The Arm Ethos-U65/85 NPUs are designed for edge AI inference applications[0].
The driver works with Mesa Teflon. A merge request for Ethos support is here[1]. The UAPI should also be compatible with the downstream (open source) driver stack[2] and Vela compiler though that has not been implemented.
Testing so far has been on i.MX93 boards with Ethos-U65 and a FVP model with Ethos-U85. More work is needed in mesa for handling U85 command stream differences, but that doesn't affect the UABI.
A git tree is here[3].
Rob
[0] https://www.arm.com/products/silicon-ip-cpu?families=ethos%20npus [1] https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/36699/ [2] https://gitlab.arm.com/artificial-intelligence/ethos-u/ [3] git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git ethos-v4
Signed-off-by: Rob Herring (Arm) robh@kernel.org --- Changes in v4: - Use bulk clk API - Various whitespace fixes mostly due to ethos->ethosu rename - Drop error check on dma_set_mask_and_coherent() - Drop unnecessary pm_runtime_mark_last_busy() call - Move variable declarations out of switch (a riscv/clang build failure) - Use lowercase hex in all defines - Drop unused ethosu_device.coherent member - Add comments on all locks - Link to v3: https://lore.kernel.org/r/20250926-ethos-v3-0-6bd24373e4f5@kernel.org
Changes in v3: - Rework and improve job submit validation - Rename ethos to ethosu. There was an Ethos-Nxx that's unrelated. - Add missing init for sched_lock mutex - Drop some prints to debug level - Fix i.MX93 SRAM accesses (AXI config) - Add U85 AXI configuration and test on FVP with U85 - Print the current cmd value on timeout - Link to v2: https://lore.kernel.org/r/20250811-ethos-v2-0-a219fc52a95b@kernel.org
Changes in v2: - Rebase on v6.17-rc1 adapting to scheduler changes - scheduler: Drop the reset workqueue. According to the scheduler docs, we don't need it since we have a single h/w queue. - scheduler: Rework the timeout handling to continue running if we are making progress. Fixes timeouts on larger jobs. - Reset the NPU on resume so it's in a known state - Add error handling on clk_get() calls - Fix drm_mm splat on module unload. We were missing a put on the cmdstream BO in the scheduler clean-up. - Fix 0-day report needing explicit bitfield.h include - Link to v1: https://lore.kernel.org/r/20250722-ethos-v1-0-cc1c5a0cbbfb@kernel.org
--- Rob Herring (Arm) (2): dt-bindings: npu: Add Arm Ethos-U65/U85 accel: Add Arm Ethos-U NPU driver
.../devicetree/bindings/npu/arm,ethos.yaml | 79 +++ MAINTAINERS | 9 + drivers/accel/Kconfig | 1 + drivers/accel/Makefile | 1 + drivers/accel/ethosu/Kconfig | 10 + drivers/accel/ethosu/Makefile | 4 + drivers/accel/ethosu/ethosu_device.h | 190 ++++++ drivers/accel/ethosu/ethosu_drv.c | 418 ++++++++++++ drivers/accel/ethosu/ethosu_drv.h | 15 + drivers/accel/ethosu/ethosu_gem.c | 710 +++++++++++++++++++++ drivers/accel/ethosu/ethosu_gem.h | 46 ++ drivers/accel/ethosu/ethosu_job.c | 539 ++++++++++++++++ drivers/accel/ethosu/ethosu_job.h | 41 ++ include/uapi/drm/ethosu_accel.h | 261 ++++++++ 14 files changed, 2324 insertions(+) --- base-commit: 3a8660878839faadb4f1a6dd72c3179c1df56787 change-id: 20250715-ethos-3fdd39ef6f19
Best regards, -- Rob Herring (Arm) robh@kernel.org