Arm System Control and Management Interface (SCMI) firmware stack
Linux's implementation of the Arm SCMI standard, which lets the kernel talk to dedicated system-control firmware (often on a separate management processor) to handle power domains, clocks, voltage regulators, DVFS, sensors, and reset on Arm SoCs. It is widely used on modern Arm platforms shipping in 2025, including ST's STM32MP2x family and many Qualcomm, Rockchip, and Amlogic designs.
recommendation
It should stay because SCMI is Arm's current standard interface for letting Linux ask system firmware to handle power, clocks, voltage regulators, performance scaling, and sensors on modern Arm SoCs. Upstream activity is heavy and ongoing into 2026, with new features like telemetry support still landing, and silicon vendors including ST (STM32MP2x), Qualcomm, Rockchip, and Amlogic ship current parts that depend on it. There is no replacement because this code is itself the common abstraction layer.
repository signals
sources
- lore.kernel.org
Recent 2026 upstream activity adds new SCMI core functionality, indicating active maintenance rather than retirement.
- lore.kernel.org
Large 2026 feature series added basic Telemetry support to arm_scmi, showing ongoing feature growth.
- arm.com
Arm still positions SCMI as a current standard firmware interface for power, performance, and system management in Arm-based designs.
- wiki.st.com
ST documents SCMI configuration for current STM32MP13/15/21/23/25 lines, evidence of present-day deployment on shipping embedded platforms.
codex reasoning notes (technical)
Real driver directory implementing the Linux SCMI stack and transports. `lore_file_timeline` on drivers/firmware/arm_scmi/driver.c showed heavy activity through 2026-04-21, including new API work and telemetry support; sampled lore traffic showed active development, not removal. `lore_regex` removal-scan timed out and `lei` was blocked by sandbox socket permissions, so absence of removal talk is inferred from the recent activity sample rather than a full negative search. Web search found Arm's current system-firmware page describing SCMI as a standard interface, and ST's 2025-approved SCMI configuration page covering STM32MP2x families, which supports 'still sold new' and ongoing deployment. Local tree grep also showed arm,scmi bindings in many current DTS files (including recent Qualcomm/ST/Rockchip/Amlogic-era platforms), reinforcing broad modern use. No natural replacement upstream driver exists because arm_scmi is the common abstraction layer itself.