78 lines
2.5 KiB
Nix
78 lines
2.5 KiB
Nix
{ config, lib, ... }:
|
|
|
|
let
|
|
cfg = config.hardware.raspberry-pi."4".dwc2;
|
|
in
|
|
{
|
|
options.hardware = {
|
|
raspberry-pi."4".dwc2 = {
|
|
enable = lib.mkEnableOption ''
|
|
Enable the UDC controller to support USB OTG gadget functions.
|
|
|
|
In order to verify that this works, connect the Raspberry Pi with
|
|
another computer via the USB C cable, and then do one of:
|
|
|
|
- `modprobe g_serial`
|
|
- `modprobe g_mass_storage file=/path/to/some/iso-file.iso`
|
|
|
|
On the Raspberry Pi, `dmesg` should then show success-indicating output
|
|
that is related to the dwc2 and g_serial/g_mass_storage modules.
|
|
On the other computer, a serial/mass-storage device should pop up in
|
|
the system logs.
|
|
|
|
For more information about what gadget functions exist along with handy
|
|
guides on how to test them, please refer to:
|
|
https://www.kernel.org/doc/Documentation/usb/gadget-testing.txt
|
|
'';
|
|
dr_mode = lib.mkOption {
|
|
type = lib.types.enum [ "host" "peripheral" "otg" ];
|
|
default = "otg";
|
|
description = ''
|
|
Dual role mode setting for the dwc2 USB controller driver.
|
|
'';
|
|
};
|
|
};
|
|
};
|
|
|
|
config = lib.mkIf cfg.enable {
|
|
# Configure for modesetting in the device tree
|
|
hardware.deviceTree = {
|
|
overlays = [
|
|
# this *should* be equivalent to (which doesn't work):
|
|
# https://github.com/raspberrypi/linux/blob/rpi-5.10.y/arch/arm/boot/dts/overlays/dwc2-overlay.dts
|
|
# but actually it's obtained using
|
|
# dtc -I dtb -O dts ${config.hardware.deviceTree.kernelPackage}/dtbs/overlays/dwc2.dtbo
|
|
# (changes: modified top-level "compatible" field)
|
|
# which is slightly different and works
|
|
{
|
|
name = "dwc2-overlay";
|
|
dtsText = ''
|
|
/dts-v1/;
|
|
/plugin/;
|
|
|
|
/ {
|
|
compatible = "brcm,bcm2711";
|
|
|
|
fragment@0 {
|
|
target = <&usb>;
|
|
#address-cells = <0x01>;
|
|
#size-cells = <0x01>;
|
|
|
|
__overlay__ {
|
|
compatible = "brcm,bcm2835-usb";
|
|
dr_mode = "${cfg.dr_mode}";
|
|
g-np-tx-fifo-size = <0x20>;
|
|
g-rx-fifo-size = <0x22e>;
|
|
g-tx-fifo-size = <0x200 0x200 0x200 0x200 0x200 0x100 0x100>;
|
|
status = "okay";
|
|
phandle = <0x01>;
|
|
};
|
|
};
|
|
};
|
|
'';
|
|
}
|
|
];
|
|
};
|
|
};
|
|
}
|