[PATCH 2/5] accel/thames: Add driver for the C7x DSPs in TI SoCs

[Robert Nelson]

On Tue, Jan 13, 2026 at 11:45 AM Tomeu Vizoso <tomeu at tomeuvizoso.net> wrote:
>
> Some SoCs from Texas Instruments contain DSPs that can be used for
> general compute tasks.
>
> This driver provides a drm/accel UABI to userspace for submitting jobs
> to the DSP cores and managing the input, output and intermediate memory.
>
> Signed-off-by: Tomeu Vizoso <tomeu at tomeuvizoso.net>
> ---
>  Documentation/accel/thames/index.rst |  28 +++++
>  MAINTAINERS                          |   9 ++
>  drivers/accel/Kconfig                |   1 +
>  drivers/accel/Makefile               |   3 +-
>  drivers/accel/thames/Kconfig         |  26 +++++
>  drivers/accel/thames/Makefile        |   9 ++
>  drivers/accel/thames/thames_core.c   | 155 ++++++++++++++++++++++++++
>  drivers/accel/thames/thames_core.h   |  53 +++++++++
>  drivers/accel/thames/thames_device.c |  93 ++++++++++++++++
>  drivers/accel/thames/thames_device.h |  46 ++++++++
>  drivers/accel/thames/thames_drv.c    | 156 +++++++++++++++++++++++++++
>  drivers/accel/thames/thames_drv.h    |  21 ++++
>  drivers/accel/thames/thames_ipc.h    | 204 +++++++++++++++++++++++++++++++++++
>  drivers/accel/thames/thames_rpmsg.c  | 155 ++++++++++++++++++++++++++
>  drivers/accel/thames/thames_rpmsg.h  |  27 +++++
>  15 files changed, 985 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/accel/thames/index.rst b/Documentation/accel/thames/index.rst
> new file mode 100644
> index 0000000000000000000000000000000000000000..ca8391031f226f7ef1dc210a356c86acbe126c6f
> --- /dev/null
> +++ b/Documentation/accel/thames/index.rst
> @@ -0,0 +1,28 @@
> +.. SPDX-License-Identifier: GPL-2.0-only
> +
> +============================================================
> + accel/thames Driver for the C7x DSPs from Texas Instruments
> +============================================================
> +
> +The accel/thames driver supports the C7x DSPs inside some Texas Instruments SoCs
> +such as the J722S. These can be used as accelerators for various workloads,
> +including machine learning inference.
> +
> +This driver controls the power state of the hardware via :doc:`remoteproc </staging/remoteproc>`
> +and communicates with the firmware running on the DSP via :doc:`rpmsg_virtio </staging/rpmsg_virtio>`.
> +The kernel driver itself allocates buffers, manages contexts, and submits jobs
> +to the DSP firmware. Buffers are mapped by the DSP itself using its MMU,
> +providing memory isolation among different clients.
> +
> +The source code for the firmware running on the DSP is available at:
> +https://gitlab.freedesktop.org/tomeu/thames_firmware/.
> +
> +Everything else is done in userspace, as a Gallium driver (also called thames)
> +that is part of the Mesa3D project: https://docs.mesa3d.org/teflon.html
> +
> +If there is more than one core that advertises the same rpmsg_virtio service
> +name, the driver will load balance jobs between them with drm-gpu-scheduler.
> +
> +Hardware currently supported:
> +
> +* J722S
> diff --git a/MAINTAINERS b/MAINTAINERS
> index dc731d37c8feeff25613c59fe9c929927dadaa7e..a3fc809c797269d0792dfe5202cc1b49f6ff57e9 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -7731,6 +7731,15 @@ F:       Documentation/devicetree/bindings/npu/rockchip,rk3588-rknn-core.yaml
>  F:     drivers/accel/rocket/
>  F:     include/uapi/drm/rocket_accel.h
>
> +DRM ACCEL DRIVER FOR TI C7x DSPS
> +M:     Tomeu Vizoso <tomeu at tomeuvizoso.net>
> +L:     dri-devel at lists.freedesktop.org
> +S:     Supported
> +T:     git https://gitlab.freedesktop.org/drm/misc/kernel.git
> +F:     Documentation/accel/thames/
> +F:     drivers/accel/thames/
> +F:     include/uapi/drm/thames_accel.h

Oh where is this "thames_accel.h" ? ;)


2026-01-13T18:16:11.881084Z 01E
drivers/accel/thames/thames_drv.c:8:10: fatal error:
drm/thames_accel.h: No such file or directory
2026-01-13T18:16:11.881086Z 01E     8 | #include <drm/thames_accel.h>
2026-01-13T18:16:11.881087Z 01E       |          ^~~~~~~~~~~~~~~~~~~~
2026-01-13T18:16:11.881115Z 01E compilation terminated.
2026-01-13T18:16:11.884552Z 01E make[8]: ***
[scripts/Makefile.build:287: drivers/accel/thames/thames_drv.o] Error
1
2026-01-13T18:16:11.884694Z 01E make[7]: ***
[scripts/Makefile.build:544: drivers/accel/thames] Error 2
2026-01-13T18:16:11.884926Z 01E make[6]: ***
[scripts/Makefile.build:544: drivers/accel] Error 2
2026-01-13T18:16:11.884976Z 01E make[6]: *** Waiting for unfinished jobs....

$ find . | grep thames_accel.h
$ grep -R "thames_accel.h" ./*
./drivers/accel/thames/Kconfig:      include/uapi/drm/thames_accel.h
and is used by the Thames userspace
./drivers/accel/thames/thames_job.c:#include <drm/thames_accel.h>
./drivers/accel/thames/thames_drv.c:#include <drm/thames_accel.h>
./drivers/accel/thames/thames_gem.c:#include <drm/thames_accel.h>
./MAINTAINERS:F:    include/uapi/drm/thames_accel.h

Regards,

-- 
Robert Nelson
https://rcn-ee.com/