Re: [PATCH v1 02/17] tee: Add probe, remove and shutdown bus callbacks to tee_client_driver

Sumit Garg
2025-12-15T07:23:13Z

On Thu, Dec 11, 2025 at 06:14:56PM +0100, Uwe Kleine-König wrote:
> Introduce a bus specific probe, remove and shutdown function. For now
> this only allows to get rid of a cast of the generic device to a
> tee_client device in the drivers and changes the remove prototype to
> return void---a non-zero return value is ignored anyhow.
>
> The objective is to get rid of users of struct device_driver callbacks
> .probe(), .remove() and .shutdown() to eventually remove these. Until
> all tee_client drivers are converted this results in a runtime warning
> about the drivers needing an update because there is a bus probe
> function and a driver probe function.
>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
> ---
> drivers/tee/tee_core.c | 68 +++++++++++++++++++++++++++++++++++++++++
> include/linux/tee_drv.h | 3 ++
> 2 files changed, 71 insertions(+)
>
> diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
> index 51379f7fc5d5..89164d35fc5c 100644
> --- a/drivers/tee/tee_core.c
> +++ b/drivers/tee/tee_core.c
> @@ -1398,19 +1398,87 @@ static int tee_client_device_uevent(const struct device *dev,
> return add_uevent_var(env, "MODALIAS=tee:%pUb", dev_id);
> }
>
> +static int tee_client_device_probe(struct device *dev)
> +{
> + struct tee_client_device *tcdev= to_tee_client_device(dev);

missing space: s/tcdev=/tcdev =/

> + struct tee_client_driver *drv = to_tee_client_driver(dev->driver);
> +
> + if (drv->probe)
> + return drv->probe(tcdev);
> + else
> + return 0;
> +}
> +
> +static void tee_client_device_remove(struct device *dev)
> +{
> + struct tee_client_device *tcdev= to_tee_client_device(dev);

ditto.

> + struct tee_client_driver *drv = to_tee_client_driver(dev->driver);
> +
> + if (drv->remove)
> + drv->remove(tcdev);
> +}
> +
> +static void tee_client_device_shutdown(struct device *dev)
> +{
> + struct tee_client_device *tcdev= to_tee_client_device(dev);

ditto.

> + struct tee_client_driver *drv = to_tee_client_driver(dev->driver);
> +
> + if (dev->driver && drv->remove)
> + drv->remove(tcdev);

don't we need to check and invoke drv->shutdown here?

> +}
> +
> const struct bus_type tee_bus_type = {
> .name = "tee",
> .match = tee_client_device_match,
> .uevent = tee_client_device_uevent,
> + .probe = tee_client_device_probe,
> + .remove = tee_client_device_remove,
> + .shutdown = tee_client_device_shutdown,
> };
> EXPORT_SYMBOL_GPL(tee_bus_type);
>
> +static int tee_client_device_probe_legacy(struct tee_client_device *tcdev)
> +{
> + struct device *dev = &tcdev->dev;
> + struct device_driver *driver = dev->driver;
> +
> + return driver->probe(dev);
> +}
> +
> +static void tee_client_device_remove_legacy(struct tee_client_device *tcdev)
> +{
> + struct device *dev = &tcdev->dev;
> + struct device_driver *driver = dev->driver;
> +
> + driver->remove(dev);
> +}
> +
> +static void tee_client_device_shutdown_legacy(struct tee_client_device *tcdev)
> +{
> + struct device *dev = &tcdev->dev;
> + struct device_driver *driver = dev->driver;
> +
> + driver->shutdown(dev);
> +}
> +
> int __tee_client_driver_register(struct tee_client_driver *tee_driver,
> struct module *owner)
> {
> tee_driver->driver.owner = owner;
> tee_driver->driver.bus = &tee_bus_type;
>
> + /*
> + * Drivers that have callbacks set for tee_driver->driver need updating
> + * to use the callbacks in tee_driver instead. driver_register() warns
> + * about that, so no need to warn here, too.
> + */
> + if (!tee_driver->probe && tee_driver->driver.probe)
> + tee_driver->probe = tee_client_device_probe_legacy;
> + if (!tee_driver->remove && tee_driver->driver.remove)
> + tee_driver->remove= tee_client_device_remove_legacy;

missing space: s/tee_driver->remove=/tee_driver->remove =/

> + if (!tee_driver->shutdown && tee_driver->driver.probe)

you should rather check here for tee_driver->driver.shutdown?

-Sumit

> + tee_driver->shutdown = tee_client_device_shutdown_legacy;
> +
> return driver_register(&tee_driver->driver);
> }
> EXPORT_SYMBOL_GPL(__tee_client_driver_register);
> diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h
> index 850c03b2cdea..e561a26f537a 100644
> --- a/include/linux/tee_drv.h
> +++ b/include/linux/tee_drv.h
> @@ -315,6 +315,9 @@ struct tee_client_device {
> * @driver: driver structure
> */
> struct tee_client_driver {
> + int (*probe)(struct tee_client_device *);
> + void (*remove)(struct tee_client_device *);
> + void (*shutdown)(struct tee_client_device *);
> const struct tee_client_device_id *id_table;
> struct device_driver driver;
> };
> --
> 2.47.3
>