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linux/drivers/net/phy/phy.c
Linus Torvalds 68380b5813 Add "run_scheduled_work()" workqueue function 
This allows workqueue users to run just their own pending work, rather
than wait for the whole workqueue to finish running.  This solves the
deadlock with networking libphy that was due to other workqueue entries
possibly needing a lock that was held by the routine that wanted to
flush its own work.

It's not wonderful: if you absolutely need to synchronize with the work
function having been executed, any user strictly speaking should have
its own completion tracking logic, since when we run things explicitly
by hand, the generic workqueue layer can no longer help us synchronize.

Also, this is strictly only usable for work that has been scheduled
without any delayed timers.  You can not mix the new interface with
schedule_delayed_work().

But it's better than what we had currently.

Acked-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 09:28:19 -08:00

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/*
* drivers/net/phy/phy.c
*
* Framework for configuring and reading PHY devices
* Based on code in sungem_phy.c and gianfar_phy.c
*
* Author: Andy Fleming
*
* Copyright (c) 2004 Freescale Semiconductor, Inc.
* Copyright (c) 2006 Maciej W. Rozycki
*
* 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/sched.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 <linux/timer.h>
#include <linux/workqueue.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
/* Convenience function to print out the current phy status
*/
void phy_print_status(struct phy_device *phydev)
{
pr_info("PHY: %s - Link is %s", phydev->dev.bus_id,
phydev->link ? "Up" : "Down");
if (phydev->link)
printk(" - %d/%s", phydev->speed,
DUPLEX_FULL == phydev->duplex ?
"Full" : "Half");
printk("\n");
}
EXPORT_SYMBOL(phy_print_status);
/* Convenience functions for reading/writing a given PHY
* register. They MUST NOT be called from interrupt context,
* because the bus read/write functions may wait for an interrupt
* to conclude the operation. */
int phy_read(struct phy_device *phydev, u16 regnum)
{
int retval;
struct mii_bus *bus = phydev->bus;
spin_lock_bh(&bus->mdio_lock);
retval = bus->read(bus, phydev->addr, regnum);
spin_unlock_bh(&bus->mdio_lock);
return retval;
}
EXPORT_SYMBOL(phy_read);
int phy_write(struct phy_device *phydev, u16 regnum, u16 val)
{
int err;
struct mii_bus *bus = phydev->bus;
spin_lock_bh(&bus->mdio_lock);
err = bus->write(bus, phydev->addr, regnum, val);
spin_unlock_bh(&bus->mdio_lock);
return err;
}
EXPORT_SYMBOL(phy_write);
int phy_clear_interrupt(struct phy_device *phydev)
{
int err = 0;
if (phydev->drv->ack_interrupt)
err = phydev->drv->ack_interrupt(phydev);
return err;
}
int phy_config_interrupt(struct phy_device *phydev, u32 interrupts)
{
int err = 0;
phydev->interrupts = interrupts;
if (phydev->drv->config_intr)
err = phydev->drv->config_intr(phydev);
return err;
}
/* phy_aneg_done
*
* description: Reads the status register and returns 0 either if
* auto-negotiation is incomplete, or if there was an error.
* Returns BMSR_ANEGCOMPLETE if auto-negotiation is done.
*/
static inline int phy_aneg_done(struct phy_device *phydev)
{
int retval;
retval = phy_read(phydev, MII_BMSR);
return (retval < 0) ? retval : (retval & BMSR_ANEGCOMPLETE);
}
/* A structure for mapping a particular speed and duplex
* combination to a particular SUPPORTED and ADVERTISED value */
struct phy_setting {
int speed;
int duplex;
u32 setting;
};
/* A mapping of all SUPPORTED settings to speed/duplex */
static const struct phy_setting settings[] = {
{
.speed = 10000,
.duplex = DUPLEX_FULL,
.setting = SUPPORTED_10000baseT_Full,
},
{
.speed = SPEED_1000,
.duplex = DUPLEX_FULL,
.setting = SUPPORTED_1000baseT_Full,
},
{
.speed = SPEED_1000,
.duplex = DUPLEX_HALF,
.setting = SUPPORTED_1000baseT_Half,
},
{
.speed = SPEED_100,
.duplex = DUPLEX_FULL,
.setting = SUPPORTED_100baseT_Full,
},
{
.speed = SPEED_100,
.duplex = DUPLEX_HALF,
.setting = SUPPORTED_100baseT_Half,
},
{
.speed = SPEED_10,
.duplex = DUPLEX_FULL,
.setting = SUPPORTED_10baseT_Full,
},
{
.speed = SPEED_10,
.duplex = DUPLEX_HALF,
.setting = SUPPORTED_10baseT_Half,
},
};
#define MAX_NUM_SETTINGS (sizeof(settings)/sizeof(struct phy_setting))
/* phy_find_setting
*
* description: Searches the settings array for the setting which
* matches the desired speed and duplex, and returns the index
* of that setting. Returns the index of the last setting if
* none of the others match.
*/
static inline int phy_find_setting(int speed, int duplex)
{
int idx = 0;
while (idx < ARRAY_SIZE(settings) &&
(settings[idx].speed != speed ||
settings[idx].duplex != duplex))
idx++;
return idx < MAX_NUM_SETTINGS ? idx : MAX_NUM_SETTINGS - 1;
}
/* phy_find_valid
* idx: The first index in settings[] to search
* features: A mask of the valid settings
*
* description: Returns the index of the first valid setting less
* than or equal to the one pointed to by idx, as determined by
* the mask in features. Returns the index of the last setting
* if nothing else matches.
*/
static inline int phy_find_valid(int idx, u32 features)
{
while (idx < MAX_NUM_SETTINGS && !(settings[idx].setting & features))
idx++;
return idx < MAX_NUM_SETTINGS ? idx : MAX_NUM_SETTINGS - 1;
}
/* phy_sanitize_settings
*
* description: Make sure the PHY is set to supported speeds and
* duplexes. Drop down by one in this order: 1000/FULL,
* 1000/HALF, 100/FULL, 100/HALF, 10/FULL, 10/HALF
*/
void phy_sanitize_settings(struct phy_device *phydev)
{
u32 features = phydev->supported;
int idx;
/* Sanitize settings based on PHY capabilities */
if ((features & SUPPORTED_Autoneg) == 0)
phydev->autoneg = 0;
idx = phy_find_valid(phy_find_setting(phydev->speed, phydev->duplex),
features);
phydev->speed = settings[idx].speed;
phydev->duplex = settings[idx].duplex;
}
EXPORT_SYMBOL(phy_sanitize_settings);
/* phy_ethtool_sset:
* A generic ethtool sset function. Handles all the details
*
* A few notes about parameter checking:
* - We don't set port or transceiver, so we don't care what they
* were set to.
* - phy_start_aneg() will make sure forced settings are sane, and
* choose the next best ones from the ones selected, so we don't
* care if ethtool tries to give us bad values
*
*/
int phy_ethtool_sset(struct phy_device *phydev, struct ethtool_cmd *cmd)
{
if (cmd->phy_address != phydev->addr)
return -EINVAL;
/* We make sure that we don't pass unsupported
* values in to the PHY */
cmd->advertising &= phydev->supported;
/* Verify the settings we care about. */
if (cmd->autoneg != AUTONEG_ENABLE && cmd->autoneg != AUTONEG_DISABLE)
return -EINVAL;
if (cmd->autoneg == AUTONEG_ENABLE && cmd->advertising == 0)
return -EINVAL;
if (cmd->autoneg == AUTONEG_DISABLE
&& ((cmd->speed != SPEED_1000
&& cmd->speed != SPEED_100
&& cmd->speed != SPEED_10)
|| (cmd->duplex != DUPLEX_HALF
&& cmd->duplex != DUPLEX_FULL)))
return -EINVAL;
phydev->autoneg = cmd->autoneg;
phydev->speed = cmd->speed;
phydev->advertising = cmd->advertising;
if (AUTONEG_ENABLE == cmd->autoneg)
phydev->advertising |= ADVERTISED_Autoneg;
else
phydev->advertising &= ~ADVERTISED_Autoneg;
phydev->duplex = cmd->duplex;
/* Restart the PHY */
phy_start_aneg(phydev);
return 0;
}
int phy_ethtool_gset(struct phy_device *phydev, struct ethtool_cmd *cmd)
{
cmd->supported = phydev->supported;
cmd->advertising = phydev->advertising;
cmd->speed = phydev->speed;
cmd->duplex = phydev->duplex;
cmd->port = PORT_MII;
cmd->phy_address = phydev->addr;
cmd->transceiver = XCVR_EXTERNAL;
cmd->autoneg = phydev->autoneg;
return 0;
}
/* Note that this function is currently incompatible with the
* PHYCONTROL layer. It changes registers without regard to
* current state. Use at own risk
*/
int phy_mii_ioctl(struct phy_device *phydev,
struct mii_ioctl_data *mii_data, int cmd)
{
u16 val = mii_data->val_in;
switch (cmd) {
case SIOCGMIIPHY:
mii_data->phy_id = phydev->addr;
break;
case SIOCGMIIREG:
mii_data->val_out = phy_read(phydev, mii_data->reg_num);
break;
case SIOCSMIIREG:
if (!capable(CAP_NET_ADMIN))
return -EPERM;
if (mii_data->phy_id == phydev->addr) {
switch(mii_data->reg_num) {
case MII_BMCR:
if (val & (BMCR_RESET|BMCR_ANENABLE))
phydev->autoneg = AUTONEG_DISABLE;
else
phydev->autoneg = AUTONEG_ENABLE;
if ((!phydev->autoneg) && (val & BMCR_FULLDPLX))
phydev->duplex = DUPLEX_FULL;
else
phydev->duplex = DUPLEX_HALF;
break;
case MII_ADVERTISE:
phydev->advertising = val;
break;
default:
/* do nothing */
break;
}
}
phy_write(phydev, mii_data->reg_num, val);
if (mii_data->reg_num == MII_BMCR
&& val & BMCR_RESET
&& phydev->drv->config_init)
phydev->drv->config_init(phydev);
break;
}
return 0;
}
/* phy_start_aneg
*
* description: Sanitizes the settings (if we're not
* autonegotiating them), and then calls the driver's
* config_aneg function. If the PHYCONTROL Layer is operating,
* we change the state to reflect the beginning of
* Auto-negotiation or forcing.
*/
int phy_start_aneg(struct phy_device *phydev)
{
int err;
spin_lock(&phydev->lock);
if (AUTONEG_DISABLE == phydev->autoneg)
phy_sanitize_settings(phydev);
err = phydev->drv->config_aneg(phydev);
if (err < 0)
goto out_unlock;
if (phydev->state != PHY_HALTED) {
if (AUTONEG_ENABLE == phydev->autoneg) {
phydev->state = PHY_AN;
phydev->link_timeout = PHY_AN_TIMEOUT;
} else {
phydev->state = PHY_FORCING;
phydev->link_timeout = PHY_FORCE_TIMEOUT;
}
}
out_unlock:
spin_unlock(&phydev->lock);
return err;
}
EXPORT_SYMBOL(phy_start_aneg);
static void phy_change(struct work_struct *work);
static void phy_timer(unsigned long data);
/* phy_start_machine:
*
* description: The PHY infrastructure can run a state machine
* which tracks whether the PHY is starting up, negotiating,
* etc. This function starts the timer which tracks the state
* of the PHY. If you want to be notified when the state
* changes, pass in the callback, otherwise, pass NULL. If you
* want to maintain your own state machine, do not call this
* function. */
void phy_start_machine(struct phy_device *phydev,
void (*handler)(struct net_device *))
{
phydev->adjust_state = handler;
init_timer(&phydev->phy_timer);
phydev->phy_timer.function = &phy_timer;
phydev->phy_timer.data = (unsigned long) phydev;
mod_timer(&phydev->phy_timer, jiffies + HZ);
}
/* phy_stop_machine
*
* description: Stops the state machine timer, sets the state to UP
* (unless it wasn't up yet). This function must be called BEFORE
* phy_detach.
*/
void phy_stop_machine(struct phy_device *phydev)
{
del_timer_sync(&phydev->phy_timer);
spin_lock(&phydev->lock);
if (phydev->state > PHY_UP)
phydev->state = PHY_UP;
spin_unlock(&phydev->lock);
phydev->adjust_state = NULL;
}
/* phy_force_reduction
*
* description: Reduces the speed/duplex settings by
* one notch. The order is so:
* 1000/FULL, 1000/HALF, 100/FULL, 100/HALF,
* 10/FULL, 10/HALF. The function bottoms out at 10/HALF.
*/
static void phy_force_reduction(struct phy_device *phydev)
{
int idx;
idx = phy_find_setting(phydev->speed, phydev->duplex);
idx++;
idx = phy_find_valid(idx, phydev->supported);
phydev->speed = settings[idx].speed;
phydev->duplex = settings[idx].duplex;
pr_info("Trying %d/%s\n", phydev->speed,
DUPLEX_FULL == phydev->duplex ?
"FULL" : "HALF");
}
/* phy_error:
*
* Moves the PHY to the HALTED state in response to a read
* or write error, and tells the controller the link is down.
* Must not be called from interrupt context, or while the
* phydev->lock is held.
*/
void phy_error(struct phy_device *phydev)
{
spin_lock(&phydev->lock);
phydev->state = PHY_HALTED;
spin_unlock(&phydev->lock);
}
/* phy_interrupt
*
* description: When a PHY interrupt occurs, the handler disables
* interrupts, and schedules a work task to clear the interrupt.
*/
static irqreturn_t phy_interrupt(int irq, void *phy_dat)
{
struct phy_device *phydev = phy_dat;
if (PHY_HALTED == phydev->state)
return IRQ_NONE; /* It can't be ours. */
/* The MDIO bus is not allowed to be written in interrupt
* context, so we need to disable the irq here. A work
* queue will write the PHY to disable and clear the
* interrupt, and then reenable the irq line. */
disable_irq_nosync(irq);
schedule_work(&phydev->phy_queue);
return IRQ_HANDLED;
}
/* Enable the interrupts from the PHY side */
int phy_enable_interrupts(struct phy_device *phydev)
{
int err;
err = phy_clear_interrupt(phydev);
if (err < 0)
return err;
err = phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED);
return err;
}
EXPORT_SYMBOL(phy_enable_interrupts);
/* Disable the PHY interrupts from the PHY side */
int phy_disable_interrupts(struct phy_device *phydev)
{
int err;
/* Disable PHY interrupts */
err = phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED);
if (err)
goto phy_err;
/* Clear the interrupt */
err = phy_clear_interrupt(phydev);
if (err)
goto phy_err;
return 0;
phy_err:
phy_error(phydev);
return err;
}
EXPORT_SYMBOL(phy_disable_interrupts);
/* phy_start_interrupts
*
* description: Request the interrupt for the given PHY. If
* this fails, then we set irq to PHY_POLL.
* Otherwise, we enable the interrupts in the PHY.
* Returns 0 on success.
* This should only be called with a valid IRQ number.
*/
int phy_start_interrupts(struct phy_device *phydev)
{
int err = 0;
INIT_WORK(&phydev->phy_queue, phy_change);
if (request_irq(phydev->irq, phy_interrupt,
IRQF_SHARED,
"phy_interrupt",
phydev) < 0) {
printk(KERN_WARNING "%s: Can't get IRQ %d (PHY)\n",
phydev->bus->name,
phydev->irq);
phydev->irq = PHY_POLL;
return 0;
}
err = phy_enable_interrupts(phydev);
return err;
}
EXPORT_SYMBOL(phy_start_interrupts);
int phy_stop_interrupts(struct phy_device *phydev)
{
int err;
err = phy_disable_interrupts(phydev);
if (err)
phy_error(phydev);
/*
* Finish any pending work; we might have been scheduled
* to be called from keventd ourselves, though.
*/
run_scheduled_work(&phydev->phy_queue);
free_irq(phydev->irq, phydev);
return err;
}
EXPORT_SYMBOL(phy_stop_interrupts);
/* Scheduled by the phy_interrupt/timer to handle PHY changes */
static void phy_change(struct work_struct *work)
{
int err;
struct phy_device *phydev =
container_of(work, struct phy_device, phy_queue);
err = phy_disable_interrupts(phydev);
if (err)
goto phy_err;
spin_lock(&phydev->lock);
if ((PHY_RUNNING == phydev->state) || (PHY_NOLINK == phydev->state))
phydev->state = PHY_CHANGELINK;
spin_unlock(&phydev->lock);
enable_irq(phydev->irq);
/* Reenable interrupts */
if (PHY_HALTED != phydev->state)
err = phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED);
if (err)
goto irq_enable_err;
return;
irq_enable_err:
disable_irq(phydev->irq);
phy_err:
phy_error(phydev);
}
/* Bring down the PHY link, and stop checking the status. */
void phy_stop(struct phy_device *phydev)
{
spin_lock(&phydev->lock);
if (PHY_HALTED == phydev->state)
goto out_unlock;
phydev->state = PHY_HALTED;
if (phydev->irq != PHY_POLL) {
/* Disable PHY Interrupts */
phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED);
/* Clear any pending interrupts */
phy_clear_interrupt(phydev);
}
out_unlock:
spin_unlock(&phydev->lock);
/*
* Cannot call flush_scheduled_work() here as desired because
* of rtnl_lock(), but PHY_HALTED shall guarantee phy_change()
* will not reenable interrupts.
*/
}
/* phy_start
*
* description: Indicates the attached device's readiness to
* handle PHY-related work. Used during startup to start the
* PHY, and after a call to phy_stop() to resume operation.
* Also used to indicate the MDIO bus has cleared an error
* condition.
*/
void phy_start(struct phy_device *phydev)
{
spin_lock(&phydev->lock);
switch (phydev->state) {
case PHY_STARTING:
phydev->state = PHY_PENDING;
break;
case PHY_READY:
phydev->state = PHY_UP;
break;
case PHY_HALTED:
phydev->state = PHY_RESUMING;
default:
break;
}
spin_unlock(&phydev->lock);
}
EXPORT_SYMBOL(phy_stop);
EXPORT_SYMBOL(phy_start);
/* PHY timer which handles the state machine */
static void phy_timer(unsigned long data)
{
struct phy_device *phydev = (struct phy_device *)data;
int needs_aneg = 0;
int err = 0;
spin_lock(&phydev->lock);
if (phydev->adjust_state)
phydev->adjust_state(phydev->attached_dev);
switch(phydev->state) {
case PHY_DOWN:
case PHY_STARTING:
case PHY_READY:
case PHY_PENDING:
break;
case PHY_UP:
needs_aneg = 1;
phydev->link_timeout = PHY_AN_TIMEOUT;
break;
case PHY_AN:
err = phy_read_status(phydev);
if (err < 0)
break;
/* If the link is down, give up on
* negotiation for now */
if (!phydev->link) {
phydev->state = PHY_NOLINK;
netif_carrier_off(phydev->attached_dev);
phydev->adjust_link(phydev->attached_dev);
break;
}
/* Check if negotiation is done. Break
* if there's an error */
err = phy_aneg_done(phydev);
if (err < 0)
break;
/* If AN is done, we're running */
if (err > 0) {
phydev->state = PHY_RUNNING;
netif_carrier_on(phydev->attached_dev);
phydev->adjust_link(phydev->attached_dev);
} else if (0 == phydev->link_timeout--) {
int idx;
needs_aneg = 1;
/* If we have the magic_aneg bit,
* we try again */
if (phydev->drv->flags & PHY_HAS_MAGICANEG)
break;
/* The timer expired, and we still
* don't have a setting, so we try
* forcing it until we find one that
* works, starting from the fastest speed,
* and working our way down */
idx = phy_find_valid(0, phydev->supported);
phydev->speed = settings[idx].speed;
phydev->duplex = settings[idx].duplex;
phydev->autoneg = AUTONEG_DISABLE;
pr_info("Trying %d/%s\n", phydev->speed,
DUPLEX_FULL ==
phydev->duplex ?
"FULL" : "HALF");
}
break;
case PHY_NOLINK:
err = phy_read_status(phydev);
if (err)
break;
if (phydev->link) {
phydev->state = PHY_RUNNING;
netif_carrier_on(phydev->attached_dev);
phydev->adjust_link(phydev->attached_dev);
}
break;
case PHY_FORCING:
err = genphy_update_link(phydev);
if (err)
break;
if (phydev->link) {
phydev->state = PHY_RUNNING;
netif_carrier_on(phydev->attached_dev);
} else {
if (0 == phydev->link_timeout--) {
phy_force_reduction(phydev);
needs_aneg = 1;
}
}
phydev->adjust_link(phydev->attached_dev);
break;
case PHY_RUNNING:
/* Only register a CHANGE if we are
* polling */
if (PHY_POLL == phydev->irq)
phydev->state = PHY_CHANGELINK;
break;
case PHY_CHANGELINK:
err = phy_read_status(phydev);
if (err)
break;
if (phydev->link) {
phydev->state = PHY_RUNNING;
netif_carrier_on(phydev->attached_dev);
} else {
phydev->state = PHY_NOLINK;
netif_carrier_off(phydev->attached_dev);
}
phydev->adjust_link(phydev->attached_dev);
if (PHY_POLL != phydev->irq)
err = phy_config_interrupt(phydev,
PHY_INTERRUPT_ENABLED);
break;
case PHY_HALTED:
if (phydev->link) {
phydev->link = 0;
netif_carrier_off(phydev->attached_dev);
phydev->adjust_link(phydev->attached_dev);
}
break;
case PHY_RESUMING:
err = phy_clear_interrupt(phydev);
if (err)
break;
err = phy_config_interrupt(phydev,
PHY_INTERRUPT_ENABLED);
if (err)
break;
if (AUTONEG_ENABLE == phydev->autoneg) {
err = phy_aneg_done(phydev);
if (err < 0)
break;
/* err > 0 if AN is done.
* Otherwise, it's 0, and we're
* still waiting for AN */
if (err > 0) {
phydev->state = PHY_RUNNING;
} else {
phydev->state = PHY_AN;
phydev->link_timeout = PHY_AN_TIMEOUT;
}
} else
phydev->state = PHY_RUNNING;
break;
}
spin_unlock(&phydev->lock);
if (needs_aneg)
err = phy_start_aneg(phydev);
if (err < 0)
phy_error(phydev);
mod_timer(&phydev->phy_timer, jiffies + PHY_STATE_TIME * HZ);
}
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