Cadence Torrent, Sierra, Salvo, and MIPI D-PHY controllers
A collection of PHY (physical-layer) controller blocks designed by Cadence and licensed into many modern system-on-chip designs. They handle the analog signalling for high-speed interfaces such as PCIe, USB 3.0, MIPI camera and display links, and other multi-protocol SerDes lanes found in current ARM SoCs like NXP's i.MX95.
recommendation
It should stay in the kernel because the underlying Cadence PHY IP is still being licensed into new silicon shipping in 2025, and upstream activity reflects that — Torrent, Sierra, and D-PHY all received fixes on the linux-phy list during 2025. NXP's i.MX95 and other current SoCs rely on these blocks, and no other in-tree driver covers the same Cadence-specific hardware, so there is no replacement to migrate to.
repository signals
sources
- lore.kernel.org
linux-phy saw a Cadence Torrent functional fix in December 2025, indicating active upstream maintenance rather than retirement.
- lore.kernel.org
linux-phy carried a substantial Cadence D-PHY fix series in September 2025, showing ongoing bug-fix traffic for this directory.
- lore.kernel.org
Cadence Sierra still received 2025 cleanup touches in linux-phy, so the code is not abandoned.
- nxp.com
NXP lists the i.MX95 family as Active and exposes USB 3.0, USB 2.0, PCIe Gen3, and MIPI camera/display PHY-equipped connectivity, consistent with continued deployment of Cadence-backed PHY IP in current SoCs.
- cadence.com
Cadence still markets multi-protocol SerDes PHY IP as a current product line for volume-production SoCs, supporting the view that this class of Cadence PHY hardware remains commercially relevant.
- cadence.com
Cadence continues to sell newer PCIe/CXL PHY IP, indicating the vendor's PHY portfolio is current rather than legacy-only.
codex reasoning notes (technical)
Real driver directory: local tree inspection showed platform PHY drivers and Kconfig entries for Torrent, Sierra, Salvo, and D-PHY variants. Active-maintenance evidence came from lore-http `lore_regex` on linux-phy patch diffs, which returned 2025 Cadence Torrent/D-PHY/Sierra patches at the cited lore URLs. Deployment evidence came from web search results on NXP i.MX95 and Cadence product pages. Salvo is locally described as legacy USB-only, but the directory overall covers multiple still-current Cadence PHY IP blocks. No natural upstream replacement driver covers the same Cadence-specific PHY blocks, so removal/deprecation is not justified.