Re: [PATCH v1 00/17] tee: Use bus callbacks instead of driver callbacks

[Sumit Garg <sumit.garg@kernel.org>]

On Thu, Dec 11, 2025 at 06:14:54PM +0100, Uwe Kleine-König 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 These were superseded by bus methods in 2006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.)
> 
> The patches #4 - #17 depend on the first two, so if they should be
> applied to their respective subsystem trees these must contain the first
> two patches first.

Thanks Uwe for your efforts to clean up the boilerplate code for TEE bus
drivers.

> 
> Note that after patch #2 is applied, unconverted drivers provoke a
> warning in driver_register(), so it would be good for the user
> experience if the whole series goes in during a single merge window.

+1

I suggest the whole series goes via the Jens tree since there shouldn't
be any chances for conflict here.

> So
> I guess an immutable branch containing the frist three patches that can
> be merged into the other subsystem trees would be sensible.
> 
> After all patches are applied, tee_bus_type can be made private to
> drivers/tee as it's not used in other places any more.
> 

Feel free to make the tee_bus_type private as the last patch in the series
such that any followup driver follows this clean approach.

-Sumit

> Best regards
> Uwe
> 
> 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: 7d0a66e4bb9081d75c82ec4957c50034cb0ea449
> -- 
> 2.47.3
>