phylib: Add support for board-level PHY fixups

Sometimes the specific interaction between the platform and the PHY
requires special handling.  For instance, to change where the PHY's
clock input is, or to add a delay to account for latency issues in the
data path.  We add a mechanism for registering a callback with the PHY
Lib to be called on matching PHYs when they are brought up, or reset.

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

1 files changed, 117 insertions, 12 deletions

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 8b1121b02f98..ddf8d51832a6 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -53,6 +53,96 @@ static void phy_device_release(struct device *dev)
         phy_device_free(to_phy_device(dev));
 }
 
+static LIST_HEAD(phy_fixup_list);
+static DEFINE_MUTEX(phy_fixup_lock);
+
+/*
+ * Creates a new phy_fixup and adds it to the list
+ * @bus_id: A string which matches phydev->dev.bus_id (or PHY_ANY_ID)
+ * @phy_uid: Used to match against phydev->phy_id (the UID of the PHY)
+ *      It can also be PHY_ANY_UID
+ * @phy_uid_mask: Applied to phydev->phy_id and fixup->phy_uid before
+ *      comparison
+ * @run: The actual code to be run when a matching PHY is found
+ */
+int phy_register_fixup(const char *bus_id, u32 phy_uid, u32 phy_uid_mask,
+                int (*run)(struct phy_device *))
+{
+        struct phy_fixup *fixup;
+
+        fixup = kzalloc(sizeof(struct phy_fixup), GFP_KERNEL);
+        if (!fixup)
+                return -ENOMEM;
+
+        strncpy(fixup->bus_id, bus_id, BUS_ID_SIZE);
+        fixup->phy_uid = phy_uid;
+        fixup->phy_uid_mask = phy_uid_mask;
+        fixup->run = run;
+
+        mutex_lock(&phy_fixup_lock);
+        list_add_tail(&fixup->list, &phy_fixup_list);
+        mutex_unlock(&phy_fixup_lock);
+
+        return 0;
+}
+EXPORT_SYMBOL(phy_register_fixup);
+
+/* Registers a fixup to be run on any PHY with the UID in phy_uid */
+int phy_register_fixup_for_uid(u32 phy_uid, u32 phy_uid_mask,
+                int (*run)(struct phy_device *))
+{
+        return phy_register_fixup(PHY_ANY_ID, phy_uid, phy_uid_mask, run);
+}
+EXPORT_SYMBOL(phy_register_fixup_for_uid);
+
+/* Registers a fixup to be run on the PHY with id string bus_id */
+int phy_register_fixup_for_id(const char *bus_id,
+                int (*run)(struct phy_device *))
+{
+        return phy_register_fixup(bus_id, PHY_ANY_UID, 0xffffffff, run);
+}
+EXPORT_SYMBOL(phy_register_fixup_for_id);
+
+/*
+ * Returns 1 if fixup matches phydev in bus_id and phy_uid.
+ * Fixups can be set to match any in one or more fields.
+ */
+static int phy_needs_fixup(struct phy_device *phydev, struct phy_fixup *fixup)
+{
+        if (strcmp(fixup->bus_id, phydev->dev.bus_id) != 0)
+                if (strcmp(fixup->bus_id, PHY_ANY_ID) != 0)
+                        return 0;
+
+        if ((fixup->phy_uid & fixup->phy_uid_mask) !=
+                        (phydev->phy_id & fixup->phy_uid_mask))
+                if (fixup->phy_uid != PHY_ANY_UID)
+                        return 0;
+
+        return 1;
+}
+
+/* Runs any matching fixups for this phydev */
+int phy_scan_fixups(struct phy_device *phydev)
+{
+        struct phy_fixup *fixup;
+
+        mutex_lock(&phy_fixup_lock);
+        list_for_each_entry(fixup, &phy_fixup_list, list) {
+                if (phy_needs_fixup(phydev, fixup)) {
+                        int err;
+
+                        err = fixup->run(phydev);
+
+                        if (err < 0)
+                                return err;
+                }
+        }
+        mutex_unlock(&phy_fixup_lock);
+
+        return 0;
+}
+EXPORT_SYMBOL(phy_scan_fixups);
+
 struct phy_device* phy_device_create(struct mii_bus *bus, int addr, int phy_id)
 {
         struct phy_device *dev;
@@ -179,13 +269,13 @@ void phy_prepare_link(struct phy_device *phydev,
  *   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,
+struct phy_device * phy_connect(struct net_device *dev, const char *bus_id,
                 void (*handler)(struct net_device *), u32 flags,
                 phy_interface_t interface)
 {
         struct phy_device *phydev;
 
-        phydev = phy_attach(dev, phy_id, flags, interface);
+        phydev = phy_attach(dev, bus_id, flags, interface);
 
         if (IS_ERR(phydev))
                 return phydev;
@@ -226,7 +316,7 @@ static int phy_compare_id(struct device *dev, void *data)
 /**
  * phy_attach - attach a network device to a particular PHY device
  * @dev: network device to attach
- * @phy_id: PHY device to attach
+ * @bus_id: PHY device to attach
  * @flags: PHY device's dev_flags
  * @interface: PHY device's interface
  *
@@ -238,7 +328,7 @@ static int phy_compare_id(struct device *dev, void *data)
  *     change.  The phy_device is returned to the attaching driver.
  */
 struct phy_device *phy_attach(struct net_device *dev,
-                const char *phy_id, u32 flags, phy_interface_t interface)
+                const char *bus_id, u32 flags, phy_interface_t interface)
 {
         struct bus_type *bus = &mdio_bus_type;
         struct phy_device *phydev;
@@ -246,12 +336,12 @@ struct phy_device *phy_attach(struct net_device *dev,
 
         /* 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);
+        d = bus_find_device(bus, NULL, (void *)bus_id, phy_compare_id);
 
         if (d) {
                 phydev = to_phy_device(d);
         } else {
-                printk(KERN_ERR "%s not found\n", phy_id);
+                printk(KERN_ERR "%s not found\n", bus_id);
                 return ERR_PTR(-ENODEV);
         }
 
@@ -271,7 +361,7 @@ struct phy_device *phy_attach(struct net_device *dev,
 
         if (phydev->attached_dev) {
                 printk(KERN_ERR "%s: %s already attached\n",
-                                dev->name, phy_id);
+                                dev->name, bus_id);
                 return ERR_PTR(-EBUSY);
         }
 
@@ -287,6 +377,11 @@ struct phy_device *phy_attach(struct net_device *dev,
         if (phydev->drv->config_init) {
                 int err;
 
+                err = phy_scan_fixups(phydev);
+
+                if (err < 0)
+                        return ERR_PTR(err);
+
                 err = phydev->drv->config_init(phydev);
 
                 if (err < 0)
@@ -395,6 +490,7 @@ EXPORT_SYMBOL(genphy_config_advert);
  */
 int genphy_setup_forced(struct phy_device *phydev)
 {
+        int err;
         int ctl = 0;
 
         phydev->pause = phydev->asym_pause = 0;
@@ -407,17 +503,26 @@ int genphy_setup_forced(struct phy_device *phydev)
         if (DUPLEX_FULL == phydev->duplex)
                 ctl |= BMCR_FULLDPLX;
         
-        ctl = phy_write(phydev, MII_BMCR, ctl);
+        err = phy_write(phydev, MII_BMCR, ctl);
 
-        if (ctl < 0)
-                return ctl;
+        if (err < 0)
+                return err;
+
+        /*
+         * Run the fixups on this PHY, just in case the
+         * board code needs to change something after a reset
+         */
+        err = phy_scan_fixups(phydev);
+
+        if (err < 0)
+                return err;
 
         /* 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);
+                err = phydev->drv->config_init(phydev);
 
-        return ctl;
+        return err;
 }