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
 22ACPI_MODULE_NAME("platform");
 23
 24static const struct acpi_device_id forbidden_id_list[] = {
 25	{"PNP0000",  0},	/* PIC */
 26	{"PNP0100",  0},	/* Timer */
 27	{"PNP0200",  0},	/* AT DMA Controller */
 28	{"ACPI0009", 0},	/* IOxAPIC */
 29	{"ACPI000A", 0},	/* IOAPIC */
 30	{"SMB0001",  0},	/* ACPI SMBUS virtual device */
 31	{"", 0},
 32};
 33
 34static struct platform_device *acpi_platform_device_find_by_companion(struct acpi_device *adev)
 35{
 36	struct device *dev;
 37
 38	dev = bus_find_device_by_acpi_dev(&platform_bus_type, adev);
 39	return dev ? to_platform_device(dev) : NULL;
 40}
 41
 42static int acpi_platform_device_remove_notify(struct notifier_block *nb,
 43					      unsigned long value, void *arg)
 44{
 45	struct acpi_device *adev = arg;
 46	struct platform_device *pdev;
 47
 48	switch (value) {
 49	case ACPI_RECONFIG_DEVICE_ADD:
 50		/* Nothing to do here */
 51		break;
 52	case ACPI_RECONFIG_DEVICE_REMOVE:
 53		if (!acpi_device_enumerated(adev))
 54			break;
 55
 56		pdev = acpi_platform_device_find_by_companion(adev);
 57		if (!pdev)
 58			break;
 59
 60		platform_device_unregister(pdev);
 61		put_device(&pdev->dev);
 62		break;
 63	}
 64
 65	return NOTIFY_OK;
 66}
 67
 68static struct notifier_block acpi_platform_notifier = {
 69	.notifier_call = acpi_platform_device_remove_notify,
 70};
 71
 72static void acpi_platform_fill_resource(struct acpi_device *adev,
 73	const struct resource *src, struct resource *dest)
 74{
 75	struct device *parent;
 76
 77	*dest = *src;
 78
 79	/*
 80	 * If the device has parent we need to take its resources into
 81	 * account as well because this device might consume part of those.
 82	 */
 83	parent = acpi_get_first_physical_node(adev->parent);
 84	if (parent && dev_is_pci(parent))
 85		dest->parent = pci_find_resource(to_pci_dev(parent), dest);
 86}
 87
 88/**
 89 * acpi_create_platform_device - Create platform device for ACPI device node
 90 * @adev: ACPI device node to create a platform device for.
 91 * @properties: Optional collection of build-in properties.
 92 *
 93 * Check if the given @adev can be represented as a platform device and, if
 94 * that's the case, create and register a platform device, populate its common
 95 * resources and returns a pointer to it.  Otherwise, return %NULL.
 96 *
 97 * Name of the platform device will be the same as @adev's.
 98 */
 99struct platform_device *acpi_create_platform_device(struct acpi_device *adev,
100					struct property_entry *properties)
101{
102	struct platform_device *pdev = NULL;
103	struct platform_device_info pdevinfo;
104	struct resource_entry *rentry;
105	struct list_head resource_list;
106	struct resource *resources = NULL;
107	int count;
108
109	/* If the ACPI node already has a physical device attached, skip it. */
110	if (adev->physical_node_count)
111		return NULL;
112
113	if (!acpi_match_device_ids(adev, forbidden_id_list))
114		return ERR_PTR(-EINVAL);
115
116	INIT_LIST_HEAD(&resource_list);
117	count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
118	if (count < 0) {
119		return NULL;
120	} else if (count > 0) {
121		resources = kcalloc(count, sizeof(struct resource),
122				    GFP_KERNEL);
123		if (!resources) {
124			dev_err(&adev->dev, "No memory for resources\n");
125			acpi_dev_free_resource_list(&resource_list);
126			return ERR_PTR(-ENOMEM);
127		}
128		count = 0;
129		list_for_each_entry(rentry, &resource_list, node)
130			acpi_platform_fill_resource(adev, rentry->res,
131						    &resources[count++]);
132
133		acpi_dev_free_resource_list(&resource_list);
134	}
135
136	memset(&pdevinfo, 0, sizeof(pdevinfo));
137	/*
138	 * If the ACPI node has a parent and that parent has a physical device
139	 * attached to it, that physical device should be the parent of the
140	 * platform device we are about to create.
141	 */
142	pdevinfo.parent = adev->parent ?
143		acpi_get_first_physical_node(adev->parent) : NULL;
144	pdevinfo.name = dev_name(&adev->dev);
145	pdevinfo.id = -1;
146	pdevinfo.res = resources;
147	pdevinfo.num_res = count;
148	pdevinfo.fwnode = acpi_fwnode_handle(adev);
149	pdevinfo.properties = properties;
150
151	if (acpi_dma_supported(adev))
152		pdevinfo.dma_mask = DMA_BIT_MASK(32);
153	else
154		pdevinfo.dma_mask = 0;
155
156	pdev = platform_device_register_full(&pdevinfo);
157	if (IS_ERR(pdev))
158		dev_err(&adev->dev, "platform device creation failed: %ld\n",
159			PTR_ERR(pdev));
160	else {
161		set_dev_node(&pdev->dev, acpi_get_node(adev->handle));
162		dev_dbg(&adev->dev, "created platform device %s\n",
163			dev_name(&pdev->dev));
164	}
165
166	kfree(resources);
167
168	return pdev;
169}
170EXPORT_SYMBOL_GPL(acpi_create_platform_device);
171
172void __init acpi_platform_init(void)
173{
174	acpi_reconfig_notifier_register(&acpi_platform_notifier);
175}