4 files changed, 237 insertions, 111 deletions

diff --git a/drivers/tty/serdev/Kconfig b/drivers/tty/serdev/Kconfig
index 1dbc8352e027..46ae732bfc68 100644
--- a/drivers/tty/serdev/Kconfig
+++ b/drivers/tty/serdev/Kconfig
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 #
 # Serial bus device driver configuration
 #
diff --git a/drivers/tty/serdev/Makefile b/drivers/tty/serdev/Makefile
index 0cbdb9444d9d..078417e5b068 100644
--- a/drivers/tty/serdev/Makefile
+++ b/drivers/tty/serdev/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 serdev-objs := core.o
 
 obj-$(CONFIG_SERIAL_DEV_BUS) += serdev.o
diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
index a0ac16ee6575..b33e708cb245 100644
--- a/drivers/tty/serdev/core.c
+++ b/drivers/tty/serdev/core.c
@@ -15,10 +15,13 @@
 #include <linux/of_device.h>
 #include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
+#include <linux/property.h>
 #include <linux/sched.h>
 #include <linux/serdev.h>
 #include <linux/slab.h>
 
+#include <linux/platform_data/x86/apple.h>
+
 static bool is_registered;
 static DEFINE_IDA(ctrl_ida);
 
@@ -41,7 +44,7 @@ static struct attribute *serdev_device_attrs[] = {
 };
 ATTRIBUTE_GROUPS(serdev_device);
 
-static int serdev_device_uevent(struct device *dev, struct kobj_uevent_env *env)
+static int serdev_device_uevent(const struct device *dev, struct kobj_uevent_env *env)
 {
 	int rc;
 
@@ -74,7 +77,7 @@ static bool is_serdev_device(const struct device *dev)
 static void serdev_ctrl_release(struct device *dev)
 {
 	struct serdev_controller *ctrl = to_serdev_controller(dev);
-	ida_simple_remove(&ctrl_ida, ctrl->nr);
+	ida_free(&ctrl_ida, ctrl->nr);
 	kfree(ctrl);
 }
 
@@ -82,7 +85,7 @@ static const struct device_type serdev_ctrl_type = {
 	.release	= serdev_ctrl_release,
 };
 
-static int serdev_device_match(struct device *dev, struct device_driver *drv)
+static int serdev_device_match(struct device *dev, const struct device_driver *drv)
 {
 	if (!is_serdev_device(dev))
 		return 0;
@@ -115,12 +118,11 @@ int serdev_device_add(struct serdev_device *serdev)
 
 	err = device_add(&serdev->dev);
 	if (err < 0) {
-		dev_err(&serdev->dev, "Can't add %s, status %d\n",
-			dev_name(&serdev->dev), err);
+		dev_err(&serdev->dev, "Failed to add serdev: %d\n", err);
 		goto err_clear_serdev;
 	}
 
-	dev_dbg(&serdev->dev, "device %s registered\n", dev_name(&serdev->dev));
+	dev_dbg(&serdev->dev, "serdev registered successfully\n");
 
 	return 0;
 
@@ -184,30 +186,20 @@ void serdev_device_close(struct serdev_device *serdev)
 }
 EXPORT_SYMBOL_GPL(serdev_device_close);
 
-static void devm_serdev_device_release(struct device *dev, void *dr)
+static void devm_serdev_device_close(void *serdev)
 {
-	serdev_device_close(*(struct serdev_device **)dr);
+	serdev_device_close(serdev);
 }
 
 int devm_serdev_device_open(struct device *dev, struct serdev_device *serdev)
 {
-	struct serdev_device **dr;
 	int ret;
 
-	dr = devres_alloc(devm_serdev_device_release, sizeof(*dr), GFP_KERNEL);
-	if (!dr)
-		return -ENOMEM;
-
 	ret = serdev_device_open(serdev);
-	if (ret) {
-		devres_free(dr);
+	if (ret)
 		return ret;
-	}
-
-	*dr = serdev;
-	devres_add(dev, dr);
 
-	return 0;
+	return devm_add_action_or_reset(dev, devm_serdev_device_close, serdev);
 }
 EXPORT_SYMBOL_GPL(devm_serdev_device_open);
 
@@ -232,8 +224,7 @@ EXPORT_SYMBOL_GPL(serdev_device_write_wakeup);
  * Return: The number of bytes written (less than count if not enough room in
  * the write buffer), or a negative errno on errors.
  */
-int serdev_device_write_buf(struct serdev_device *serdev,
-			    const unsigned char *buf, size_t count)
+int serdev_device_write_buf(struct serdev_device *serdev, const u8 *buf, size_t count)
 {
 	struct serdev_controller *ctrl = serdev->ctrl;
 
@@ -266,13 +257,12 @@ EXPORT_SYMBOL_GPL(serdev_device_write_buf);
  * -ETIMEDOUT or -ERESTARTSYS if interrupted before any bytes were written, or
  * a negative errno on errors.
  */
-int serdev_device_write(struct serdev_device *serdev,
-			const unsigned char *buf, size_t count,
-			long timeout)
+ssize_t serdev_device_write(struct serdev_device *serdev, const u8 *buf,
+			    size_t count, long timeout)
 {
 	struct serdev_controller *ctrl = serdev->ctrl;
-	int written = 0;
-	int ret;
+	size_t written = 0;
+	ssize_t ret;
 
 	if (!ctrl || !ctrl->ops->write_buf || !serdev->ops->write_wakeup)
 		return -EINVAL;
@@ -325,17 +315,6 @@ void serdev_device_write_flush(struct serdev_device *serdev)
 }
 EXPORT_SYMBOL_GPL(serdev_device_write_flush);
 
-int serdev_device_write_room(struct serdev_device *serdev)
-{
-	struct serdev_controller *ctrl = serdev->ctrl;
-
-	if (!ctrl || !ctrl->ops->write_room)
-		return 0;
-
-	return serdev->ctrl->ops->write_room(ctrl);
-}
-EXPORT_SYMBOL_GPL(serdev_device_write_room);
-
 unsigned int serdev_device_set_baudrate(struct serdev_device *serdev, unsigned int speed)
 {
 	struct serdev_controller *ctrl = serdev->ctrl;
@@ -365,7 +344,7 @@ int serdev_device_set_parity(struct serdev_device *serdev,
 	struct serdev_controller *ctrl = serdev->ctrl;
 
 	if (!ctrl || !ctrl->ops->set_parity)
-		return -ENOTSUPP;
+		return -EOPNOTSUPP;
 
 	return ctrl->ops->set_parity(ctrl, parity);
 }
@@ -387,7 +366,7 @@ int serdev_device_get_tiocm(struct serdev_device *serdev)
 	struct serdev_controller *ctrl = serdev->ctrl;
 
 	if (!ctrl || !ctrl->ops->get_tiocm)
-		return -ENOTSUPP;
+		return -EOPNOTSUPP;
 
 	return ctrl->ops->get_tiocm(ctrl);
 }
@@ -398,40 +377,44 @@ int serdev_device_set_tiocm(struct serdev_device *serdev, int set, int clear)
 	struct serdev_controller *ctrl = serdev->ctrl;
 
 	if (!ctrl || !ctrl->ops->set_tiocm)
-		return -ENOTSUPP;
+		return -EOPNOTSUPP;
 
 	return ctrl->ops->set_tiocm(ctrl, set, clear);
 }
 EXPORT_SYMBOL_GPL(serdev_device_set_tiocm);
 
+int serdev_device_break_ctl(struct serdev_device *serdev, int break_state)
+{
+	struct serdev_controller *ctrl = serdev->ctrl;
+
+	if (!ctrl || !ctrl->ops->break_ctl)
+		return -EOPNOTSUPP;
+
+	return ctrl->ops->break_ctl(ctrl, break_state);
+}
+EXPORT_SYMBOL_GPL(serdev_device_break_ctl);
+
 static int serdev_drv_probe(struct device *dev)
 {
 	const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);
 	int ret;
 
-	ret = dev_pm_domain_attach(dev, true);
+	ret = dev_pm_domain_attach(dev, PD_FLAG_ATTACH_POWER_ON |
+					PD_FLAG_DETACH_POWER_OFF);
 	if (ret)
 		return ret;
 
-	ret = sdrv->probe(to_serdev_device(dev));
-	if (ret)
-		dev_pm_domain_detach(dev, true);
-
-	return ret;
+	return sdrv->probe(to_serdev_device(dev));
 }
 
-static int serdev_drv_remove(struct device *dev)
+static void serdev_drv_remove(struct device *dev)
 {
 	const struct serdev_device_driver *sdrv = to_serdev_device_driver(dev->driver);
 	if (sdrv->remove)
 		sdrv->remove(to_serdev_device(dev));
-
-	dev_pm_domain_detach(dev, true);
-
-	return 0;
 }
 
-static struct bus_type serdev_bus_type = {
+static const struct bus_type serdev_bus_type = {
 	.name		= "serial",
 	.match		= serdev_device_match,
 	.probe		= serdev_drv_probe,
@@ -466,6 +449,7 @@ EXPORT_SYMBOL_GPL(serdev_device_alloc);
 
 /**
  * serdev_controller_alloc() - Allocate a new serdev controller
+ * @host:	serial port hardware controller device
  * @parent:	parent device
  * @size:	size of private data
  *
@@ -474,8 +458,9 @@ EXPORT_SYMBOL_GPL(serdev_device_alloc);
  * The allocated private data region may be accessed via
  * serdev_controller_get_drvdata()
  */
-struct serdev_controller *serdev_controller_alloc(struct device *parent,
-					      size_t size)
+struct serdev_controller *serdev_controller_alloc(struct device *host,
+						  struct device *parent,
+						  size_t size)
 {
 	struct serdev_controller *ctrl;
 	int id;
@@ -487,7 +472,7 @@ struct serdev_controller *serdev_controller_alloc(struct device *parent,
 	if (!ctrl)
 		return NULL;
 
-	id = ida_simple_get(&ctrl_ida, 0, 0, GFP_KERNEL);
+	id = ida_alloc(&ctrl_ida, GFP_KERNEL);
 	if (id < 0) {
 		dev_err(parent,
 			"unable to allocate serdev controller identifier.\n");
@@ -500,7 +485,8 @@ struct serdev_controller *serdev_controller_alloc(struct device *parent,
 	ctrl->dev.type = &serdev_ctrl_type;
 	ctrl->dev.bus = &serdev_bus_type;
 	ctrl->dev.parent = parent;
-	ctrl->dev.of_node = parent->of_node;
+	ctrl->host = host;
+	device_set_node(&ctrl->dev, dev_fwnode(host));
 	serdev_controller_set_drvdata(ctrl, &ctrl[1]);
 
 	dev_set_name(&ctrl->dev, "serial%d", id);
@@ -526,7 +512,7 @@ static int of_serdev_register_devices(struct serdev_controller *ctrl)
 	bool found = false;
 
 	for_each_available_child_of_node(ctrl->dev.of_node, node) {
-		if (!of_get_property(node, "compatible", NULL))
+		if (!of_property_present(node, "compatible"))
 			continue;
 
 		dev_dbg(&ctrl->dev, "adding child %pOF\n", node);
@@ -535,12 +521,13 @@ static int of_serdev_register_devices(struct serdev_controller *ctrl)
 		if (!serdev)
 			continue;
 
-		serdev->dev.of_node = node;
+		device_set_node(&serdev->dev, of_fwnode_handle(node));
 
 		err = serdev_device_add(serdev);
 		if (err) {
 			dev_err(&serdev->dev,
-				"failure adding device. status %d\n", err);
+				"failure adding device. status %pe\n",
+				ERR_PTR(err));
 			serdev_device_put(serdev);
 		} else
 			found = true;
@@ -552,16 +539,128 @@ static int of_serdev_register_devices(struct serdev_controller *ctrl)
 }
 
 #ifdef CONFIG_ACPI
+
+#define SERDEV_ACPI_MAX_SCAN_DEPTH 32
+
+struct acpi_serdev_lookup {
+	acpi_handle device_handle;
+	acpi_handle controller_handle;
+	int n;
+	int index;
+};
+
+/**
+ * serdev_acpi_get_uart_resource - Gets UARTSerialBus resource if type matches
+ * @ares:	ACPI resource
+ * @uart:	Pointer to UARTSerialBus resource will be returned here
+ *
+ * Checks if the given ACPI resource is of type UARTSerialBus.
+ * In this case, returns a pointer to it to the caller.
+ *
+ * Return: True if resource type is of UARTSerialBus, otherwise false.
+ */
+bool serdev_acpi_get_uart_resource(struct acpi_resource *ares,
+				   struct acpi_resource_uart_serialbus **uart)
+{
+	struct acpi_resource_uart_serialbus *sb;
+
+	if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
+		return false;
+
+	sb = &ares->data.uart_serial_bus;
+	if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_UART)
+		return false;
+
+	*uart = sb;
+	return true;
+}
+EXPORT_SYMBOL_GPL(serdev_acpi_get_uart_resource);
+
+static int acpi_serdev_parse_resource(struct acpi_resource *ares, void *data)
+{
+	struct acpi_serdev_lookup *lookup = data;
+	struct acpi_resource_uart_serialbus *sb;
+	acpi_status status;
+
+	if (!serdev_acpi_get_uart_resource(ares, &sb))
+		return 1;
+
+	if (lookup->index != -1 && lookup->n++ != lookup->index)
+		return 1;
+
+	status = acpi_get_handle(lookup->device_handle,
+				 sb->resource_source.string_ptr,
+				 &lookup->controller_handle);
+	if (ACPI_FAILURE(status))
+		return 1;
+
+	/*
+	 * NOTE: Ideally, we would also want to retrieve other properties here,
+	 * once setting them before opening the device is supported by serdev.
+	 */
+
+	return 1;
+}
+
+static int acpi_serdev_do_lookup(struct acpi_device *adev,
+                                 struct acpi_serdev_lookup *lookup)
+{
+	struct list_head resource_list;
+	int ret;
+
+	lookup->device_handle = acpi_device_handle(adev);
+	lookup->controller_handle = NULL;
+	lookup->n = 0;
+
+	INIT_LIST_HEAD(&resource_list);
+	ret = acpi_dev_get_resources(adev, &resource_list,
+				     acpi_serdev_parse_resource, lookup);
+	acpi_dev_free_resource_list(&resource_list);
+
+	if (ret < 0)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int acpi_serdev_check_resources(struct serdev_controller *ctrl,
+				       struct acpi_device *adev)
+{
+	struct acpi_serdev_lookup lookup;
+	int ret;
+
+	if (acpi_bus_get_status(adev) || !adev->status.present)
+		return -EINVAL;
+
+	/* Look for UARTSerialBusV2 resource */
+	lookup.index = -1;	// we only care for the last device
+
+	ret = acpi_serdev_do_lookup(adev, &lookup);
+	if (ret)
+		return ret;
+
+	/*
+	 * Apple machines provide an empty resource template, so on those
+	 * machines just look for immediate children with a "baud" property
+	 * (from the _DSM method) instead.
+	 */
+	if (!lookup.controller_handle && x86_apple_machine &&
+	    !acpi_dev_get_property(adev, "baud", ACPI_TYPE_BUFFER, NULL))
+		acpi_get_parent(adev->handle, &lookup.controller_handle);
+
+	/* Make sure controller and ResourceSource handle match */
+	if (!device_match_acpi_handle(ctrl->host, lookup.controller_handle))
+		return -ENODEV;
+
+	return 0;
+}
+
 static acpi_status acpi_serdev_register_device(struct serdev_controller *ctrl,
-					    struct acpi_device *adev)
+					       struct acpi_device *adev)
 {
-	struct serdev_device *serdev = NULL;
+	struct serdev_device *serdev;
 	int err;
 
-	if (acpi_bus_get_status(adev) || !adev->status.present ||
-	    acpi_device_enumerated(adev))
-		return AE_OK;
-
 	serdev = serdev_device_alloc(ctrl);
 	if (!serdev) {
 		dev_err(&ctrl->dev, "failed to allocate serdev device for %s\n",
@@ -575,38 +674,66 @@ static acpi_status acpi_serdev_register_device(struct serdev_controller *ctrl,
 	err = serdev_device_add(serdev);
 	if (err) {
 		dev_err(&serdev->dev,
-			"failure adding ACPI serdev device. status %d\n", err);
+			"failure adding ACPI serdev device. status %pe\n",
+			ERR_PTR(err));
 		serdev_device_put(serdev);
 	}
 
 	return AE_OK;
 }
 
+static const struct acpi_device_id serdev_acpi_devices_blacklist[] = {
+	{ "INT3511", 0 },
+	{ "INT3512", 0 },
+	{ },
+};
+
 static acpi_status acpi_serdev_add_device(acpi_handle handle, u32 level,
-				       void *data, void **return_value)
+					  void *data, void **return_value)
 {
+	struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
 	struct serdev_controller *ctrl = data;
-	struct acpi_device *adev;
 
-	if (acpi_bus_get_device(handle, &adev))
+	if (!adev || acpi_device_enumerated(adev))
+		return AE_OK;
+
+	/* Skip if black listed */
+	if (!acpi_match_device_ids(adev, serdev_acpi_devices_blacklist))
+		return AE_OK;
+
+	if (acpi_serdev_check_resources(ctrl, adev))
 		return AE_OK;
 
 	return acpi_serdev_register_device(ctrl, adev);
 }
 
+
 static int acpi_serdev_register_devices(struct serdev_controller *ctrl)
 {
 	acpi_status status;
-	acpi_handle handle;
+	bool skip;
+	int ret;
 
-	handle = ACPI_HANDLE(ctrl->dev.parent);
-	if (!handle)
+	if (!has_acpi_companion(ctrl->host))
 		return -ENODEV;
 
-	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
+	/*
+	 * Skip registration on boards where the ACPI tables are known to
+	 * contain buggy devices. Note serdev_controller_add() must still
+	 * succeed in this case, so that the proper serdev devices can be
+	 * added "manually" later.
+	 */
+	ret = acpi_quirk_skip_serdev_enumeration(ctrl->host, &skip);
+	if (ret)
+		return ret;
+	if (skip)
+		return 0;
+
+	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+				     SERDEV_ACPI_MAX_SCAN_DEPTH,
 				     acpi_serdev_add_device, NULL, ctrl, NULL);
 	if (ACPI_FAILURE(status))
-		dev_dbg(&ctrl->dev, "failed to enumerate serdev slaves\n");
+		dev_warn(&ctrl->dev, "failed to enumerate serdev slaves\n");
 
 	if (!ctrl->serdev)
 		return -ENODEV;
@@ -644,14 +771,13 @@ int serdev_controller_add(struct serdev_controller *ctrl)
 	ret_of = of_serdev_register_devices(ctrl);
 	ret_acpi = acpi_serdev_register_devices(ctrl);
 	if (ret_of && ret_acpi) {
-		dev_dbg(&ctrl->dev, "no devices registered: of:%d acpi:%d\n",
-			ret_of, ret_acpi);
+		dev_dbg(&ctrl->dev, "no devices registered: of:%pe acpi:%pe\n",
+			ERR_PTR(ret_of), ERR_PTR(ret_acpi));
 		ret = -ENODEV;
 		goto err_rpm_disable;
 	}
 
-	dev_dbg(&ctrl->dev, "serdev%d registered: dev:%p\n",
-		ctrl->nr, &ctrl->dev);
+	dev_dbg(&ctrl->dev, "serdev controller registered: dev:%p\n", &ctrl->dev);
 	return 0;
 
 err_rpm_disable:
@@ -679,21 +805,19 @@ static int serdev_remove_device(struct device *dev, void *data)
  */
 void serdev_controller_remove(struct serdev_controller *ctrl)
 {
-	int dummy;
-
 	if (!ctrl)
 		return;
 
-	dummy = device_for_each_child(&ctrl->dev, NULL,
-				      serdev_remove_device);
+	device_for_each_child(&ctrl->dev, NULL, serdev_remove_device);
 	pm_runtime_disable(&ctrl->dev);
 	device_del(&ctrl->dev);
 }
 EXPORT_SYMBOL_GPL(serdev_controller_remove);
 
 /**
- * serdev_driver_register() - Register client driver with serdev core
+ * __serdev_device_driver_register() - Register client driver with serdev core
  * @sdrv:	client driver to be associated with client-device.
+ * @owner:	client driver owner to set.
  *
  * This API will register the client driver with the serdev framework.
  * It is typically called from the driver's module-init function.
diff --git a/drivers/tty/serdev/serdev-ttyport.c b/drivers/tty/serdev/serdev-ttyport.c
index fa1672993b4c..bab1b143b8a6 100644
--- a/drivers/tty/serdev/serdev-ttyport.c
+++ b/drivers/tty/serdev/serdev-ttyport.c
@@ -22,24 +22,22 @@ struct serport {
  * Callback functions from the tty port.
  */
 
-static int ttyport_receive_buf(struct tty_port *port, const unsigned char *cp,
-				const unsigned char *fp, size_t count)
+static size_t ttyport_receive_buf(struct tty_port *port, const u8 *cp,
+				  const u8 *fp, size_t count)
 {
 	struct serdev_controller *ctrl = port->client_data;
 	struct serport *serport = serdev_controller_get_drvdata(ctrl);
-	int ret;
+	size_t ret;
 
 	if (!test_bit(SERPORT_ACTIVE, &serport->flags))
 		return 0;
 
 	ret = serdev_controller_receive_buf(ctrl, cp, count);
 
-	dev_WARN_ONCE(&ctrl->dev, ret < 0 || ret > count,
-				"receive_buf returns %d (count = %zu)\n",
+	dev_WARN_ONCE(&ctrl->dev, ret > count,
+				"receive_buf returns %zu (count = %zu)\n",
 				ret, count);
-	if (ret < 0)
-		return 0;
-	else if (ret > count)
+	if (ret > count)
 		return count;
 
 	return ret;
@@ -74,7 +72,7 @@ static const struct tty_port_client_operations client_ops = {
  * Callback functions from the serdev core.
  */
 
-static int ttyport_write_buf(struct serdev_controller *ctrl, const unsigned char *data, size_t len)
+static ssize_t ttyport_write_buf(struct serdev_controller *ctrl, const u8 *data, size_t len)
 {
 	struct serport *serport = serdev_controller_get_drvdata(ctrl);
 	struct tty_struct *tty = serport->tty;
@@ -94,14 +92,6 @@ static void ttyport_write_flush(struct serdev_controller *ctrl)
 	tty_driver_flush_buffer(tty);
 }
 
-static int ttyport_write_room(struct serdev_controller *ctrl)
-{
-	struct serport *serport = serdev_controller_get_drvdata(ctrl);
-	struct tty_struct *tty = serport->tty;
-
-	return tty_write_room(tty);
-}
-
 static int ttyport_open(struct serdev_controller *ctrl)
 {
 	struct serport *serport = serdev_controller_get_drvdata(ctrl);
@@ -231,9 +221,9 @@ static int ttyport_get_tiocm(struct serdev_controller *ctrl)
 	struct tty_struct *tty = serport->tty;
 
 	if (!tty->ops->tiocmget)
-		return -ENOTSUPP;
+		return -EOPNOTSUPP;
 
-	return tty->driver->ops->tiocmget(tty);
+	return tty->ops->tiocmget(tty);
 }
 
 static int ttyport_set_tiocm(struct serdev_controller *ctrl, unsigned int set, unsigned int clear)
@@ -242,15 +232,25 @@ static int ttyport_set_tiocm(struct serdev_controller *ctrl, unsigned int set, u
 	struct tty_struct *tty = serport->tty;
 
 	if (!tty->ops->tiocmset)
-		return -ENOTSUPP;
+		return -EOPNOTSUPP;
+
+	return tty->ops->tiocmset(tty, set, clear);
+}
+
+static int ttyport_break_ctl(struct serdev_controller *ctrl, unsigned int break_state)
+{
+	struct serport *serport = serdev_controller_get_drvdata(ctrl);
+	struct tty_struct *tty = serport->tty;
+
+	if (!tty->ops->break_ctl)
+		return -EOPNOTSUPP;
 
-	return tty->driver->ops->tiocmset(tty, set, clear);
+	return tty->ops->break_ctl(tty, break_state);
 }
 
 static const struct serdev_controller_ops ctrl_ops = {
 	.write_buf = ttyport_write_buf,
 	.write_flush = ttyport_write_flush,
-	.write_room = ttyport_write_room,
 	.open = ttyport_open,
 	.close = ttyport_close,
 	.set_flow_control = ttyport_set_flow_control,
@@ -259,13 +259,14 @@ static const struct serdev_controller_ops ctrl_ops = {
 	.wait_until_sent = ttyport_wait_until_sent,
 	.get_tiocm = ttyport_get_tiocm,
 	.set_tiocm = ttyport_set_tiocm,
+	.break_ctl = ttyport_break_ctl,
 };
 
 struct device *serdev_tty_port_register(struct tty_port *port,
+					struct device *host,
 					struct device *parent,
 					struct tty_driver *drv, int idx)
 {
-	const struct tty_port_client_operations *old_ops;
 	struct serdev_controller *ctrl;
 	struct serport *serport;
 	int ret;
@@ -273,7 +274,7 @@ struct device *serdev_tty_port_register(struct tty_port *port,
 	if (!port || !drv || !parent)
 		return ERR_PTR(-ENODEV);
 
-	ctrl = serdev_controller_alloc(parent, sizeof(struct serport));
+	ctrl = serdev_controller_alloc(host, parent, sizeof(struct serport));
 	if (!ctrl)
 		return ERR_PTR(-ENOMEM);
 	serport = serdev_controller_get_drvdata(ctrl);
@@ -284,7 +285,6 @@ struct device *serdev_tty_port_register(struct tty_port *port,
 
 	ctrl->ops = &ctrl_ops;
 
-	old_ops = port->client_ops;
 	port->client_ops = &client_ops;
 	port->client_data = ctrl;
 
@@ -297,7 +297,7 @@ struct device *serdev_tty_port_register(struct tty_port *port,
 
 err_reset_data:
 	port->client_data = NULL;
-	port->client_ops = old_ops;
+	port->client_ops = &tty_port_default_client_ops;
 	serdev_controller_put(ctrl);
 
 	return ERR_PTR(ret);
@@ -312,8 +312,8 @@ int serdev_tty_port_unregister(struct tty_port *port)
 		return -ENODEV;
 
 	serdev_controller_remove(ctrl);
-	port->client_ops = NULL;
 	port->client_data = NULL;
+	port->client_ops = &tty_port_default_client_ops;
 	serdev_controller_put(ctrl);
 
 	return 0;