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path: root/drivers/net/ethernet/broadcom/genet/bcmmii.c
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Diffstat (limited to 'drivers/net/ethernet/broadcom/genet/bcmmii.c')
-rw-r--r--drivers/net/ethernet/broadcom/genet/bcmmii.c54
1 files changed, 50 insertions, 4 deletions
diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c
index 6bef04e2f735..adf23d2ac488 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmmii.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmmii.c
@@ -408,6 +408,52 @@ static int bcmgenet_mii_probe(struct net_device *dev)
return 0;
}
+/* Workaround for integrated BCM7xxx Gigabit PHYs which have a problem with
+ * their internal MDIO management controller making them fail to successfully
+ * be read from or written to for the first transaction. We insert a dummy
+ * BMSR read here to make sure that phy_get_device() and get_phy_id() can
+ * correctly read the PHY MII_PHYSID1/2 registers and successfully register a
+ * PHY device for this peripheral.
+ *
+ * Once the PHY driver is registered, we can workaround subsequent reads from
+ * there (e.g: during system-wide power management).
+ *
+ * bus->reset is invoked before mdiobus_scan during mdiobus_register and is
+ * therefore the right location to stick that workaround. Since we do not want
+ * to read from non-existing PHYs, we either use bus->phy_mask or do a manual
+ * Device Tree scan to limit the search area.
+ */
+static int bcmgenet_mii_bus_reset(struct mii_bus *bus)
+{
+ struct net_device *dev = bus->priv;
+ struct bcmgenet_priv *priv = netdev_priv(dev);
+ struct device_node *np = priv->mdio_dn;
+ struct device_node *child = NULL;
+ u32 read_mask = 0;
+ int addr = 0;
+
+ if (!np) {
+ read_mask = 1 << priv->phy_addr;
+ } else {
+ for_each_available_child_of_node(np, child) {
+ addr = of_mdio_parse_addr(&dev->dev, child);
+ if (addr < 0)
+ continue;
+
+ read_mask |= 1 << addr;
+ }
+ }
+
+ for (addr = 0; addr < PHY_MAX_ADDR; addr++) {
+ if (read_mask & 1 << addr) {
+ dev_dbg(&dev->dev, "Workaround for PHY @ %d\n", addr);
+ mdiobus_read(bus, addr, MII_BMSR);
+ }
+ }
+
+ return 0;
+}
+
static int bcmgenet_mii_alloc(struct bcmgenet_priv *priv)
{
struct mii_bus *bus;
@@ -427,6 +473,7 @@ static int bcmgenet_mii_alloc(struct bcmgenet_priv *priv)
bus->parent = &priv->pdev->dev;
bus->read = bcmgenet_mii_read;
bus->write = bcmgenet_mii_write;
+ bus->reset = bcmgenet_mii_bus_reset;
snprintf(bus->id, MII_BUS_ID_SIZE, "%s-%d",
priv->pdev->name, priv->pdev->id);
@@ -443,7 +490,6 @@ static int bcmgenet_mii_of_init(struct bcmgenet_priv *priv)
{
struct device_node *dn = priv->pdev->dev.of_node;
struct device *kdev = &priv->pdev->dev;
- struct device_node *mdio_dn;
char *compat;
int ret;
@@ -451,14 +497,14 @@ static int bcmgenet_mii_of_init(struct bcmgenet_priv *priv)
if (!compat)
return -ENOMEM;
- mdio_dn = of_find_compatible_node(dn, NULL, compat);
+ priv->mdio_dn = of_find_compatible_node(dn, NULL, compat);
kfree(compat);
- if (!mdio_dn) {
+ if (!priv->mdio_dn) {
dev_err(kdev, "unable to find MDIO bus node\n");
return -ENODEV;
}
- ret = of_mdiobus_register(priv->mii_bus, mdio_dn);
+ ret = of_mdiobus_register(priv->mii_bus, priv->mdio_dn);
if (ret) {
dev_err(kdev, "failed to register MDIO bus\n");
return ret;