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

[Alexandre Belloni]

On 18/12/2025 08:21:27+0100, Jens Wiklander wrote:
> Hi,
> 
> On Mon, Dec 15, 2025 at 3:17 PM Uwe Kleine-König
> <u.kleine-koenig at baylibre.com> 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 These were superseded by bus methods in 2006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@baylibre.com
> >
> > 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.

6 and 7 can go through your branch.

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com