Socionext UniPhier SoC pin controllers
Pin multiplexing and GPIO configuration for Socionext's UniPhier family of ARM SoCs (LD4, sLD8, Pro5, PXs3 and siblings), which Panasonic originally developed for digital TVs, set-top boxes, and consumer AV gear before the line was spun out to Socionext in the mid-2010s. It tells the chip which physical pins should act as UART, I2C, SD, Ethernet, and so on for a given board.
recommendation
Worth keeping but documenting as legacy because UniPhier-branded SoCs are no longer Socionext's commercial focus (the company has pivoted to custom automotive, data center, and industrial chips), yet the pin controller code still receives routine upstream maintenance as recently as 2022-2023 and the broader ARCH_UNIPHIER platform remains supported. There is no drop-in replacement for a SoC's own pin multiplexing block, so removal would silently break any board still booting these chips.
repository signals
sources
- lore.kernel.org
The driver saw upstream maintenance in 2023 via a pinctrl/uniphier hardening annotation patch, indicating it is not abandoned.
- lore.kernel.org
The driver also received a 2022 build-fix/header cleanup patch on linux-gpio, showing ongoing upkeep rather than removal work.
- cateee.net
CONFIG_ARCH_UNIPHIER remains present through current kernel series and HEAD in LKDDb, so the broader SoC family is still supported upstream.
- socionext.com
Socionext's current public business focus is custom SoCs for automotive, data center/networking, smart devices, and industrial markets.
codex reasoning notes (technical)
UniPhier pinctrl is real SoC-specific driver code (local shell `rg` over the directory showed multiple `builtin_platform_driver()` instances and DT compatibles for SLD8/PRO5/PXS3-class parts). Lore evidence was obtained with `lore_activity` on `drivers/pinctrl/uniphier/pinctrl-uniphier-core.c`; it shows recent upstream maintenance patches and no removal/deprecation thread in the gathered evidence, so `remove`/`deprecate` is not justified. LKDDb URL was obtained by web search and supports that ARCH_UNIPHIER is still in current kernels. Socionext's current official site, also found by web search, emphasizes newer custom-SoC markets rather than UniPhier-branded products; that supports treating UniPhier hardware as legacy with low ongoing deployments. Because the hardware appears legacy but upstream support is still alive and there is no natural drop-in replacement for a SoC pinctrl block, the best fit is `keep-annotate`.