/*
 * Copyright (c) 2002-2003 Matthew Wilcox for Hewlett-Packard
 * Copyright (C) 2004 Hewlett-Packard Co
 *	Bjorn Helgaas <bjorn.helgaas@hp.com>
 *
 * 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/acpi.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/serial_core.h>

#include <acpi/acpi_bus.h>

#include <asm/io.h>

#include "8250.h"

struct serial_private {
	int	line;
};

static acpi_status acpi_serial_mmio(struct uart_port *port,
				    struct acpi_resource_address64 *addr)
{
	port->mapbase = addr->minimum;
	port->iotype = UPIO_MEM;
	port->flags |= UPF_IOREMAP;
	return AE_OK;
}

static acpi_status acpi_serial_port(struct uart_port *port,
				    struct acpi_resource_io *io)
{
	if (io->address_length) {
		port->iobase = io->minimum;
		port->iotype = UPIO_PORT;
	} else
		printk(KERN_ERR "%s: zero-length IO port range?\n", __FUNCTION__);
	return AE_OK;
}

static acpi_status acpi_serial_ext_irq(struct uart_port *port,
				       struct acpi_resource_extended_irq *ext_irq)
{
	int rc;

	if (ext_irq->interrupt_count > 0) {
		rc = acpi_register_gsi(ext_irq->interrupts[0],
	                   ext_irq->triggering, ext_irq->polarity);
		if (rc < 0)
			return AE_ERROR;
		port->irq = rc;
	}
	return AE_OK;
}

static acpi_status acpi_serial_irq(struct uart_port *port,
				   struct acpi_resource_irq *irq)
{
	int rc;

	if (irq->interrupt_count > 0) {
		rc = acpi_register_gsi(irq->interrupts[0],
	                   irq->triggering, irq->polarity);
		if (rc < 0)
			return AE_ERROR;
		port->irq = rc;
	}
	return AE_OK;
}

static acpi_status acpi_serial_resource(struct acpi_resource *res, void *data)
{
	struct uart_port *port = (struct uart_port *) data;
	struct acpi_resource_address64 addr;
	acpi_status status;

	status = acpi_resource_to_address64(res, &addr);
	if (ACPI_SUCCESS(status))
		return acpi_serial_mmio(port, &addr);
	else if (res->type == ACPI_RESOURCE_TYPE_IO)
		return acpi_serial_port(port, &res->data.io);
	else if (res->type == ACPI_RESOURCE_TYPE_EXTENDED_IRQ)
		return acpi_serial_ext_irq(port, &res->data.extended_irq);
	else if (res->type == ACPI_RESOURCE_TYPE_IRQ)
		return acpi_serial_irq(port, &res->data.irq);
	return AE_OK;
}

static int acpi_serial_add(struct acpi_device *device)
{
	struct serial_private *priv;
	acpi_status status;
	struct uart_port port;
	int result;

	memset(&port, 0, sizeof(struct uart_port));

	port.uartclk = 1843200;
	port.flags = UPF_SKIP_TEST | UPF_BOOT_AUTOCONF;

	priv = kmalloc(sizeof(struct serial_private), GFP_KERNEL);
	if (!priv) {
		result = -ENOMEM;
		goto fail;
	}
	memset(priv, 0, sizeof(*priv));

	status = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
				     acpi_serial_resource, &port);
	if (ACPI_FAILURE(status)) {
		result = -ENODEV;
		goto fail;
	}

	if (!port.mapbase && !port.iobase) {
		printk(KERN_ERR "%s: no iomem or port address in %s _CRS\n",
			__FUNCTION__, device->pnp.bus_id);
		result = -ENODEV;
		goto fail;
	}

	priv->line = serial8250_register_port(&port);
	if (priv->line < 0) {
		printk(KERN_WARNING "Couldn't register serial port %s: %d\n",
			device->pnp.bus_id, priv->line);
		result = -ENODEV;
		goto fail;
	}

	acpi_driver_data(device) = priv;
	return 0;

fail:
	kfree(priv);

	return result;
}

static int acpi_serial_remove(struct acpi_device *device, int type)
{
	struct serial_private *priv;

	if (!device || !acpi_driver_data(device))
		return -EINVAL;

	priv = acpi_driver_data(device);
	serial8250_unregister_port(priv->line);
	kfree(priv);

	return 0;
}

static struct acpi_driver acpi_serial_driver = {
	.name =		"serial",
	.class =	"",
	.ids =		"PNP0501",
	.ops =	{
		.add =		acpi_serial_add,
		.remove =	acpi_serial_remove,
	},
};

static int __init acpi_serial_init(void)
{
	return acpi_bus_register_driver(&acpi_serial_driver);
}

static void __exit acpi_serial_exit(void)
{
	acpi_bus_unregister_driver(&acpi_serial_driver);
}

module_init(acpi_serial_init);
module_exit(acpi_serial_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Generic 8250/16x50 ACPI serial driver");