[PATCH] PHY Layer fixup

This patch adds back the code that was taken out, thus re-enabling:

* The PHY Layer to initialize without crashing
* Drivers to actually connect to PHYs
* The entire PHY Control Layer

This patch is used by the gianfar driver, and other drivers which are in
development.

Signed-off-by: Andy Fleming <[e-mail]>
Signed-off-by: Jeff Garzik <[e-mail]>

drivers/net/phy/Kconfig

···
 	  devices.  This option provides infrastructure for
 	  managing PHY devices.
 
+config PHYCONTROL
+	bool "  Support for automatically handling PHY state changes"
+	depends on PHYLIB
+	help
+	  Adds code to perform all the work for keeping PHY link
+	  state (speed/duplex/etc) up-to-date.  Also handles
+	  interrupts.
+
 comment "MII PHY device drivers"
 	depends on PHYLIB
 

drivers/net/phy/Makefile

···
 
 libphy-objs			:= phy.o phy_device.o mdio_bus.o
 
-obj-$(CONFIG_MARVELL_PHY)	+= libphy.o marvell.o
-obj-$(CONFIG_DAVICOM_PHY)	+= libphy.o davicom.o
-obj-$(CONFIG_CICADA_PHY)	+= libphy.o cicada.o
-obj-$(CONFIG_LXT_PHY)		+= libphy.o lxt.o
-obj-$(CONFIG_QSEMI_PHY)		+= libphy.o qsemi.o
+obj-$(CONFIG_PHYLIB)		+= libphy.o
+obj-$(CONFIG_MARVELL_PHY)	+= marvell.o
+obj-$(CONFIG_DAVICOM_PHY)	+= davicom.o
+obj-$(CONFIG_CICADA_PHY)	+= cicada.o
+obj-$(CONFIG_LXT_PHY)		+= lxt.o
+obj-$(CONFIG_QSEMI_PHY)		+= qsemi.o

drivers/net/phy/mdio_bus.c

···
 #include <asm/irq.h>
 #include <asm/uaccess.h>
 
+/* mdiobus_register 
+ *
+ * description: Called by a bus driver to bring up all the PHYs
+ *   on a given bus, and attach them to the bus
+ */
+int mdiobus_register(struct mii_bus *bus)
+{
+	int i;
+	int err = 0;
+
+	spin_lock_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;
+
+		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;
+			sprintf(phydev->dev.bus_id, "phy%d:%d", bus->id, i);
+
+			phydev->bus = bus;
+
+			err = device_register(&phydev->dev);
+
+			if (err)
+				printk(KERN_ERR "phy %d failed to register\n",
+						i);
+		}
+
+		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);
+			kfree(bus->phy_map[i]);
+		}
+	}
+}
+EXPORT_SYMBOL(mdiobus_unregister);
+
 /* mdio_bus_match
  *
  * description: Given a PHY device, and a PHY driver, return 1 if
···
 	return bus_register(&mdio_bus_type);
 }
 
-
+void __exit mdio_bus_exit(void)
+{
+	bus_unregister(&mdio_bus_type);
+}

drivers/net/phy/phy.c

···
 #include <asm/irq.h>
 #include <asm/uaccess.h>
 
-static void phy_timer(unsigned long data);
-static int phy_disable_interrupts(struct phy_device *phydev);
-static void phy_sanitize_settings(struct phy_device *phydev);
-static int phy_stop_interrupts(struct phy_device *phydev);
+/* Convenience function to print out the current phy status
+ */
+void phy_print_status(struct phy_device *phydev)
+{
+	pr_info("%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
···
 	retval = phy_read(phydev, MII_BMSR);
 
 	return (retval < 0) ? retval : (retval & BMSR_ANEGCOMPLETE);
-}
-
-/* phy_start_aneg
- *
- * description: Calls the PHY driver's config_aneg, and then
- *   sets the PHY state to PHY_AN if auto-negotiation is enabled,
- *   and to PHY_FORCING if auto-negotiation is disabled. Unless
- *   the PHY is currently HALTED.
- */
-static 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;
 }
 
 /* A structure for mapping a particular speed and duplex
···
  *   duplexes.  Drop down by one in this order:  1000/FULL,
  *   1000/HALF, 100/FULL, 100/HALF, 10/FULL, 10/HALF
  */
-static void phy_sanitize_settings(struct phy_device *phydev)
+void phy_sanitize_settings(struct phy_device *phydev)
 {
 	u32 features = phydev->supported;
 	int idx;
···
 	phydev->speed = settings[idx].speed;
 	phydev->duplex = settings[idx].duplex;
 }
-
-/* 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");
-}
+EXPORT_SYMBOL(phy_sanitize_settings);
 
 /* phy_ethtool_sset:
  * A generic ethtool sset function.  Handles all the details
···
  * - 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
+ *
+ * A note about the PHYCONTROL Layer.  If you turn off
+ * CONFIG_PHYCONTROL, you will need to read the PHY status
+ * registers after this function completes, and update your
+ * controller manually.
  */
 int phy_ethtool_sset(struct phy_device *phydev, struct ethtool_cmd *cmd)
 {
···
 	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);
+
+#ifdef CONFIG_PHYCONTROL
+	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:
+#endif
+	spin_unlock(&phydev->lock);
+	return err;
+}
+EXPORT_SYMBOL(phy_start_aneg);
+
+
+#ifdef CONFIG_PHYCONTROL
+static void phy_change(void *data);
+static void phy_timer(unsigned long data);
+
 /* phy_start_machine:
  *
  * description: The PHY infrastructure can run a state machine
···
 	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
···
 	spin_unlock(&phydev->lock);
 }
 
-static int phy_stop_interrupts(struct phy_device *phydev)
+/* 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_disable_interrupts(phydev);
+	err = phy_clear_interrupt(phydev);
 
-	if (err)
-		phy_error(phydev);
+	if (err < 0)
+		return err;
 
-	free_irq(phydev->irq, phydev);
+	err = phy_config_interrupt(phydev, PHY_INTERRUPT_ENABLED);
 
 	return err;
 }
+EXPORT_SYMBOL(phy_enable_interrupts);
 
 /* Disable the PHY interrupts from the PHY side */
-static int phy_disable_interrupts(struct phy_device *phydev)
+int phy_disable_interrupts(struct phy_device *phydev)
 {
 	int err;
 
···
 
 	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)
···
 	mod_timer(&phydev->phy_timer, jiffies + PHY_STATE_TIME * HZ);
 }
 
+#endif /* CONFIG_PHYCONTROL */

drivers/net/phy/phy_device.c

···
 #include <asm/irq.h>
 #include <asm/uaccess.h>
 
-static int genphy_config_init(struct phy_device *phydev);
-
-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 struct phy_driver genphy_driver;
+extern int mdio_bus_init(void);
+extern void mdio_bus_exit(void);
 
 /* get_phy_device
  *
···
 	return dev;
 }
 
+#ifdef CONFIG_PHYCONTROL
 /* phy_prepare_link:
  *
  * description: Tells the PHY infrastructure to handle the
···
 	phydev->adjust_link = handler;
 }
 
+/* phy_connect:
+ *
+ * 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)
+{
+	struct phy_device *phydev;
+
+	phydev = phy_attach(dev, phy_id, flags);
+
+	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);
+
+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);
+
+#endif /* CONFIG_PHYCONTROL */
+
+/* phy_attach:
+ *
+ *   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.
+ */
+static int phy_compare_id(struct device *dev, void *data)
+{
+	return strcmp((char *)data, dev->bus_id) ? 0 : 1;
+}
+
+struct phy_device *phy_attach(struct net_device *dev,
+		const char *phy_id, u32 flags)
+{
+	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;
+		down_write(&d->bus->subsys.rwsem);
+		d->driver = &genphy_driver.driver;
+
+		err = d->driver->probe(d);
+
+		if (err < 0)
+			return ERR_PTR(err);
+
+		device_bind_driver(d);
+		up_write(&d->bus->subsys.rwsem);
+	}
+
+	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;
+
+	return phydev;
+}
+EXPORT_SYMBOL(phy_attach);
+
+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) {
+		down_write(&phydev->dev.bus->subsys.rwsem);
+		device_release_driver(&phydev->dev);
+		up_write(&phydev->dev.bus->subsys.rwsem);
+	}
+}
+EXPORT_SYMBOL(phy_detach);
+
+
 /* Generic PHY support and helper functions */
 
 /* genphy_config_advert
···
  *   after sanitizing the values to make sure we only advertise
  *   what is supported
  */
-static int genphy_config_advert(struct phy_device *phydev)
+int genphy_config_advert(struct phy_device *phydev)
 {
 	u32 advertise;
 	int adv;
···
 
 	return adv;
 }
+EXPORT_SYMBOL(genphy_config_advert);
 
 /* genphy_setup_forced
  *
···
 }
 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;
-	extern int mdio_bus_init(void);
-
-	rc = phy_driver_register(&genphy_driver);
-	if (rc)
-		goto out;
 
 	rc = mdio_bus_init();
 	if (rc)
-		goto out_unreg;
+		return rc;
 
-	return 0;
+	rc = phy_driver_register(&genphy_driver);
+	if (rc)
+		mdio_bus_exit();
 
-out_unreg:
-	phy_driver_unregister(&genphy_driver);
-out:
 	return rc;
 }
 
 static void __exit phy_exit(void)
 {
 	phy_driver_unregister(&genphy_driver);
+	mdio_bus_exit();
 }
 
-module_init(phy_init);
+subsys_initcall(phy_init);
 module_exit(phy_exit);

include/linux/phy.h

···
 struct phy_device* get_phy_device(struct mii_bus *bus, int addr);
 int phy_clear_interrupt(struct phy_device *phydev);
 int phy_config_interrupt(struct phy_device *phydev, u32 interrupts);
+struct phy_device * phy_attach(struct net_device *dev,
+		const char *phy_id, u32 flags);
+struct phy_device * phy_connect(struct net_device *dev, const char *phy_id,
+		void (*handler)(struct net_device *), u32 flags);
+void phy_disconnect(struct phy_device *phydev);
+void phy_detach(struct phy_device *phydev);
+void phy_start(struct phy_device *phydev);
+void phy_stop(struct phy_device *phydev);
+int phy_start_aneg(struct phy_device *phydev);
+
+int mdiobus_register(struct mii_bus *bus);
+void mdiobus_unregister(struct mii_bus *bus);
+void phy_sanitize_settings(struct phy_device *phydev);
+int phy_stop_interrupts(struct phy_device *phydev);
 
 static inline int phy_read_status(struct phy_device *phydev) {
 	return phydev->drv->read_status(phydev);
 }
 
+int genphy_config_advert(struct phy_device *phydev);
 int genphy_setup_forced(struct phy_device *phydev);
 int genphy_restart_aneg(struct phy_device *phydev);
 int genphy_config_aneg(struct phy_device *phydev);
···
 int phy_ethtool_gset(struct phy_device *phydev, struct ethtool_cmd *cmd);
 int phy_mii_ioctl(struct phy_device *phydev,
 		struct mii_ioctl_data *mii_data, int cmd);
+int phy_start_interrupts(struct phy_device *phydev);
+void phy_print_status(struct phy_device *phydev);
 
 extern struct bus_type mdio_bus_type;
 #endif /* __PHY_H */