--- zzzz-none-000/linux-5.4.213/include/linux/serdev.h	2022-09-15 10:04:56.000000000 +0000
+++ alder-5690pro-762/linux-5.4.213/include/linux/serdev.h	2024-08-14 09:02:08.000000000 +0000
@@ -91,6 +91,8 @@
 	void (*wait_until_sent)(struct serdev_controller *, long);
 	int (*get_tiocm)(struct serdev_controller *);
 	int (*set_tiocm)(struct serdev_controller *, unsigned int, unsigned int);
+	int (*ioctl)(struct serdev_controller *ctrl, unsigned int cmd,
+		     unsigned long arg);
 };
 
 /**
@@ -201,6 +203,8 @@
 void serdev_device_wait_until_sent(struct serdev_device *, long);
 int serdev_device_get_tiocm(struct serdev_device *);
 int serdev_device_set_tiocm(struct serdev_device *, int, int);
+int serdev_device_ioctl(struct serdev_device *serdev,
+			unsigned int cmd, unsigned long arg);
 void serdev_device_write_wakeup(struct serdev_device *);
 int serdev_device_write(struct serdev_device *, const unsigned char *, size_t, long);
 void serdev_device_write_flush(struct serdev_device *);
@@ -254,6 +258,13 @@
 {
 	return -ENOTSUPP;
 }
+
+static inline int serdev_device_ioctl(struct serdev_device *serdev,
+				      unsigned int cmd, unsigned long arg)
+{
+	return -ENOTTY;
+}
+
 static inline int serdev_device_write(struct serdev_device *sdev, const unsigned char *buf,
 				      size_t count, unsigned long timeout)
 {