xref: /openbmc/linux/drivers/acpi/acpi_platform.c (revision a266ef69)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * ACPI support for platform bus type.
4  *
5  * Copyright (C) 2012, Intel Corporation
6  * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
7  *          Mathias Nyman <mathias.nyman@linux.intel.com>
8  *          Rafael J. Wysocki <rafael.j.wysocki@intel.com>
9  */
10 
11 #include <linux/acpi.h>
12 #include <linux/device.h>
13 #include <linux/err.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/dma-mapping.h>
17 #include <linux/pci.h>
18 #include <linux/platform_device.h>
19 
20 #include "internal.h"
21 
22 static const struct acpi_device_id forbidden_id_list[] = {
23 	{"ACPI0009", 0},	/* IOxAPIC */
24 	{"ACPI000A", 0},	/* IOAPIC */
25 	{"PNP0000",  0},	/* PIC */
26 	{"PNP0100",  0},	/* Timer */
27 	{"PNP0200",  0},	/* AT DMA Controller */
28 	{"SMB0001",  0},	/* ACPI SMBUS virtual device */
29 	{ }
30 };
31 
32 static struct platform_device *acpi_platform_device_find_by_companion(struct acpi_device *adev)
33 {
34 	struct device *dev;
35 
36 	dev = bus_find_device_by_acpi_dev(&platform_bus_type, adev);
37 	return dev ? to_platform_device(dev) : NULL;
38 }
39 
40 static int acpi_platform_device_remove_notify(struct notifier_block *nb,
41 					      unsigned long value, void *arg)
42 {
43 	struct acpi_device *adev = arg;
44 	struct platform_device *pdev;
45 
46 	switch (value) {
47 	case ACPI_RECONFIG_DEVICE_ADD:
48 		/* Nothing to do here */
49 		break;
50 	case ACPI_RECONFIG_DEVICE_REMOVE:
51 		if (!acpi_device_enumerated(adev))
52 			break;
53 
54 		pdev = acpi_platform_device_find_by_companion(adev);
55 		if (!pdev)
56 			break;
57 
58 		platform_device_unregister(pdev);
59 		put_device(&pdev->dev);
60 		break;
61 	}
62 
63 	return NOTIFY_OK;
64 }
65 
66 static struct notifier_block acpi_platform_notifier = {
67 	.notifier_call = acpi_platform_device_remove_notify,
68 };
69 
70 static void acpi_platform_fill_resource(struct acpi_device *adev,
71 	const struct resource *src, struct resource *dest)
72 {
73 	struct device *parent;
74 
75 	*dest = *src;
76 
77 	/*
78 	 * If the device has parent we need to take its resources into
79 	 * account as well because this device might consume part of those.
80 	 */
81 	parent = acpi_get_first_physical_node(acpi_dev_parent(adev));
82 	if (parent && dev_is_pci(parent))
83 		dest->parent = pci_find_resource(to_pci_dev(parent), dest);
84 }
85 
86 /**
87  * acpi_create_platform_device - Create platform device for ACPI device node
88  * @adev: ACPI device node to create a platform device for.
89  * @properties: Optional collection of build-in properties.
90  *
91  * Check if the given @adev can be represented as a platform device and, if
92  * that's the case, create and register a platform device, populate its common
93  * resources and returns a pointer to it.  Otherwise, return %NULL.
94  *
95  * Name of the platform device will be the same as @adev's.
96  */
97 struct platform_device *acpi_create_platform_device(struct acpi_device *adev,
98 						    const struct property_entry *properties)
99 {
100 	struct acpi_device *parent = acpi_dev_parent(adev);
101 	struct platform_device *pdev = NULL;
102 	struct platform_device_info pdevinfo;
103 	struct resource_entry *rentry;
104 	struct list_head resource_list;
105 	struct resource *resources = NULL;
106 	int count;
107 
108 	/* If the ACPI node already has a physical device attached, skip it. */
109 	if (adev->physical_node_count)
110 		return NULL;
111 
112 	if (!acpi_match_device_ids(adev, forbidden_id_list))
113 		return ERR_PTR(-EINVAL);
114 
115 	INIT_LIST_HEAD(&resource_list);
116 	count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
117 	if (count < 0)
118 		return NULL;
119 	if (count > 0) {
120 		resources = kcalloc(count, sizeof(*resources), GFP_KERNEL);
121 		if (!resources) {
122 			acpi_dev_free_resource_list(&resource_list);
123 			return ERR_PTR(-ENOMEM);
124 		}
125 		count = 0;
126 		list_for_each_entry(rentry, &resource_list, node)
127 			acpi_platform_fill_resource(adev, rentry->res,
128 						    &resources[count++]);
129 
130 		acpi_dev_free_resource_list(&resource_list);
131 	}
132 
133 	memset(&pdevinfo, 0, sizeof(pdevinfo));
134 	/*
135 	 * If the ACPI node has a parent and that parent has a physical device
136 	 * attached to it, that physical device should be the parent of the
137 	 * platform device we are about to create.
138 	 */
139 	pdevinfo.parent = parent ? acpi_get_first_physical_node(parent) : NULL;
140 	pdevinfo.name = dev_name(&adev->dev);
141 	pdevinfo.id = PLATFORM_DEVID_NONE;
142 	pdevinfo.res = resources;
143 	pdevinfo.num_res = count;
144 	pdevinfo.fwnode = acpi_fwnode_handle(adev);
145 	pdevinfo.properties = properties;
146 
147 	if (acpi_dma_supported(adev))
148 		pdevinfo.dma_mask = DMA_BIT_MASK(32);
149 	else
150 		pdevinfo.dma_mask = 0;
151 
152 	pdev = platform_device_register_full(&pdevinfo);
153 	if (IS_ERR(pdev))
154 		dev_err(&adev->dev, "platform device creation failed: %ld\n",
155 			PTR_ERR(pdev));
156 	else {
157 		set_dev_node(&pdev->dev, acpi_get_node(adev->handle));
158 		dev_dbg(&adev->dev, "created platform device %s\n",
159 			dev_name(&pdev->dev));
160 	}
161 
162 	kfree(resources);
163 
164 	return pdev;
165 }
166 EXPORT_SYMBOL_GPL(acpi_create_platform_device);
167 
168 void __init acpi_platform_init(void)
169 {
170 	acpi_reconfig_notifier_register(&acpi_platform_notifier);
171 }
172