Re: [U-Boot] DM ethernet driver with multiple interfaces per device

+Marek

Hi Stefan,

On 1 February 2016 at 06:27, Stefan Roese sr@denx.de wrote:

Hi!

I'm currently porting the Marvell mvpp2 driver for the Armada 375 to U-Boot. This controller is a bit different, as it exposes multiple interfaces per controller. In this specific case its 2 interfaces. Here the current dts node:

    /* Network controller */
    ethernet@f0000 {
            compatible = "marvell,armada-375-pp2";
            reg = <0xf0000 0xa000>, /* Packet Processor regs */
                  <0xc0000 0x3060>, /* LMS regs */
                  <0xc4000 0x100>,  /* eth0 regs */
                  <0xc5000 0x100>;  /* eth1 regs */
            clocks = <&gateclk 3>, <&gateclk 19>;
            clock-names = "pp_clk", "gop_clk";
            status = "disabled";

            eth0: eth0@c4000 {
                    interrupts = <GIC_SPI 37 IRQ_TYPE_LEVEL_HIGH>;
                    port-id = <0>;
                    status = "disabled";
            };

            eth1: eth1@c5000 {
                    interrupts = <GIC_SPI 41 IRQ_TYPE_LEVEL_HIGH>;
                    port-id = <1>;
                    status = "disabled";
            };
    };

Now I'm unsure, how to support those multiple network interfaces with DM. As the driver will only get called once. And I can't instantiate 2 network interfaces from the one probe function call.

I could work around this problem, by restructuring the DT node into 2 separate DT nodes, each referencing the shared resources. But this would be a ugly, since it results in a different DT source between Linux and U-Boot.

So my question is, is this something that is supported by the current DM networking infrastructure? And if not, if you have some hints on how to best support such a constellation with multiple network interfaces via one ethernet controller.

My suggestion would be to make this device a UCLASS_MISC or something like that, then in its bind() method, bind two new child devices in UCLASS_ETH.

Marek was talking about something similar on IRC and I pointed him to the way the USB PHYs work, but clearly the device tree binding you have anticipates having two devices.

Regards, Simon