linux-vybrid_public/drivers/acpi/motherboard.c

/* 
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *  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.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

/* Purpose: Prevent PCMCIA cards from using motherboard resources. */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/ioport.h>
#include <asm/io.h>

#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>

#define _COMPONENT		ACPI_SYSTEM_COMPONENT
ACPI_MODULE_NAME("acpi_motherboard")

/* Dell use PNP0C01 instead of PNP0C02 */
#define ACPI_MB_HID			"PNP0C01,PNP0C02"
/**
 * Doesn't care about legacy IO ports, only IO ports beyond 0x1000 are reserved
 * Doesn't care about the failure of 'request_region', since other may reserve
 * the io ports as well
 */
#define IS_RESERVED_ADDR(base, len) \
	(((len) > 0) && ((base) > 0) && ((base) + (len) < IO_SPACE_LIMIT) \
	&& ((base) + (len) > PCIBIOS_MIN_IO))
/*
 * Clearing the flag (IORESOURCE_BUSY) allows drivers to use
 * the io ports if they really know they can use it, while
 * still preventing hotplug PCI devices from using it.
 */

/*
 * When CONFIG_PNP is enabled, pnp/system.c binds to PNP0C01
 * and PNP0C02, redundant with acpi_reserve_io_ranges().
 * But acpi_reserve_io_ranges() is necessary for !CONFIG_PNP.
 */
static acpi_status acpi_reserve_io_ranges(struct acpi_resource *res, void *data)
{
	struct resource *requested_res = NULL;


	if (res->type == ACPI_RESOURCE_TYPE_IO) {
		struct acpi_resource_io *io_res = &res->data.io;

		if (io_res->minimum != io_res->maximum)
			return AE_OK;
		if (IS_RESERVED_ADDR
		    (io_res->minimum, io_res->address_length)) {
			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
					  "Motherboard resources 0x%08x - 0x%08x\n",
					  io_res->minimum,
					  io_res->minimum +
					  io_res->address_length));
			requested_res =
			    request_region(io_res->minimum,
					   io_res->address_length, "motherboard");
		}
	} else if (res->type == ACPI_RESOURCE_TYPE_FIXED_IO) {
		struct acpi_resource_fixed_io *fixed_io_res =
		    &res->data.fixed_io;

		if (IS_RESERVED_ADDR
		    (fixed_io_res->address, fixed_io_res->address_length)) {
			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
					  "Motherboard resources 0x%08x - 0x%08x\n",
					  fixed_io_res->address,
					  fixed_io_res->address +
					  fixed_io_res->address_length));
			requested_res =
			    request_region(fixed_io_res->address,
					   fixed_io_res->address_length,
					   "motherboard");
		}
	} else {
		/* Memory mapped IO? */
	}

	if (requested_res)
		requested_res->flags &= ~IORESOURCE_BUSY;
	return AE_OK;
}

static int acpi_motherboard_add(struct acpi_device *device)
{
	if (!device)
		return -EINVAL;
	acpi_walk_resources(device->handle, METHOD_NAME__CRS,
			    acpi_reserve_io_ranges, NULL);

	return 0;
}

static struct acpi_driver acpi_motherboard_driver = {
	.name = "motherboard",
	.class = "",
	.ids = ACPI_MB_HID,
	.ops = {
		.add = acpi_motherboard_add,
		},
};

static int __init acpi_motherboard_init(void)
{
	acpi_bus_register_driver(&acpi_motherboard_driver);
	return 0;
}

/**
 * Reserve motherboard resources after PCI claim BARs,
 * but before PCI assign resources for uninitialized PCI devices
 */
fs_initcall(acpi_motherboard_init);