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 v8:
- Fix coding style.

 drivers/usb/typec/Makefile       |  2 +-
 drivers/usb/typec/bus.h          |  2 ++
 drivers/usb/typec/class.c        |  3 +++
 drivers/usb/typec/notify.c       | 24 ++++++++++++++++++++++++
 include/linux/usb/typec_notify.h | 16 ++++++++++++++++
 5 files changed, 46 insertions(+), 1 deletion(-)
 create mode 100644 drivers/usb/typec/notify.c
 create mode 100644 include/linux/usb/typec_notify.h

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..51e971bc68d1 100644
--- a/drivers/usb/typec/class.c
+++ b/drivers/usb/typec/class.c
@@ -13,6 +13,7 @@
 #include <linux/string_choices.h>
 #include <linux/usb/pd_vdo.h>
 #include <linux/usb/typec_mux.h>
+#include <linux/usb/typec_notify.h>
 #include <linux/usb/typec_retimer.h>
 #include <linux/usb.h>
 
@@ -600,6 +601,8 @@ typec_register_altmode(struct device *parent,
 		return ERR_PTR(ret);
 	}
 
+	typec_notify_event(TYPEC_ALTMODE_REGISTERED, &alt->adev);
+
 	return &alt->adev;
 }
 
diff --git a/drivers/usb/typec/notify.c b/drivers/usb/typec/notify.c
new file mode 100644
index 000000000000..0a14d3ae224e
--- /dev/null
+++ b/drivers/usb/typec/notify.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/notifier.h>
+#include <linux/usb/typec_notify.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_notify.h b/include/linux/usb/typec_notify.h
new file mode 100644
index 000000000000..f3a7b5f5b05b
--- /dev/null
+++ b/include/linux/usb/typec_notify.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __USB_TYPEC_NOTIFY
+#define __USB_TYPEC_NOTIFY
+
+#include <linux/notifier.h>
+
+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);
+
+#endif /* __USB_TYPEC_NOTIFY */
-- 
2.49.0

Hi,

> diff --git a/include/linux/usb/typec_notify.h b/include/linux/usb/typec_notify.h
> new file mode 100644
> index 000000000000..f3a7b5f5b05b
> --- /dev/null
> +++ b/include/linux/usb/typec_notify.h
> @@ -0,0 +1,16 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +
> +#ifndef __USB_TYPEC_NOTIFY
> +#define __USB_TYPEC_NOTIFY
> +
> +#include <linux/notifier.h>

Replace that include with a forward declaration:

struct notifier_block;

> +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);
> +
> +#endif /* __USB_TYPEC_NOTIFY */

I don't see any need for a separate header file for this. Intoduce
those in typec_altmode.h.

thanks,

-- 
heikki

On 10/31/2025 9:39 PM, Heikki Krogerus wrote:

> Hi,
>
>> diff --git a/include/linux/usb/typec_notify.h b/include/linux/usb/typec_notify.h
>> new file mode 100644
>> index 000000000000..f3a7b5f5b05b
>> --- /dev/null
>> +++ b/include/linux/usb/typec_notify.h
>> @@ -0,0 +1,16 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +
>> +#ifndef __USB_TYPEC_NOTIFY
>> +#define __USB_TYPEC_NOTIFY
>> +
>> +#include <linux/notifier.h>
> Replace that include with a forward declaration:
>
> struct notifier_block;
>
>> +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);
>> +
>> +#endif /* __USB_TYPEC_NOTIFY */
> I don't see any need for a separate header file for this. Intoduce
> those in typec_altmode.h.

Will fix these in v9. Thank you.


>
> thanks,
>
-- 
Best,
Chaoyi