USB host not working

[matangk]

Hi, Thanks for the effort to put this manual/image together. I just downloaded and installed the image on my Cora z7. Jupiter notebook works nicely, but the USB A seems to be non-functional. I looked in the base design Vivado project and it seems to be connected. Any hint why that might be? Best,

[dspsandbox]

Hi, I am glad that the Pynq image works for you. Regarding your questions:

• USB0 is enabled within the Zynq processing system IP. It corresponds to a configuration of the MMIOs and it does not require to be routed on the FPGA side. Similarly, you could erase from the FPGA design the connection to the DDR and FIXED_IO without affecting their functionality (see discussion), In other words, the USB0, DDR, FIXED_IO... are part of the MMIOs, which do not go through the FPGA logic and are directly routed from the Processor to the physical pins.
• The Cora-Z7 documentation states that if your design uses the USB Host port (embedded or general purpose), then the Cora Z7 should be powered via a wall adapter capable of providing more power (see doc).

I hope this helps :)

Cheers, Pau

[matangk]

Hi, Yes, I noticed that the USB is connected through the PS. No reason for it not to work. It's not the power supply. I tried with both PC and external supply and no-go. In my experience there's usually no problem in working with PC power for low-power devices attached to the host (e.g. Arduino). The min. 100mA from a USB socket is plenty.

I did solve this issue by rebuilding PYNQ using your git repo project (great work by the way). I do have some limited experience with installing Vivado and Petalinux.

Eventually, what solved the issue is one of two things, not sure which:

1. I built PYNQ 2.5.1, but still used the board agnostic image and tarball of 2.5.
2. I added another config file: system-user.dtsi in the following location (similar to the example pre-built boards): ./Pynq-Cora-Z7-07S/petalinux_bsp/meta-user/recipes-bsp/device-tree/files/system-user.dtsi

Its content is meant to take care of ethernet and USB:

/include/ "system-conf.dtsi"
/ {
    model = "Zynq Cora Z7 Development Board";
    compatible = "digilent,zynq-coraz7", "xlnx,zynq-7000";

    usb_phy0: phy0@e0002000 {
        compatible = "ulpi-phy";
        #phy-cells = <0>;
        reg = <0xe0002000 0x1000>;
        view-port = <0x0170>;
        drv-vbus;
    };

};

&gem0 {
    phy-handle = <&ethernet_phy>;
    /*phy-reset-gpio = <&gpio0 GPIO_ACTIVE_LOW>;
    phy-reset-active-low;   
    phy-reset-duration = <10>;  */
    ethernet_phy: ethernet-phy@1 { /* rtl8211e-vl */
            reg = <1>;
        device_type = "ethernet-phy";
    };
};
&usb0 { 
    dr_mode = "host";
    usb-phy = <&usb_phy0>;
};

I saw some forum remark that said it solved their issue, so I took it from Digilent's Petalinux example here: https://github.com/Digilent/Petalinux-Cora-Z7-07S/tree/master/Cora-Z7-07S/project-spec/meta-user/recipes-bsp/device-tree/files

You're welcome to try it and tell me if you see any difference. Anyway, as far as it looks like problem solved! Cheers, Matan

[dspsandbox]

Hi Matan, thanks for sharing your findings. I believe that changing the device-tree (.dtsi) to include the configuration for USB0 was the key. I will definitely try the same approach on my end and see if I can also get USB0 to work. Best regards, Pau