2 * ACPI related functions for PCI Express Hot Plug driver.
4 * Copyright (C) 2008 Kenji Kaneshige
5 * Copyright (C) 2008 Fujitsu Limited.
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.
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
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.
26 #include <linux/acpi.h>
29 #define PCIEHP_DETECT_PCIE (0)
30 #define PCIEHP_DETECT_ACPI (1)
31 #define PCIEHP_DETECT_AUTO (2)
32 #define PCIEHP_DETECT_DEFAULT PCIEHP_DETECT_AUTO
34 static int slot_detection_mode;
35 static char *pciehp_detect_mode;
36 module_param(pciehp_detect_mode, charp, 0444);
37 MODULE_PARM_DESC(pciehp_detect_mode,
38 "Slot detection mode: pcie, acpi, auto\n"
39 " pcie - Use PCIe based slot detection\n"
40 " acpi - Use ACPI for slot detection\n"
41 " auto(default) - Auto select mode. Use acpi option if duplicate\n"
42 " slot ids are found. Otherwise, use pcie option\n");
44 static int is_ejectable(acpi_handle handle)
48 unsigned long long removable;
49 status = acpi_get_handle(handle, "_ADR", &tmp);
50 if (ACPI_FAILURE(status))
52 status = acpi_get_handle(handle, "_EJ0", &tmp);
53 if (ACPI_SUCCESS(status))
55 status = acpi_evaluate_integer(handle, "_RMV", NULL, &removable);
56 if (ACPI_SUCCESS(status) && removable)
62 check_hotplug(acpi_handle handle, u32 lvl, void *context, void **rv)
64 int *found = (int *)context;
65 if (is_ejectable(handle)) {
67 return AE_CTRL_TERMINATE;
72 static int pciehp_detect_acpi_slot(struct pci_bus *pbus)
75 struct pci_dev *pdev = pbus->self;
79 int seg = pci_domain_nr(pbus), busnr = pbus->number;
80 handle = acpi_get_pci_rootbridge_handle(seg, busnr);
82 handle = DEVICE_ACPI_HANDLE(&(pdev->dev));
87 acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
88 check_hotplug, (void *)&found, NULL);
92 int pciehp_acpi_slot_detection_check(struct pci_dev *dev)
94 if (slot_detection_mode != PCIEHP_DETECT_ACPI)
96 if (pciehp_detect_acpi_slot(dev->subordinate))
101 static int __init parse_detect_mode(void)
103 if (!pciehp_detect_mode)
104 return PCIEHP_DETECT_DEFAULT;
105 if (!strcmp(pciehp_detect_mode, "pcie"))
106 return PCIEHP_DETECT_PCIE;
107 if (!strcmp(pciehp_detect_mode, "acpi"))
108 return PCIEHP_DETECT_ACPI;
109 if (!strcmp(pciehp_detect_mode, "auto"))
110 return PCIEHP_DETECT_AUTO;
111 warn("bad specifier '%s' for pciehp_detect_mode. Use default\n",
113 return PCIEHP_DETECT_DEFAULT;
116 static struct pcie_port_service_id __initdata port_pci_ids[] = {
118 .vendor = PCI_ANY_ID,
119 .device = PCI_ANY_ID,
120 .port_type = PCIE_ANY_PORT,
121 .service_type = PCIE_PORT_SERVICE_HP,
123 }, { /* end: all zeroes */ }
126 static int __initdata dup_slot_id;
127 static int __initdata acpi_slot_detected;
128 static struct list_head __initdata dummy_slots = LIST_HEAD_INIT(dummy_slots);
130 /* Dummy driver for dumplicate name detection */
131 static int __init dummy_probe(struct pcie_device *dev,
132 const struct pcie_port_service_id *id)
136 struct slot *slot, *tmp;
137 struct pci_dev *pdev = dev->port;
138 if (!(slot = kzalloc(sizeof(*slot), GFP_KERNEL)))
140 /* Note: pciehp_detect_mode != PCIEHP_DETECT_ACPI here */
141 if (pciehp_get_hp_hw_control_from_firmware(pdev))
143 if (!(pos = pci_find_capability(pdev, PCI_CAP_ID_EXP)))
145 pci_read_config_dword(pdev, pos + PCI_EXP_SLTCAP, &slot_cap);
146 slot->number = slot_cap >> 19;
147 list_for_each_entry(tmp, &dummy_slots, slot_list) {
148 if (tmp->number == slot->number)
151 list_add_tail(&slot->slot_list, &dummy_slots);
152 if (!acpi_slot_detected && pciehp_detect_acpi_slot(pdev->subordinate))
153 acpi_slot_detected = 1;
154 return -ENODEV; /* dummy driver always returns error */
157 static struct pcie_port_service_driver __initdata dummy_driver = {
158 .name = "pciehp_dummy",
159 .id_table = port_pci_ids,
160 .probe = dummy_probe,
163 static int __init select_detection_mode(void)
165 struct slot *slot, *tmp;
166 pcie_port_service_register(&dummy_driver);
167 pcie_port_service_unregister(&dummy_driver);
168 list_for_each_entry_safe(slot, tmp, &dummy_slots, slot_list) {
169 list_del(&slot->slot_list);
172 if (acpi_slot_detected && dup_slot_id)
173 return PCIEHP_DETECT_ACPI;
174 return PCIEHP_DETECT_PCIE;
177 void __init pciehp_acpi_slot_detection_init(void)
179 slot_detection_mode = parse_detect_mode();
180 if (slot_detection_mode != PCIEHP_DETECT_AUTO)
182 slot_detection_mode = select_detection_mode();
184 if (slot_detection_mode == PCIEHP_DETECT_ACPI)
185 info("Using ACPI for slot detection.\n");