Re: [PATCH V3] net: emac: emac gigabit ethernet controller driver

From: Andrew Lunn
Date: Thu Apr 07 2016 - 16:10:23 EST


> I'm back to working on this driver, and I need some more help with
> how to handle the phy. mdio-gpio.txt doesn't really tell me much.
> I'm actually working on an ACPI system and not DT.

I can help you with DT, but not ACPI.

The MDIO bus can be a separate Linux device. Since you have GPIO lines
for the MDIO bus, it makes sense for this to be a mdio-gpio device. So
in DT, you would have:

mdio0: mdio {
compatible = "virtual,mdio-gpio";
#address-cells = <1>;
#size-cells = <0>;
gpios = <&qcomgpio 123 0
&qcomgpio 124 0>;

phy0: ethernet-phy@8 {
reg = <9>;
};
};

Here i've assumed the PHY is using address 8 on the bus. Change as
needed.

In your MAC DT node, you then have phy-handle pointing to this phy:

emac0: qcom,emac@feb20000 {
cell-index = <0>;
compatible = "qcom,emac";
reg-names = "base", "csr", "ptp", "sgmii";
reg = <0xfeb20000 0x10000>,
<0xfeb36000 0x1000>,
<0xfeb3c000 0x4000>,
<0xfeb38000 0x400>;
#address-cells = <0>;
interrupt-parent = <&emac0>;
#interrupt-cells = <1>;
interrupts = <0 1>;
interrupt-map-mask = <0xffffffff>;
interrupt-map = <0 &intc 0 76 0
1 &intc 0 80 0>;
interrupt-names = "emac_core0", "sgmii_irq";
qcom,emac-tstamp-en;
qcom,emac-ptp-frac-ns-adj = <125000000 1>;

phy-handle = <&phy0>
}

In the driver, you need to connect the PHY to the MAC. You do this
using something like:

if (dev->of_node) {
phy_np = of_parse_phandle(dev->of_node, "phy-handle", 0);
if (!phy_np) {
netdev_dbg(ndev, "No phy-handle found in DT\n");
return -ENODEV;
}

phy_dev = of_phy_connect(ndev, phy_np, &xxxx_enet_adjust_link,
0, pdata->phy_mode);
if (!phy_dev) {
netdev_err(ndev, "Could not connect to PHY\n");
return -ENODEV;
}

Do you have an ACPI table describing this hardware? What does it look
like?

Andrew