v4.19.13 snapshot.
diff --git a/drivers/acpi/acpi_platform.c b/drivers/acpi/acpi_platform.c
new file mode 100644
index 0000000..1f32caa
--- /dev/null
+++ b/drivers/acpi/acpi_platform.c
@@ -0,0 +1,135 @@
+/*
+ * ACPI support for platform bus type.
+ *
+ * Copyright (C) 2012, Intel Corporation
+ * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
+ *          Mathias Nyman <mathias.nyman@linux.intel.com>
+ *          Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/dma-mapping.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+
+#include "internal.h"
+
+ACPI_MODULE_NAME("platform");
+
+static const struct acpi_device_id forbidden_id_list[] = {
+	{"PNP0000",  0},	/* PIC */
+	{"PNP0100",  0},	/* Timer */
+	{"PNP0200",  0},	/* AT DMA Controller */
+	{"ACPI0009", 0},	/* IOxAPIC */
+	{"ACPI000A", 0},	/* IOAPIC */
+	{"SMB0001",  0},	/* ACPI SMBUS virtual device */
+	{"", 0},
+};
+
+static void acpi_platform_fill_resource(struct acpi_device *adev,
+	const struct resource *src, struct resource *dest)
+{
+	struct device *parent;
+
+	*dest = *src;
+
+	/*
+	 * If the device has parent we need to take its resources into
+	 * account as well because this device might consume part of those.
+	 */
+	parent = acpi_get_first_physical_node(adev->parent);
+	if (parent && dev_is_pci(parent))
+		dest->parent = pci_find_resource(to_pci_dev(parent), dest);
+}
+
+/**
+ * acpi_create_platform_device - Create platform device for ACPI device node
+ * @adev: ACPI device node to create a platform device for.
+ * @properties: Optional collection of build-in properties.
+ *
+ * Check if the given @adev can be represented as a platform device and, if
+ * that's the case, create and register a platform device, populate its common
+ * resources and returns a pointer to it.  Otherwise, return %NULL.
+ *
+ * Name of the platform device will be the same as @adev's.
+ */
+struct platform_device *acpi_create_platform_device(struct acpi_device *adev,
+					struct property_entry *properties)
+{
+	struct platform_device *pdev = NULL;
+	struct platform_device_info pdevinfo;
+	struct resource_entry *rentry;
+	struct list_head resource_list;
+	struct resource *resources = NULL;
+	int count;
+
+	/* If the ACPI node already has a physical device attached, skip it. */
+	if (adev->physical_node_count)
+		return NULL;
+
+	if (!acpi_match_device_ids(adev, forbidden_id_list))
+		return ERR_PTR(-EINVAL);
+
+	INIT_LIST_HEAD(&resource_list);
+	count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
+	if (count < 0) {
+		return NULL;
+	} else if (count > 0) {
+		resources = kcalloc(count, sizeof(struct resource),
+				    GFP_KERNEL);
+		if (!resources) {
+			dev_err(&adev->dev, "No memory for resources\n");
+			acpi_dev_free_resource_list(&resource_list);
+			return ERR_PTR(-ENOMEM);
+		}
+		count = 0;
+		list_for_each_entry(rentry, &resource_list, node)
+			acpi_platform_fill_resource(adev, rentry->res,
+						    &resources[count++]);
+
+		acpi_dev_free_resource_list(&resource_list);
+	}
+
+	memset(&pdevinfo, 0, sizeof(pdevinfo));
+	/*
+	 * If the ACPI node has a parent and that parent has a physical device
+	 * attached to it, that physical device should be the parent of the
+	 * platform device we are about to create.
+	 */
+	pdevinfo.parent = adev->parent ?
+		acpi_get_first_physical_node(adev->parent) : NULL;
+	pdevinfo.name = dev_name(&adev->dev);
+	pdevinfo.id = -1;
+	pdevinfo.res = resources;
+	pdevinfo.num_res = count;
+	pdevinfo.fwnode = acpi_fwnode_handle(adev);
+	pdevinfo.properties = properties;
+
+	if (acpi_dma_supported(adev))
+		pdevinfo.dma_mask = DMA_BIT_MASK(32);
+	else
+		pdevinfo.dma_mask = 0;
+
+	pdev = platform_device_register_full(&pdevinfo);
+	if (IS_ERR(pdev))
+		dev_err(&adev->dev, "platform device creation failed: %ld\n",
+			PTR_ERR(pdev));
+	else {
+		set_dev_node(&pdev->dev, acpi_get_node(adev->handle));
+		dev_dbg(&adev->dev, "created platform device %s\n",
+			dev_name(&pdev->dev));
+	}
+
+	kfree(resources);
+
+	return pdev;
+}
+EXPORT_SYMBOL_GPL(acpi_create_platform_device);