xref: /openbmc/linux/drivers/acpi/acpi_platform.c (revision 275876e2)
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 static const struct acpi_device_id forbidden_id_list[] = {
26 	{"PNP0000", 0},	/* PIC */
27 	{"PNP0100", 0},	/* Timer */
28 	{"PNP0200", 0},	/* AT DMA Controller */
29 	{"", 0},
30 };
31 
32 /**
33  * acpi_create_platform_device - Create platform device for ACPI device node
34  * @adev: ACPI device node to create a platform device for.
35  *
36  * Check if the given @adev can be represented as a platform device and, if
37  * that's the case, create and register a platform device, populate its common
38  * resources and returns a pointer to it.  Otherwise, return %NULL.
39  *
40  * Name of the platform device will be the same as @adev's.
41  */
42 struct platform_device *acpi_create_platform_device(struct acpi_device *adev)
43 {
44 	struct platform_device *pdev = NULL;
45 	struct acpi_device *acpi_parent;
46 	struct platform_device_info pdevinfo;
47 	struct resource_list_entry *rentry;
48 	struct list_head resource_list;
49 	struct resource *resources = NULL;
50 	int count;
51 
52 	/* If the ACPI node already has a physical device attached, skip it. */
53 	if (adev->physical_node_count)
54 		return NULL;
55 
56 	if (!acpi_match_device_ids(adev, forbidden_id_list))
57 		return ERR_PTR(-EINVAL);
58 
59 	INIT_LIST_HEAD(&resource_list);
60 	count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
61 	if (count < 0) {
62 		return NULL;
63 	} else if (count > 0) {
64 		resources = kmalloc(count * sizeof(struct resource),
65 				    GFP_KERNEL);
66 		if (!resources) {
67 			dev_err(&adev->dev, "No memory for resources\n");
68 			acpi_dev_free_resource_list(&resource_list);
69 			return ERR_PTR(-ENOMEM);
70 		}
71 		count = 0;
72 		list_for_each_entry(rentry, &resource_list, node)
73 			resources[count++] = rentry->res;
74 
75 		acpi_dev_free_resource_list(&resource_list);
76 	}
77 
78 	memset(&pdevinfo, 0, sizeof(pdevinfo));
79 	/*
80 	 * If the ACPI node has a parent and that parent has a physical device
81 	 * attached to it, that physical device should be the parent of the
82 	 * platform device we are about to create.
83 	 */
84 	pdevinfo.parent = NULL;
85 	acpi_parent = adev->parent;
86 	if (acpi_parent) {
87 		struct acpi_device_physical_node *entry;
88 		struct list_head *list;
89 
90 		mutex_lock(&acpi_parent->physical_node_lock);
91 		list = &acpi_parent->physical_node_list;
92 		if (!list_empty(list)) {
93 			entry = list_first_entry(list,
94 					struct acpi_device_physical_node,
95 					node);
96 			pdevinfo.parent = entry->dev;
97 		}
98 		mutex_unlock(&acpi_parent->physical_node_lock);
99 	}
100 	pdevinfo.name = dev_name(&adev->dev);
101 	pdevinfo.id = -1;
102 	pdevinfo.res = resources;
103 	pdevinfo.num_res = count;
104 	pdevinfo.acpi_node.companion = adev;
105 	pdev = platform_device_register_full(&pdevinfo);
106 	if (IS_ERR(pdev))
107 		dev_err(&adev->dev, "platform device creation failed: %ld\n",
108 			PTR_ERR(pdev));
109 	else
110 		dev_dbg(&adev->dev, "created platform device %s\n",
111 			dev_name(&pdev->dev));
112 
113 	kfree(resources);
114 	return pdev;
115 }
116