Subaru SNG

[martinl]

***** Template: Refactor *****

Description
Subaru Stop and Go support for both global and preglobal models (for initial review).

Subaru stock ACC stops behind stopped cars but does not resume automatically. We send Throttle:Throttle_Pedal signal from openpilot to ACC when car in front starts moving to resume from ACC Hold state (mimicking stock ACC resume using gas press behaviour). It works for cars with electric parking brake and does not change stock ACC behaviour for cars with manual parking brake (which disengage 3 seconds after stopping).

For Global models, we also allow setting ACC hold manually when stopped with no lead car (eg at intersection/traffic light) and resume from manual hold only using ACC resume button press, same as stock ACC behaviour.

We tried to resume by sending ACC resume button press signals but that did not work since ACC buttons are directly wired to Eyesight and not accepted as input from CAN messages.

Prerequisites:

• Subaru signals update opendbc#474
• Subaru SNG panda#794
• Subaru Pre-Global: Rename ES_CruiseThrottle to ES_Distance #23024
• Subaru: Use SI units for ACC distance signals opendbc#604

Verification
Subaru SNG implementation has been tested for several months in subaru-community branch. I will submit sample routes once this is ready to merge

Credit for initial implementation: @letsdudiss1

[adeebshihadeh]

Is this ready for review yet? If not, can you convert the PR to a draft?

[martinl]

I would like to change global dbc to use real distance unit (m) at some point in the future, otherwise it's ready for review

[martinl]

Rebased the PR to latest master and changed Global models to use SI units (m) for ACC Close_Distance signal (with prerequisite commaai/opendbc#604)

[martinl]

I'll close this, new stop and go autoresume PR is #28064