2 * ACPI support for platform bus type.
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>
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.
14 #include <linux/acpi.h>
15 #include <linux/device.h>
16 #include <linux/err.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
23 ACPI_MODULE_NAME("platform");
26 * The following ACPI IDs are known to be suitable for representing as
29 static const struct acpi_device_id acpi_platform_device_ids[] = {
38 * acpi_create_platform_device - Create platform device for ACPI device node
39 * @adev: ACPI device node to create a platform device for.
40 * @id: ACPI device ID used to match @adev.
42 * Check if the given @adev can be represented as a platform device and, if
43 * that's the case, create and register a platform device, populate its common
44 * resources and returns a pointer to it. Otherwise, return %NULL.
46 * Name of the platform device will be the same as @adev's.
48 int acpi_create_platform_device(struct acpi_device *adev,
49 const struct acpi_device_id *id)
51 struct platform_device *pdev = NULL;
52 struct acpi_device *acpi_parent;
53 struct platform_device_info pdevinfo;
54 struct resource_list_entry *rentry;
55 struct list_head resource_list;
56 struct resource *resources = NULL;
59 /* If the ACPI node already has a physical device attached, skip it. */
60 if (adev->physical_node_count)
63 INIT_LIST_HEAD(&resource_list);
64 count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
67 } else if (count > 0) {
68 resources = kmalloc(count * sizeof(struct resource),
71 dev_err(&adev->dev, "No memory for resources\n");
72 acpi_dev_free_resource_list(&resource_list);
76 list_for_each_entry(rentry, &resource_list, node)
77 resources[count++] = rentry->res;
79 acpi_dev_free_resource_list(&resource_list);
82 memset(&pdevinfo, 0, sizeof(pdevinfo));
84 * If the ACPI node has a parent and that parent has a physical device
85 * attached to it, that physical device should be the parent of the
86 * platform device we are about to create.
88 pdevinfo.parent = NULL;
89 acpi_parent = adev->parent;
91 struct acpi_device_physical_node *entry;
92 struct list_head *list;
94 mutex_lock(&acpi_parent->physical_node_lock);
95 list = &acpi_parent->physical_node_list;
96 if (!list_empty(list)) {
97 entry = list_first_entry(list,
98 struct acpi_device_physical_node,
100 pdevinfo.parent = entry->dev;
102 mutex_unlock(&acpi_parent->physical_node_lock);
104 pdevinfo.name = dev_name(&adev->dev);
106 pdevinfo.res = resources;
107 pdevinfo.num_res = count;
108 pdevinfo.acpi_node.handle = adev->handle;
109 pdev = platform_device_register_full(&pdevinfo);
111 dev_err(&adev->dev, "platform device creation failed: %ld\n",
115 dev_dbg(&adev->dev, "created platform device %s\n",
116 dev_name(&pdev->dev));
123 static struct acpi_scan_handler platform_handler = {
124 .ids = acpi_platform_device_ids,
125 .attach = acpi_create_platform_device,
128 void __init acpi_platform_init(void)
130 acpi_scan_add_handler(&platform_handler);