Tue, Nov 11, 2025 at 06:50:31PM +0800, Chaoyi Chen kirjoitti:
> From: Chaoyi Chen <[email protected]>
>
> Some other part of kernel may want to know the event of typec bus.
>
> This patch add common notifier function to notify these event.
>
> Signed-off-by: Chaoyi Chen <[email protected]>
> ---
>
> Changes in v9:
> - Remove redundant header files.
>
> Changes in v8:
> - Fix coding style.
>
> drivers/usb/typec/Makefile | 2 +-
> drivers/usb/typec/bus.h | 2 ++
> drivers/usb/typec/class.c | 2 ++
> drivers/usb/typec/notify.c | 23 +++++++++++++++++++++++
> include/linux/usb/typec_altmode.h | 9 +++++++++
> 5 files changed, 37 insertions(+), 1 deletion(-)
> create mode 100644 drivers/usb/typec/notify.c
>
> diff --git a/drivers/usb/typec/Makefile b/drivers/usb/typec/Makefile
> index 7a368fea61bc..20d09c5314d7 100644
> --- a/drivers/usb/typec/Makefile
> +++ b/drivers/usb/typec/Makefile
> @@ -1,6 +1,6 @@
> # SPDX-License-Identifier: GPL-2.0
> obj-$(CONFIG_TYPEC) += typec.o
> -typec-y := class.o mux.o bus.o pd.o retimer.o
> +typec-y := class.o mux.o notify.o bus.o pd.o
> retimer.o
> typec-$(CONFIG_ACPI) += port-mapper.o
> obj-$(CONFIG_TYPEC) += altmodes/
> obj-$(CONFIG_TYPEC_TCPM) += tcpm/
> diff --git a/drivers/usb/typec/bus.h b/drivers/usb/typec/bus.h
> index 643b8c81786d..820b59b6d434 100644
> --- a/drivers/usb/typec/bus.h
> +++ b/drivers/usb/typec/bus.h
> @@ -26,6 +26,8 @@ struct altmode {
> struct altmode *plug[2];
> };
>
> +void typec_notify_event(unsigned long event, void *data);
> +
> #define to_altmode(d) container_of(d, struct altmode, adev)
>
> extern const struct bus_type typec_bus;
> diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
> index 9b2647cb199b..9d2aa3dd3f56 100644
> --- a/drivers/usb/typec/class.c
> +++ b/drivers/usb/typec/class.c
> @@ -600,6 +600,8 @@ typec_register_altmode(struct device *parent,
> return ERR_PTR(ret);
> }
>
> + typec_notify_event(TYPEC_ALTMODE_REGISTERED, &alt->adev);
> +
> return &alt->adev;
> }
You need to also send TYPEC_ALTMODE_UNREGISTERED notification in
typec_unregister_altmode().
thanks,
> diff --git a/drivers/usb/typec/notify.c b/drivers/usb/typec/notify.c
> new file mode 100644
> index 000000000000..9e50b54da359
> --- /dev/null
> +++ b/drivers/usb/typec/notify.c
> @@ -0,0 +1,23 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include <linux/notifier.h>
> +
> +#include "bus.h"
> +
> +static BLOCKING_NOTIFIER_HEAD(typec_notifier_list);
> +
> +int typec_altmode_register_notify(struct notifier_block *nb)
> +{
> + return blocking_notifier_chain_register(&typec_notifier_list, nb);
> +}
> +EXPORT_SYMBOL_GPL(typec_altmode_register_notify);
> +
> +int typec_altmode_unregister_notify(struct notifier_block *nb)
> +{
> + return blocking_notifier_chain_unregister(&typec_notifier_list, nb);
> +}
> +EXPORT_SYMBOL_GPL(typec_altmode_unregister_notify);
> +
> +void typec_notify_event(unsigned long event, void *data)
> +{
> + blocking_notifier_call_chain(&typec_notifier_list, event, data);
> +}
> diff --git a/include/linux/usb/typec_altmode.h
> b/include/linux/usb/typec_altmode.h
> index f7db3bd4c90e..59e20702504b 100644
> --- a/include/linux/usb/typec_altmode.h
> +++ b/include/linux/usb/typec_altmode.h
> @@ -10,6 +10,7 @@
> #define MODE_DISCOVERY_MAX 6
>
> struct typec_altmode_ops;
> +struct notifier_block;
>
> /**
> * struct typec_altmode - USB Type-C alternate mode device
> @@ -77,6 +78,14 @@ int typec_altmode_notify(struct typec_altmode *altmode,
> unsigned long conf,
> const struct typec_altmode *
> typec_altmode_get_partner(struct typec_altmode *altmode);
>
> +enum usb_typec_event {
> + TYPEC_ALTMODE_REGISTERED,
> + TYPEC_ALTMODE_UNREGISTERED,
> +};
> +
> +int typec_altmode_register_notify(struct notifier_block *nb);
> +int typec_altmode_unregister_notify(struct notifier_block *nb);
> +
> /**
> * struct typec_cable_ops - Cable alternate mode operations vector
> * @enter: Operations to be executed with Enter Mode Command
> --
> 2.51.1
--
heikki
