phy.c

linux 内核源代码

 *   phy_detach.
 */
void phy_stop_machine(struct phy_device *phydev)
{
	del_timer_sync(&phydev->phy_timer);

	spin_lock_bh(&phydev->lock);
	if (phydev->state > PHY_UP)
		phydev->state = PHY_UP;
	spin_unlock_bh(&phydev->lock);

	phydev->adjust_state = NULL;
}

/**
 * phy_force_reduction - reduce PHY speed/duplex settings by one step
 * @phydev: target phy_device struct
 *
 * Description: Reduces the speed/duplex settings by one notch,
 *   in this order--
 *   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 - enter HALTED state for this PHY device
 * @phydev: target phy_device struct
 *
 * 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_bh(&phydev->lock);
	phydev->state = PHY_HALTED;
	spin_unlock_bh(&phydev->lock);
}

/**
 * phy_interrupt - PHY interrupt handler
 * @irq: interrupt line
 * @phy_dat: phy_device pointer
 *
 * 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);
	atomic_inc(&phydev->irq_disable);

	schedule_work(&phydev->phy_queue);

	return IRQ_HANDLED;
}

/**
 * phy_enable_interrupts - Enable the interrupts from the PHY side
 * @phydev: target phy_device struct
 */
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);

/**
 * phy_disable_interrupts - Disable the PHY interrupts from the PHY side
 * @phydev: target phy_device struct
 */
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 - request and enable interrupts for a PHY device
 * @phydev: target phy_device struct
 *
 * 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.
 *   This should only be called with a valid IRQ number.
 *   Returns 0 on success or < 0 on error.
 */
int phy_start_interrupts(struct phy_device *phydev)
{
	int err = 0;

	INIT_WORK(&phydev->phy_queue, phy_change);

	atomic_set(&phydev->irq_disable, 0);
	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);

/**
 * phy_stop_interrupts - disable interrupts from a PHY device
 * @phydev: target phy_device struct
 */
int phy_stop_interrupts(struct phy_device *phydev)
{
	int err;

	err = phy_disable_interrupts(phydev);

	if (err)
		phy_error(phydev);

	free_irq(phydev->irq, phydev);

	/*
	 * Cannot call flush_scheduled_work() here as desired because
	 * of rtnl_lock(), but we do not really care about what would
	 * be done, except from enable_irq(), so cancel any work
	 * possibly pending and take care of the matter below.
	 */
	cancel_work_sync(&phydev->phy_queue);
	/*
	 * If work indeed has been cancelled, disable_irq() will have
	 * been left unbalanced from phy_interrupt() and enable_irq()
	 * has to be called so that other devices on the line work.
	 */
	while (atomic_dec_return(&phydev->irq_disable) >= 0)
		enable_irq(phydev->irq);

	return err;
}
EXPORT_SYMBOL(phy_stop_interrupts);


/**
 * phy_change - Scheduled by the phy_interrupt/timer to handle PHY changes
 * @work: work_struct that describes the work to be done
 */
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_bh(&phydev->lock);
	if ((PHY_RUNNING == phydev->state) || (PHY_NOLINK == phydev->state))
		phydev->state = PHY_CHANGELINK;
	spin_unlock_bh(&phydev->lock);

	atomic_dec(&phydev->irq_disable);
	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);
	atomic_inc(&phydev->irq_disable);
phy_err:
	phy_error(phydev);
}

/**
 * phy_stop - Bring down the PHY link, and stop checking the status
 * @phydev: target phy_device struct
 */
void phy_stop(struct phy_device *phydev)
{
	spin_lock_bh(&phydev->lock);

	if (PHY_HALTED == phydev->state)
		goto out_unlock;

	if (phydev->irq != PHY_POLL) {
		/* Disable PHY Interrupts */
		phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED);

		/* Clear any pending interrupts */
		phy_clear_interrupt(phydev);
	}

	phydev->state = PHY_HALTED;

out_unlock:
	spin_unlock_bh(&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 - start or restart a PHY device
 * @phydev: target phy_device struct
 *
 * 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_bh(&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_bh(&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_bh(&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_bh(&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);
}