linux-drivers/
drivers/rtc

Real-Time Clock (RTC) subsystem and chip drivers

Real-time clocks are the small battery-backed timekeeping chips that remember the date and time when a computer is powered off and can wake it on schedule. This directory is the umbrella for dozens of them, from the legacy PC CMOS clock to discrete I2C and SPI parts like the NXP PCF85063A and Analog Devices DS3231, plus RTC blocks built into SoCs in servers, embedded boards, and VMs.

keep conf=0.95 deploy=high replacement=none subsystem=rtc category=infrastructure
95%

recommendation

It should stay because this is an actively maintained core subsystem under Alexandre Belloni and the linux-rtc list, with regular pull requests and fixes landing through 2025. The hardware class is universal and still being designed into new products, with vendors like NXP and Analog Devices shipping current parts, so there is no plausible path to removal.

repository signals

195 files
84,441 source lines
833 commits, 5y
+19,945 / −8,847 lines added / removed, 5y
228 authors, 5y
monthly commits · 2021-04-21 → 2026-04-21 · 833 total · active in 59/61 months
2021 2022 2023 2024 2025 2026 2021-04: 13 commits · +235 −90 2021-05: 9 commits · +33 −328 2021-06: 9 commits · +314 −94 2021-07: 14 commits · +129 −152 2021-08: 9 commits · +313 −41 2021-09: 11 commits · +46 −8 2021-10: 23 commits · +510 −652 2021-11: 19 commits · +220 −161 2021-12: 18 commits · +1,184 −173 2022-01: 8 commits · +39 −15 2022-02: 18 commits · +196 −131 2022-03: 33 commits · +442 −109 2022-04: 8 commits · +165 −53 2022-05: 16 commits · +509 −27 2022-06: 12 commits · +1,176 −103 2022-07: 6 commits · +585 −383 2022-08: 13 commits · +54 −143 2022-09: 15 commits · +57 −157 2022-10: 19 commits · +140 −1,181 2022-11: 18 commits · +374 −226 2022-12: 8 commits · +97 −29 2023-01: 28 commits · +324 −246 2023-02: 24 commits · +615 −352 2023-03: 53 commits · +110 −179 2023-04: 1 commit · +2 −1 2023-05: 9 commits · +49 −64 2023-06: 31 commits · +1,405 −479 2023-07: 16 commits · +168 −170 2023-08: 27 commits · +206 −191 2023-09: 4 commits · +606 −1 2023-10: 18 commits · +86 −41 2023-11: 12 commits · +1,682 −30 2023-12: 2 commits · +1 −21 2024-01: 8 commits · +56 −71 2024-02: 20 commits · +175 −284 2024-03: 4 commits · +57 −23 2024-04: 4 commits · +24 −8 2024-05: 2 commits · +29 −29 2024-06: 12 commits · +121 −43 2024-07: 6 commits · +368 −2 2024-08: 5 commits · +414 −2 2024-09: 11 commits · +280 −47 2024-10: 10 commits · +1,177 −198 2024-11: 15 commits · +562 −117 2024-12: 7 commits · +83 −76 2025-01: 3 commits · +107 −16 2025-02: 25 commits · +391 −447 2025-03: 29 commits · +311 −598 2025-04: 29 commits · +803 −166 2025-05: 14 commits · +343 −25 2025-06: 5 commits · +38 −29 2025-07: 30 commits · +647 −278 2025-08: 7 commits · +184 −82 2025-09: 6 commits · +729 −10 2025-10: 12 commits · +592 −75 2025-11: 19 commits · +174 −32 2025-12: 5 commits · +56 −28 2026-01: 15 commits · +143 −121 2026-02: 4 commits · +7 −7 2026-03: 0 commits · +0 −0 2026-04: 0 commits · +0 −0

sources

  1. docs.kernel.org

    Kernel documentation describes the RTC class framework as supporting a wide variety of RTCs, including SoC-integrated and discrete I2C/SPI chips, with /dev/rtcN interfaces across many systems.

  2. patchwork.ozlabs.org

    Patchwork shows accepted RTC subsystem pull requests and driver fixes in 2025, indicating active upstream maintenance rather than retirement.

  3. lore.kernel.org

    The linux-rtc mailing list had fresh traffic on 2026-04-24, confirming the subsystem is still live upstream.

  4. nxp.com

    NXP lists the PCF85063A RTC as Active and shows a 2025 datasheet revision, evidence that new RTC hardware covered by this subsystem is still sold.

  5. analog.com

    Analog Devices lists the DS3231 RTC in PRODUCTION with sample/buy availability, further showing ongoing new-hardware deployment for RTC devices.

codex reasoning notes (technical)

This is the maintained RTC subsystem, not a dead single-chip driver bucket. Local MAINTAINERS inspection shows drivers/rtc/ is under the REAL TIME CLOCK (RTC) SUBSYSTEM with Alexandre Belloni and linux-rtc@vger.kernel.org; local git grep over drivers/rtc since 2023 found no explicit remove/deprecate/obsolete subjects. URLs were obtained via web search for kernel docs, Patchwork, and vendor product pages, plus one lore URL from `lore_eq(list=linux-rtc)` on the linux-rtc list. The directory has heavy recent churn from the provided stats, upstream list traffic is current, and the hardware class remains broadly deployed in PCs, servers, industrial/embedded boards, and virtualized environments. No single replacement driver exists because this directory is the umbrella subsystem for many unrelated RTC chips and controllers.