[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 These were superseded by bus methods in 2006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 12/17] firmware: tee_bnxt: Make use of module_tee_client_driver()

[Uwe Kleine-König]

Reduce boilerplate by using the newly introduced module_tee_client_driver().
That takes care of assigning the driver's bus, so the explicit assigning
in this driver can be dropped.

Reviewed-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
---
 drivers/firmware/broadcom/tee_bnxt_fw.c | 14 +-------------
 1 file changed, 1 insertion(+), 13 deletions(-)

diff --git a/drivers/firmware/broadcom/tee_bnxt_fw.c b/drivers/firmware/broadcom/tee_bnxt_fw.c
index 40e3183a3d11..fbdf1aa97c82 100644
--- a/drivers/firmware/broadcom/tee_bnxt_fw.c
+++ b/drivers/firmware/broadcom/tee_bnxt_fw.c
@@ -261,25 +261,13 @@ static struct tee_client_driver tee_bnxt_fw_driver = {
 	.id_table	= tee_bnxt_fw_id_table,
 	.driver		= {
 		.name		= KBUILD_MODNAME,
-		.bus		= &tee_bus_type,
 		.probe		= tee_bnxt_fw_probe,
 		.remove		= tee_bnxt_fw_remove,
 		.shutdown	= tee_bnxt_fw_shutdown,
 	},
 };
 
-static int __init tee_bnxt_fw_mod_init(void)
-{
-	return driver_register(&tee_bnxt_fw_driver.driver);
-}
-
-static void __exit tee_bnxt_fw_mod_exit(void)
-{
-	driver_unregister(&tee_bnxt_fw_driver.driver);
-}
-
-module_init(tee_bnxt_fw_mod_init);
-module_exit(tee_bnxt_fw_mod_exit);
+module_tee_client_driver(tee_bnxt_fw_driver);
 
 MODULE_AUTHOR("Vikas Gupta <vikas.gupta@broadcom.com>");
 MODULE_DESCRIPTION("Broadcom bnxt firmware manager");
-- 
2.47.3

[PATCH v2 13/17] firmware: tee_bnxt: Make use of tee bus methods

[Uwe Kleine-König]

The tee bus got dedicated callbacks for probe and remove.
Make use of these. This fixes a runtime warning about the driver needing
to be converted to the bus methods.

Reviewed-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
---
 drivers/firmware/broadcom/tee_bnxt_fw.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/drivers/firmware/broadcom/tee_bnxt_fw.c b/drivers/firmware/broadcom/tee_bnxt_fw.c
index fbdf1aa97c82..a706c84eb2b6 100644
--- a/drivers/firmware/broadcom/tee_bnxt_fw.c
+++ b/drivers/firmware/broadcom/tee_bnxt_fw.c
@@ -181,9 +181,9 @@ static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data)
 	return (ver->impl_id == TEE_IMPL_ID_OPTEE);
 }
 
-static int tee_bnxt_fw_probe(struct device *dev)
+static int tee_bnxt_fw_probe(struct tee_client_device *bnxt_device)
 {
-	struct tee_client_device *bnxt_device = to_tee_client_device(dev);
+	struct device *dev = &bnxt_device->dev;
 	int ret, err = -ENODEV;
 	struct tee_ioctl_open_session_arg sess_arg;
 	struct tee_shm *fw_shm_pool;
@@ -231,17 +231,15 @@ static int tee_bnxt_fw_probe(struct device *dev)
 	return err;
 }
 
-static int tee_bnxt_fw_remove(struct device *dev)
+static void tee_bnxt_fw_remove(struct tee_client_device *bnxt_device)
 {
 	tee_shm_free(pvt_data.fw_shm_pool);
 	tee_client_close_session(pvt_data.ctx, pvt_data.session_id);
 	tee_client_close_context(pvt_data.ctx);
 	pvt_data.ctx = NULL;
-
-	return 0;
 }
 
-static void tee_bnxt_fw_shutdown(struct device *dev)
+static void tee_bnxt_fw_shutdown(struct tee_client_device *bnxt_device)
 {
 	tee_shm_free(pvt_data.fw_shm_pool);
 	tee_client_close_session(pvt_data.ctx, pvt_data.session_id);
@@ -258,12 +256,12 @@ static const struct tee_client_device_id tee_bnxt_fw_id_table[] = {
 MODULE_DEVICE_TABLE(tee, tee_bnxt_fw_id_table);
 
 static struct tee_client_driver tee_bnxt_fw_driver = {
+	.probe		= tee_bnxt_fw_probe,
+	.remove		= tee_bnxt_fw_remove,
+	.shutdown	= tee_bnxt_fw_shutdown,
 	.id_table	= tee_bnxt_fw_id_table,
 	.driver		= {
 		.name		= KBUILD_MODNAME,
-		.probe		= tee_bnxt_fw_probe,
-		.remove		= tee_bnxt_fw_remove,
-		.shutdown	= tee_bnxt_fw_shutdown,
 	},
 };
 
-- 
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