[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 These were superseded by bus methods in 2006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 14/17] KEYS: trusted: Migrate to use tee specific driver registration function

[Uwe Kleine-König]

The tee subsystem recently got a set of dedicated functions to register
(and unregister) a tee driver. Make use of them. These care for setting the
driver's bus (so the explicit assignment can be dropped) and the driver
owner (which is an improvement this driver benefits from).

Reviewed-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
---
 security/keys/trusted-keys/trusted_tee.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/security/keys/trusted-keys/trusted_tee.c b/security/keys/trusted-keys/trusted_tee.c
index aa3d477de6db..3cea9a377955 100644
--- a/security/keys/trusted-keys/trusted_tee.c
+++ b/security/keys/trusted-keys/trusted_tee.c
@@ -264,7 +264,6 @@ static struct tee_client_driver trusted_key_driver = {
 	.id_table	= trusted_key_id_table,
 	.driver		= {
 		.name		= DRIVER_NAME,
-		.bus		= &tee_bus_type,
 		.probe		= trusted_key_probe,
 		.remove		= trusted_key_remove,
 	},
@@ -272,12 +271,12 @@ static struct tee_client_driver trusted_key_driver = {
 
 static int trusted_tee_init(void)
 {
-	return driver_register(&trusted_key_driver.driver);
+	return tee_client_driver_register(&trusted_key_driver);
 }
 
 static void trusted_tee_exit(void)
 {
-	driver_unregister(&trusted_key_driver.driver);
+	tee_client_driver_unregister(&trusted_key_driver);
 }
 
 struct trusted_key_ops trusted_key_tee_ops = {
-- 
2.47.3

Re: [PATCH v2 14/17] KEYS: trusted: Migrate to use tee specific driver registration function

[Jarkko Sakkinen]

On Mon, Dec 15, 2025 at 03:16:44PM +0100, Uwe Kleine-König wrote:
> The tee subsystem recently got a set of dedicated functions to register
> (and unregister) a tee driver. Make use of them. These care for setting the
> driver's bus (so the explicit assignment can be dropped) and the driver
> owner (which is an improvement this driver benefits from).
> 
> Reviewed-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
> ---
>  security/keys/trusted-keys/trusted_tee.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/security/keys/trusted-keys/trusted_tee.c b/security/keys/trusted-keys/trusted_tee.c
> index aa3d477de6db..3cea9a377955 100644
> --- a/security/keys/trusted-keys/trusted_tee.c
> +++ b/security/keys/trusted-keys/trusted_tee.c
> @@ -264,7 +264,6 @@ static struct tee_client_driver trusted_key_driver = {
>  	.id_table	= trusted_key_id_table,
>  	.driver		= {
>  		.name		= DRIVER_NAME,
> -		.bus		= &tee_bus_type,
>  		.probe		= trusted_key_probe,
>  		.remove		= trusted_key_remove,
>  	},
> @@ -272,12 +271,12 @@ static struct tee_client_driver trusted_key_driver = {
>  
>  static int trusted_tee_init(void)
>  {
> -	return driver_register(&trusted_key_driver.driver);
> +	return tee_client_driver_register(&trusted_key_driver);
>  }
>  
>  static void trusted_tee_exit(void)
>  {
> -	driver_unregister(&trusted_key_driver.driver);
> +	tee_client_driver_unregister(&trusted_key_driver);
>  }
>  
>  struct trusted_key_ops trusted_key_tee_ops = {
> -- 
> 2.47.3
> 

Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>

BR, Jarkko

[PATCH v2 15/17] KEYS: trusted: 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>
---
 security/keys/trusted-keys/trusted_tee.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/security/keys/trusted-keys/trusted_tee.c b/security/keys/trusted-keys/trusted_tee.c
index 3cea9a377955..6e465c8bef5e 100644
--- a/security/keys/trusted-keys/trusted_tee.c
+++ b/security/keys/trusted-keys/trusted_tee.c
@@ -202,9 +202,9 @@ static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data)
 		return 0;
 }
 
-static int trusted_key_probe(struct device *dev)
+static int trusted_key_probe(struct tee_client_device *rng_device)
 {
-	struct tee_client_device *rng_device = to_tee_client_device(dev);
+	struct device *dev = &rng_device->dev;
 	int ret;
 	struct tee_ioctl_open_session_arg sess_arg;
 
@@ -244,13 +244,11 @@ static int trusted_key_probe(struct device *dev)
 	return ret;
 }
 
-static int trusted_key_remove(struct device *dev)
+static void trusted_key_remove(struct tee_client_device *dev)
 {
 	unregister_key_type(&key_type_trusted);
 	tee_client_close_session(pvt_data.ctx, pvt_data.session_id);
 	tee_client_close_context(pvt_data.ctx);
-
-	return 0;
 }
 
 static const struct tee_client_device_id trusted_key_id_table[] = {
@@ -261,11 +259,11 @@ static const struct tee_client_device_id trusted_key_id_table[] = {
 MODULE_DEVICE_TABLE(tee, trusted_key_id_table);
 
 static struct tee_client_driver trusted_key_driver = {
+	.probe		= trusted_key_probe,
+	.remove		= trusted_key_remove,
 	.id_table	= trusted_key_id_table,
 	.driver		= {
 		.name		= DRIVER_NAME,
-		.probe		= trusted_key_probe,
-		.remove		= trusted_key_remove,
 	},
 };
 
-- 
2.47.3

Re: [PATCH v2 15/17] KEYS: trusted: Make use of tee bus methods

[Jarkko Sakkinen]

On Mon, Dec 15, 2025 at 03:16:45PM +0100, Uwe Kleine-König wrote:
> 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>
> ---
>  security/keys/trusted-keys/trusted_tee.c | 12 +++++-------
>  1 file changed, 5 insertions(+), 7 deletions(-)
> 
> diff --git a/security/keys/trusted-keys/trusted_tee.c b/security/keys/trusted-keys/trusted_tee.c
> index 3cea9a377955..6e465c8bef5e 100644
> --- a/security/keys/trusted-keys/trusted_tee.c
> +++ b/security/keys/trusted-keys/trusted_tee.c
> @@ -202,9 +202,9 @@ static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data)
>  		return 0;
>  }
>  
> -static int trusted_key_probe(struct device *dev)
> +static int trusted_key_probe(struct tee_client_device *rng_device)
>  {
> -	struct tee_client_device *rng_device = to_tee_client_device(dev);
> +	struct device *dev = &rng_device->dev;
>  	int ret;
>  	struct tee_ioctl_open_session_arg sess_arg;

I'm sorry but cannot help saying but these not being in reverse tree
order hurts my eyes ;-)

I.e., I'd personally move declaration of sess_arg right after rng_device
despite being additional change to the scope of the patch.

That said, Sumit has the ultimate veto right here, and this not any kind
of fault in this patch so I will obviously ack the patch;

Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>


>  
> @@ -244,13 +244,11 @@ static int trusted_key_probe(struct device *dev)
>  	return ret;
>  }
>  
> -static int trusted_key_remove(struct device *dev)
> +static void trusted_key_remove(struct tee_client_device *dev)
>  {
>  	unregister_key_type(&key_type_trusted);
>  	tee_client_close_session(pvt_data.ctx, pvt_data.session_id);
>  	tee_client_close_context(pvt_data.ctx);
> -
> -	return 0;
>  }
>  
>  static const struct tee_client_device_id trusted_key_id_table[] = {
> @@ -261,11 +259,11 @@ static const struct tee_client_device_id trusted_key_id_table[] = {
>  MODULE_DEVICE_TABLE(tee, trusted_key_id_table);
>  
>  static struct tee_client_driver trusted_key_driver = {
> +	.probe		= trusted_key_probe,
> +	.remove		= trusted_key_remove,
>  	.id_table	= trusted_key_id_table,
>  	.driver		= {
>  		.name		= DRIVER_NAME,
> -		.probe		= trusted_key_probe,
> -		.remove		= trusted_key_remove,
>  	},
>  };
>  
> -- 
> 2.47.3
> 

BR, Jarkko

[PATCH v2 16/17] tpm/tpm_ftpm_tee: Make use of tee specific driver registration

[Uwe Kleine-König]

tee_client_driver_register() is typed more strongly and cares about
assigning the driver's bus. Similar for tee_client_driver_unregister().

Make use of these functions.

Reviewed-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
---
 drivers/char/tpm/tpm_ftpm_tee.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/char/tpm/tpm_ftpm_tee.c b/drivers/char/tpm/tpm_ftpm_tee.c
index 4e63c30aeaf1..e5fbc70b0eca 100644
--- a/drivers/char/tpm/tpm_ftpm_tee.c
+++ b/drivers/char/tpm/tpm_ftpm_tee.c
@@ -338,7 +338,6 @@ static struct tee_client_driver ftpm_tee_driver = {
 	.id_table	= optee_ftpm_id_table,
 	.driver		= {
 		.name		= "optee-ftpm",
-		.bus		= &tee_bus_type,
 		.probe		= ftpm_tee_probe,
 		.remove		= ftpm_tee_remove,
 	},
@@ -352,7 +351,7 @@ static int __init ftpm_mod_init(void)
 	if (rc)
 		return rc;
 
-	rc = driver_register(&ftpm_tee_driver.driver);
+	rc = tee_client_driver_register(&ftpm_tee_driver);
 	if (rc) {
 		platform_driver_unregister(&ftpm_tee_plat_driver);
 		return rc;
@@ -364,7 +363,7 @@ static int __init ftpm_mod_init(void)
 static void __exit ftpm_mod_exit(void)
 {
 	platform_driver_unregister(&ftpm_tee_plat_driver);
-	driver_unregister(&ftpm_tee_driver.driver);
+	tee_client_driver_unregister(&ftpm_tee_driver);
 }
 
 module_init(ftpm_mod_init);
-- 
2.47.3

Re: [PATCH v2 16/17] tpm/tpm_ftpm_tee: Make use of tee specific driver registration

[Jarkko Sakkinen]

On Mon, Dec 15, 2025 at 03:16:46PM +0100, Uwe Kleine-König wrote:
> tee_client_driver_register() is typed more strongly and cares about
> assigning the driver's bus. Similar for tee_client_driver_unregister().
> 
> Make use of these functions.
> 
> Reviewed-by: Sumit Garg <sumit.garg@oss.qualcomm.com>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
> ---
>  drivers/char/tpm/tpm_ftpm_tee.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm_ftpm_tee.c b/drivers/char/tpm/tpm_ftpm_tee.c
> index 4e63c30aeaf1..e5fbc70b0eca 100644
> --- a/drivers/char/tpm/tpm_ftpm_tee.c
> +++ b/drivers/char/tpm/tpm_ftpm_tee.c
> @@ -338,7 +338,6 @@ static struct tee_client_driver ftpm_tee_driver = {
>  	.id_table	= optee_ftpm_id_table,
>  	.driver		= {
>  		.name		= "optee-ftpm",
> -		.bus		= &tee_bus_type,
>  		.probe		= ftpm_tee_probe,
>  		.remove		= ftpm_tee_remove,
>  	},
> @@ -352,7 +351,7 @@ static int __init ftpm_mod_init(void)
>  	if (rc)
>  		return rc;
>  
> -	rc = driver_register(&ftpm_tee_driver.driver);
> +	rc = tee_client_driver_register(&ftpm_tee_driver);
>  	if (rc) {
>  		platform_driver_unregister(&ftpm_tee_plat_driver);
>  		return rc;
> @@ -364,7 +363,7 @@ static int __init ftpm_mod_init(void)
>  static void __exit ftpm_mod_exit(void)
>  {
>  	platform_driver_unregister(&ftpm_tee_plat_driver);
> -	driver_unregister(&ftpm_tee_driver.driver);
> +	tee_client_driver_unregister(&ftpm_tee_driver);
>  }
>  
>  module_init(ftpm_mod_init);
> -- 
> 2.47.3
> 

Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>

BR, Jarkko

[PATCH v2 17/17] tpm/tpm_ftpm_tee: 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>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
---
 drivers/char/tpm/tpm_ftpm_tee.c | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/drivers/char/tpm/tpm_ftpm_tee.c b/drivers/char/tpm/tpm_ftpm_tee.c
index e5fbc70b0eca..20294d1953a3 100644
--- a/drivers/char/tpm/tpm_ftpm_tee.c
+++ b/drivers/char/tpm/tpm_ftpm_tee.c
@@ -169,7 +169,7 @@ static int ftpm_tee_match(struct tee_ioctl_version_data *ver, const void *data)
  * Return:
  *	On success, 0. On failure, -errno.
  */
-static int ftpm_tee_probe(struct device *dev)
+static int ftpm_tee_probe_generic(struct device *dev)
 {
 	int rc;
 	struct tpm_chip *chip;
@@ -251,11 +251,18 @@ static int ftpm_tee_probe(struct device *dev)
 	return rc;
 }
 
+static int ftpm_tee_probe(struct tee_client_device *tcdev)
+{
+	struct device *dev = &tcdev->dev;
+
+	return ftpm_tee_probe_generic(dev);
+}
+
 static int ftpm_plat_tee_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 
-	return ftpm_tee_probe(dev);
+	return ftpm_tee_probe_generic(dev);
 }
 
 /**
@@ -265,7 +272,7 @@ static int ftpm_plat_tee_probe(struct platform_device *pdev)
  * Return:
  *	0 always.
  */
-static int ftpm_tee_remove(struct device *dev)
+static void ftpm_tee_remove_generic(struct device *dev)
 {
 	struct ftpm_tee_private *pvt_data = dev_get_drvdata(dev);
 
@@ -285,15 +292,20 @@ static int ftpm_tee_remove(struct device *dev)
 	tee_client_close_context(pvt_data->ctx);
 
 	/* memory allocated with devm_kzalloc() is freed automatically */
+}
 
-	return 0;
+static void ftpm_tee_remove(struct tee_client_device *tcdev)
+{
+	struct device *dev = &tcdev->dev;
+
+	ftpm_tee_remove_generic(dev);
 }
 
 static void ftpm_plat_tee_remove(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 
-	ftpm_tee_remove(dev);
+	ftpm_tee_remove_generic(dev);
 }
 
 /**
@@ -335,11 +347,11 @@ static const struct tee_client_device_id optee_ftpm_id_table[] = {
 MODULE_DEVICE_TABLE(tee, optee_ftpm_id_table);
 
 static struct tee_client_driver ftpm_tee_driver = {
+	.probe		= ftpm_tee_probe,
+	.remove		= ftpm_tee_remove,
 	.id_table	= optee_ftpm_id_table,
 	.driver		= {
 		.name		= "optee-ftpm",
-		.probe		= ftpm_tee_probe,
-		.remove		= ftpm_tee_remove,
 	},
 };
 
-- 
2.47.3

Re: [PATCH v2 17/17] tpm/tpm_ftpm_tee: Make use of tee bus methods

[Jarkko Sakkinen]

On Mon, Dec 15, 2025 at 03:16:47PM +0100, Uwe Kleine-König wrote:
> The tee bus got dedicated callbacks for probe and remove.

nit: "TEE subsystem has implemented callbacks for probe() and remove()".

Or this what I presume has happened: someone has implemented new
callbacks to subsystem (vs randomly appearing from the divine
skies).

> 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>
> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
> ---
>  drivers/char/tpm/tpm_ftpm_tee.c | 26 +++++++++++++++++++-------
>  1 file changed, 19 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm_ftpm_tee.c b/drivers/char/tpm/tpm_ftpm_tee.c
> index e5fbc70b0eca..20294d1953a3 100644
> --- a/drivers/char/tpm/tpm_ftpm_tee.c
> +++ b/drivers/char/tpm/tpm_ftpm_tee.c
> @@ -169,7 +169,7 @@ static int ftpm_tee_match(struct tee_ioctl_version_data *ver, const void *data)
>   * Return:
>   *	On success, 0. On failure, -errno.
>   */
> -static int ftpm_tee_probe(struct device *dev)
> +static int ftpm_tee_probe_generic(struct device *dev)
>  {
>  	int rc;
>  	struct tpm_chip *chip;
> @@ -251,11 +251,18 @@ static int ftpm_tee_probe(struct device *dev)
>  	return rc;
>  }
>  
> +static int ftpm_tee_probe(struct tee_client_device *tcdev)
> +{
> +	struct device *dev = &tcdev->dev;
> +
> +	return ftpm_tee_probe_generic(dev);
> +}
> +
>  static int ftpm_plat_tee_probe(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
>  
> -	return ftpm_tee_probe(dev);
> +	return ftpm_tee_probe_generic(dev);
>  }
>  
>  /**
> @@ -265,7 +272,7 @@ static int ftpm_plat_tee_probe(struct platform_device *pdev)
>   * Return:
>   *	0 always.
>   */
> -static int ftpm_tee_remove(struct device *dev)
> +static void ftpm_tee_remove_generic(struct device *dev)
>  {
>  	struct ftpm_tee_private *pvt_data = dev_get_drvdata(dev);
>  
> @@ -285,15 +292,20 @@ static int ftpm_tee_remove(struct device *dev)
>  	tee_client_close_context(pvt_data->ctx);
>  
>  	/* memory allocated with devm_kzalloc() is freed automatically */
> +}
>  
> -	return 0;
> +static void ftpm_tee_remove(struct tee_client_device *tcdev)
> +{
> +	struct device *dev = &tcdev->dev;
> +
> +	ftpm_tee_remove_generic(dev);
>  }
>  
>  static void ftpm_plat_tee_remove(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
>  
> -	ftpm_tee_remove(dev);
> +	ftpm_tee_remove_generic(dev);
>  }
>  
>  /**
> @@ -335,11 +347,11 @@ static const struct tee_client_device_id optee_ftpm_id_table[] = {
>  MODULE_DEVICE_TABLE(tee, optee_ftpm_id_table);
>  
>  static struct tee_client_driver ftpm_tee_driver = {
> +	.probe		= ftpm_tee_probe,
> +	.remove		= ftpm_tee_remove,
>  	.id_table	= optee_ftpm_id_table,
>  	.driver		= {
>  		.name		= "optee-ftpm",
> -		.probe		= ftpm_tee_probe,
> -		.remove		= ftpm_tee_remove,
>  	},
>  };
>  
> -- 
> 2.47.3
> 

BR, Jarkko