xref: /linux/drivers/acpi/acpi_platform.c (revision b85d45947951d23cb22d90caecf4c1eb81342c96)
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/dma-mapping.h>
20 #include <linux/platform_device.h>
21 
22 #include "internal.h"
23 
24 ACPI_MODULE_NAME("platform");
25 
26 static const struct acpi_device_id forbidden_id_list[] = {
27 	{"PNP0000", 0},	/* PIC */
28 	{"PNP0100", 0},	/* Timer */
29 	{"PNP0200", 0},	/* AT DMA Controller */
30 	{"", 0},
31 };
32 
33 /**
34  * acpi_create_platform_device - Create platform device for ACPI device node
35  * @adev: ACPI device node to create a platform device for.
36  *
37  * Check if the given @adev can be represented as a platform device and, if
38  * that's the case, create and register a platform device, populate its common
39  * resources and returns a pointer to it.  Otherwise, return %NULL.
40  *
41  * Name of the platform device will be the same as @adev's.
42  */
43 struct platform_device *acpi_create_platform_device(struct acpi_device *adev)
44 {
45 	struct platform_device *pdev = NULL;
46 	struct acpi_device *acpi_parent;
47 	struct platform_device_info pdevinfo;
48 	struct resource_entry *rentry;
49 	struct list_head resource_list;
50 	struct resource *resources = NULL;
51 	int count;
52 
53 	/* If the ACPI node already has a physical device attached, skip it. */
54 	if (adev->physical_node_count)
55 		return NULL;
56 
57 	if (!acpi_match_device_ids(adev, forbidden_id_list))
58 		return ERR_PTR(-EINVAL);
59 
60 	INIT_LIST_HEAD(&resource_list);
61 	count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
62 	if (count < 0) {
63 		return NULL;
64 	} else if (count > 0) {
65 		resources = kmalloc(count * sizeof(struct resource),
66 				    GFP_KERNEL);
67 		if (!resources) {
68 			dev_err(&adev->dev, "No memory for resources\n");
69 			acpi_dev_free_resource_list(&resource_list);
70 			return ERR_PTR(-ENOMEM);
71 		}
72 		count = 0;
73 		list_for_each_entry(rentry, &resource_list, node)
74 			resources[count++] = *rentry->res;
75 
76 		acpi_dev_free_resource_list(&resource_list);
77 	}
78 
79 	memset(&pdevinfo, 0, sizeof(pdevinfo));
80 	/*
81 	 * If the ACPI node has a parent and that parent has a physical device
82 	 * attached to it, that physical device should be the parent of the
83 	 * platform device we are about to create.
84 	 */
85 	pdevinfo.parent = NULL;
86 	acpi_parent = adev->parent;
87 	if (acpi_parent) {
88 		struct acpi_device_physical_node *entry;
89 		struct list_head *list;
90 
91 		mutex_lock(&acpi_parent->physical_node_lock);
92 		list = &acpi_parent->physical_node_list;
93 		if (!list_empty(list)) {
94 			entry = list_first_entry(list,
95 					struct acpi_device_physical_node,
96 					node);
97 			pdevinfo.parent = entry->dev;
98 		}
99 		mutex_unlock(&acpi_parent->physical_node_lock);
100 	}
101 	pdevinfo.name = dev_name(&adev->dev);
102 	pdevinfo.id = -1;
103 	pdevinfo.res = resources;
104 	pdevinfo.num_res = count;
105 	pdevinfo.fwnode = acpi_fwnode_handle(adev);
106 	pdevinfo.dma_mask = acpi_check_dma(adev, NULL) ? DMA_BIT_MASK(32) : 0;
107 	pdev = platform_device_register_full(&pdevinfo);
108 	if (IS_ERR(pdev))
109 		dev_err(&adev->dev, "platform device creation failed: %ld\n",
110 			PTR_ERR(pdev));
111 	else
112 		dev_dbg(&adev->dev, "created platform device %s\n",
113 			dev_name(&pdev->dev));
114 
115 	kfree(resources);
116 	return pdev;
117 }
118 EXPORT_SYMBOL_GPL(acpi_create_platform_device);
119