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 struct pcie_port_service_id __initdata port_pci_ids
[] = {
74 .port_type
= PCIE_ANY_PORT
,
75 .service_type
= PCIE_PORT_SERVICE_HP
,
77 }, { /* end: all zeroes */ }
80 static int __initdata dup_slot_id
;
81 static int __initdata acpi_slot_detected
;
82 static struct list_head __initdata dummy_slots
= LIST_HEAD_INIT(dummy_slots
);
84 /* Dummy driver for dumplicate name detection */
85 static int __init
dummy_probe(struct pcie_device
*dev
,
86 const struct pcie_port_service_id
*id
)
90 struct slot
*slot
, *tmp
;
91 struct pci_dev
*pdev
= dev
->port
;
92 struct pci_bus
*pbus
= pdev
->subordinate
;
93 if (!(slot
= kzalloc(sizeof(*slot
), GFP_KERNEL
)))
95 /* Note: pciehp_detect_mode != PCIEHP_DETECT_ACPI here */
96 if (pciehp_get_hp_hw_control_from_firmware(pdev
))
98 if (!(pos
= pci_find_capability(pdev
, PCI_CAP_ID_EXP
)))
100 pci_read_config_dword(pdev
, pos
+ PCI_EXP_SLTCAP
, &slot_cap
);
101 slot
->number
= slot_cap
>> 19;
102 list_for_each_entry(tmp
, &dummy_slots
, slot_list
) {
103 if (tmp
->number
== slot
->number
)
106 list_add_tail(&slot
->slot_list
, &dummy_slots
);
107 if (!acpi_slot_detected
&& acpi_pci_detect_ejectable(pbus
))
108 acpi_slot_detected
= 1;
109 return -ENODEV
; /* dummy driver always returns error */
112 static struct pcie_port_service_driver __initdata dummy_driver
= {
113 .name
= "pciehp_dummy",
114 .id_table
= port_pci_ids
,
115 .probe
= dummy_probe
,
118 static int __init
select_detection_mode(void)
120 struct slot
*slot
, *tmp
;
121 pcie_port_service_register(&dummy_driver
);
122 pcie_port_service_unregister(&dummy_driver
);
123 list_for_each_entry_safe(slot
, tmp
, &dummy_slots
, slot_list
) {
124 list_del(&slot
->slot_list
);
127 if (acpi_slot_detected
&& dup_slot_id
)
128 return PCIEHP_DETECT_ACPI
;
129 return PCIEHP_DETECT_PCIE
;
132 void __init
pciehp_acpi_slot_detection_init(void)
134 slot_detection_mode
= parse_detect_mode();
135 if (slot_detection_mode
!= PCIEHP_DETECT_AUTO
)
137 slot_detection_mode
= select_detection_mode();
139 if (slot_detection_mode
== PCIEHP_DETECT_ACPI
)
140 info("Using ACPI for slot detection.\n");