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

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




Andrew Lunn wrote:
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;
                  }

Thank you very much.  I'll study this in detail.

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

So a little background. There are several versions of this driver floating in Qualcomm, and this is the first serious attempt to upstream it. I'm trying to reconcile Gilad's driver with the one we use internally for our ACPI-enabled ARM server platform (the QDF2432).

My goal is to get Gilad's driver accepted upstream with minimal changes on my part. I will then follow up with several patches that enable ACPI and our SOC, as well as adding missing parts like ethtool and 1588 support.

On my platform, firmware (UEFI) configures all of the GPIOs. I need to get confirmation, but it appears that we don't actually make any GPIO calls at all. I see code that looks like this:

	for (i = 0; (!adpt->no_mdio_gpio) && i < EMAC_NUM_GPIO; i++) {
		gpio_info = &adpt->gpio_info[i];
		retval = of_get_named_gpio(node, gpio_info->name, 0);
		if (retval < 0)
			return retval;

And on our ACPI system, adpt->no_mdio_gpio is always true:

	/* Assume GPIOs required for MDC/MDIO are enabled in firmware */
	adpt->no_mdio_gpio = true;

--
Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
Forum, a Linux Foundation collaborative project.
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Device Tree Compilter]     [Device Tree Spec]     [Linux Driver Backports]     [Video for Linux]     [Linux USB Devel]     [Linux PCI Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Yosemite Backpacking]
  Powered by Linux