RTSS MD SW Stack - DLKM and UMD mainlining - phase 1 changes

[sargarram7]

Target milestone: QLI-2.1

Phase 1 Commitments

• Enable RTSS MD SW Stack - DLKM and UMD
• Enable user space CAN low latency and CAN Socket based loopback:
  • CAN user <->socket <-> CAN User Space Deamon <-> RTSS Mailbox Interface
  • CAN user space client <-> RTSS Mailbox Interface

Purpose

Tracking issue for mainlining the RTSS mailbox stack into the open-source tree and reaching the QLI-2.1 release milestone. Central place to discuss
sequencing, dependencies, and review status across the PR set below, rather than splitting the same discussion across four separate PR threads.

Source repos (released)

• rtss-mailbox-kmd — https://github.com/qualcomm-linux/rtss-mailbox-kmd
  (tag v1.0.0)
• rtss-mailbox-umd — https://github.com/qualcomm-linux/rtss-mailbox-umd
  (tag v1.0.0)

PRs in this set

• Recipes (meta-qcom): meta-qcom: add RTSS mailbox DLKM/UMD recipes (phase 1) #3084
• Image wiring (meta-qcom-distro): qcom-multimedia-proprietary-image: add RTSS mailbox DLKM/UMD packages meta-qcom-distro#457
• Device-tree wiring (kernel-topics): QCLINUX: arm64: dts: qcom: lemans and monaco: Rework RTSS Mailbox DT to use syscon and staging overlays kernel-topics#1768

backport to qli2.1 status

• waiting for approvals

Why this stack

Customer use cases - CAN communication, RTSS-to-HLOS user space communication, OTA updates, and on-device programming/flashing - all
need a working IPC path between the application processor and RTSS. This is phase 1 of bringing downstream, out-of-tree RTSS mailbox stack into the open-source tree to support these use cases.

Status / sequencing

Recipe PR (#3084) and image-wiring PR (#457) depend on each other's recipe names landing, DT PRs (#1042, #1768) wire up the
qcom,rtss-mailbox node independently. Verified on target: staging DTBO overlay carrying the mailbox node, both bootup and DTBO patching.

RTSS Feature Enablement Exception

https://jira-dc.qualcomm.com/jira/browse/QLIJIRA-123