1 files changed, 200 insertions, 0 deletions

diff --git a/drivers/tty/serial/serial_base_bus.c b/drivers/tty/serial/serial_base_bus.c
new file mode 100644
index 000000000000..1b37833b8f66
--- /dev/null
+++ b/drivers/tty/serial/serial_base_bus.c
@@ -0,0 +1,200 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Serial base bus layer for controllers
+ *
+ * Copyright (C) 2023 Texas Instruments Incorporated - https://www.ti.com/
+ * Author: Tony Lindgren <tony@atomide.com>
+ *
+ * The serial core bus manages the serial core controller instances.
+ */
+
+#include <linux/container_of.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include "serial_base.h"
+
+static int serial_base_match(struct device *dev, struct device_driver *drv)
+{
+	int len = strlen(drv->name);
+
+	return !strncmp(dev_name(dev), drv->name, len);
+}
+
+static struct bus_type serial_base_bus_type = {
+	.name = "serial-base",
+	.match = serial_base_match,
+};
+
+int serial_base_driver_register(struct device_driver *driver)
+{
+	driver->bus = &serial_base_bus_type;
+
+	return driver_register(driver);
+}
+
+void serial_base_driver_unregister(struct device_driver *driver)
+{
+	driver_unregister(driver);
+}
+
+static int serial_base_device_init(struct uart_port *port,
+				   struct device *dev,
+				   struct device *parent_dev,
+				   const struct device_type *type,
+				   void (*release)(struct device *dev),
+				   int id)
+{
+	device_initialize(dev);
+	dev->type = type;
+	dev->parent = parent_dev;
+	dev->bus = &serial_base_bus_type;
+	dev->release = release;
+
+	return dev_set_name(dev, "%s.%s.%d", type->name, dev_name(port->dev), id);
+}
+
+static const struct device_type serial_ctrl_type = {
+	.name = "ctrl",
+};
+
+static void serial_base_ctrl_release(struct device *dev)
+{
+	struct serial_ctrl_device *ctrl_dev = to_serial_base_ctrl_device(dev);
+
+	kfree(ctrl_dev);
+}
+
+void serial_base_ctrl_device_remove(struct serial_ctrl_device *ctrl_dev)
+{
+	if (!ctrl_dev)
+		return;
+
+	device_del(&ctrl_dev->dev);
+}
+
+struct serial_ctrl_device *serial_base_ctrl_add(struct uart_port *port,
+						struct device *parent)
+{
+	struct serial_ctrl_device *ctrl_dev;
+	int err;
+
+	ctrl_dev = kzalloc(sizeof(*ctrl_dev), GFP_KERNEL);
+	if (!ctrl_dev)
+		return ERR_PTR(-ENOMEM);
+
+	err = serial_base_device_init(port, &ctrl_dev->dev,
+				      parent, &serial_ctrl_type,
+				      serial_base_ctrl_release,
+				      port->ctrl_id);
+	if (err)
+		goto err_free_ctrl_dev;
+
+	err = device_add(&ctrl_dev->dev);
+	if (err)
+		goto err_put_device;
+
+	return ctrl_dev;
+
+err_put_device:
+	put_device(&ctrl_dev->dev);
+err_free_ctrl_dev:
+	kfree(ctrl_dev);
+
+	return ERR_PTR(err);
+}
+
+static const struct device_type serial_port_type = {
+	.name = "port",
+};
+
+static void serial_base_port_release(struct device *dev)
+{
+	struct serial_port_device *port_dev = to_serial_base_port_device(dev);
+
+	kfree(port_dev);
+}
+
+struct serial_port_device *serial_base_port_add(struct uart_port *port,
+						struct serial_ctrl_device *ctrl_dev)
+{
+	struct serial_port_device *port_dev;
+	int err;
+
+	port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL);
+	if (!port_dev)
+		return ERR_PTR(-ENOMEM);
+
+	err = serial_base_device_init(port, &port_dev->dev,
+				      &ctrl_dev->dev, &serial_port_type,
+				      serial_base_port_release,
+				      port->line);
+	if (err)
+		goto err_free_port_dev;
+
+	port_dev->port = port;
+
+	err = device_add(&port_dev->dev);
+	if (err)
+		goto err_put_device;
+
+	return port_dev;
+
+err_put_device:
+	put_device(&port_dev->dev);
+err_free_port_dev:
+	kfree(port_dev);
+
+	return ERR_PTR(err);
+}
+
+void serial_base_port_device_remove(struct serial_port_device *port_dev)
+{
+	if (!port_dev)
+		return;
+
+	device_del(&port_dev->dev);
+}
+
+static int serial_base_init(void)
+{
+	int ret;
+
+	ret = bus_register(&serial_base_bus_type);
+	if (ret)
+		return ret;
+
+	ret = serial_base_ctrl_init();
+	if (ret)
+		goto err_bus_unregister;
+
+	ret = serial_base_port_init();
+	if (ret)
+		goto err_ctrl_exit;
+
+	return 0;
+
+err_ctrl_exit:
+	serial_base_ctrl_exit();
+
+err_bus_unregister:
+	bus_unregister(&serial_base_bus_type);
+
+	return ret;
+}
+module_init(serial_base_init);
+
+static void serial_base_exit(void)
+{
+	serial_base_port_exit();
+	serial_base_ctrl_exit();
+	bus_unregister(&serial_base_bus_type);
+}
+module_exit(serial_base_exit);
+
+MODULE_AUTHOR("Tony Lindgren <tony@atomide.com>");
+MODULE_DESCRIPTION("Serial core bus");
+MODULE_LICENSE("GPL");