From e6c84e7eaf1c1f4ec31330208a7ca76ade600f46 Mon Sep 17 00:00:00 2001 From: Jacek Galowicz Date: Thu, 27 May 2021 04:42:19 +0000 Subject: [PATCH] raspberry-pi/4: Add dwc2 option --- raspberry-pi/4/default.nix | 1 + raspberry-pi/4/dwc2.nix | 77 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 78 insertions(+) create mode 100644 raspberry-pi/4/dwc2.nix diff --git a/raspberry-pi/4/default.nix b/raspberry-pi/4/default.nix index 3e2f7cc..d50325a 100644 --- a/raspberry-pi/4/default.nix +++ b/raspberry-pi/4/default.nix @@ -2,6 +2,7 @@ { imports = [ + ./dwc2.nix ./modesetting.nix ]; diff --git a/raspberry-pi/4/dwc2.nix b/raspberry-pi/4/dwc2.nix new file mode 100644 index 0000000..4ee3091 --- /dev/null +++ b/raspberry-pi/4/dwc2.nix @@ -0,0 +1,77 @@ +{ config, lib, pkgs, ... }: + +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>; + }; + }; + }; + ''; + } + ]; + }; + }; +}