Make the virtual hid-steam device a selectable per-session host gamepad,
end-to-end on Linux: PUNKTFUNK_GAMEPAD=steamdeck now builds a
SteamControllerManager that creates a /dev/uhid 28DE:1205 Deck, enters
gamepad_mode, and feeds the byte-exact Deck report (M1).
- inject/linux/steam_controller.rs: SteamControllerManager / SteamDeckPad,
mirroring dualsense.rs (open/create2, GET/SET_REPORT pump, heartbeat, RAII
destroy). Two Steam-specific quirks beyond the DualSense path:
* gamepad_mode entry — best-effort `lizard_mode=0` via sysfs, plus a b9.6
creation pulse (MODE_ENTER) so steam_do_deck_input_event stops
early-returning, plus an anti-toggle guard (MENU_HOLD_CAP) so a long
in-game Start-hold can't flip gamepad_mode back off.
* UHID_SET_REPORT answered err=0 (DualSense omits it; the kernel stalls
~5s/cmd otherwise); the 0xEB rumble report parsed onto the 0xCA plane.
- core config.rs: GamepadPref::SteamDeck (wire byte 6) + SteamController
(byte 5, reserved — folds to Xbox360 until its backend lands); from_u8 /
from_name / as_str. Forward-compatible (unknown byte -> Auto); the C-ABI
PUNKTFUNK_GAMEPAD_* constants stay M3, so no generated-header drift.
- punktfunk1.rs: PadBackend::SteamDeck variant + select / handle / apply_rich
/ pump / heartbeat arms; pick_gamepad Linux arm.
On-box: an #[ignore]d backend test (backend_binds_and_input_flows) drives the
real SteamDeckPad — it binds hid-steam (gamepad + IMU evdevs), enters gamepad
mode, BTN_A reaches the evdev, and the device tears down on drop. Workspace
clippy/fmt/test green. Not pushed. Next: M3 (protocol/ABI wire) + M4 (client
capture).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Flesh out inject/proto/steam_proto.rs into the full Steam Deck HID contract,
transcribed verbatim from the kernel steam_do_deck_input_event /
steam_do_deck_sensors_event and validated field-for-field against kernel 7.0:
- SteamState: the u64 button map (bytes 8..16), sticks/triggers/trackpads/IMU
stored as raw little-endian report values; serialize_deck_state is a pure,
byte-exact memcpy into the 64-byte unnumbered frame.
- from_gamepad (XInput frame -> Deck buttons/sticks/triggers) + apply_rich
(RichInput touchpad -> right pad, motion -> IMU).
- parse_steam_output: the 0xEB ID_TRIGGER_RUMBLE_CMD feedback -> (low, high)
for the universal rumble plane.
- serial_reply fixed: prepend the report-id-0 byte the kernel strips
(steam_recv_report does memcpy(data, buf+1, ...)); M0's reply lacked it, so
the kernel fell back to the "XXXXXXXXXX" serial.
- SteamModel (Deck now; classic Controller later), command/feature IDs.
The spike is repurposed as the M1 validator: it pulses the b9.6 mode-switch to
enter gamepad_mode (steam_do_deck_input_event early-returns under the default
lizard_mode otherwise), then holds a known test pattern. Reading both evdevs via
EVIOCGABS/EVIOCGKEY, every field matched: ABS_X/Y/RX/RY (incl. the kernel
Y-negation), both triggers, the touched right-pad HAT1X/Y, the IMU accel/gyro
(with ABS_Z/RZ negations), and the 6 expected buttons incl. the L4/R5 grips.
5 unit tests + workspace clippy/fmt/test green. Next: M2 (SteamControllerManager
UHID backend + PadBackend wiring). Not pushed — pipeline not yet shippable.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Greenfield virtual Steam Deck controller, the Steam analogue of the shipped
virtual DualSense. Proves the kernel hid-steam driver binds a /dev/uhid
28DE:1205 device, registers it as a real Steam Deck, and parses our input
reports — the go/no-go gate for the full Steam Controller/Deck pipeline.
- inject/proto/steam_proto.rs: keeper module — the vendor HID descriptor (one
feature report, the sole thing steam_is_valve_interface() checks), the
command/feature IDs, serialize_deck_state, and the serial GET_REPORT reply.
Unit-tested.
- src/bin/steam_uhid_spike.rs: throwaway M0 spike (Linux-only) — opens
/dev/uhid, creates the device, services the handshake including
UHID_SET_REPORT (which the DualSense backend omits and which hid-steam
stalls ~5s/cmd without), and heartbeats a neutral report.
- design/steam-controller-deck-support.md: full design + M0–M7 plan; the two
walls (Steam Input capture ownership; virtual-Steam recognition) and the
fidelity ceiling. Status: M0 GREEN.
On-box (headless Ubuntu 26.04, kernel 7.0, no Steam): journalctl -k shows
hid-steam binding the device (rebind off hid-generic), "Steam Controller
connected", and the kernel creating BOTH a "Steam Deck" gamepad evdev and a
"Steam Deck Motion Sensors" IMU evdev (INPUT_PROP_ACCELEROMETER). A
layout-agnostic mash-probe drove 23 distinct BTN_* codes through
hid-steam -> evdev, proving the input-report parse path. M1 line-checks the
exact per-bit report layout against the lab kernel.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
enricobuehler