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/bits.h>
 13#include <linux/device.h>
 14#include <linux/err.h>
 15#include <linux/kernel.h>
 16#include <linux/module.h>
 17#include <linux/dma-mapping.h>
 18#include <linux/pci.h>
 19#include <linux/platform_device.h>
 20
 21#include "internal.h"
 22
 23/* Exclude devices that have no _CRS resources provided */
 24#define ACPI_ALLOW_WO_RESOURCES		BIT(0)
 25
 26static const struct acpi_device_id forbidden_id_list[] = {
 27	{"ACPI0009", 0},	/* IOxAPIC */
 28	{"ACPI000A", 0},	/* IOAPIC */
 29	{"PNP0000",  0},	/* PIC */
 30	{"PNP0100",  0},	/* Timer */
 31	{"PNP0200",  0},	/* AT DMA Controller */
 32	{ACPI_SMBUS_MS_HID,  ACPI_ALLOW_WO_RESOURCES},	/* ACPI SMBUS virtual device */
 33	{ }
 34};
 35
 36static struct platform_device *acpi_platform_device_find_by_companion(struct acpi_device *adev)
 37{
 38	struct device *dev;
 39
 40	dev = bus_find_device_by_acpi_dev(&platform_bus_type, adev);
 41	return dev ? to_platform_device(dev) : NULL;
 42}
 43
 44static int acpi_platform_device_remove_notify(struct notifier_block *nb,
 45					      unsigned long value, void *arg)
 46{
 47	struct acpi_device *adev = arg;
 48	struct platform_device *pdev;
 49
 50	switch (value) {
 51	case ACPI_RECONFIG_DEVICE_ADD:
 52		/* Nothing to do here */
 53		break;
 54	case ACPI_RECONFIG_DEVICE_REMOVE:
 55		if (!acpi_device_enumerated(adev))
 56			break;
 57
 58		pdev = acpi_platform_device_find_by_companion(adev);
 59		if (!pdev)
 60			break;
 61
 62		platform_device_unregister(pdev);
 63		put_device(&pdev->dev);
 64		break;
 65	}
 66
 67	return NOTIFY_OK;
 68}
 69
 70static struct notifier_block acpi_platform_notifier = {
 71	.notifier_call = acpi_platform_device_remove_notify,
 72};
 73
 74static void acpi_platform_fill_resource(struct acpi_device *adev,
 75	const struct resource *src, struct resource *dest)
 76{
 77	struct device *parent;
 78
 79	*dest = *src;
 80
 81	/*
 82	 * If the device has parent we need to take its resources into
 83	 * account as well because this device might consume part of those.
 84	 */
 85	parent = acpi_get_first_physical_node(acpi_dev_parent(adev));
 86	if (parent && dev_is_pci(parent))
 87		dest->parent = pci_find_resource(to_pci_dev(parent), dest);
 88}
 89
 90static unsigned int acpi_platform_resource_count(struct acpi_resource *ares, void *data)
 91{
 92	bool *has_resources = data;
 93
 94	*has_resources = true;
 95
 96	return AE_CTRL_TERMINATE;
 97}
 98
 99/**
100 * acpi_create_platform_device - Create platform device for ACPI device node
101 * @adev: ACPI device node to create a platform device for.
102 * @properties: Optional collection of build-in properties.
103 *
104 * Check if the given @adev can be represented as a platform device and, if
105 * that's the case, create and register a platform device, populate its common
106 * resources and returns a pointer to it.  Otherwise, return %NULL.
107 *
108 * Name of the platform device will be the same as @adev's.
109 */
110struct platform_device *acpi_create_platform_device(struct acpi_device *adev,
111						    const struct property_entry *properties)
112{
113	struct acpi_device *parent = acpi_dev_parent(adev);
114	struct platform_device *pdev = NULL;
115	struct platform_device_info pdevinfo;
116	const struct acpi_device_id *match;
117	struct resource_entry *rentry;
118	struct list_head resource_list;
119	struct resource *resources = NULL;
120	int count;
121
122	/* If the ACPI node already has a physical device attached, skip it. */
123	if (adev->physical_node_count)
124		return NULL;
125
126	match = acpi_match_acpi_device(forbidden_id_list, adev);
127	if (match) {
128		if (match->driver_data & ACPI_ALLOW_WO_RESOURCES) {
129			bool has_resources = false;
130
131			acpi_walk_resources(adev->handle, METHOD_NAME__CRS,
132					    acpi_platform_resource_count, &has_resources);
133			if (has_resources)
134				return ERR_PTR(-EINVAL);
135		} else {
136			return ERR_PTR(-EINVAL);
137		}
138	}
139
140	INIT_LIST_HEAD(&resource_list);
141	count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
142	if (count < 0)
143		return NULL;
144	if (count > 0) {
145		resources = kcalloc(count, sizeof(*resources), GFP_KERNEL);
146		if (!resources) {
147			acpi_dev_free_resource_list(&resource_list);
148			return ERR_PTR(-ENOMEM);
149		}
150		count = 0;
151		list_for_each_entry(rentry, &resource_list, node)
152			acpi_platform_fill_resource(adev, rentry->res,
153						    &resources[count++]);
154
155		acpi_dev_free_resource_list(&resource_list);
156	}
157
158	memset(&pdevinfo, 0, sizeof(pdevinfo));
159	/*
160	 * If the ACPI node has a parent and that parent has a physical device
161	 * attached to it, that physical device should be the parent of the
162	 * platform device we are about to create.
163	 */
164	pdevinfo.parent = parent ? acpi_get_first_physical_node(parent) : NULL;
165	pdevinfo.name = dev_name(&adev->dev);
166	pdevinfo.id = PLATFORM_DEVID_NONE;
167	pdevinfo.res = resources;
168	pdevinfo.num_res = count;
169	pdevinfo.fwnode = acpi_fwnode_handle(adev);
170	pdevinfo.properties = properties;
171
172	if (acpi_dma_supported(adev))
173		pdevinfo.dma_mask = DMA_BIT_MASK(32);
174	else
175		pdevinfo.dma_mask = 0;
176
177	pdev = platform_device_register_full(&pdevinfo);
178	if (IS_ERR(pdev))
179		dev_err(&adev->dev, "platform device creation failed: %ld\n",
180			PTR_ERR(pdev));
181	else {
182		set_dev_node(&pdev->dev, acpi_get_node(adev->handle));
183		dev_dbg(&adev->dev, "created platform device %s\n",
184			dev_name(&pdev->dev));
185	}
186
187	kfree(resources);
188
189	return pdev;
190}
191EXPORT_SYMBOL_GPL(acpi_create_platform_device);
192
193void __init acpi_platform_init(void)
194{
195	acpi_reconfig_notifier_register(&acpi_platform_notifier);
196}