feat(core,host,android): Steam Controller 2 as-is passthrough to Linux hosts

The 2026 Steam Controller (Valve "Ibex" / SDL "Triton") captured on an
Android client is passed through AS-IS: the host presents a virtual pad
with the real wired identity (28DE:1302) and mirrors the physical pad's
raw HID reports, so Steam on the host drives it over hidraw exactly like
the real thing — trackpads, gyro, paddles, and its rumble/settings writes
flow back onto the physical controller. Protocol ground truth: SDL's
Valve-maintained SDL_hidapi_steam_triton.c + steam/controller_structs.h.

Core:
- GamepadPref::SteamController2 (wire byte 9; names steamcontroller2/
  sc2/ibex) + PUNKTFUNK_GAMEPAD_STEAMCONTROLLER2 in the C ABI.
- Raw HID planes: RichInput::HidReport (0xCC/0x04, client→host input
  reports verbatim, Copy fixed-64 body) and HidOutput::HidRaw (0xCD/0x05,
  host→client feature/output writes for replay). Best-effort is sound by
  the device protocol's own design (rumble re-sent every ~40 ms, settings
  every ~3 s — losses self-heal); HidRaw bypasses hidout dedup for
  exactly that reason.

Host (Linux):
- triton_proto.rs + steam_controller2.rs: Triton2Manager UHID backend —
  no kernel driver binds the PID (hidraw only; Steam Input is the
  consumer), raw mirroring with a typed-fallback 0x42 synthesizer until
  the first raw report, SET_REPORT ack + raw forward, canned GET_REPORT
  serial reply, rumble also parsed onto the universal 0xCA plane (phone
  mirror). Rides the uhid + 28DE-conflict degrades; UHID promotion by
  Steam is flagged in the creation log (usbip transport is the known
  follow-up if Steam ignores Interface:-1 devices for Triton too).

Android:
- Sc2UsbLink (wired/Puck: vendor-interface claim detaches the OS driver,
  interrupt read loop, lizard-off on the watchdog cadence, raw replay via
  interrupt-OUT / SET_REPORT with hidapi report-id framing) and Sc2BleLink
  (Valve vendor GATT service, notify subscribe machine, 0x45 re-framing,
  HIGH connection priority).
- Sc2Capture orchestrator: raw plane + typed mirror (exit chord + host
  degrade paths keep working) on a GamepadRouter external slot; raw
  return path via GamepadFeedback.onHidRaw.
- nativeSendPadHidReport JNI (direct ByteBuffer, no per-report copy),
  hidout raw decode, usb-host/BLUETOOTH_CONNECT manifest bits, opt-out
  settings toggle, StreamScreen engagement incl. the USB permission flow.

Verified: core 149 + host 312 tests green on Linux (.21), on-box uhid
smoke creates/mirrors/tears down the virtual 28DE:1302, C ABI harness
round-trips, Android compileDebugKotlin green. On-glass with the real
controller owed.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

clients/android/kit/src/main/kotlin/io/unom/punktfunk/kit/Gamepad.kt

@@ -36,6 +36,16 @@ object Gamepad {
     const val BTN_X = 0x4000
     const val BTN_Y = 0x8000
 
+    // Extended bits (Moonlight `buttonFlags2 << 16` namespace — `input.rs::gamepad`): the four
+    // back grips (Steam L4/L5/R4/R5 ≙ Elite P1–P4), touchpad click, and the misc/QAM button.
+    // Android's standard InputDevice path never produces these; the SC2 capture link does.
+    const val BTN_PADDLE1 = 0x10000
+    const val BTN_PADDLE2 = 0x20000
+    const val BTN_PADDLE3 = 0x40000
+    const val BTN_PADDLE4 = 0x80000
+    const val BTN_TOUCHPAD = 0x100000
+    const val BTN_MISC1 = 0x200000
+
     // Axis ids — must equal `input.rs::gamepad::AXIS_*`.
     const val AXIS_LS_X = 0
     const val AXIS_LS_Y = 1
@@ -54,6 +64,7 @@ object Gamepad {
     const val PREF_STEAMDECK = 6
     const val PREF_DUALSENSEEDGE = 7
     const val PREF_SWITCHPRO = 8
+    const val PREF_STEAMCONTROLLER2 = 9
 
     // USB vendor ids of the controllers we can identify by VID/PID.
     private const val VID_SONY = 0x054C

clients/android/kit/src/main/kotlin/io/unom/punktfunk/kit/GamepadFeedback.kt

@@ -51,6 +51,7 @@ class GamepadFeedback(
         const val TAG_LED: Byte = 0x01
         const val TAG_PLAYER_LEDS: Byte = 0x02
         const val TAG_TRIGGER: Byte = 0x03
+        const val TAG_HID_RAW: Byte = 0x05
         // Fallback one-shot duration against a legacy host (no v2 TTL lease): the prior fixed value.
         // A new host renews far below this, so it never actually holds this long there.
         const val LEGACY_RUMBLE_MS = 60_000L
@@ -112,7 +113,8 @@ class GamepadFeedback(
         }, "pf-rumble").apply { isDaemon = true; start() }
 
         hidoutThread = Thread({
-            val buf = ByteBuffer.allocateDirect(64)
+            // 128: the raw as-is passthrough events are [pad][kind tag][report kind][≤64 bytes].
+            val buf = ByteBuffer.allocateDirect(128)
             while (running) {
                 val n = NativeBridge.nativeNextHidout(handle, buf)
                 if (n < 0) continue // timeout / closed
@@ -331,10 +333,32 @@ class GamepadFeedback(
                     "hidout pad=$pad Trigger which=$which effLen=$effLen mode=0x%02x (adaptive triggers unsupported on Android)".format(mode),
                 )
             }
+            TAG_HID_RAW -> {
+                // As-is SC2 passthrough: a raw report the host's Steam wrote to the virtual pad —
+                // [kind: 0=output, 1=feature][report bytes, id first]. Handed to the capture link
+                // for verbatim replay on the physical controller; dropped when no link owns the pad.
+                val kind = buf.get().toInt() and 0xFF
+                val len = n - 3
+                if (len > 0) {
+                    val data = ByteArray(len)
+                    buf.get(data)
+                    onHidRaw?.invoke(pad, kind, data)
+                }
+            }
             else -> Log.d(TAG, "hidout: unknown kind, dropped")
         }
     }
 
+    /**
+     * Raw HID-report replay hook for the as-is Steam Controller 2 passthrough: invoked (on the
+     * hidout poll thread) with the wire pad index, the report kind (0 = output report, 1 =
+     * feature report), and the full report bytes (id first) the host's hidraw consumer wrote.
+     * `StreamScreen` wires this to the SC2 capture so Steam's rumble/settings land on the
+     * physical controller.
+     */
+    @Volatile
+    var onHidRaw: ((pad: Int, kind: Int, data: ByteArray) -> Unit)? = null
+
     /** hid-playstation 5-LED pattern → player index 1..4 (0 = off); falls back to a bit count. */
     private fun playerIndexForBits(bits: Int): Int = when (bits and 0x1F) {
         0b00000 -> 0

clients/android/kit/src/main/kotlin/io/unom/punktfunk/kit/GamepadRouter.kt

@@ -91,21 +91,29 @@ class GamepadRouter(context: Context, private val handle: Long, private val sett
     fun onButton(event: KeyEvent, bit: Int) {
         val slot = slotFor(event.device) ?: return
         when (event.action) {
-            KeyEvent.ACTION_DOWN -> {
-                // repeatCount guard: don't re-send a held button as auto-repeat.
-                if (event.repeatCount == 0) NativeBridge.nativeSendGamepadButton(handle, bit, true, slot.index)
-                slot.held = slot.held or bit
-                // Full chord now held on this pad → start the hold countdown (idempotent while held).
-                if (slot.held and EXIT_CHORD == EXIT_CHORD) armExit()
-            }
-            KeyEvent.ACTION_UP -> {
-                NativeBridge.nativeSendGamepadButton(handle, bit, false, slot.index)
-                slot.held = slot.held and bit.inv()
-                // A chord button lifted before the hold elapsed → cancel, unless another pad still
-                // holds the full chord.
-                if (bit and EXIT_CHORD != 0 && slots.values.none { it.held and EXIT_CHORD == EXIT_CHORD }) {
-                    disarmExit()
-                }
+            // repeatCount guard: don't re-send a held button as auto-repeat.
+            KeyEvent.ACTION_DOWN -> slotButton(slot, bit, down = true, send = event.repeatCount == 0)
+            KeyEvent.ACTION_UP -> slotButton(slot, bit, down = false, send = true)
+        }
+    }
+
+    /**
+     * One button transition on [slot] — the shared body behind [onButton] and an [ExternalPad]'s
+     * transitions: forward the wire event, track held state, and arm/disarm the exit chord.
+     */
+    private fun slotButton(slot: Slot, bit: Int, down: Boolean, send: Boolean) {
+        if (down) {
+            if (send) NativeBridge.nativeSendGamepadButton(handle, bit, true, slot.index)
+            slot.held = slot.held or bit
+            // Full chord now held on this pad → start the hold countdown (idempotent while held).
+            if (slot.held and EXIT_CHORD == EXIT_CHORD) armExit()
+        } else {
+            if (send) NativeBridge.nativeSendGamepadButton(handle, bit, false, slot.index)
+            slot.held = slot.held and bit.inv()
+            // A chord button lifted before the hold elapsed → cancel, unless another pad still
+            // holds the full chord.
+            if (bit and EXIT_CHORD != 0 && slots.values.none { it.held and EXIT_CHORD == EXIT_CHORD }) {
+                disarmExit()
             }
         }
     }
@@ -152,8 +160,9 @@ class GamepadRouter(context: Context, private val handle: Long, private val sett
 
     /**
      * The controller currently mapped to wire pad [pad], for feedback routing; null if that index
-     * holds no live slot (a pad that just unplugged — the update is then dropped). Read from the
-     * feedback poll threads.
+     * holds no live slot (a pad that just unplugged — the update is then dropped) OR the slot is
+     * an [ExternalPad] (its synthetic id resolves to no InputDevice, so rumble binds naturally
+     * fall through to the capture link's own feedback path). Read from the feedback poll threads.
      */
     fun deviceForPad(pad: Int): InputDevice? {
         for ((deviceId, slot) in slots) {
@@ -162,6 +171,50 @@ class GamepadRouter(context: Context, private val handle: Long, private val sett
         return null
     }
 
+    /**
+     * A capture-link pad occupying a wire slot without an Android [InputDevice] — the as-is Steam
+     * Controller 2 passthrough (USB/BLE claimed directly, invisible to the input stack). Shares
+     * the real slots' lifecycle: a stable lowest-free index, Arrival-before-input, held-state
+     * flush + Remove on [close], and full participation in the emergency exit chord.
+     */
+    inner class ExternalPad internal constructor(private val syntheticId: Int, val index: Int) {
+        // Live lookup instead of a captured reference: after [close] (or a router release) the
+        // slot is gone from the table and every entry point below degrades to a safe no-op.
+        private val slot get() = slots[syntheticId]
+
+        /** One button transition (a wire [Gamepad].BTN_* bit). On-change only — the caller diffs. */
+        fun button(bit: Int, down: Boolean) {
+            slot?.let { slotButton(it, bit, down, send = true) }
+        }
+
+        /** One axis update ([Gamepad].AXIS_*: stick i16 +y=up / trigger 0..255). On-change only. */
+        fun axis(id: Int, value: Int) {
+            if (slot != null) NativeBridge.nativeSendGamepadAxis(handle, id, value, index)
+        }
+
+        /** One raw HID report, forwarded verbatim for the host's as-is virtual pad. */
+        fun hidReport(buf: java.nio.ByteBuffer, len: Int) {
+            if (slot != null) NativeBridge.nativeSendPadHidReport(handle, index, buf, len)
+        }
+
+        /** Flush held state, signal the removal, and free the wire index. Idempotent. */
+        fun close() = closeSlot(syntheticId)
+    }
+
+    /**
+     * Open a slot for a capture-link pad, declaring [pref] as its kind; null when all 16 wire
+     * indices are taken. Main thread (like the hot-plug callbacks).
+     */
+    fun openExternal(pref: Int): ExternalPad? {
+        val index = lowestFreeIndex() ?: return null
+        // Synthetic ids live below any real InputDevice id (those are positive), so they can't
+        // collide and InputDevice.getDevice(id) resolves them to null for the feedback path.
+        val syntheticId = EXTERNAL_ID_BASE - index
+        NativeBridge.nativeSendGamepadArrival(handle, pref, index)
+        slots[syntheticId] = Slot(index, Gamepad.AxisMapper(handle, index))
+        return ExternalPad(syntheticId, index)
+    }
+
     /**
      * Flush + drop every slot and unregister the hot-plug listener. Call on session teardown, AFTER
      * the feedback poll threads are joined (they read [deviceForPad]).
@@ -252,5 +305,8 @@ class GamepadRouter(context: Context, private val handle: Long, private val sett
 
         /** How long the exit chord must be held before the stream leaves — matches SDL/Apple `DISCONNECT_HOLD`. */
         const val EXIT_HOLD_MS = 1500L
+
+        /** Synthetic slot-key base for [ExternalPad]s — below every real (positive) InputDevice id. */
+        const val EXTERNAL_ID_BASE = -1000
     }
 }

clients/android/kit/src/main/kotlin/io/unom/punktfunk/kit/NativeBridge.kt

@@ -301,6 +301,14 @@ object NativeBridge {
     /** Signal wire pad [pad] (0..15) was unplugged so the host tears its virtual device down. The core stamps the seq + re-sends. */
     external fun nativeSendGamepadRemove(handle: Long, pad: Int)
 
+    /**
+     * One raw HID input report from a client-captured controller (the as-is Steam Controller 2
+     * passthrough), forwarded verbatim on the rich-input plane. [buf] is a DIRECT ByteBuffer whose
+     * first [len] bytes are the report, id byte first (0x42/0x45/0x47 state, 0x43 battery, …);
+     * len is clamped to 64. Called from the capture thread at the controller's own report rate.
+     */
+    external fun nativeSendPadHidReport(handle: Long, pad: Int, buf: java.nio.ByteBuffer, len: Int)
+
     // ---- Host→client gamepad feedback: Rust pulls block ~100ms, Kotlin renders (see GamepadFeedback) ----
 
     /**
@@ -312,10 +320,11 @@ object NativeBridge {
     external fun nativeNextRumble(handle: Long): Long
 
     /**
-     * Block up to ~100 ms for the next DualSense HID-output event, written into [buf] (a direct
-     * ByteBuffer, capacity >= 64) as `[pad][kind][fields…]` (leading pad = the wire pad index to
-     * route to): Led=pad 01 r g b, PlayerLeds=pad 02 bits, Trigger=pad 03 which effect…. Returns the
-     * byte count, or -1 on timeout / session closed.
+     * Block up to ~100 ms for the next HID-output event, written into [buf] (a direct ByteBuffer,
+     * capacity >= 128) as `[pad][kind][fields…]` (leading pad = the wire pad index to route to):
+     * Led=pad 01 r g b, PlayerLeds=pad 02 bits, Trigger=pad 03 which effect…, raw as-is
+     * passthrough report=pad 05 kind report-bytes (kind 0 = output report, 1 = feature report).
+     * Returns the byte count, or -1 on timeout / session closed.
      */
     external fun nativeNextHidout(handle: Long, buf: java.nio.ByteBuffer): Int
 }

clients/android/kit/src/main/kotlin/io/unom/punktfunk/kit/Sc2BleLink.kt

@@ -0,0 +1,241 @@
+package io.unom.punktfunk.kit
+
+import android.annotation.SuppressLint
+import android.bluetooth.BluetoothDevice
+import android.bluetooth.BluetoothGatt
+import android.bluetooth.BluetoothGattCallback
+import android.bluetooth.BluetoothGattCharacteristic
+import android.bluetooth.BluetoothGattDescriptor
+import android.bluetooth.BluetoothManager
+import android.bluetooth.BluetoothProfile
+import android.content.Context
+import android.util.Log
+import java.util.UUID
+import java.util.concurrent.atomic.AtomicBoolean
+
+/**
+ * BLE transport for a Steam Controller 2 paired directly with the device (no Puck). The standard
+ * HID service (0x1812) is claimed by the OS (and would feed the pad through the ordinary input
+ * stack in lizard-crippled form), so this talks Valve's vendor GATT service instead — the same
+ * approach Steam itself uses on hosts without a dongle.
+ *
+ * GATT operations are serialized by a small state machine (connect → MTU → discover → subscribe
+ * each notify char → lizard-off → ready); duplicate callbacks (the Android stack sometimes fires
+ * `onMtuChanged` twice) are ignored. Notified state reports arrive with the report-id byte
+ * stripped by the transport, so `0x45` (`ID_STATE_BLE`) is re-prepended for ≥40-byte payloads —
+ * the wire then carries the same id-first framing as USB.
+ *
+ * Requires BLUETOOTH_CONNECT (the caller gates on it); connection priority is bumped to HIGH to
+ * pull the connection interval from ~50 ms down to ~11 ms.
+ */
+@SuppressLint("MissingPermission")
+class Sc2BleLink(
+    private val context: Context,
+    private val onReport: (report: ByteArray, len: Int) -> Unit,
+    private val onClosed: () -> Unit,
+) {
+    private enum class State { IDLE, CONNECTING, MTU_REQUESTED, DISCOVERING, SUBSCRIBING, READY }
+
+    private val manager = context.getSystemService(Context.BLUETOOTH_SERVICE) as BluetoothManager
+
+    private var gatt: BluetoothGatt? = null
+    private var writeChar: BluetoothGattCharacteristic? = null
+    private val pendingSubs = mutableListOf<BluetoothGattCharacteristic>()
+    private var subsIndex = 0
+    private val writeBusy = AtomicBoolean(false)
+    private var lizardTicker: Thread? = null
+
+    @Volatile private var state = State.IDLE
+
+    /** Bonded devices that look like a Steam Controller (name heuristic — BLE exposes no PID here). */
+    fun pairedControllers(): List<BluetoothDevice> = runCatching {
+        manager.adapter?.bondedDevices.orEmpty().filter { dev ->
+            val n = runCatching { dev.name }.getOrNull() ?: return@filter false
+            NAME_HINTS.any { n.contains(it, ignoreCase = true) }
+        }
+    }.getOrDefault(emptyList())
+
+    /** Connect to the bonded controller at [address]. Reports start flowing once READY. */
+    fun start(address: String): Boolean {
+        val adapter = manager.adapter ?: return false
+        if (!adapter.isEnabled) return false
+        val device = runCatching { adapter.getRemoteDevice(address) }.getOrNull() ?: return false
+        state = State.CONNECTING
+        gatt = device.connectGatt(context, false, callback, BluetoothDevice.TRANSPORT_LE)
+        return true
+    }
+
+    /**
+     * Replay one raw report from the host: output reports (rumble) ride WRITE_NO_RESPONSE so they
+     * can't queue behind acks at the 25 Hz resend rate; feature reports (settings) use an acked
+     * write. The report-id byte stays in the payload (the firmware's vendor-channel framing).
+     */
+    fun writeRaw(kind: Int, data: ByteArray) {
+        if (state != State.READY || data.isEmpty()) return
+        val g = gatt ?: return
+        val ch = writeChar ?: return
+        runCatching {
+            ch.value = data
+            ch.writeType = if (kind == 0) {
+                BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE
+            } else {
+                BluetoothGattCharacteristic.WRITE_TYPE_DEFAULT
+            }
+            g.writeCharacteristic(ch)
+        }
+    }
+
+    private fun sendLizardOff() {
+        if (state != State.READY) return
+        val g = gatt ?: return
+        val ch = writeChar ?: return
+        if (!writeBusy.compareAndSet(false, true)) return // previous acked write still in flight
+        runCatching {
+            ch.value = Sc2Device.DISABLE_LIZARD
+            ch.writeType = BluetoothGattCharacteristic.WRITE_TYPE_DEFAULT
+            if (!g.writeCharacteristic(ch)) writeBusy.set(false)
+        }.onFailure { writeBusy.set(false) }
+    }
+
+    /** Disconnect and stop the lizard ticker. Idempotent; does not fire [onClosed]. */
+    fun stop() {
+        lizardTicker?.interrupt()
+        lizardTicker = null
+        runCatching { gatt?.disconnect() }
+        runCatching { gatt?.close() }
+        gatt = null
+        writeChar = null
+        pendingSubs.clear()
+        subsIndex = 0
+        state = State.IDLE
+    }
+
+    private val callback = object : BluetoothGattCallback() {
+        override fun onConnectionStateChange(g: BluetoothGatt, status: Int, newState: Int) {
+            when (newState) {
+                BluetoothProfile.STATE_CONNECTED -> {
+                    // ~11 ms connection interval instead of the ~50 ms default — input latency.
+                    g.requestConnectionPriority(BluetoothGatt.CONNECTION_PRIORITY_HIGH)
+                    if (state == State.CONNECTING) {
+                        state = State.MTU_REQUESTED
+                        if (!g.requestMtu(DESIRED_MTU)) {
+                            state = State.DISCOVERING
+                            g.discoverServices()
+                        }
+                    }
+                }
+                BluetoothProfile.STATE_DISCONNECTED -> {
+                    val wasLive = state != State.IDLE
+                    runCatching { g.close() }
+                    gatt = null
+                    writeChar = null
+                    pendingSubs.clear()
+                    subsIndex = 0
+                    state = State.IDLE
+                    if (wasLive) onClosed()
+                }
+            }
+        }
+
+        override fun onMtuChanged(g: BluetoothGatt, mtu: Int, status: Int) {
+            if (state != State.MTU_REQUESTED) return // fired twice on some stacks — act once
+            state = State.DISCOVERING
+            g.discoverServices()
+        }
+
+        override fun onServicesDiscovered(g: BluetoothGatt, status: Int) {
+            if (state != State.DISCOVERING || status != BluetoothGatt.GATT_SUCCESS) return
+            val valve = g.getService(VALVE_SERVICE) ?: run {
+                Log.e(TAG, "Valve vendor service missing — not an SC2?")
+                return
+            }
+            pendingSubs.clear()
+            writeChar = null
+            for (ch in valve.characteristics) {
+                val short = shortUuid(ch.uuid) ?: continue
+                val canNotify = ch.properties and BluetoothGattCharacteristic.PROPERTY_NOTIFY != 0
+                val canWrite = ch.properties and (
+                    BluetoothGattCharacteristic.PROPERTY_WRITE or
+                        BluetoothGattCharacteristic.PROPERTY_WRITE_NO_RESPONSE
+                    ) != 0
+                if (canNotify && short in NOTIFY_LOW..NOTIFY_HIGH) pendingSubs.add(ch)
+                if (canWrite && short in WRITE_LOW..WRITE_HIGH && writeChar == null) writeChar = ch
+            }
+            subsIndex = 0
+            state = State.SUBSCRIBING
+            subscribeNext(g)
+        }
+
+        override fun onDescriptorWrite(g: BluetoothGatt, d: BluetoothGattDescriptor, status: Int) {
+            if (state == State.SUBSCRIBING) subscribeNext(g)
+        }
+
+        override fun onCharacteristicWrite(g: BluetoothGatt, ch: BluetoothGattCharacteristic, status: Int) {
+            writeBusy.set(false)
+        }
+
+        override fun onCharacteristicChanged(g: BluetoothGatt, ch: BluetoothGattCharacteristic) {
+            val data = ch.value ?: return
+            // BLE strips the report-id prefix; restore 0x45 on state-sized payloads so the raw
+            // wire framing matches USB. Short payloads (battery/status) pass through as-is.
+            if (data.size >= 40) {
+                val framed = ByteArray(data.size + 1)
+                framed[0] = Sc2Device.ID_STATE_BLE.toByte()
+                System.arraycopy(data, 0, framed, 1, data.size)
+                onReport(framed, framed.size)
+            } else {
+                onReport(data, data.size)
+            }
+        }
+    }
+
+    private fun subscribeNext(g: BluetoothGatt) {
+        if (subsIndex >= pendingSubs.size) {
+            state = State.READY
+            Log.i(TAG, "SC2 BLE link up (${pendingSubs.size} notify chars)")
+            sendLizardOff()
+            // The firmware watchdog re-enables lizard mode; refresh on SDL's cadence until the
+            // host's Steam takes over via the raw plane (its writes land through writeRaw too).
+            lizardTicker = Thread({
+                while (state == State.READY) {
+                    try {
+                        Thread.sleep(Sc2Device.LIZARD_REFRESH_MS)
+                    } catch (_: InterruptedException) {
+                        return@Thread
+                    }
+                    sendLizardOff()
+                }
+            }, "pf-sc2-lizard").apply { isDaemon = true; start() }
+            return
+        }
+        val ch = pendingSubs[subsIndex++]
+        g.setCharacteristicNotification(ch, true)
+        val cccd = ch.getDescriptor(CCCD) ?: return subscribeNext(g)
+        cccd.value = BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE
+        if (!g.writeDescriptor(cccd)) subscribeNext(g) // lose this one, try the rest
+    }
+
+    /** The 32-bit short id of a Valve vendor UUID, or null for foreign UUIDs. */
+    private fun shortUuid(uuid: UUID): Long? {
+        val s = uuid.toString()
+        if (!s.endsWith(VALVE_UUID_TAIL)) return null
+        return s.substring(0, 8).toLongOrNull(16)
+    }
+
+    private companion object {
+        const val TAG = "Sc2BleLink"
+
+        val VALVE_SERVICE: UUID = UUID.fromString("100f6c32-1735-4313-b402-38567131e5f3")
+        const val VALVE_UUID_TAIL = "-1735-4313-b402-38567131e5f3"
+        const val NOTIFY_LOW = 0x100f6c75L
+        const val NOTIFY_HIGH = 0x100f6c7aL
+        const val WRITE_LOW = 0x100f6cb5L
+        const val WRITE_HIGH = 0x100f6cbeL
+        val CCCD: UUID = UUID.fromString("00002902-0000-1000-8000-00805f9b34fb")
+
+        val NAME_HINTS = listOf("Steam Ctrl", "Steam Controller", "SteamController", "Valve")
+
+        /** Enough for a state payload (45 B) + ATT header with margin. */
+        const val DESIRED_MTU = 100
+    }
+}

clients/android/kit/src/main/kotlin/io/unom/punktfunk/kit/Sc2Capture.kt

@@ -0,0 +1,161 @@
+package io.unom.punktfunk.kit
+
+import android.content.Context
+import android.hardware.usb.UsbDevice
+import android.util.Log
+import java.nio.ByteBuffer
+
+/**
+ * One captured Steam Controller 2 for one stream session — the glue between a transport link
+ * ([Sc2UsbLink] / [Sc2BleLink]) and the wire:
+ *
+ * - **Raw plane (the point):** every input report is forwarded verbatim
+ *   ([GamepadRouter.ExternalPad.hidReport]) for the host's as-is virtual `28DE:1302` pad, which
+ *   Steam Input drives like the physical controller.
+ * - **Typed mirror:** buttons/sticks/triggers are ALSO diffed onto the ordinary per-transition
+ *   plane, so the emergency exit chord works, and a host that degraded the kind (no UHID → the
+ *   Xbox 360 pad) still gets a playable controller.
+ * - **Raw return:** the host's hidraw writes (Steam's `0x80` rumble output reports, lizard/IMU
+ *   feature settings) arrive via [GamepadFeedback.onHidRaw] → [onHidRaw] → the link, landing on
+ *   the real controller's motors/firmware.
+ *
+ * The wire slot is claimed lazily on the FIRST state report — a Puck with no controller powered
+ * on stays invisible to the host — and released (with a wireless-disconnect event or on [stop])
+ * so pad indices never leak. Report callbacks arrive on the link's own thread; the router's slot
+ * table and chord timer are thread-safe for this (same contract as the feedback poll threads).
+ */
+class Sc2Capture(
+    context: Context,
+    private val router: GamepadRouter,
+) {
+    private val usb = Sc2UsbLink(context, ::onReport, ::onLinkClosed)
+    private val ble = Sc2BleLink(context, ::onReport, ::onLinkClosed)
+    private var activeLink: Int = LINK_NONE
+
+    private var pad: GamepadRouter.ExternalPad? = null
+    private val rawBuf: ByteBuffer = ByteBuffer.allocateDirect(64)
+
+    // Typed-mirror diff state (wire units).
+    private val state = Sc2Device.State()
+    private var wireButtons = 0
+    private val lastAxis = IntArray(6) { Int.MIN_VALUE }
+
+    /** First attached SC2/Puck USB device, for the permission flow. */
+    fun findUsbDevice(): UsbDevice? = usb.findDevice()
+
+    /**
+     * The first already-bonded BLE Steam Controller's address, or null. The caller checks
+     * BLUETOOTH_CONNECT first (without it the bonded list reads as empty anyway).
+     */
+    fun pairedBleAddress(): String? = ble.pairedControllers().firstOrNull()?.address
+
+    /** Start capturing [dev] over USB (permission already granted). */
+    fun startUsb(dev: UsbDevice): Boolean {
+        if (activeLink != LINK_NONE) return false
+        val ok = usb.start(dev)
+        if (ok) activeLink = LINK_USB
+        return ok
+    }
+
+    /** Start capturing the bonded BLE controller at [address]. */
+    fun startBle(address: String): Boolean {
+        if (activeLink != LINK_NONE) return false
+        val ok = ble.start(address)
+        if (ok) activeLink = LINK_BLE
+        return ok
+    }
+
+    /** Replay a host raw write on the physical pad — wire to [GamepadFeedback.onHidRaw]. */
+    fun onHidRaw(padIndex: Int, kind: Int, data: ByteArray) {
+        if (padIndex != pad?.index) return // addressed to some other controller
+        when (activeLink) {
+            LINK_USB -> usb.writeRaw(kind, data)
+            LINK_BLE -> ble.writeRaw(kind, data)
+        }
+    }
+
+    /** Stop the link and free the wire slot (host tears the virtual pad down). Idempotent. */
+    fun stop() {
+        when (activeLink) {
+            LINK_USB -> usb.stop()
+            LINK_BLE -> ble.stop()
+        }
+        activeLink = LINK_NONE
+        releaseSlot()
+    }
+
+    // ---- link callbacks (link thread) ----
+
+    private fun onReport(report: ByteArray, len: Int) {
+        val id = report[0].toInt() and 0xFF
+        // A Puck relays connect/disconnect for its controller — track the slot accordingly, so
+        // powering the pad off frees its wire index (and the host's virtual device).
+        if ((id == Sc2Device.ID_WIRELESS || id == Sc2Device.ID_WIRELESS_X) && len >= 2) {
+            if ((report[1].toInt() and 0xFF) == Sc2Device.WIRELESS_DISCONNECT) releaseSlot()
+            return
+        }
+        if (!Sc2Device.parseState(report, len, state)) {
+            // Battery/status and future report types still belong to the as-is stream.
+            forwardRaw(report, len)
+            return
+        }
+        val p = pad ?: router.openExternal(Gamepad.PREF_STEAMCONTROLLER2)?.also {
+            pad = it
+            Log.i(TAG, "SC2 captured → wire pad ${it.index} (as-is passthrough)")
+        } ?: return // all 16 wire indices taken — drop until one frees
+        forwardRaw(report, len)
+        mirrorTyped(p)
+    }
+
+    private fun forwardRaw(report: ByteArray, len: Int) {
+        val p = pad ?: return
+        val n = len.coerceAtMost(rawBuf.capacity())
+        rawBuf.clear()
+        rawBuf.put(report, 0, n)
+        p.hidReport(rawBuf, n)
+    }
+
+    /** Diff the parsed state onto the per-transition plane (buttons + axes, on change only). */
+    private fun mirrorTyped(p: GamepadRouter.ExternalPad) {
+        val wired = Sc2Device.wireButtons(state.buttons)
+        var changed = wired xor wireButtons
+        while (changed != 0) {
+            val bit = changed and -changed // lowest changed bit
+            p.button(bit, wired and bit != 0)
+            changed = changed and bit.inv()
+        }
+        wireButtons = wired
+        axis(p, Gamepad.AXIS_LS_X, state.lsX)
+        axis(p, Gamepad.AXIS_LS_Y, state.lsY)
+        axis(p, Gamepad.AXIS_RS_X, state.rsX)
+        axis(p, Gamepad.AXIS_RS_Y, state.rsY)
+        axis(p, Gamepad.AXIS_LT, state.lt)
+        axis(p, Gamepad.AXIS_RT, state.rt)
+    }
+
+    private fun axis(p: GamepadRouter.ExternalPad, id: Int, v: Int) {
+        if (lastAxis[id] == v) return
+        lastAxis[id] = v
+        p.axis(id, v)
+    }
+
+    private fun onLinkClosed() {
+        Log.i(TAG, "SC2 link closed (unplug / power-off)")
+        activeLink = LINK_NONE
+        releaseSlot()
+    }
+
+    private fun releaseSlot() {
+        pad?.close()
+        pad = null
+        wireButtons = 0
+        lastAxis.fill(Int.MIN_VALUE)
+    }
+
+    private companion object {
+        const val TAG = "Sc2Capture"
+        const val LINK_NONE = 0
+        const val LINK_USB = 1
+        const val LINK_BLE = 2
+    }
+}

clients/android/kit/src/main/kotlin/io/unom/punktfunk/kit/Sc2Device.kt

@@ -0,0 +1,151 @@
+package io.unom.punktfunk.kit
+
+/**
+ * Steam Controller 2 (2026, Valve "Ibex" / SDL "Triton") protocol constants + the light state
+ * parser the CLIENT needs. The full report rides the wire verbatim (`nativeSendPadHidReport` →
+ * the host's as-is virtual pad); this parser only extracts what the client itself consumes: the
+ * button word for the typed mirror + exit chord, and sticks/triggers for the degrade path.
+ *
+ * Protocol ground truth: SDL's `SDL_hidapi_steam_triton.c` + `steam/controller_structs.h`
+ * (Valve-maintained), mirrored host-side in `punktfunk-host`'s `triton_proto.rs`.
+ */
+object Sc2Device {
+    const val VID_VALVE = 0x28DE
+
+    /** Wired controller. */
+    const val PID_WIRED = 0x1302
+
+    /** Direct BLE identity (transport handled by [Sc2BleLink], not USB). */
+    const val PID_BLE = 0x1303
+
+    /** The wireless Puck dongles (Proteus / Nereid) — controller on USB interfaces 2..5. */
+    const val PID_DONGLE_PROTEUS = 0x1304
+    const val PID_DONGLE_NEREID = 0x1305
+
+    val USB_PIDS = setOf(PID_WIRED, PID_DONGLE_PROTEUS, PID_DONGLE_NEREID)
+
+    /** Dongle interface range that carries controllers (SDL: "interfaces 2..5, currently"). */
+    val DONGLE_IFACES = 2..5
+
+    // Input report ids (`ETritonReportIDTypes`). State layouts share every offset the client
+    // reads (seq/buttons/triggers/sticks); 0x47 only diverges from byte 18 (trackpad timestamp).
+    const val ID_STATE = 0x42
+    const val ID_BATTERY = 0x43
+    const val ID_STATE_BLE = 0x45
+    const val ID_WIRELESS_X = 0x46
+    const val ID_STATE_TIMESTAMP = 0x47
+    const val ID_WIRELESS = 0x79
+
+    /** Wireless status payload byte: controller connected/disconnected through the Puck. */
+    const val WIRELESS_DISCONNECT = 1
+    const val WIRELESS_CONNECT = 2
+
+    // Button bits in the state report's u32 (SDL `TritonButtons`).
+    const val A = 0x00000001
+    const val B = 0x00000002
+    const val X = 0x00000004
+    const val Y = 0x00000008
+    const val QAM = 0x00000010
+    const val R3 = 0x00000020
+    const val VIEW = 0x00000040
+    const val R4 = 0x00000080
+    const val R5 = 0x00000100
+    const val RB = 0x00000200
+    const val DPAD_DOWN = 0x00000400
+    const val DPAD_RIGHT = 0x00000800
+    const val DPAD_LEFT = 0x00001000
+    const val DPAD_UP = 0x00002000
+    const val MENU = 0x00004000
+    const val L3 = 0x00008000
+    const val STEAM = 0x00010000
+    const val L4 = 0x00020000
+    const val L5 = 0x00040000
+    const val LB = 0x00080000
+    const val RPAD_CLICK = 0x00400000
+
+    /**
+     * The feature report that turns lizard mode (built-in keyboard/mouse emulation) off:
+     * `[report id 1][ID_SET_SETTINGS_VALUES 0x87][length 3][SETTING_LIZARD_MODE 9]
+     * [LIZARD_MODE_OFF u16]`, zero-padded to the 64-byte feature size. The firmware watchdog
+     * re-enables lizard mode after a few seconds of silence, so this is re-sent every
+     * [LIZARD_REFRESH_MS] (SDL's cadence) — and the host's Steam sends its own through the raw
+     * plane once it grabs the virtual pad, which lands here too.
+     */
+    val DISABLE_LIZARD: ByteArray = ByteArray(64).also {
+        it[0] = 0x01 // feature report id
+        it[1] = 0x87.toByte() // ID_SET_SETTINGS_VALUES
+        it[2] = 3 // one ControllerSetting {u8 num, u16 value}
+        it[3] = 9 // SETTING_LIZARD_MODE
+        // [4..6] = LIZARD_MODE_OFF (0) — already zero
+    }
+
+    const val LIZARD_REFRESH_MS = 3000L
+
+    /** Wire mapping: SC2 button bit → punktfunk `Gamepad.BTN_*`, the inverse of the host's
+     *  typed-fallback mapping (`triton_proto::from_gamepad`): paddles R4/L4/R5/L5 =
+     *  PADDLE1/2/3/4, QAM = MISC1, right-pad click = the touchpad wire bit. */
+    private val WIRE_MAP = intArrayOf(
+        A, Gamepad.BTN_A,
+        B, Gamepad.BTN_B,
+        X, Gamepad.BTN_X,
+        Y, Gamepad.BTN_Y,
+        LB, Gamepad.BTN_LB,
+        RB, Gamepad.BTN_RB,
+        VIEW, Gamepad.BTN_BACK,
+        MENU, Gamepad.BTN_START,
+        STEAM, Gamepad.BTN_GUIDE,
+        L3, Gamepad.BTN_LS_CLICK,
+        R3, Gamepad.BTN_RS_CLICK,
+        DPAD_UP, Gamepad.BTN_DPAD_UP,
+        DPAD_DOWN, Gamepad.BTN_DPAD_DOWN,
+        DPAD_LEFT, Gamepad.BTN_DPAD_LEFT,
+        DPAD_RIGHT, Gamepad.BTN_DPAD_RIGHT,
+        QAM, Gamepad.BTN_MISC1,
+        R4, Gamepad.BTN_PADDLE1,
+        L4, Gamepad.BTN_PADDLE2,
+        R5, Gamepad.BTN_PADDLE3,
+        L5, Gamepad.BTN_PADDLE4,
+        RPAD_CLICK, Gamepad.BTN_TOUCHPAD,
+    )
+
+    /** Translate an SC2 button word into the wire `Gamepad.BTN_*` bitmask. */
+    fun wireButtons(sc2: Int): Int {
+        var out = 0
+        var i = 0
+        while (i < WIRE_MAP.size) {
+            if (sc2 and WIRE_MAP[i] != 0) out = out or WIRE_MAP[i + 1]
+            i += 2
+        }
+        return out
+    }
+
+    /** The typed-mirror fields of one state report (buttons/sticks/triggers only). */
+    class State {
+        var buttons = 0 // SC2 bit layout
+        var lsX = 0; var lsY = 0 // i16, +y = up (device convention = wire convention)
+        var rsX = 0; var rsY = 0
+        var lt = 0; var rt = 0 // 0..255 (device 0..32767 scaled down)
+    }
+
+    /**
+     * Parse the client-consumed fields out of a state report (`0x42`/`0x45`/`0x47` — identical
+     * offsets for everything read here) into [out]. Returns false for non-state / short reports.
+     */
+    fun parseState(report: ByteArray, len: Int, out: State): Boolean {
+        if (len < 18) return false
+        when (report[0].toInt() and 0xFF) {
+            ID_STATE, ID_STATE_BLE, ID_STATE_TIMESTAMP -> {}
+            else -> return false
+        }
+        fun i16(o: Int) = ((report[o + 1].toInt() shl 8) or (report[o].toInt() and 0xFF)).toShort().toInt()
+        out.buttons = (report[2].toInt() and 0xFF) or
+            ((report[3].toInt() and 0xFF) shl 8) or
+            ((report[4].toInt() and 0xFF) shl 16) or
+            ((report[5].toInt() and 0xFF) shl 24)
+        out.lt = (i16(6).coerceIn(0, 32767)) shr 7
+        out.rt = (i16(8).coerceIn(0, 32767)) shr 7
+        out.lsX = i16(10); out.lsY = i16(12)
+        out.rsX = i16(14); out.rsY = i16(16)
+        return true
+    }
+}

clients/android/kit/src/main/kotlin/io/unom/punktfunk/kit/Sc2UsbLink.kt

@@ -0,0 +1,223 @@
+package io.unom.punktfunk.kit
+
+import android.content.Context
+import android.hardware.usb.UsbConstants
+import android.hardware.usb.UsbDevice
+import android.hardware.usb.UsbDeviceConnection
+import android.hardware.usb.UsbEndpoint
+import android.hardware.usb.UsbInterface
+import android.hardware.usb.UsbManager
+import android.util.Log
+
+/**
+ * USB transport for a Steam Controller 2 — wired (`28DE:1302`) or through the wireless Puck
+ * dongle (`1304`/`1305`, controller on interfaces 2..5). Claims the Valve vendor interface
+ * (detaching any kernel/OS consumer), runs a read loop on its interrupt-IN endpoint, keeps
+ * lizard mode off on the firmware watchdog cadence, and replays the host's raw writes (Steam's
+ * rumble output reports / settings feature reports) back to the device.
+ *
+ * One controller per link in v1: on a dongle the first claimable controller interface wins
+ * (multi-pad-per-Puck is a follow-up).
+ */
+class Sc2UsbLink(
+    context: Context,
+    private val onReport: (report: ByteArray, len: Int) -> Unit,
+    private val onClosed: () -> Unit,
+) {
+    private val usb = context.getSystemService(Context.USB_SERVICE) as UsbManager
+
+    private var connection: UsbDeviceConnection? = null
+    private var iface: UsbInterface? = null
+    private var epIn: UsbEndpoint? = null
+    private var epOut: UsbEndpoint? = null
+
+    private var reader: Thread? = null
+
+    @Volatile private var running = false
+
+    /** First attached SC2 (wired or Puck), or null. Does not need USB permission to enumerate. */
+    fun findDevice(): UsbDevice? = usb.deviceList.values.firstOrNull {
+        it.vendorId == Sc2Device.VID_VALVE && it.productId in Sc2Device.USB_PIDS
+    }
+
+    /**
+     * Claim [dev] and start the read + lizard-heartbeat loop. The caller has already obtained
+     * USB permission ([UsbManager.hasPermission]). Returns false when no controller interface
+     * could be claimed.
+     */
+    fun start(dev: UsbDevice): Boolean {
+        if (!usb.hasPermission(dev)) {
+            Log.e(TAG, "no USB permission for ${dev.deviceName}")
+            return false
+        }
+        val conn = usb.openDevice(dev) ?: run {
+            Log.e(TAG, "openDevice failed for ${dev.deviceName}")
+            return false
+        }
+        val claimed = claimControllerInterface(dev, conn) ?: run {
+            Log.e(TAG, "no claimable SC2 interface on ${dev.deviceName} (PID=0x%04x)".format(dev.productId))
+            conn.close()
+            return false
+        }
+        connection = conn
+        iface = claimed.first
+        epIn = claimed.second
+        epOut = claimed.third
+        running = true
+        Log.i(
+            TAG,
+            "SC2 USB link up: PID=0x%04x iface=%d in=0x%02x out=%s".format(
+                dev.productId, claimed.first.id, claimed.second.address,
+                claimed.third?.let { "0x%02x".format(it.address) } ?: "control",
+            ),
+        )
+        writeFeature(Sc2Device.DISABLE_LIZARD)
+        reader = Thread({ readLoop(conn, claimed.second) }, "pf-sc2-usb").apply {
+            isDaemon = true
+            start()
+        }
+        return true
+    }
+
+    /**
+     * Pick the controller interface: vendor-defined (0xFF) class with an interrupt/bulk IN
+     * endpoint, restricted to interfaces 2..5 on a Puck dongle (the SDL-documented controller
+     * range — the other interfaces are the dongle's own control/lizard endpoints).
+     */
+    private fun claimControllerInterface(
+        dev: UsbDevice,
+        conn: UsbDeviceConnection,
+    ): Triple<UsbInterface, UsbEndpoint, UsbEndpoint?>? {
+        val dongle = dev.productId != Sc2Device.PID_WIRED
+        val candidates = (0 until dev.interfaceCount)
+            .map { dev.getInterface(it) }
+            .filter { !dongle || it.id in Sc2Device.DONGLE_IFACES }
+            .sortedByDescending {
+                when (it.interfaceClass) {
+                    0xFF -> 2 // vendor-defined first — the Valve gamepad interface
+                    UsbConstants.USB_CLASS_HID -> 1
+                    else -> 0
+                }
+            }
+        for (candidate in candidates) {
+            var inEp: UsbEndpoint? = null
+            var outEp: UsbEndpoint? = null
+            for (i in 0 until candidate.endpointCount) {
+                val ep = candidate.getEndpoint(i)
+                val usable = ep.type == UsbConstants.USB_ENDPOINT_XFER_INT ||
+                    ep.type == UsbConstants.USB_ENDPOINT_XFER_BULK
+                if (!usable) continue
+                if (ep.direction == UsbConstants.USB_DIR_IN && inEp == null) inEp = ep
+                if (ep.direction == UsbConstants.USB_DIR_OUT && outEp == null) outEp = ep
+            }
+            if (inEp == null) continue
+            // force=true detaches the kernel/OS driver — while claimed, the controller vanishes
+            // from Android's own input stack (no double input alongside our capture).
+            if (conn.claimInterface(candidate, true)) return Triple(candidate, inEp, outEp)
+            Log.w(TAG, "could not claim iface ${candidate.id}, trying next")
+        }
+        return null
+    }
+
+    private fun readLoop(conn: UsbDeviceConnection, ep: UsbEndpoint) {
+        val buf = ByteArray(64)
+        var lastLizard = 0L
+        var failures = 0
+        while (running) {
+            val now = android.os.SystemClock.elapsedRealtime()
+            if (now - lastLizard >= Sc2Device.LIZARD_REFRESH_MS) {
+                writeFeature(Sc2Device.DISABLE_LIZARD)
+                lastLizard = now
+            }
+            val n = conn.bulkTransfer(ep, buf, buf.size, READ_TIMEOUT_MS)
+            when {
+                n > 0 -> {
+                    failures = 0
+                    onReport(buf, n)
+                }
+                n == 0 -> {} // empty read — keep going
+                else -> {
+                    // -1 covers both timeout (normal, idle controller) and unplug. A real unplug
+                    // makes every subsequent transfer fail instantly, so many consecutive fast
+                    // failures = the device is gone.
+                    if (++failures >= 64) {
+                        Log.i(TAG, "SC2 USB read failing persistently — treating as unplug")
+                        break
+                    }
+                }
+            }
+        }
+        if (running) {
+            running = false
+            onClosed()
+        }
+    }
+
+    /**
+     * Replay one raw report from the host on the device: kind 0 = output report (Steam's `0x80`
+     * rumble & friends — interrupt-OUT when the interface has one, else a `SET_REPORT(Output)`
+     * control transfer), kind 1 = feature report (`SET_REPORT(Feature)`). [data] is the full
+     * report, id byte first, exactly as hidapi framed it host-side.
+     */
+    fun writeRaw(kind: Int, data: ByteArray) {
+        if (data.isEmpty()) return
+        when (kind) {
+            0 -> {
+                val out = epOut
+                val conn = connection ?: return
+                if (out != null) {
+                    conn.bulkTransfer(out, data, data.size, WRITE_TIMEOUT_MS)
+                } else {
+                    setReport(REPORT_TYPE_OUTPUT, data)
+                }
+            }
+            1 -> writeFeature(data)
+        }
+    }
+
+    private fun writeFeature(data: ByteArray) {
+        setReport(REPORT_TYPE_FEATURE, data)
+    }
+
+    /**
+     * HID `SET_REPORT` control transfer with hidapi's report-id framing: a non-zero leading byte
+     * is the report id (sent in wValue AND kept in the payload); a zero leading byte means
+     * "unnumbered" (id 0 in wValue, id byte stripped from the payload).
+     */
+    private fun setReport(type: Int, data: ByteArray) {
+        val conn = connection ?: return
+        val ifId = iface?.id ?: return
+        val id = data[0].toInt() and 0xFF
+        val payload = if (id == 0) data.copyOfRange(1, data.size) else data
+        conn.controlTransfer(
+            0x21, // host→device, class, interface
+            0x09, // SET_REPORT
+            (type shl 8) or id,
+            ifId,
+            payload,
+            payload.size,
+            WRITE_TIMEOUT_MS,
+        )
+    }
+
+    /** Stop the read loop and release the interface. Idempotent; does not fire [onClosed]. */
+    fun stop() {
+        running = false
+        runCatching { reader?.join(1000) }
+        reader = null
+        runCatching { iface?.let { connection?.releaseInterface(it) } }
+        runCatching { connection?.close() }
+        connection = null
+        iface = null
+        epIn = null
+        epOut = null
+    }
+
+    private companion object {
+        const val TAG = "Sc2UsbLink"
+        const val READ_TIMEOUT_MS = 100
+        const val WRITE_TIMEOUT_MS = 250
+        const val REPORT_TYPE_OUTPUT = 0x02
+        const val REPORT_TYPE_FEATURE = 0x03
+    }
+}