Re: [PATCH v2 00/17] tee: Use bus callbacks instead of driver callbacks

[Jens Wiklander]

Hi,

On Mon, Dec 15, 2025 at 3:17 PM Uwe Kleine-König
<u.kleine-koenig@xxxxxxxxxxxx> wrote:
>
> Hello,
>
> the objective of this series is to make tee driver stop using callbacks
> in struct device_driver. These were superseded by bus methods in 2006
> (commit 594c8281f905 ("[PATCH] Add bus_type probe, remove, shutdown
> methods.")) but nobody cared to convert all subsystems accordingly.
>
> Here the tee drivers are converted. The first commit is somewhat
> unrelated, but simplifies the conversion (and the drivers). It
> introduces driver registration helpers that care about setting the bus
> and owner. (The latter is missing in all drivers, so by using these
> helpers the drivers become more correct.)
>
> v1 of this series is available at
> https://lore.kernel.org/all/cover.1765472125.git.u.kleine-koenig@xxxxxxxxxxxx
>
> Changes since v1:
>
>  - rebase to v6.19-rc1 (no conflicts)
>  - add tags received so far
>  - fix whitespace issues pointed out by Sumit Garg
>  - fix shutdown callback to shutdown and not remove
>
> As already noted in v1's cover letter, this series should go in during a
> single merge window as there are runtime warnings when the series is
> only applied partially. Sumit Garg suggested to apply the whole series
> via Jens Wiklander's tree.
> If this is done the dependencies in this series are honored, in case the
> plan changes: Patches #4 - #17 depend on the first two.
>
> Note this series is only build tested.
>
> Uwe Kleine-König (17):
>   tee: Add some helpers to reduce boilerplate for tee client drivers
>   tee: Add probe, remove and shutdown bus callbacks to tee_client_driver
>   tee: Adapt documentation to cover recent additions
>   hwrng: optee - Make use of module_tee_client_driver()
>   hwrng: optee - Make use of tee bus methods
>   rtc: optee: Migrate to use tee specific driver registration function
>   rtc: optee: Make use of tee bus methods
>   efi: stmm: Make use of module_tee_client_driver()
>   efi: stmm: Make use of tee bus methods
>   firmware: arm_scmi: optee: Make use of module_tee_client_driver()
>   firmware: arm_scmi: Make use of tee bus methods
>   firmware: tee_bnxt: Make use of module_tee_client_driver()
>   firmware: tee_bnxt: Make use of tee bus methods
>   KEYS: trusted: Migrate to use tee specific driver registration
>     function
>   KEYS: trusted: Make use of tee bus methods
>   tpm/tpm_ftpm_tee: Make use of tee specific driver registration
>   tpm/tpm_ftpm_tee: Make use of tee bus methods
>
>  Documentation/driver-api/tee.rst             | 18 +----
>  drivers/char/hw_random/optee-rng.c           | 26 ++----
>  drivers/char/tpm/tpm_ftpm_tee.c              | 31 +++++---
>  drivers/firmware/arm_scmi/transports/optee.c | 32 +++-----
>  drivers/firmware/broadcom/tee_bnxt_fw.c      | 30 ++-----
>  drivers/firmware/efi/stmm/tee_stmm_efi.c     | 25 ++----
>  drivers/rtc/rtc-optee.c                      | 27 ++-----
>  drivers/tee/tee_core.c                       | 84 ++++++++++++++++++++
>  include/linux/tee_drv.h                      | 12 +++
>  security/keys/trusted-keys/trusted_tee.c     | 17 ++--
>  10 files changed, 164 insertions(+), 138 deletions(-)
>
> base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
> --
> 2.47.3
>

Thank you for the nice cleanup, Uwe.

I've applied patch 1-3 to the branch tee_bus_callback_for_6.20 in my
tree at https://git.kernel.org/pub/scm/linux/kernel/git/jenswi/linux-tee.git/

The branch is based on v6.19-rc1, and I'll try to keep it stable for
others to depend on, if needed. Let's see if we can agree on taking
the remaining patches via that branch.

Cheers,
Jens