[PATCH net-next 1/3] net: nixge: Add support for fixed-link subnodes

Moritz Fischer
2018-08-30T00:49:59Z

Add support for fixed-link cases where no MDIO is
actually required to run the device.
In that case no MDIO bus is instantiated since the
actual registers are not available in hardware.

Signed-off-by: Moritz Fischer <mdf@kernel.org>
---
drivers/net/ethernet/ni/nixge.c | 72 ++++++++++++++++++++++++---------
1 file changed, 53 insertions(+), 19 deletions(-)

diff --git a/drivers/net/ethernet/ni/nixge.c b/drivers/net/ethernet/ni/nixge.c
index 74cf52e3fb09..670249313ff0 100644
--- a/drivers/net/ethernet/ni/nixge.c
+++ b/drivers/net/ethernet/ni/nixge.c
@@ -1189,9 +1189,36 @@ static int nixge_mdio_write(struct mii_bus *bus, int phy_id, int reg, u16 val)
return err;
}

+static int nixge_of_get_phy(struct nixge_priv *priv, struct device_node *np)
+{
+ priv->phy_mode = of_get_phy_mode(np);
+ if (priv->phy_mode < 0) {
+ dev_err(priv->dev, "not find \"phy-mode\" property\n");
+ return -EINVAL;
+ }
+
+ if (of_phy_is_fixed_link(np)) {
+ if (of_phy_register_fixed_link(np) < 0) {
+ dev_err(priv->dev, "broken fixed link spec\n");
+ return -EINVAL;
+ }
+
+ priv->phy_node = of_node_get(np);
+ } else {
+ priv->phy_node = of_parse_phandle(np, "phy-handle", 0);
+ if (!priv->phy_node) {
+ dev_err(priv->dev, "not find \"phy-handle\" property\n");
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
static int nixge_mdio_setup(struct nixge_priv *priv, struct device_node *np)
{
struct mii_bus *bus;
+ int err;

bus = devm_mdiobus_alloc(priv->dev);
if (!bus)
@@ -1230,6 +1257,7 @@ static int nixge_probe(struct platform_device *pdev)
struct nixge_priv *priv;
struct net_device *ndev;
struct resource *dmares;
+ struct device_node *np;
const u8 *mac_addr;
int err;

@@ -1237,6 +1265,8 @@ static int nixge_probe(struct platform_device *pdev)
if (!ndev)
return -ENOMEM;

+ np = pdev->dev.of_node;
+
platform_set_drvdata(pdev, ndev);
SET_NETDEV_DEV(ndev, &pdev->dev);

@@ -1286,24 +1316,19 @@ static int nixge_probe(struct platform_device *pdev)
priv->coalesce_count_rx = XAXIDMA_DFT_RX_THRESHOLD;
priv->coalesce_count_tx = XAXIDMA_DFT_TX_THRESHOLD;

- err = nixge_mdio_setup(priv, pdev->dev.of_node);
- if (err) {
- netdev_err(ndev, "error registering mdio bus");
- goto free_netdev;
- }
-
- priv->phy_mode = of_get_phy_mode(pdev->dev.of_node);
- if (priv->phy_mode < 0) {
- netdev_err(ndev, "not find \"phy-mode\" property\n");
- err = -EINVAL;
- goto unregister_mdio;
+ if (np) {
+ err = nixge_of_get_phy(priv, np);
+ if (err)
+ goto free_netdev;
}

- priv->phy_node = of_parse_phandle(pdev->dev.of_node, "phy-handle", 0);
- if (!priv->phy_node) {
- netdev_err(ndev, "not find \"phy-handle\" property\n");
- err = -EINVAL;
- goto unregister_mdio;
+ /* only if it's not a fixed link, do we care about MDIO at all */
+ if (priv->phy_node && !of_phy_is_fixed_link(np)) {
+ err = nixge_mdio_setup(priv, np);
+ if (err) {
+ dev_err(&pdev->dev, "error registering mdio bus");
+ goto free_phy;
+ }
}

err = register_netdev(priv->ndev);
@@ -1315,8 +1340,13 @@ static int nixge_probe(struct platform_device *pdev)
return 0;

unregister_mdio:
- mdiobus_unregister(priv->mii_bus);
-
+ if (priv->mii_bus)
+ mdiobus_unregister(priv->mii_bus);
+free_phy:
+ if (np && of_phy_is_fixed_link(np)) {
+ of_phy_deregister_fixed_link(np);
+ of_node_put(np);
+ }
free_netdev:
free_netdev(ndev);

@@ -1330,7 +1360,11 @@ static int nixge_remove(struct platform_device *pdev)

unregister_netdev(ndev);

- mdiobus_unregister(priv->mii_bus);
+ if (priv->mii_bus)
+ mdiobus_unregister(priv->mii_bus);
+
+ if (np && of_phy_is_fixed_link(np))
+ of_phy_deregister_fixed_link(np);

free_netdev(ndev);

--
2.18.0