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/*
* Serial Port driver for Open Firmware platform devices
*
* Copyright (C) 2006 Arnd Bergmann <arnd@arndb.de>, IBM Corp.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/serial_core.h>
#include <linux/serial_8250.h>
#include <asm/of_platform.h>
#include <asm/prom.h>
/*
* Fill a struct uart_port for a given device node
*/
static int __devinit of_platform_serial_setup(struct of_device *ofdev,
int type, struct uart_port *port)
{
struct resource resource;
struct device_node *np = ofdev->node;
const unsigned int *clk, *spd;
int ret;
memset(port, 0, sizeof *port);
spd = of_get_property(np, "current-speed", NULL);
clk = of_get_property(np, "clock-frequency", NULL);
if (!clk) {
dev_warn(&ofdev->dev, "no clock-frequency property set\n");
return -ENODEV;
}
ret = of_address_to_resource(np, 0, &resource);
if (ret) {
dev_warn(&ofdev->dev, "invalid address\n");
return ret;
}
spin_lock_init(&port->lock);
port->mapbase = resource.start;
port->irq = irq_of_parse_and_map(np, 0);
port->iotype = UPIO_MEM;
port->type = type;
port->uartclk = *clk;
port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
| UPF_FIXED_PORT;
port->dev = &ofdev->dev;
port->custom_divisor = *clk / (16 * (*spd));
return 0;
}
/*
* Try to register a serial port
*/
static int __devinit of_platform_serial_probe(struct of_device *ofdev,
const struct of_device_id *id)
{
struct uart_port port;
int port_type;
int ret;
if (of_find_property(ofdev->node, "used-by-rtas", NULL))
return -EBUSY;
port_type = (unsigned long)id->data;
ret = of_platform_serial_setup(ofdev, port_type, &port);
if (ret)
goto out;
switch (port_type) {
case PORT_UNKNOWN:
dev_info(&ofdev->dev, "Unknown serial port found, "
"attempting to use 8250 driver\n");
/* fallthrough */
case PORT_8250 ... PORT_MAX_8250:
ret = serial8250_register_port(&port);
break;
default:
/* need to add code for these */
ret = -ENODEV;
break;
}
if (ret < 0)
goto out;
ofdev->dev.driver_data = (void *)(unsigned long)ret;
return 0;
out:
irq_dispose_mapping(port.irq);
return ret;
}
/*
* Release a line
*/
static int of_platform_serial_remove(struct of_device *ofdev)
{
int line = (unsigned long)ofdev->dev.driver_data;
serial8250_unregister_port(line);
return 0;
}
/*
* A few common types, add more as needed.
*/
static struct of_device_id __devinitdata of_platform_serial_table[] = {
{ .type = "serial", .compatible = "ns8250", .data = (void *)PORT_8250, },
{ .type = "serial", .compatible = "ns16450", .data = (void *)PORT_16450, },
{ .type = "serial", .compatible = "ns16550", .data = (void *)PORT_16550, },
{ .type = "serial", .compatible = "ns16750", .data = (void *)PORT_16750, },
{ .type = "serial", .data = (void *)PORT_UNKNOWN, },
{ /* end of list */ },
};
static struct of_platform_driver __devinitdata of_platform_serial_driver = {
.owner = THIS_MODULE,
.name = "of_serial",
.probe = of_platform_serial_probe,
.remove = of_platform_serial_remove,
.match_table = of_platform_serial_table,
};
static int __init of_platform_serial_init(void)
{
return of_register_platform_driver(&of_platform_serial_driver);
}
module_init(of_platform_serial_init);
static void __exit of_platform_serial_exit(void)
{
return of_unregister_platform_driver(&of_platform_serial_driver);
};
module_exit(of_platform_serial_exit);
MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Serial Port driver for Open Firmware platform devices");
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