PTP Hardware Clock subsystem and IEEE 1588 timing drivers
Linux's IEEE 1588 Precision Time Protocol subsystem, providing both real timing hardware support — Intel PCH, NXP QorIQ, Renesas/IDT ClockMatrix, and OCP TimeCard cards used in telecom, broadcast, finance, and hyperscale data centres — and virtual PTP clocks that let KVM and VMware guests read accurate time from their host. In use since the early 2010s.
recommendation
It should stay because this directory is the kernel's umbrella for IEEE 1588 Precision Time Protocol support, covering both virtual clocks used by KVM and VMware guests and physical timing hardware still sold new in 2025, including Renesas ClockMatrix devices and OCP TimeCard precision NICs used in data centres and finance. Upstream fixes were still landing and being backported to stable trees in late 2025, so the code is actively maintained rather than legacy.
repository signals
sources
- lore.kernel.org
PTP core code in this directory was still receiving upstream fixes in late 2025.
- lore.kernel.org
PTP core fixes were being backported to stable trees in late 2025, indicating maintained relevance rather than retirement.
- docs.kernel.org
The kernel documents this as the common PTP hardware clock infrastructure supporting multiple concrete clock drivers, including modern hardware such as Renesas ClockMatrix.
- docs.kernel.org
PTP_KVM remains a documented virtual-clock feature for current KVM guests, showing ongoing deployment in virtualization use cases.
- timebeat.app
An OCP TimeCard class device supported by this directory is marketed as current hardware, supporting the conclusion that relevant hardware is still sold new.
codex reasoning notes (technical)
Shell inspection of drivers/ptp/Kconfig showed this is an active mixed subsystem directory, not one obsolete chip driver: core PTP infrastructure plus KVM, VMCLOCK, VMware, OCP TimeCard, QorIQ, Intel PCH, Renesas/IDT and others. `lore_activity` on drivers/ptp/ptp_clock.c produced 2025 fix and stable-backport lore URLs, so upstream attention is current. A directory-level `lore_file_timeline` returned no matches for the path prefix, and a broad `lore_regex` removal/deprecation scan timed out; no positive removal evidence was found. Web search provided the kernel PTP/PTP_KVM docs and a current OCP-TAP Timecard product page. Because this directory underpins both present-day VM guest clocks and still-sold precision timing hardware, the correct recommendation is keep, not deprecate.