[IA64] Update comment to describe modes set in default control register.
[linux-2.6] / arch / ia64 / kernel / acpi-ext.c
1 /*
2  * arch/ia64/kernel/acpi-ext.c
3  *
4  * Copyright (C) 2003 Hewlett-Packard
5  * Copyright (C) Alex Williamson
6  * Copyright (C) Bjorn Helgaas
7  *
8  * Vendor specific extensions to ACPI.
9  */
10
11 #include <linux/config.h>
12 #include <linux/module.h>
13 #include <linux/types.h>
14 #include <linux/acpi.h>
15 #include <linux/efi.h>
16
17 #include <asm/acpi-ext.h>
18
19 struct acpi_vendor_descriptor {
20         u8                              guid_id;
21         efi_guid_t                      guid;
22 };
23
24 struct acpi_vendor_info {
25         struct acpi_vendor_descriptor   *descriptor;
26         u8                              *data;
27         u32                             length;
28 };
29
30 acpi_status
31 acpi_vendor_resource_match(struct acpi_resource *resource, void *context)
32 {
33         struct acpi_vendor_info *info = (struct acpi_vendor_info *) context;
34         struct acpi_resource_vendor *vendor;
35         struct acpi_vendor_descriptor *descriptor;
36         u32 length;
37
38         if (resource->id != ACPI_RSTYPE_VENDOR)
39                 return AE_OK;
40
41         vendor = (struct acpi_resource_vendor *) &resource->data;
42         descriptor = (struct acpi_vendor_descriptor *) vendor->reserved;
43         if (vendor->length <= sizeof(*info->descriptor) ||
44             descriptor->guid_id != info->descriptor->guid_id ||
45             efi_guidcmp(descriptor->guid, info->descriptor->guid))
46                 return AE_OK;
47
48         length = vendor->length - sizeof(struct acpi_vendor_descriptor);
49         info->data = acpi_os_allocate(length);
50         if (!info->data)
51                 return AE_NO_MEMORY;
52
53         memcpy(info->data, vendor->reserved + sizeof(struct acpi_vendor_descriptor), length);
54         info->length = length;
55         return AE_CTRL_TERMINATE;
56 }
57
58 acpi_status
59 acpi_find_vendor_resource(acpi_handle obj, struct acpi_vendor_descriptor *id,
60                 u8 **data, u32 *length)
61 {
62         struct acpi_vendor_info info;
63
64         info.descriptor = id;
65         info.data = NULL;
66
67         acpi_walk_resources(obj, METHOD_NAME__CRS, acpi_vendor_resource_match, &info);
68         if (!info.data)
69                 return AE_NOT_FOUND;
70
71         *data = info.data;
72         *length = info.length;
73         return AE_OK;
74 }
75
76 struct acpi_vendor_descriptor hp_ccsr_descriptor = {
77         .guid_id = 2,
78         .guid    = EFI_GUID(0x69e9adf9, 0x924f, 0xab5f, 0xf6, 0x4a, 0x24, 0xd2, 0x01, 0x37, 0x0e, 0xad)
79 };
80
81 acpi_status
82 hp_acpi_csr_space(acpi_handle obj, u64 *csr_base, u64 *csr_length)
83 {
84         acpi_status status;
85         u8 *data;
86         u32 length;
87
88         status = acpi_find_vendor_resource(obj, &hp_ccsr_descriptor, &data, &length);
89
90         if (ACPI_FAILURE(status) || length != 16)
91                 return AE_NOT_FOUND;
92
93         memcpy(csr_base, data, sizeof(*csr_base));
94         memcpy(csr_length, data + 8, sizeof(*csr_length));
95         acpi_os_free(data);
96
97         return AE_OK;
98 }
99
100 EXPORT_SYMBOL(hp_acpi_csr_space);