T-Head TH1520 RISC-V SoC power domain controller
Power domain management for the T-Head TH1520, a quad-core RISC-V system-on-chip from Alibaba's T-Head division that powers boards like Sipeed's LicheePi 4A and the Lichee Book 4A laptop. It coordinates which on-chip blocks (CPU clusters, GPU, peripherals) are powered up or down via the SoC's always-on firmware.
recommendation
It should stay because the code was only added in March 2025 and is still being actively extended, with follow-on work in June 2025 adding GPU power sequencing. The TH1520 silicon continues to ship in new RISC-V developer boards and laptops from Sipeed in 2025, and the upstream pmdomain maintainer accepted the initial series through normal channels with no deprecation signals.
repository signals
sources
- lkml.org
March 2025 upstream patch series introduced TH1520 AON firmware and power-domain support, explicitly for the T-Head TH1520 SoC used on the LicheePi 4A board.
- lkml.org
In review, pmdomain maintainer Ulf Hansson said he could pick up patches 1-4 via the pmdomain tree, indicating normal upstream acceptance rather than deprecation/removal.
- lists.infradead.org
June 2025 follow-on work added TH1520 GPU power sequencing and included a pmdomain/thead change, showing active feature development around this driver after initial merge.
- wiki.sipeed.com
Sipeed's official Lichee Pi 4A documentation identifies TH1520 as the SoC for a Linux development board and mentions an online store link.
- wiki.sipeed.com
Sipeed's official Lichee Book 4A documentation describes a TH1520-based laptop product family, indicating the silicon remained in new-product documentation beyond initial 2023 bring-up.
codex reasoning notes (technical)
Local file inspection showed a real platform_driver implementing TH1520 SoC power domains, not helper-only code. Local git history shows five substantive commits from 2025-03-13 through 2025-09-26, including bug fixes and new auxiliary-device hookups, so the directory is newly added and still receiving upstream work. The cited LKML/Linux-RISC-V URLs were obtained via web.search_query for TH1520 power-domain lore activity; Sipeed product pages were also obtained via web.search_query. Those sources support 'keep': active upstream maintenance, no removal discussion surfaced in the lore-oriented searches, and hardware appears to persist in niche new deployments (developer boards/laptops), though at low volume rather than mass-market scale.