/*
* 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 "pciehp.h"
#define PCIEHP_DETECT_PCIE (0)
#define PCIEHP_DETECT_ACPI (1)
#define PCIEHP_DETECT_DEFAULT PCIEHP_DETECT_PCIE
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\n"
" pcie - Use PCIe based slot detection (default)\n"
" acpi - Use ACPI for slot detection\n");
static int is_ejectable(acpi_handle handle)
{
acpi_status status;
acpi_handle tmp;
unsigned long long removable;
status = acpi_get_handle(handle, "_ADR", &tmp);
if (ACPI_FAILURE(status))
return 0;
status = acpi_get_handle(handle, "_EJ0", &tmp);
if (ACPI_SUCCESS(status))
return 1;
status = acpi_evaluate_integer(handle, "_RMV", NULL, &removable);
if (ACPI_SUCCESS(status) && removable)
return 1;
return 0;
}
static acpi_status
check_hotplug(acpi_handle handle, u32 lvl, void *context, void **rv)
{
int *found = (int *)context;
if (is_ejectable(handle)) {
*found = 1;
return AE_CTRL_TERMINATE;
}
return AE_OK;
}
static int pciehp_detect_acpi_slot(struct pci_bus *pbus)
{
acpi_handle handle;
struct pci_dev *pdev = pbus->self;
int found = 0;
if (!pdev){
int seg = pci_domain_nr(pbus), busnr = pbus->number;
handle = acpi_get_pci_rootbridge_handle(seg, busnr);
} else
handle = DEVICE_ACPI_HANDLE(&(pdev->dev));
if (!handle)
return 0;
acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
check_hotplug, (void *)&found, NULL);
return found;
}
int pciehp_acpi_slot_detection_check(struct pci_dev *dev)
{
if (slot_detection_mode != PCIEHP_DETECT_ACPI)
return 0;
if (pciehp_detect_acpi_slot(dev->subordinate))
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;
warn("bad specifier '%s' for pciehp_detect_mode. Use default\n",
pciehp_detect_mode);
return PCIEHP_DETECT_DEFAULT;
}
void __init pciehp_acpi_slot_detection_init(void)
{
slot_detection_mode = parse_detect_mode();
}
