| Kenji Kaneshige | c9ffa5a | 2008-12-17 12:07:38 +0900 | [diff] [blame^] | 1 | /* |
| 2 | * ACPI related functions for PCI Express Hot Plug driver. |
| 3 | * |
| 4 | * Copyright (C) 2008 Kenji Kaneshige |
| 5 | * Copyright (C) 2008 Fujitsu Limited. |
| 6 | * |
| 7 | * All rights reserved. |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License as published by |
| 11 | * the Free Software Foundation; either version 2 of the License, or (at |
| 12 | * your option) any later version. |
| 13 | * |
| 14 | * This program is distributed in the hope that it will be useful, but |
| 15 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or |
| 17 | * NON INFRINGEMENT. See the GNU General Public License for more |
| 18 | * details. |
| 19 | * |
| 20 | * You should have received a copy of the GNU General Public License |
| 21 | * along with this program; if not, write to the Free Software |
| 22 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 23 | * |
| 24 | */ |
| 25 | |
| 26 | #include <linux/acpi.h> |
| 27 | #include "pciehp.h" |
| 28 | |
| 29 | #define PCIEHP_DETECT_PCIE (0) |
| 30 | #define PCIEHP_DETECT_ACPI (1) |
| 31 | #define PCIEHP_DETECT_DEFAULT PCIEHP_DETECT_PCIE |
| 32 | |
| 33 | static int slot_detection_mode; |
| 34 | static char *pciehp_detect_mode; |
| 35 | module_param(pciehp_detect_mode, charp, 0444); |
| 36 | MODULE_PARM_DESC(pciehp_detect_mode, |
| 37 | "Slot detection mode: pcie, acpi\n" |
| 38 | " pcie - Use PCIe based slot detection (default)\n" |
| 39 | " acpi - Use ACPI for slot detection\n"); |
| 40 | |
| 41 | static int is_ejectable(acpi_handle handle) |
| 42 | { |
| 43 | acpi_status status; |
| 44 | acpi_handle tmp; |
| 45 | unsigned long long removable; |
| 46 | status = acpi_get_handle(handle, "_ADR", &tmp); |
| 47 | if (ACPI_FAILURE(status)) |
| 48 | return 0; |
| 49 | status = acpi_get_handle(handle, "_EJ0", &tmp); |
| 50 | if (ACPI_SUCCESS(status)) |
| 51 | return 1; |
| 52 | status = acpi_evaluate_integer(handle, "_RMV", NULL, &removable); |
| 53 | if (ACPI_SUCCESS(status) && removable) |
| 54 | return 1; |
| 55 | return 0; |
| 56 | } |
| 57 | |
| 58 | static acpi_status |
| 59 | check_hotplug(acpi_handle handle, u32 lvl, void *context, void **rv) |
| 60 | { |
| 61 | int *found = (int *)context; |
| 62 | if (is_ejectable(handle)) { |
| 63 | *found = 1; |
| 64 | return AE_CTRL_TERMINATE; |
| 65 | } |
| 66 | return AE_OK; |
| 67 | } |
| 68 | |
| 69 | static int pciehp_detect_acpi_slot(struct pci_bus *pbus) |
| 70 | { |
| 71 | acpi_handle handle; |
| 72 | struct pci_dev *pdev = pbus->self; |
| 73 | int found = 0; |
| 74 | |
| 75 | if (!pdev){ |
| 76 | int seg = pci_domain_nr(pbus), busnr = pbus->number; |
| 77 | handle = acpi_get_pci_rootbridge_handle(seg, busnr); |
| 78 | } else |
| 79 | handle = DEVICE_ACPI_HANDLE(&(pdev->dev)); |
| 80 | |
| 81 | if (!handle) |
| 82 | return 0; |
| 83 | |
| 84 | acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1, |
| 85 | check_hotplug, (void *)&found, NULL); |
| 86 | return found; |
| 87 | } |
| 88 | |
| 89 | int pciehp_acpi_slot_detection_check(struct pci_dev *dev) |
| 90 | { |
| 91 | if (slot_detection_mode != PCIEHP_DETECT_ACPI) |
| 92 | return 0; |
| 93 | if (pciehp_detect_acpi_slot(dev->subordinate)) |
| 94 | return 0; |
| 95 | return -ENODEV; |
| 96 | } |
| 97 | |
| 98 | static int __init parse_detect_mode(void) |
| 99 | { |
| 100 | if (!pciehp_detect_mode) |
| 101 | return PCIEHP_DETECT_DEFAULT; |
| 102 | if (!strcmp(pciehp_detect_mode, "pcie")) |
| 103 | return PCIEHP_DETECT_PCIE; |
| 104 | if (!strcmp(pciehp_detect_mode, "acpi")) |
| 105 | return PCIEHP_DETECT_ACPI; |
| 106 | warn("bad specifier '%s' for pciehp_detect_mode. Use default\n", |
| 107 | pciehp_detect_mode); |
| 108 | return PCIEHP_DETECT_DEFAULT; |
| 109 | } |
| 110 | |
| 111 | void __init pciehp_acpi_slot_detection_init(void) |
| 112 | { |
| 113 | slot_detection_mode = parse_detect_mode(); |
| 114 | } |