xref: /linux/drivers/acpi/acpi_platform.c (revision cc9b94029e9ef51787af908e9856b1eed314bc00)
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/pci.h>
21 #include <linux/platform_device.h>
22 
23 #include "internal.h"
24 
25 ACPI_MODULE_NAME("platform");
26 
27 static const struct acpi_device_id forbidden_id_list[] = {
28 	{"PNP0000", 0},	/* PIC */
29 	{"PNP0100", 0},	/* Timer */
30 	{"PNP0200", 0},	/* AT DMA Controller */
31 	{"", 0},
32 };
33 
34 static void acpi_platform_fill_resource(struct acpi_device *adev,
35 	const struct resource *src, struct resource *dest)
36 {
37 	struct device *parent;
38 
39 	*dest = *src;
40 
41 	/*
42 	 * If the device has parent we need to take its resources into
43 	 * account as well because this device might consume part of those.
44 	 */
45 	parent = acpi_get_first_physical_node(adev->parent);
46 	if (parent && dev_is_pci(parent))
47 		dest->parent = pci_find_resource(to_pci_dev(parent), dest);
48 }
49 
50 /**
51  * acpi_create_platform_device - Create platform device for ACPI device node
52  * @adev: ACPI device node to create a platform device for.
53  *
54  * Check if the given @adev can be represented as a platform device and, if
55  * that's the case, create and register a platform device, populate its common
56  * resources and returns a pointer to it.  Otherwise, return %NULL.
57  *
58  * Name of the platform device will be the same as @adev's.
59  */
60 struct platform_device *acpi_create_platform_device(struct acpi_device *adev)
61 {
62 	struct platform_device *pdev = NULL;
63 	struct platform_device_info pdevinfo;
64 	struct resource_entry *rentry;
65 	struct list_head resource_list;
66 	struct resource *resources = NULL;
67 	int count;
68 
69 	/* If the ACPI node already has a physical device attached, skip it. */
70 	if (adev->physical_node_count)
71 		return NULL;
72 
73 	if (!acpi_match_device_ids(adev, forbidden_id_list))
74 		return ERR_PTR(-EINVAL);
75 
76 	INIT_LIST_HEAD(&resource_list);
77 	count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
78 	if (count < 0) {
79 		return NULL;
80 	} else if (count > 0) {
81 		resources = kzalloc(count * sizeof(struct resource),
82 				    GFP_KERNEL);
83 		if (!resources) {
84 			dev_err(&adev->dev, "No memory for resources\n");
85 			acpi_dev_free_resource_list(&resource_list);
86 			return ERR_PTR(-ENOMEM);
87 		}
88 		count = 0;
89 		list_for_each_entry(rentry, &resource_list, node)
90 			acpi_platform_fill_resource(adev, rentry->res,
91 						    &resources[count++]);
92 
93 		acpi_dev_free_resource_list(&resource_list);
94 	}
95 
96 	memset(&pdevinfo, 0, sizeof(pdevinfo));
97 	/*
98 	 * If the ACPI node has a parent and that parent has a physical device
99 	 * attached to it, that physical device should be the parent of the
100 	 * platform device we are about to create.
101 	 */
102 	pdevinfo.parent = adev->parent ?
103 		acpi_get_first_physical_node(adev->parent) : NULL;
104 	pdevinfo.name = dev_name(&adev->dev);
105 	pdevinfo.id = -1;
106 	pdevinfo.res = resources;
107 	pdevinfo.num_res = count;
108 	pdevinfo.fwnode = acpi_fwnode_handle(adev);
109 
110 	if (acpi_dma_supported(adev))
111 		pdevinfo.dma_mask = DMA_BIT_MASK(32);
112 	else
113 		pdevinfo.dma_mask = 0;
114 
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 	else
120 		dev_dbg(&adev->dev, "created platform device %s\n",
121 			dev_name(&pdev->dev));
122 
123 	kfree(resources);
124 	return pdev;
125 }
126 EXPORT_SYMBOL_GPL(acpi_create_platform_device);
127