hardwared: non blocking read for touch events (#34263)

* slow

* slow

* non blocking

* 10

* try

* simple

* int

* test

* get

* try

* clean

* read all

* nested

* simpler

* indent

* cleanup

system/hardware/hardwared.py

@@ -1,4 +1,5 @@
 #!/usr/bin/env python3
+import fcntl
 import os
 import json
 import queue
@@ -61,6 +62,8 @@ def set_offroad_alert_if_changed(offroad_alert: str, show_alert: bool, extra_tex
   set_offroad_alert(offroad_alert, show_alert, extra_text)
 
 def touch_thread(end_event):
+  count = 0
+
   pm = messaging.PubMaster(["touch"])
 
   event_format = "llHHi"
@@ -68,7 +71,9 @@ def touch_thread(end_event):
   event_frame = []
 
   with open("/dev/input/by-path/platform-894000.i2c-event", "rb") as event_file:
+    fcntl.fcntl(event_file, fcntl.F_SETFL, os.O_NONBLOCK)
     while not end_event.is_set():
+      if (count % int(1. / DT_HW)) == 0:
         event = event_file.read(event_size)
         if event:
           (sec, usec, etype, code, value) = struct.unpack(event_format, event)
@@ -85,6 +90,10 @@ def touch_thread(end_event):
             msg.touch = event_frame
             pm.send('touch', msg)
             event_frame = []
+          continue
+
+      count += 1
+      time.sleep(DT_HW)
 
 
 def hw_state_thread(end_event, hw_queue):