phy.c

底层驱动开发

{
	del_timer_sync(&phydev->phy_timer);

	spin_lock(&phydev->lock);
	if (phydev->state > PHY_UP)
		phydev->state = PHY_UP;
	spin_unlock(&phydev->lock);

	if (phydev->irq != PHY_POLL)
		phy_stop_interrupts(phydev);

	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 pt_regs *regs)
{
	struct phy_device *phydev = phy_dat;

	/* 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, phydev);

	if (request_irq(phydev->irq, phy_interrupt,
				SA_SHIRQ,
				"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);

	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(void *data)
{
	int err;
	struct phy_device *phydev = data;

	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 */
	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;

	if (phydev->irq != PHY_POLL) {
		/* Clear any pending interrupts */
		phy_clear_interrupt(phydev);

		/* Disable PHY Interrupts */
		phy_config_interrupt(phydev, PHY_INTERRUPT_DISABLED);
	}

	phydev->state = PHY_HALTED;

out_unlock:
	spin_unlock(&phydev->lock);
}


/* 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:
			/* Check if negotiation is done.  Break
			 * if there's an error */
			err = phy_aneg_done(phydev);
			if (err < 0)
				break;

			/* If auto-negotiation is done, we change to
			 * either RUNNING, or NOLINK */
			if (err > 0) {
				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);

			} else if (0 == phydev->link_timeout--) {
				/* The counter expired, so either we
				 * switch to forced mode, or the
				 * magic_aneg bit exists, and we try aneg
				 * again */
				if (!(phydev->drv->flags & PHY_HAS_MAGICANEG)) {
					int idx;

					/* We'll start from the
					 * fastest speed, and work
					 * our way down */
					idx = phy_find_valid(0,
							phydev->supported);

					phydev->speed = settings[idx].speed;
					phydev->duplex = settings[idx].duplex;
					
					phydev->autoneg = AUTONEG_DISABLE;
					phydev->state = PHY_FORCING;
					phydev->link_timeout =
						PHY_FORCE_TIMEOUT;

					pr_info("Trying %d/%s\n",
							phydev->speed,
							DUPLEX_FULL ==
							phydev->duplex ?
							"FULL" : "HALF");
				}

				needs_aneg = 1;
			}
			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 = phy_read_status(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);
}

#endif /* CONFIG_PHYCONTROL */