Re: [PATCH v9 01/10] usb: typec: Add notifier functions

[Heikki Krogerus <heikki.krogerus@linux.intel.com>]

Tue, Nov 11, 2025 at 06:50:31PM +0800, Chaoyi Chen kirjoitti:
> From: Chaoyi Chen <chaoyi.chen@rock-chips.com>
> 
> 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 <chaoyi.chen@rock-chips.com>
> ---
> 
> 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