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// 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/idr.h>
#include <linux/module.h>
#include <linux/serial_core.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include "serial_base.h"
static bool serial_base_initialized;
static const struct device_type serial_ctrl_type = {
.name = "ctrl",
};
static const struct device_type serial_port_type = {
.name = "port",
};
static int serial_base_match(struct device *dev, struct device_driver *drv)
{
if (dev->type == &serial_ctrl_type &&
str_has_prefix(drv->name, serial_ctrl_type.name))
return 1;
if (dev->type == &serial_port_type &&
str_has_prefix(drv->name, serial_port_type.name))
return 1;
return 0;
}
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),
unsigned int ctrl_id,
unsigned int port_id)
{
device_initialize(dev);
dev->type = type;
dev->parent = parent_dev;
dev->bus = &serial_base_bus_type;
dev->release = release;
if (!serial_base_initialized) {
dev_dbg(port->dev, "uart_add_one_port() called before arch_initcall()?\n");
return -EPROBE_DEFER;
}
if (type == &serial_ctrl_type)
return dev_set_name(dev, "%s:%d", dev_name(port->dev), ctrl_id);
if (type == &serial_port_type)
return dev_set_name(dev, "%s:%d.%d", dev_name(port->dev),
ctrl_id, port_id);
return -EINVAL;
}
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);
put_device(&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);
ida_init(&ctrl_dev->port_ida);
err = serial_base_device_init(port, &ctrl_dev->dev,
parent, &serial_ctrl_type,
serial_base_ctrl_release,
port->ctrl_id, 0);
if (err)
goto err_put_device;
err = device_add(&ctrl_dev->dev);
if (err)
goto err_put_device;
return ctrl_dev;
err_put_device:
put_device(&ctrl_dev->dev);
return ERR_PTR(err);
}
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 min = 0, max = -1; /* Use -1 for max to apply IDA defaults */
int err;
port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL);
if (!port_dev)
return ERR_PTR(-ENOMEM);
/* Device driver specified port_id vs automatic assignment? */
if (port->port_id) {
min = port->port_id;
max = port->port_id;
}
err = ida_alloc_range(&ctrl_dev->port_ida, min, max, GFP_KERNEL);
if (err < 0) {
kfree(port_dev);
return ERR_PTR(err);
}
port->port_id = err;
err = serial_base_device_init(port, &port_dev->dev,
&ctrl_dev->dev, &serial_port_type,
serial_base_port_release,
port->ctrl_id, port->port_id);
if (err)
goto err_put_device;
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);
ida_free(&ctrl_dev->port_ida, port->port_id);
return ERR_PTR(err);
}
void serial_base_port_device_remove(struct serial_port_device *port_dev)
{
struct serial_ctrl_device *ctrl_dev;
struct device *parent;
if (!port_dev)
return;
parent = port_dev->dev.parent;
ctrl_dev = to_serial_base_ctrl_device(parent);
device_del(&port_dev->dev);
ida_free(&ctrl_dev->port_ida, port_dev->port->port_id);
put_device(&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;
serial_base_initialized = true;
return 0;
err_ctrl_exit:
serial_base_ctrl_exit();
err_bus_unregister:
bus_unregister(&serial_base_bus_type);
return ret;
}
arch_initcall(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");
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