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 	{"PNP0000",  0},	/* PIC */
24 	{"PNP0100",  0},	/* Timer */
25 	{"PNP0200",  0},	/* AT DMA Controller */
26 	{"ACPI0009", 0},	/* IOxAPIC */
27 	{"ACPI000A", 0},	/* IOAPIC */
28 	{"SMB0001",  0},	/* ACPI SMBUS virtual device */
29 	{"", 0},
30 };
31 
acpi_platform_device_find_by_companion(struct acpi_device * adev)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 
acpi_platform_device_remove_notify(struct notifier_block * nb,unsigned long value,void * arg)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 
acpi_platform_fill_resource(struct acpi_device * adev,const struct resource * src,struct resource * dest)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(adev->parent);
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  */
acpi_create_platform_device(struct acpi_device * adev,struct property_entry * properties)97 struct platform_device *acpi_create_platform_device(struct acpi_device *adev,
98 					struct property_entry *properties)
99 {
100 	struct platform_device *pdev = NULL;
101 	struct platform_device_info pdevinfo;
102 	struct resource_entry *rentry;
103 	struct list_head resource_list;
104 	struct resource *resources = NULL;
105 	int count;
106 
107 	/* If the ACPI node already has a physical device attached, skip it. */
108 	if (adev->physical_node_count)
109 		return NULL;
110 
111 	if (!acpi_match_device_ids(adev, forbidden_id_list))
112 		return ERR_PTR(-EINVAL);
113 
114 	INIT_LIST_HEAD(&resource_list);
115 	count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
116 	if (count < 0) {
117 		return NULL;
118 	} else if (count > 0) {
119 		resources = kcalloc(count, sizeof(struct resource),
120 				    GFP_KERNEL);
121 		if (!resources) {
122 			dev_err(&adev->dev, "No memory for resources\n");
123 			acpi_dev_free_resource_list(&resource_list);
124 			return ERR_PTR(-ENOMEM);
125 		}
126 		count = 0;
127 		list_for_each_entry(rentry, &resource_list, node)
128 			acpi_platform_fill_resource(adev, rentry->res,
129 						    &resources[count++]);
130 
131 		acpi_dev_free_resource_list(&resource_list);
132 	}
133 
134 	memset(&pdevinfo, 0, sizeof(pdevinfo));
135 	/*
136 	 * If the ACPI node has a parent and that parent has a physical device
137 	 * attached to it, that physical device should be the parent of the
138 	 * platform device we are about to create.
139 	 */
140 	pdevinfo.parent = adev->parent ?
141 		acpi_get_first_physical_node(adev->parent) : NULL;
142 	pdevinfo.name = dev_name(&adev->dev);
143 	pdevinfo.id = -1;
144 	pdevinfo.res = resources;
145 	pdevinfo.num_res = count;
146 	pdevinfo.fwnode = acpi_fwnode_handle(adev);
147 	pdevinfo.properties = properties;
148 
149 	if (acpi_dma_supported(adev))
150 		pdevinfo.dma_mask = DMA_BIT_MASK(32);
151 	else
152 		pdevinfo.dma_mask = 0;
153 
154 	pdev = platform_device_register_full(&pdevinfo);
155 	if (IS_ERR(pdev))
156 		dev_err(&adev->dev, "platform device creation failed: %ld\n",
157 			PTR_ERR(pdev));
158 	else {
159 		set_dev_node(&pdev->dev, acpi_get_node(adev->handle));
160 		dev_dbg(&adev->dev, "created platform device %s\n",
161 			dev_name(&pdev->dev));
162 	}
163 
164 	kfree(resources);
165 
166 	return pdev;
167 }
168 EXPORT_SYMBOL_GPL(acpi_create_platform_device);
169 
acpi_platform_init(void)170 void __init acpi_platform_init(void)
171 {
172 	acpi_reconfig_notifier_register(&acpi_platform_notifier);
173 }
174