New solution to haptic touchpad

2026-03-26 11:08:44 +01:00
parent e7f8826dea
commit 15538c4f5a
2 changed files with 111 additions and 12 deletions
@@ -0,0 +1,95 @@
+#!/usr/bin/env python3
+
+"""Haptic feedback daemon for Synaptics touchpads with Manual Trigger.
+
+Monitors touchpad button press events and sends haptic pulses via HID
+feature reports. Required because the kernel's HID haptic subsystem only
+supports Auto Trigger with waveform enumeration, not the simpler Manual
+Trigger protocol used by these Synaptics touchpads.
+"""
+
+import fcntl, glob, os, struct, sys
+
+VENDOR = "06CB"
+PRODUCT = "D01A"
+REPORT_ID = 0x37
+INTENSITY = 40  # 0-100
+
+# input_event: struct timeval (16 bytes on 64-bit) + type(H) + code(H) + value(i)
+EVENT_FORMAT = "llHHi"
+EVENT_SIZE = struct.calcsize(EVENT_FORMAT)
+EV_KEY = 0x01
+BTN_LEFT = 272
+BTN_RIGHT = 273
+BTN_MIDDLE = 274
+
+# ioctl: HIDIOCSFEATURE(len) = _IOC(_IOC_WRITE|_IOC_READ, 'H', 0x06, len)
+def HIDIOCSFEATURE(length):
+    return 0xC0000000 | (length << 16) | (ord("H") << 8) | 0x06
+
+
+def find_hidraw():
+    for path in sorted(glob.glob("/sys/class/hidraw/hidraw*")):
+        uevent = os.path.join(path, "device", "uevent")
+        try:
+            with open(uevent) as f:
+                content = f.read().upper()
+            if f"0000{VENDOR}" in content and f"0000{PRODUCT}" in content:
+                return os.path.join("/dev", os.path.basename(path))
+        except OSError:
+            continue
+    return None
+
+
+def find_touchpad_event():
+    for path in sorted(glob.glob("/sys/class/input/event*/device/name")):
+        try:
+            with open(path) as f:
+                name = f.read().strip().upper()
+            if VENDOR in name and PRODUCT in name and "TOUCHPAD" in name:
+                event = path.split("/")[-3]
+                return os.path.join("/dev/input", event)
+        except OSError:
+            continue
+    return None
+
+
+def main():
+    hidraw = find_hidraw()
+    if not hidraw:
+        print("No Synaptics haptic touchpad hidraw device found", file=sys.stderr)
+        sys.exit(1)
+
+    event = find_touchpad_event()
+    if not event:
+        print("No Synaptics haptic touchpad input device found", file=sys.stderr)
+        sys.exit(1)
+
+    print(f"Haptic touchpad: hidraw={hidraw} input={event} intensity={INTENSITY}", flush=True)
+
+    haptic_report = struct.pack("BB", REPORT_ID, INTENSITY)
+    ioctl_req = HIDIOCSFEATURE(len(haptic_report))
+
+    hidraw_fd = os.open(hidraw, os.O_RDWR)
+    event_fd = os.open(event, os.O_RDONLY)
+
+    try:
+        while True:
+            data = os.read(event_fd, EVENT_SIZE)
+            if len(data) < EVENT_SIZE:
+                continue
+            _, _, ev_type, code, value = struct.unpack(EVENT_FORMAT, data)
+            if ev_type == EV_KEY and code in (BTN_LEFT, BTN_RIGHT, BTN_MIDDLE) and value == 1:
+                try:
+                    fcntl.ioctl(hidraw_fd, ioctl_req, haptic_report)
+                except OSError:
+                    pass
+    except KeyboardInterrupt:
+        pass
+    finally:
+        os.close(event_fd)
+        os.close(hidraw_fd)
+
+
+if __name__ == "__main__":
+    main()