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);