[PATCH v7 1/9] usb: typec: Add notifier functions

[Chaoyi Chen <kernel@airkyi.com>]

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>
---
 drivers/usb/typec/Makefile       |  2 +-
 drivers/usb/typec/class.c        |  3 +++
 drivers/usb/typec/notify.c       | 22 ++++++++++++++++++++++
 include/linux/usb/typec_notify.h | 17 +++++++++++++++++
 4 files changed, 43 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/class.c b/drivers/usb/typec/class.c
index 67a533e35150..11c80bc59cda 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..4ae14dd1f461
--- /dev/null
+++ b/drivers/usb/typec/notify.c
@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/notifier.h>
+#include <linux/usb/typec_notify.h>
+
+static BLOCKING_NOTIFIER_HEAD(typec_notifier_list);
+
+int typec_register_notify(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_register(&typec_notifier_list, nb);
+}
+EXPORT_SYMBOL_GPL(typec_register_notify);
+
+int typec_unregister_notify(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_unregister(&typec_notifier_list, nb);
+}
+EXPORT_SYMBOL_GPL(typec_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..a3f1f3b3ae47
--- /dev/null
+++ b/include/linux/usb/typec_notify.h
@@ -0,0 +1,17 @@
+/* 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
+};
+
+int typec_register_notify(struct notifier_block *nb);
+int typec_unregister_notify(struct notifier_block *nb);
+
+void typec_notify_event(unsigned long event, void *data);
+
+#endif /* __USB_TYPEC_NOTIFY */
-- 
2.49.0