ST-Ericsson Ux500 / NovaThor U8500 power domain controller
Power-domain controller found on ST-Ericsson's NovaThor U8500 mobile SoC, the chip behind several 2011–2013 smartphones such as the Samsung Galaxy S III Mini, Galaxy Beam, Galaxy Ace 2, and Sony Xperia U. It lets the kernel switch entire blocks of the SoC on and off to save power.
recommendation
Worth keeping but documenting its niche, because the hardware is firmly obsolete: ST-Ericsson was wound down in 2013 and no new NovaThor devices ship today. A handful of those phones still run mainline kernels through projects like postmarketOS (the Galaxy Beam page was updated as recently as 2025), and there is no replacement driver for this specific Ux500 power-domain binding, so removing it would break the few remaining mainlined handsets for no benefit.
repository signals
sources
- cateee.net
CONFIG_UX500_PM_DOMAIN is still present in current kernels and matches the DT compatible "stericsson,ux500-pm-domains" and platform driver "ux500_pm_domains".
- en.wikipedia.org
NovaThor U8500 was a smartphone/tablet SoC family with availability in 2011, used in handsets like Galaxy Ace 2, Galaxy Beam, Galaxy S Advance, Galaxy S III Mini, Xperia U, etc.; the ST-Ericsson venture was split up in 2013, indicating the platform is long out of mainstream production.
- wiki.postmarketos.org
A NovaThor U8500 device still has a postmarketOS page showing mainline-kernel use in 2025, which is evidence of residual enthusiast/aftermarket deployment rather than zero deployment.
codex reasoning notes (technical)
Local file inspection via shell showed this is a real platform driver for compatible "stericsson,ux500-pm-domains" and Kconfig ties it to ARCH_U8500. Local git history via `git log --follow` showed lineage back to 2014 ('ARM: ux500: Initial support for PM domains'), plus directory reshuffles in 2023 and only treewide touches in 2026; that looks like legacy maintenance, not active feature work. Targeted lore lookup was attempted first: `lei` was unavailable in this environment and web lore searches for the filename/compatible string returned no concrete thread hits, so I found no evidence of an active upstream removal series. URL acquisition: LKDDb URL from web search; NovaThor Wikipedia URL from web search/open; postmarketOS device URL from web search snippet. Recommendation is keep-annotate because the hardware is clearly obsolete and not sold new in 2025, deployments are only low-volume legacy/hobbyist/mainline-phone use, and there is no natural replacement driver for the same Ux500 power-domain binding.