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

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

[Uwe Kleine-König]

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 These were superseded by bus methods in 2006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

[PATCH v2 03/17] tee: Adapt documentation to cover recent additions

[Uwe Kleine-König]

The previous commits introduced some helpers to reduce boilerplate
and bus specific callbacks for probe and remove.

Adapt the reference example to make use of these.

Reviewed-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
---
 Documentation/driver-api/tee.rst | 18 +++---------------
 1 file changed, 3 insertions(+), 15 deletions(-)

diff --git a/Documentation/driver-api/tee.rst b/Documentation/driver-api/tee.rst
index 5eaeb8103988..4d58ac0712c1 100644
--- a/Documentation/driver-api/tee.rst
+++ b/Documentation/driver-api/tee.rst
@@ -43,24 +43,12 @@ snippet would look like::
 	MODULE_DEVICE_TABLE(tee, client_id_table);
 
 	static struct tee_client_driver client_driver = {
+		.probe		= client_probe,
+		.remove		= client_remove,
 		.id_table	= client_id_table,
 		.driver		= {
 			.name		= DRIVER_NAME,
-			.bus		= &tee_bus_type,
-			.probe		= client_probe,
-			.remove		= client_remove,
 		},
 	};
 
-	static int __init client_init(void)
-	{
-		return driver_register(&client_driver.driver);
-	}
-
-	static void __exit client_exit(void)
-	{
-		driver_unregister(&client_driver.driver);
-	}
-
-	module_init(client_init);
-	module_exit(client_exit);
+	module_tee_client_driver(client_driver);
-- 
2.47.3

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@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.

Cheers,
Jens

Re: [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@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

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

[Jens Wiklander]

On Thu, Dec 18, 2025 at 2:53 PM Alexandre Belloni
<alexandre.belloni@bootlin.com> wrote:
>
> 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@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.

Good, I've added them to my branch now.

Thanks,
Jens