GM: longitudinal support for camera-integrated cars (#1014)

* Allow brake TX on PT bus

* Initial Panda GM cam harness support
 * Complete rewrite / simplification
 * Add param for cam harness (default is OBD2)
   - Forward btw 0 and 2
   - Filter LKAS and optionally ACC from cam
 * Add param for stock ACC
   - Allows ACC on PT bus when set, not otherwise
   - Allows ACC from cam when set, not otherwise
 * Add temporary WIP EPS timing workaround in ifdef

* Remove keepalive; regen == braking

* Fix MISRA violations

* EPS timing opt-in by param

* Minor clean up

* remove timing code for readability

fix and formatting

* we only need to send one message if cam harness and stock long

* Simplify params

* Removed dup brake msg

* revised params, split 3-ways

* add test

* clean up a bit, no need to send ACC yet

like this

* split out button enable and pcm enable into seperate tests

* some formatting

some formatting

* GM CAM uses PCM cruise for controls_allowed

* fix gas safety tests

* misra

* fix static analysis

comment

* fix brake pressed

* Add OP VOACC override stock cam

* Add VOACC safetyparam to init.py

* openpilot long safety

* do this in another PR

* add back

* add safety tests

* rename

* struct for safety

* not used

* temporary fault fix

* adjust max gas

* allow PSCMStatus in long mode

* stash

* fix max gas

* fix and clean up tests

* clean up longitudinal tests into a common class

* fix pylint

* subclass

* clean that up

* rm

* blocking

* comment

* comment

* lower case

* brake bus

Co-authored-by: Shane Smiskol <shane@smiskol.com>

python/__init__.py

@@ -227,6 +227,7 @@ class Panda:
   FLAG_SUBARU_GEN2 = 1
 
   FLAG_GM_HW_CAM = 1
+  FLAG_GM_HW_CAM_LONG = 2
 
   def __init__(self, serial: Optional[str] = None, claim: bool = True, disable_checks: bool = True):
     self._serial = serial