This patch adds a PHY Abstraction Layer to the Linux Kernel, enabling

ethernet drivers to remain as ignorant as is reasonable of the connected
PHY's design and operation details.

Signed-off-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

1 files changed, 682 insertions, 0 deletions

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
new file mode 100644
index 000000000000..f0595af4c837
--- /dev/null
+++ b/drivers/net/phy/phy_device.c
@@ -0,0 +1,682 @@
+/*
+ * 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/config.h>
+#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/version.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>
+
+/* get_phy_device
+ *
+ * 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;
+
+	/* Otherwise, we allocate the device, and initialize the
+	 * default values */
+	dev = kcalloc(1, sizeof(*dev), GFP_KERNEL);
+
+	if (NULL == dev)
+		return ERR_PTR(-ENOMEM);
+
+	dev->speed = 0;
+	dev->duplex = -1;
+	dev->pause = dev->asym_pause = 0;
+	dev->link = 1;
+
+	dev->autoneg = AUTONEG_ENABLE;
+
+	dev->addr = addr;
+	dev->phy_id = phy_id;
+	dev->bus = bus;
+
+	dev->state = PHY_DOWN;
+
+	spin_lock_init(&dev->lock);
+
+	return dev;
+}
+
+/* phy_prepare_link:
+ *
+ * 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;
+}
+
+#ifdef CONFIG_PHYCONTROL
+/* 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
+ *
+ * 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
+ *
+ * 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 = BMCR_RESET;
+
+	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;
+}
+
+
+/* Enable and Restart Autonegotiation */
+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
+ *
+ * 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
+ *
+ * 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;
+}
+
+/* genphy_read_status
+ *
+ * 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)
+{
+	u32 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
+ *
+ * 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;
+
+	spin_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);
+
+	spin_unlock(&phydev->lock);
+
+	if (err < 0)
+		return err;
+
+	if (phydev->drv->config_init)
+		err = phydev->drv->config_init(phydev);
+
+	return err;
+}
+
+static int phy_remove(struct device *dev)
+{
+	struct phy_device *phydev;
+
+	phydev = to_phy_device(dev);
+
+	spin_lock(&phydev->lock);
+	phydev->state = PHY_DOWN;
+	spin_unlock(&phydev->lock);
+
+	if (phydev->drv->remove)
+		phydev->drv->remove(phydev);
+
+	put_driver(dev->driver);
+	phydev->drv = NULL;
+
+	return 0;
+}
+
+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_info("%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 genphy_init(void)
+{
+	return phy_driver_register(&genphy_driver);
+
+}
+
+static void __exit genphy_exit(void)
+{
+	phy_driver_unregister(&genphy_driver);
+}
+
+module_init(genphy_init);
+module_exit(genphy_exit);