xref: /openbmc/linux/drivers/acpi/acpi_platform.c (revision bc000245)
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/err.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 
21 #include "internal.h"
22 
23 ACPI_MODULE_NAME("platform");
24 
25 /*
26  * The following ACPI IDs are known to be suitable for representing as
27  * platform devices.
28  */
29 static const struct acpi_device_id acpi_platform_device_ids[] = {
30 
31 	{ "PNP0D40" },
32 	{ "ACPI0003" },
33 	{ "VPC2004" },
34 	{ "BCM4752" },
35 
36 	/* Intel Smart Sound Technology */
37 	{ "INT33C8" },
38 	{ "80860F28" },
39 
40 	{ }
41 };
42 
43 /**
44  * acpi_create_platform_device - Create platform device for ACPI device node
45  * @adev: ACPI device node to create a platform device for.
46  * @id: ACPI device ID used to match @adev.
47  *
48  * Check if the given @adev can be represented as a platform device and, if
49  * that's the case, create and register a platform device, populate its common
50  * resources and returns a pointer to it.  Otherwise, return %NULL.
51  *
52  * Name of the platform device will be the same as @adev's.
53  */
54 int acpi_create_platform_device(struct acpi_device *adev,
55 				const struct acpi_device_id *id)
56 {
57 	struct platform_device *pdev = NULL;
58 	struct acpi_device *acpi_parent;
59 	struct platform_device_info pdevinfo;
60 	struct resource_list_entry *rentry;
61 	struct list_head resource_list;
62 	struct resource *resources = NULL;
63 	int count;
64 
65 	/* If the ACPI node already has a physical device attached, skip it. */
66 	if (adev->physical_node_count)
67 		return 0;
68 
69 	INIT_LIST_HEAD(&resource_list);
70 	count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
71 	if (count < 0) {
72 		return 0;
73 	} else if (count > 0) {
74 		resources = kmalloc(count * sizeof(struct resource),
75 				    GFP_KERNEL);
76 		if (!resources) {
77 			dev_err(&adev->dev, "No memory for resources\n");
78 			acpi_dev_free_resource_list(&resource_list);
79 			return -ENOMEM;
80 		}
81 		count = 0;
82 		list_for_each_entry(rentry, &resource_list, node)
83 			resources[count++] = rentry->res;
84 
85 		acpi_dev_free_resource_list(&resource_list);
86 	}
87 
88 	memset(&pdevinfo, 0, sizeof(pdevinfo));
89 	/*
90 	 * If the ACPI node has a parent and that parent has a physical device
91 	 * attached to it, that physical device should be the parent of the
92 	 * platform device we are about to create.
93 	 */
94 	pdevinfo.parent = NULL;
95 	acpi_parent = adev->parent;
96 	if (acpi_parent) {
97 		struct acpi_device_physical_node *entry;
98 		struct list_head *list;
99 
100 		mutex_lock(&acpi_parent->physical_node_lock);
101 		list = &acpi_parent->physical_node_list;
102 		if (!list_empty(list)) {
103 			entry = list_first_entry(list,
104 					struct acpi_device_physical_node,
105 					node);
106 			pdevinfo.parent = entry->dev;
107 		}
108 		mutex_unlock(&acpi_parent->physical_node_lock);
109 	}
110 	pdevinfo.name = dev_name(&adev->dev);
111 	pdevinfo.id = -1;
112 	pdevinfo.res = resources;
113 	pdevinfo.num_res = count;
114 	pdevinfo.acpi_node.companion = adev;
115 	pdev = platform_device_register_full(&pdevinfo);
116 	if (IS_ERR(pdev)) {
117 		dev_err(&adev->dev, "platform device creation failed: %ld\n",
118 			PTR_ERR(pdev));
119 		pdev = NULL;
120 	} else {
121 		dev_dbg(&adev->dev, "created platform device %s\n",
122 			dev_name(&pdev->dev));
123 	}
124 
125 	kfree(resources);
126 	return 1;
127 }
128 
129 static struct acpi_scan_handler platform_handler = {
130 	.ids = acpi_platform_device_ids,
131 	.attach = acpi_create_platform_device,
132 };
133 
134 void __init acpi_platform_init(void)
135 {
136 	acpi_scan_add_handler(&platform_handler);
137 }
138