/*
* ACPI related functions for PCI Express Hot Plug driver.
*
* Copyright (C) 2008 Kenji Kaneshige
* Copyright (C) 2008 Fujitsu Limited.
*
* All rights reserved.
*
* 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, GOOD TITLE or
* NON INFRINGEMENT. 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <linux/acpi.h>
#include <linux/pci.h>
#include <linux/pci_hotplug.h>
#include <linux/slab.h>
#include "pciehp.h"
#define PCIEHP_DETECT_PCIE (0)
#define PCIEHP_DETECT_ACPI (1)
#define PCIEHP_DETECT_AUTO (2)
#define PCIEHP_DETECT_DEFAULT PCIEHP_DETECT_AUTO
struct dummy_slot {
u32 number;
struct list_head list;
};
static int slot_detection_mode;
static char *pciehp_detect_mode;
module_param(pciehp_detect_mode, charp, 0444);
MODULE_PARM_DESC(pciehp_detect_mode,
"Slot detection mode: pcie, acpi, auto\n"
" pcie - Use PCIe based slot detection\n"
" acpi - Use ACPI for slot detection\n"
" auto(default) - Auto select mode. Use acpi option if duplicate\n"
" slot ids are found. Otherwise, use pcie option\n");
int pciehp_acpi_slot_detection_check(struct pci_dev *dev)
{
if (slot_detection_mode != PCIEHP_DETECT_ACPI)
return 0;
if (acpi_pci_detect_ejectable(DEVICE_ACPI_HANDLE(&dev->dev)))
return 0;
return -ENODEV;
}
static int __init parse_detect_mode(void)
{
if (!pciehp_detect_mode)
return PCIEHP_DETECT_DEFAULT;
if (!strcmp(pciehp_detect_mode, "pcie"))
return PCIEHP_DETECT_PCIE;
if (!strcmp(pciehp_detect_mode, "acpi"))
return PCIEHP_DETECT_ACPI;
if (!strcmp(pciehp_detect_mode, "auto"))
return PCIEHP_DETECT_AUTO;
warn("bad specifier '%s' for pciehp_detect_mode. Use default\n",
pciehp_detect_mode);
return PCIEHP_DETECT_DEFAULT;
}
static int __initdata dup_slot_id;
static int __initdata acpi_slot_detected;
static struct list_head __initdata dummy_slots = LIST_HEAD_INIT(dummy_slots);
/* Dummy driver for dumplicate name detection */
static int __init dummy_probe(struct pcie_device *dev)
{
int pos;
u32 slot_cap;
acpi_handle handle;
struct dummy_slot *slot, *tmp;
struct pci_dev *pdev = dev->port;
pos = pci_pcie_cap(pdev);
if (!pos)
return -ENODEV;
pci_read_config_dword(pdev, pos + PCI_EXP_SLTCAP, &slot_cap);
slot = kzalloc(sizeof(*slot), GFP_KERNEL);
if (!slot)
return -ENOMEM;
slot->number = slot_cap >> 19;
list_for_each_entry(tmp, &dummy_slots, list) {
if (tmp->number == slot->number)
dup_slot_id++;
}
list_add_tail(&slot->list, &dummy_slots);
handle = DEVICE_ACPI_HANDLE(&pdev->dev);
if (!acpi_slot_detected && acpi_pci_detect_ejectable(handle))
acpi_slot_detected = 1;
return -ENODEV; /* dummy driver always returns error */
}
static struct pcie_port_service_driver __initdata dummy_driver = {
.name = "pciehp_dummy",
.port_type = PCIE_ANY_PORT,
.service = PCIE_PORT_SERVICE_HP,
.probe = dummy_probe,
};
static int __init select_detection_mode(void)
{
struct dummy_slot *slot, *tmp;
pcie_port_service_register(&dummy_driver);
pcie_port_service_unregister(&dummy_driver);
list_for_each_entry_safe(slot, tmp, &dummy_slots, list) {
list_del(&slot->list);
kfree(slot);
}
if (acpi_slot_detected && dup_slot_id)
return PCIEHP_DETECT_ACPI;
return PCIEHP_DETECT_PCIE;
}
void __init pciehp_acpi_slot_detection_init(void)
{
slot_detection_mode = parse_detect_mode();
if (slot_detection_mode != PCIEHP_DETECT_AUTO)
goto out;
slot_detection_mode = select_detection_mode();
out:
if (slot_detection_mode == PCIEHP_DETECT_ACPI)
info("Using ACPI for slot detection.\n");
}
