---
title: "DualSense Haptics"
description: "Feasibility and scoping for audio-driven DualSense haptics."
---

> **Status:** Audio-driven advanced (voice-coil) haptics — **NO-GO, DEFERRED.** The reachable
> HID work it scoped instead — **adaptive triggers + two-motor rumble** — **SHIPPED** (commit
> `59edeed`; see CLAUDE.md gamepad section, `inject/dualsense.rs`). This doc is trimmed to the
> deferral rationale (the three walls) + the conditions that would trigger a revisit.

Advanced voice-coil haptics on the DualSense are driven by the controller's **USB audio interface**
(4-channel surround, the back two channels carry the haptic waveform), *not* by HID reports.
Emulating that on a Linux host and faithfully replaying it on the Apple client both hit hard walls,
and the supply of software that actually *emits* these haptics on a Linux host is essentially zero.
We defer the audio-haptics feature.

(Grounded in a 4-agent feasibility read — host USB-gadget viability, DualSense audio descriptors,
Linux game demand, Apple client render path — 2026-06-10.)

## The one distinction that decides everything

| Feature | How it's driven | Reachable for us? |
|---|---|---|
| Basic rumble (2 motors) | HID output report `0x02`, bytes 3–4 | **Yes** — already parsed; client already has `nextRumble()` |
| **Adaptive triggers** (L2/R2 resistance) | HID output report `0x02`, bytes 11–22 / 22–33 | **Yes** — already parsed in `dualsense.rs`; just needs the `0xCD` back-channel + client render |
| **Advanced haptics** (voice-coil actuators) | **USB *audio* interface** — 4-ch, back 2 channels = haptic PCM | **No (for now)** — see the three walls below |

The UHID DualSense we already built is **HID-only**. It cannot present the DualSense's *audio*
interface, so it structurally cannot carry advanced haptics. That's not a bug in our implementation —
it's the wrong transport for this signal.

## The three walls (any one is fatal on its own)

### Wall 1 — Host capture needs a kernel rebuild
To *capture* haptic audio a game emits, the host must present a virtual device that owns the
DualSense audio interface. The standard way is a composite USB gadget (`configfs` + `f_hid` +
`f_uac2`) bound to a software UDC (`dummy_hcd`).

- ✅ Present & enabled on this box: `CONFIG_USB_CONFIGFS`, `CONFIG_USB_CONFIGFS_F_HID`,
  `CONFIG_USB_CONFIGFS_F_UAC2`, plus `libcomposite`/`usb_f_hid`/`usb_f_uac2`/`u_audio` modules.
- ❌ **Blocker:** `# CONFIG_USB_DUMMY_HCD is not set` in `/boot/config-7.0.0-22-generic`. No
  `dummy_hcd.ko`, no `/sys/class/udc/`. **No UDC → nothing to bind the gadget to.** Requires a
  custom kernel build to enable `CONFIG_USB_DUMMY_HCD=m`, plus root for module-load/configfs.

A lighter alternative exists — a **virtual PipeWire/ALSA sink renamed as the DualSense** (this is how
the working Linux setups capture the back-2-channels today, via WirePlumber rules). It skips the
kernel rebuild, but is gated by the same Wall 2 below, and games' audio-device detection is
hardcoded per-title so it's fragile.

### Wall 2 — Almost nothing on a Linux host emits these haptics
This is the decisive one. The *supply* that would feed our capture barely exists:

- **Steam Input (Linux):** no official advanced-haptics support (open feature request as of 2026).
- **Sony's `hid-playstation` kernel driver:** explicitly does **not** expose VCM haptics or adaptive
  triggers — basic rumble only.
- **RPCS3:** treats the DualSense as a generic pad; no advanced haptics.
- **Native Linux games:** effectively **zero** with advanced haptics.
- **The only working path** is a handful of Proton titles (FF7 Remake, Ghostwire, Deathloop, Animal
  Well, Stellar Blade) via ClearlyClaire's *custom Wine patches*, **USB-only**, Steam Input
  disabled, forced into a 4.0-surround profile, device renamed to match Windows. ~5–10 games total.
- Bluetooth can't carry it on Linux *or* Windows (Sony's proprietary A2DP repurposing isn't exposed).

A host-side capture feature is only as useful as the software willing to drive it. On Linux that set
is a niche-of-a-niche.

### Wall 3 — The Apple client can't faithfully replay it
Even with a captured waveform, the primary client (macOS/iOS) can't render it well:

- macOS GameController exposes the DualSense as a **basic gamepad** — no voice-coil / adaptive-trigger
  access. Those are PS5-only in Apple's stack.
- CoreHaptics is **discrete, pattern-based** (`CHHapticPattern` events, ≤30 s), **not** a PCM
  streaming sink. Converting a streamed haptic waveform to patterns is lossy — it throws away exactly
  the fidelity that makes voice-coil haptics worth having.
- There is **no public macOS API** to route CoreAudio to the DualSense's channels 3–4. Doing it
  anyway means private/reverse-engineered APIs that break across OS updates.

## Conditions for a future GO on audio haptics

Revisit if **all three** change:

- A real DualSense is available on the dev box to capture an authoritative `lsusb -v` + the exact
  UAC channel/sample-rate/format layout (today: undocumented, would need reverse-engineering).
- The host target gains a UDC (custom kernel with `dummy_hcd`, or real hardware OTG) **or** we accept
  the PipeWire-renamed-sink path *and* the title set that emits haptics on Linux grows beyond the
  Proton-patch niche.
- The client target shifts to one that can render PCM haptics (a Linux/Windows client with direct
  CoreAudio-style channel access, or a future Apple API) — or we accept lossy pattern conversion.

Until then the cost/benefit is upside-down: three hard subsystems (kernel, USB gadget, audio
routing) to serve ~5–10 Proton titles, rendered lossily on the one client we ship.

## Open items

- **Audio-driven advanced (voice-coil) haptics — DEFERRED.** Explicitly blocked until **all three**
  "Conditions for a future GO" above are met (a real DualSense to capture the UAC layout, a host UDC
  or grown Linux haptic-title supply, and a client that can render PCM haptics). This doc is the down
  payment to revisit then.
