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>
27 #include <linux/pci.h>
28 #include <linux/pci_hotplug.h>
31 #define PCIEHP_DETECT_PCIE (0)
32 #define PCIEHP_DETECT_ACPI (1)
33 #define PCIEHP_DETECT_AUTO (2)
34 #define PCIEHP_DETECT_DEFAULT PCIEHP_DETECT_AUTO
36 static int slot_detection_mode;
37 static char *pciehp_detect_mode;
38 module_param(pciehp_detect_mode, charp, 0444);
39 MODULE_PARM_DESC(pciehp_detect_mode,
40 "Slot detection mode: pcie, acpi, auto\n"
41 " pcie - Use PCIe based slot detection\n"
42 " acpi - Use ACPI for slot detection\n"
43 " auto(default) - Auto select mode. Use acpi option if duplicate\n"
44 " slot ids are found. Otherwise, use pcie option\n");
46 int pciehp_acpi_slot_detection_check(struct pci_dev *dev)
48 if (slot_detection_mode != PCIEHP_DETECT_ACPI)
50 if (acpi_pci_detect_ejectable(dev->subordinate))
55 static int __init parse_detect_mode(void)
57 if (!pciehp_detect_mode)
58 return PCIEHP_DETECT_DEFAULT;
59 if (!strcmp(pciehp_detect_mode, "pcie"))
60 return PCIEHP_DETECT_PCIE;
61 if (!strcmp(pciehp_detect_mode, "acpi"))
62 return PCIEHP_DETECT_ACPI;
63 if (!strcmp(pciehp_detect_mode, "auto"))
64 return PCIEHP_DETECT_AUTO;
65 warn("bad specifier '%s' for pciehp_detect_mode. Use default\n",
67 return PCIEHP_DETECT_DEFAULT;
70 static int __initdata dup_slot_id;
71 static int __initdata acpi_slot_detected;
72 static struct list_head __initdata dummy_slots = LIST_HEAD_INIT(dummy_slots);
74 /* Dummy driver for dumplicate name detection */
75 static int __init dummy_probe(struct pcie_device *dev)
79 struct slot *slot, *tmp;
80 struct pci_dev *pdev = dev->port;
81 struct pci_bus *pbus = pdev->subordinate;
82 /* Note: pciehp_detect_mode != PCIEHP_DETECT_ACPI here */
83 if (pciehp_get_hp_hw_control_from_firmware(pdev))
85 if (!(pos = pci_find_capability(pdev, PCI_CAP_ID_EXP)))
87 pci_read_config_dword(pdev, pos + PCI_EXP_SLTCAP, &slot_cap);
88 slot = kzalloc(sizeof(*slot), GFP_KERNEL);
91 slot->number = slot_cap >> 19;
92 list_for_each_entry(tmp, &dummy_slots, slot_list) {
93 if (tmp->number == slot->number)
96 list_add_tail(&slot->slot_list, &dummy_slots);
97 if (!acpi_slot_detected && acpi_pci_detect_ejectable(pbus))
98 acpi_slot_detected = 1;
99 return -ENODEV; /* dummy driver always returns error */
102 static struct pcie_port_service_driver __initdata dummy_driver = {
103 .name = "pciehp_dummy",
104 .port_type = PCIE_ANY_PORT,
105 .service = PCIE_PORT_SERVICE_HP,
106 .probe = dummy_probe,
109 static int __init select_detection_mode(void)
111 struct slot *slot, *tmp;
112 pcie_port_service_register(&dummy_driver);
113 pcie_port_service_unregister(&dummy_driver);
114 list_for_each_entry_safe(slot, tmp, &dummy_slots, slot_list) {
115 list_del(&slot->slot_list);
118 if (acpi_slot_detected && dup_slot_id)
119 return PCIEHP_DETECT_ACPI;
120 return PCIEHP_DETECT_PCIE;
123 void __init pciehp_acpi_slot_detection_init(void)
125 slot_detection_mode = parse_detect_mode();
126 if (slot_detection_mode != PCIEHP_DETECT_AUTO)
128 slot_detection_mode = select_detection_mode();
130 if (slot_detection_mode == PCIEHP_DETECT_ACPI)
131 info("Using ACPI for slot detection.\n");