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1 | /* |
2 | * ACPI support for platform bus type. | |
3 | * | |
4 | * Copyright (C) 2012, Intel Corporation | |
5 | * Authors: Mika Westerberg <mika.westerberg@linux.intel.com> | |
6 | * Mathias Nyman <mathias.nyman@linux.intel.com> | |
7 | * Rafael J. Wysocki <rafael.j.wysocki@intel.com> | |
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 version 2 as | |
11 | * published by the Free Software Foundation. | |
12 | */ | |
13 | ||
14 | #include <linux/acpi.h> | |
15 | #include <linux/device.h> | |
16 | #include <linux/kernel.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/platform_device.h> | |
19 | ||
20 | ACPI_MODULE_NAME("platform"); | |
21 | ||
91e56878 MW |
22 | /** |
23 | * acpi_create_platform_device - Create platform device for ACPI device node | |
24 | * @adev: ACPI device node to create a platform device for. | |
25 | * | |
26 | * Check if the given @adev can be represented as a platform device and, if | |
27 | * that's the case, create and register a platform device, populate its common | |
28 | * resources and returns a pointer to it. Otherwise, return %NULL. | |
29 | * | |
30 | * The platform device's name will be taken from the @adev's _HID and _UID. | |
31 | */ | |
32 | struct platform_device *acpi_create_platform_device(struct acpi_device *adev) | |
33 | { | |
34 | struct platform_device *pdev = NULL; | |
35 | struct acpi_device *acpi_parent; | |
36 | struct device *parent = NULL; | |
8e345c99 RW |
37 | struct resource_list_entry *rentry; |
38 | struct list_head resource_list; | |
39 | struct resource *resources; | |
40 | int count; | |
91e56878 MW |
41 | |
42 | /* If the ACPI node already has a physical device attached, skip it. */ | |
43 | if (adev->physical_node_count) | |
44 | return NULL; | |
45 | ||
8e345c99 RW |
46 | INIT_LIST_HEAD(&resource_list); |
47 | count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL); | |
48 | if (count <= 0) | |
91e56878 MW |
49 | return NULL; |
50 | ||
8e345c99 RW |
51 | resources = kmalloc(count * sizeof(struct resource), GFP_KERNEL); |
52 | if (!resources) { | |
53 | dev_err(&adev->dev, "No memory for resources\n"); | |
54 | acpi_dev_free_resource_list(&resource_list); | |
91e56878 MW |
55 | return NULL; |
56 | } | |
8e345c99 RW |
57 | count = 0; |
58 | list_for_each_entry(rentry, &resource_list, node) | |
59 | resources[count++] = rentry->res; | |
91e56878 | 60 | |
8e345c99 | 61 | acpi_dev_free_resource_list(&resource_list); |
91e56878 | 62 | |
91e56878 MW |
63 | /* |
64 | * If the ACPI node has a parent and that parent has a physical device | |
65 | * attached to it, that physical device should be the parent of the | |
66 | * platform device we are about to create. | |
67 | */ | |
68 | acpi_parent = adev->parent; | |
69 | if (acpi_parent) { | |
70 | struct acpi_device_physical_node *entry; | |
71 | struct list_head *list; | |
72 | ||
73 | mutex_lock(&acpi_parent->physical_node_lock); | |
74 | list = &acpi_parent->physical_node_list; | |
75 | if (!list_empty(list)) { | |
76 | entry = list_first_entry(list, | |
77 | struct acpi_device_physical_node, | |
78 | node); | |
79 | parent = entry->dev; | |
80 | } | |
81 | mutex_unlock(&acpi_parent->physical_node_lock); | |
82 | } | |
b4b6cae2 | 83 | pdev = platform_device_register_resndata(parent, dev_name(&adev->dev), |
8e345c99 | 84 | -1, resources, count, NULL, 0); |
91e56878 MW |
85 | if (IS_ERR(pdev)) { |
86 | dev_err(&adev->dev, "platform device creation failed: %ld\n", | |
87 | PTR_ERR(pdev)); | |
88 | pdev = NULL; | |
89 | } else { | |
90 | dev_dbg(&adev->dev, "created platform device %s\n", | |
91 | dev_name(&pdev->dev)); | |
92 | } | |
93 | ||
8e345c99 | 94 | kfree(resources); |
91e56878 MW |
95 | return pdev; |
96 | } | |
97 | ||
98 | static acpi_status acpi_platform_match(acpi_handle handle, u32 depth, | |
99 | void *data, void **return_value) | |
100 | { | |
101 | struct platform_device *pdev = data; | |
102 | struct acpi_device *adev; | |
103 | acpi_status status; | |
104 | ||
105 | status = acpi_bus_get_device(handle, &adev); | |
106 | if (ACPI_FAILURE(status)) | |
107 | return status; | |
108 | ||
109 | /* Skip ACPI devices that have physical device attached */ | |
110 | if (adev->physical_node_count) | |
111 | return AE_OK; | |
112 | ||
b4b6cae2 | 113 | if (!strcmp(dev_name(&pdev->dev), dev_name(&adev->dev))) { |
91e56878 MW |
114 | *(acpi_handle *)return_value = handle; |
115 | return AE_CTRL_TERMINATE; | |
116 | } | |
117 | ||
118 | return AE_OK; | |
119 | } | |
120 | ||
121 | static int acpi_platform_find_device(struct device *dev, acpi_handle *handle) | |
122 | { | |
123 | struct platform_device *pdev = to_platform_device(dev); | |
b4b6cae2 MW |
124 | char *name, *tmp, *hid; |
125 | ||
126 | /* | |
127 | * The platform device is named using the ACPI device name | |
128 | * _HID:INSTANCE so we strip the INSTANCE out in order to find the | |
129 | * correct device using its _HID. | |
130 | */ | |
131 | name = kstrdup(dev_name(dev), GFP_KERNEL); | |
132 | if (!name) | |
133 | return -ENOMEM; | |
134 | ||
135 | tmp = name; | |
136 | hid = strsep(&tmp, ":"); | |
137 | if (!hid) { | |
138 | kfree(name); | |
139 | return -ENODEV; | |
140 | } | |
91e56878 MW |
141 | |
142 | *handle = NULL; | |
b4b6cae2 | 143 | acpi_get_devices(hid, acpi_platform_match, pdev, handle); |
91e56878 | 144 | |
b4b6cae2 | 145 | kfree(name); |
91e56878 MW |
146 | return *handle ? 0 : -ENODEV; |
147 | } | |
148 | ||
149 | static struct acpi_bus_type acpi_platform_bus = { | |
150 | .bus = &platform_bus_type, | |
151 | .find_device = acpi_platform_find_device, | |
152 | }; | |
153 | ||
154 | static int __init acpi_platform_init(void) | |
155 | { | |
156 | return register_acpi_bus_type(&acpi_platform_bus); | |
157 | } | |
158 | arch_initcall(acpi_platform_init); |