[PATCH 05/11] drivers: bus: add the stm32 debug bus driver

[Jens Wiklander]

On Tue, Jan 13, 2026 at 5:09 PM Gatien CHEVALLIER
<gatien.chevallier at foss.st.com> wrote:
>
>
>
> On 1/13/26 15:45, Jens Wiklander wrote:
> > Hi,
> >
> > On Fri, Jan 9, 2026 at 11:57 AM Gatien Chevallier
> > <gatien.chevallier at foss.st.com> wrote:
> >>
> >> Add the stm32 debug bus driver that is responsible of checking the
> >> debug subsystem accessibility before probing the related peripheral
> >> drivers.
> >>
> >> This driver is OP-TEE dependent and relies on the STM32 debug access
> >> PTA.
> >>
> >> Signed-off-by: Gatien Chevallier <gatien.chevallier at foss.st.com>
> >> ---
> >>   MAINTAINERS                 |   1 +
> >>   drivers/bus/Kconfig         |  10 ++
> >>   drivers/bus/Makefile        |   1 +
> >>   drivers/bus/stm32_dbg_bus.c | 285 ++++++++++++++++++++++++++++++++++++++++++++
> >>   4 files changed, 297 insertions(+)
> >>
> >
> > [snip]
> >
> >> +
> >> +static const struct tee_client_device_id optee_dbg_bus_id_table[] = {
> >> +       {UUID_INIT(0xdd05bc8b, 0x9f3b, 0x49f0,
> >> +                  0xb6, 0x49, 0x01, 0xaa, 0x10, 0xc1, 0xc2, 0x10)},
> >> +       {}
> >> +};
> >> +
> >> +static struct tee_client_driver stm32_optee_dbg_bus_driver = {
> >> +       .id_table = optee_dbg_bus_id_table,
> >> +       .driver = {
> >> +               .name = "optee_dbg_bus",
> >> +               .bus = &tee_bus_type,
> >> +               .probe = stm32_dbg_bus_probe,
> >> +               .remove = stm32_dbg_bus_remove,
> >> +       },
> >> +};
> >
> > Just a heads up. With
> > https://lore.kernel.org/op-tee/cover.1765791463.git.u.kleine-koenig@baylibre.com/
> > we're switching to use bus methods instead of device_driver callbacks.
> > That plan is to merge that patch set in the next merge window.
> >
> > Cheers,
> > Jens
> >
>
> Hello Jens,
>
> Thank you for the link!
> Is it fine if I push on top on your "next" branch for the review along
> with the appropriate changes? I'm open to suggestions.

Please base it on the tee_bus_callback_for_6.20 branch instead.

Cheers,
Jens

>
> Thanks,
> Gatien
>
> >> +
> >> +static int __init optee_dbg_bus_mod_init(void)
> >> +{
> >> +       int ret;
> >> +
> >> +       ret = driver_register(&stm32_optee_dbg_bus_driver.driver);
> >> +       if (ret)
> >> +               return ret;
> >> +
> >> +       ret = platform_driver_register(&stm32_dbg_bus_driver);
> >> +       if (ret)
> >> +               driver_unregister(&stm32_optee_dbg_bus_driver.driver);
> >> +
> >> +       return ret;
> >> +}
> >> +
> >> +static void __exit optee_dbg_bus_mod_exit(void)
> >> +{
> >> +       platform_driver_unregister(&stm32_dbg_bus_driver);
> >> +       driver_unregister(&stm32_optee_dbg_bus_driver.driver);
> >> +}
> >> +
> >> +module_init(optee_dbg_bus_mod_init);
> >> +module_exit(optee_dbg_bus_mod_exit);
> >> +
> >> +MODULE_LICENSE("GPL");
> >> +MODULE_AUTHOR("Gatien Chevallier <gatien.chevallier at foss.st.com>");
> >> +MODULE_DESCRIPTION("OP-TEE based STM32 debug access bus driver");
> >>
> >> --
> >> 2.43.0
> >>
> >>
>