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
 22static 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
 32static 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
 40static 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
 66static struct notifier_block acpi_platform_notifier = {
 67	.notifier_call = acpi_platform_device_remove_notify,
 68};
 69
 70static 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 */
 97struct 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}
168EXPORT_SYMBOL_GPL(acpi_create_platform_device);
169
170void __init acpi_platform_init(void)
171{
172	acpi_reconfig_notifier_register(&acpi_platform_notifier);
173}