < 0)
return status;
/* Read link and autonegotiation status */
status = phy_read(phydev, MII_BMSR);
if (status < 0)
return status;
if ((status & BMSR_LSTATUS) == 0)
phydev->link = 0;
else
phydev->link = 1;
return 0;
}
EXPORT_SYMBOL(genphy_update_link);
/**
* genphy_read_status - check the link status and update current link state
* @phydev: target phy_device struct
*
* Description: Check the link, then figure out the current state
* by comparing what we advertise with what the link partner
* advertises. Start by checking the gigabit possibilities,
* then move on to 10/100.
*/
int genphy_read_status(struct phy_device *phydev)
{
int adv;
int err;
int lpa;
int lpagb = 0;
/* Update the link, but return if there
* was an error */
err = genphy_update_link(phydev);
if (err)
return err;
if (AUTONEG_ENABLE == phydev->autoneg) {
if (phydev->supported & (SUPPORTED_1000baseT_Half
| SUPPORTED_1000baseT_Full)) {
lpagb = phy_read(phydev, MII_STAT1000);
if (lpagb < 0)
return lpagb;
adv = phy_read(phydev, MII_CTRL1000);
if (adv < 0)
return adv;
lpagb &= adv << 2;
}
lpa = phy_read(phydev, MII_LPA);
if (lpa < 0)
return lpa;
adv = phy_read(phydev, MII_ADVERTISE);
if (adv < 0)
return adv;
lpa &= adv;
phydev->speed = SPEED_10;
phydev->duplex = DUPLEX_HALF;
phydev->pause = phydev->asym_pause = 0;
if (lpagb & (LPA_1000FULL | LPA_1000HALF)) {
phydev->speed = SPEED_1000;
if (lpagb & LPA_1000FULL)
phydev->duplex = DUPLEX_FULL;
} else if (lpa & (LPA_100FULL | LPA_100HALF)) {
phydev->speed = SPEED_100;
if (lpa & LPA_100FULL)
phydev->duplex = DUPLEX_FULL;
} else
if (lpa & LPA_10FULL)
phydev->duplex = DUPLEX_FULL;
if (phydev->duplex == DUPLEX_FULL){
phydev->pause = lpa & LPA_PAUSE_CAP ? 1 : 0;
phydev->asym_pause = lpa & LPA_PAUSE_ASYM ? 1 : 0;
}
} else {
int bmcr = phy_read(phydev, MII_BMCR);
if (bmcr < 0)
return bmcr;
if (bmcr & BMCR_FULLDPLX)
phydev->duplex = DUPLEX_FULL;
else
phydev->duplex = DUPLEX_HALF;
if (bmcr & BMCR_SPEED1000)
phydev->speed = SPEED_1000;
else if (bmcr & BMCR_SPEED100)
phydev->speed = SPEED_100;
else
phydev->speed = SPEED_10;
phydev->pause = phydev->asym_pause = 0;
}
return 0;
}
EXPORT_SYMBOL(genphy_read_status);
static int genphy_config_init(struct phy_device *phydev)
{
int val;
u32 features;
/* For now, I'll claim that the generic driver supports
* all possible port types */
features = (SUPPORTED_TP | SUPPORTED_MII
| SUPPORTED_AUI | SUPPORTED_FIBRE |
SUPPORTED_BNC);
/* Do we support autonegotiation? */
val = phy_read(phydev, MII_BMSR);
if (val < 0)
return val;
if (val & BMSR_ANEGCAPABLE)
features |= SUPPORTED_Autoneg;
if (val & BMSR_100FULL)
features |= SUPPORTED_100baseT_Full;
if (val & BMSR_100HALF)
features |= SUPPORTED_100baseT_Half;
if (val & BMSR_10FULL)
features |= SUPPORTED_10baseT_Full;
if (val & BMSR_10HALF)
features |= SUPPORTED_10baseT_Half;
if (val & BMSR_ESTATEN) {
val = phy_read(phydev, MII_ESTATUS);
if (val < 0)
return val;
if (val & ESTATUS_1000_TFULL)
features |= SUPPORTED_1000baseT_Full;
if (val & ESTATUS_1000_THALF)
features |= SUPPORTED_1000baseT_Half;
}
phydev->supported = features;
phydev->advertising = features;
return 0;
}
/**
* phy_probe - probe and init a PHY device
* @dev: device to probe and init
*
* Description: Take care of setting up the phy_device structure,
* set the state to READY (the driver's init function should
* set it to STARTING if needed).
*/
static int phy_probe(struct device *dev)
{
struct phy_device *phydev;
struct phy_driver *phydrv;
struct device_driver *drv;
int err = 0;
phydev = to_phy_device(dev);
/* Make sure the driver is held.
* XXX -- Is this correct? */
drv = get_driver(phydev->dev.driver);
phydrv = to_phy_driver(drv);
phydev->drv = phydrv;
/* Disable the interrupt if the PHY doesn't support it */
if (!(phydrv->flags & PHY_HAS_INTERRUPT))
phydev->irq = PHY_POLL;
mutex_lock(&phydev->lock);
/* Start out supporting everything. Eventually,
* a controller will attach, and may modify one
* or both of these values */
phydev->supported = phydrv->features;
phydev->advertising = phydrv->features;
/* Set the state to READY by default */
phydev->state = PHY_READY;
if (phydev->drv->probe)
err = phydev->drv->probe(phydev);
mutex_unlock(&phydev->lock);
return err;
}
static int phy_remove(struct device *dev)
{
struct phy_device *phydev;
phydev = to_phy_device(dev);
mutex_lock(&phydev->lock);
phydev->state = PHY_DOWN;
mutex_unlock(&phydev->lock);
if (phydev->drv->remove)
phydev->drv->remove(phydev);
put_driver(dev->driver);
phydev->drv = NULL;
return 0;
}
/**
* phy_driver_register - register a phy_driver with the PHY layer
* @new_driver: new phy_driver to register
*/
int phy_driver_register(struct phy_driver *new_driver)
{
int retval;
memset(&new_driver->driver, 0, sizeof(new_driver->driver));
new_driver->driver.name = new_driver->name;
new_driver->driver.bus = &mdio_bus_type;
new_driver->driver.probe = phy_probe;
new_driver->driver.remove = phy_remove;
retval = driver_register(&new_driver->driver);
if (retval) {
printk(KERN_ERR "%s: Error %d in registering driver\n",
new_driver->name, retval);
return retval;
}
pr_debug("%s: Registered new driver\n", new_driver->name);
return 0;
}
EXPORT_SYMBOL(phy_driver_register);
void phy_driver_unregister(struct phy_driver *drv)
{
driver_unregister(&drv->driver);
}
EXPORT_SYMBOL(phy_driver_unregister);
static struct phy_driver genphy_driver = {
.phy_id = 0xffffffff,
.phy_id_mask = 0xffffffff,
.name = "Generic PHY",
.config_init = genphy_config_init,
.features = 0,
.config_aneg = genphy_config_aneg,
.read_status = genphy_read_status,
.driver = {.owner= THIS_MODULE, },
};
static int __init phy_init(void)
{
int rc;
rc = mdio_bus_init();
if (rc)
return rc;
rc = phy_driver_register(&genphy_driver);
if (rc)
mdio_bus_exit();
return rc;
}
static void __exit phy_exit(void)
{
phy_driver_unregister(&genphy_driver);
mdio_bus_exit();
}
subsys_initcall(phy_init);
module_exit(phy_exit);