SPMI bus controllers for Apple, Qualcomm, HiSilicon, and MediaTek SoCs
SPMI (System Power Management Interface) is the MIPI-standard two-wire bus that links a modern Arm SoC to its companion power management chips. This subtree provides the bus core and the PMIC-arbiter controllers used on Qualcomm Snapdragon, MediaTek Dimensity, HiSilicon Kirin, and Apple silicon devices to read voltages, toggle regulators, and reach on-package PMIC peripherals.
recommendation
It should stay because this is the kernel's core support for the SPMI bus, the standard low-power link that connects modern smartphone and tablet SoCs to their power management chips. Qualcomm Snapdragon, MediaTek Dimensity, HiSilicon Kirin, and Apple silicon platforms all depend on it, and the subsystem is still receiving active API development and cleanups in 2025-era patch traffic. Removing it would break PMIC access on essentially every current Arm mobile platform.
repository signals
sources
- git.kernel.org
Upstream Kconfig shows this directory is active SPMI bus/controller support for Apple SoCs and Qualcomm/HiSilicon/MediaTek PMIC-arbiter hardware, not a legacy one-off driver.
- lore.kernel.org
Mainline lore shows substantive SPMI core work in 2026, indicating ongoing upstream maintenance rather than retirement.
- lore.kernel.org
A 2026 v8 patch series adds new SPMI core APIs, which is strong evidence of continued feature development and downstream demand.
- qualcomm.com
Qualcomm was still launching new flagship mobile SoCs in late 2024, supporting the inference that Qualcomm PMIC/SPMI-based platforms remained current into 2025.
- mediatek.com
MediaTek was still marketing new flagship smartphone SoCs in 2024/2025, supporting continued new-platform deployment of MediaTek SPMI/PMIC infrastructure.
codex reasoning notes (technical)
`drivers/spmi` is a real bus/controller driver subtree. Active-maintenance signal comes from `lore_file_timeline` on `drivers/spmi/spmi.c`, which returned 2026 lore URLs including new API work and cleanups; that is incompatible with deprecation/removal. Supported hardware families come from the canonical kernel Kconfig URL (canonical recall) and local tree inspection. Current deployment evidence comes from official Qualcomm and MediaTek product pages found via web search; combined with Kconfig, this supports `hardware_still_sold_new_in_2025=true`. No natural replacement driver exists because this directory is the subsystem support itself, so recommendation is `keep`.