linux-drivers/
drivers/usb/musb

Mentor Graphics Inventra MUSB HDRC USB OTG controllers

A widely-licensed USB 2.0 On-The-Go controller IP block from Mentor Graphics (the Inventra MUSB HDRC design) embedded into many SoCs over the past two decades, including TI OMAP, DaVinci, AM335x (BeagleBone), Allwinner, and more recently Microchip's PolarFire SoC FPGAs. It can act as host, peripheral, or dual-role, powering USB on a wide range of embedded Linux devices.

keep conf=0.93 deploy=medium replacement=none subsystem=usb category=bus-usb
93%

recommendation

It should stay because the controller family is still actively maintained, with bug fixes landing through 2024 and 2025 and stable backports still flowing in mid-2025. Deployments are niche rather than mainstream, but Microchip continues to ship PolarFire SoC FPGAs with a MUSB-based USB 2.0 OTG block in 2025, so current hardware still depends on this code.

repository signals

33 files
20,409 source lines
107 commits, 5y
+1,224 / −3,579 lines added / removed, 5y
59 authors, 5y
monthly commits · 2021-04-21 → 2026-04-21 · 107 total · active in 40/61 months
2021 2022 2023 2024 2025 2026 2021-04: 1 commit · +2 −2 2021-05: 8 commits · +50 −20 2021-06: 2 commits · +55 −36 2021-07: 1 commit · +38 −5 2021-08: 2 commits · +7 −7 2021-09: 2 commits · +6 −0 2021-10: 4 commits · +15 −3 2021-11: 0 commits · +0 −0 2021-12: 3 commits · +22 −59 2022-01: 0 commits · +0 −0 2022-02: 0 commits · +0 −0 2022-03: 2 commits · +1 −1 2022-04: 1 commit · +10 −63 2022-05: 0 commits · +0 −0 2022-06: 5 commits · +285 −18 2022-07: 2 commits · +4 −4 2022-08: 1 commit · +1 −1 2022-09: 6 commits · +21 −39 2022-10: 8 commits · +200 −2,399 2022-11: 4 commits · +57 −619 2022-12: 1 commit · +3 −1 2023-01: 1 commit · +2 −1 2023-02: 2 commits · +76 −35 2023-03: 2 commits · +2 −2 2023-04: 11 commits · +59 −56 2023-05: 0 commits · +0 −0 2023-06: 0 commits · +0 −0 2023-07: 2 commits · +10 −14 2023-08: 4 commits · +4 −11 2023-09: 2 commits · +9 −2 2023-10: 1 commit · +1 −0 2023-11: 0 commits · +0 −0 2023-12: 0 commits · +0 −0 2024-01: 0 commits · +0 −0 2024-02: 1 commit · +0 −4 2024-03: 0 commits · +0 −0 2024-04: 0 commits · +0 −0 2024-05: 6 commits · +20 −23 2024-06: 1 commit · +6 −2 2024-07: 0 commits · +0 −0 2024-08: 1 commit · +136 −24 2024-09: 3 commits · +22 −27 2024-10: 2 commits · +1 −3 2024-11: 2 commits · +14 −8 2024-12: 0 commits · +0 −0 2025-01: 2 commits · +23 −18 2025-02: 1 commit · +2 −2 2025-03: 0 commits · +0 −0 2025-04: 1 commit · +15 −15 2025-05: 1 commit · +7 −5 2025-06: 0 commits · +0 −0 2025-07: 4 commits · +23 −19 2025-08: 1 commit · +1 −1 2025-09: 0 commits · +0 −0 2025-10: 0 commits · +0 −0 2025-11: 1 commit · +0 −16 2025-12: 0 commits · +0 −0 2026-01: 0 commits · +0 −0 2026-02: 2 commits · +14 −14 2026-03: 0 commits · +0 −0 2026-04: 0 commits · +0 −0

sources

  1. docs.kernel.org

    Kernel documentation describes MUSB as the Linux subsystem for embedded OTG/device controllers based on the Mentor Graphics Inventra MUSB HDRC design, with multiple SoC-specific glue layers.

  2. spinics.net

    A substantive upstream bug-fix patch for drivers/usb/musb/musb_gadget.c was posted on November 10, 2024, showing ongoing maintenance rather than abandonment.

  3. spinics.net

    An upstream MUSB omap2430 fix was still being backported into stable in August 2025, indicating active maintenance and deployed users.

  4. spinics.net

    A 2025 linux-usb patch updated the DSPS glue layer, showing current list traffic on this driver family rather than removal work.

  5. cateee.net

    LKDDb shows CONFIG_USB_MUSB_POLARFIRE_SOC present through 6.19-rc+HEAD, tying this directory to currently supported Microchip PolarFire SoC hardware.

  6. microchip.com

    Microchip was still marketing PolarFire SoC devices and kits with a USB 2.0 OTG peripheral in 2025, so at least part of the MUSB hardware base remains sold new.

codex reasoning notes (technical)

Local shell inspection (`rg`, `sed`, `git -c safe.directory log`) showed this is a real multi-platform USB controller driver with recent 2025 touches across core and glue layers. `lore-http` MCP was unavailable and `lei` was not installed, so lore history was approximated via web search to public mailing-list archives: recent spinics/linux-usb and stable-commits URLs show active fixes in 2024-2025 and no evident removal series. Web search also found kernel docs, LKDDb, and Microchip's current PolarFire SoC product page; together they support a keep recommendation for a still-relevant embedded/industrial controller family with ongoing upstream maintenance, but with niche rather than broad mainstream deployment.