v4.19.13 snapshot.
diff --git a/drivers/acpi/acpi_amba.c b/drivers/acpi/acpi_amba.c
new file mode 100644
index 0000000..7f77c07
--- /dev/null
+++ b/drivers/acpi/acpi_amba.c
@@ -0,0 +1,121 @@
+
+/*
+ * ACPI support for platform bus type.
+ *
+ * Copyright (C) 2015, Linaro Ltd
+ * Author: Graeme Gregory <graeme.gregory@linaro.org>
+ *
+ * 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/amba/bus.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include "internal.h"
+
+static const struct acpi_device_id amba_id_list[] = {
+ {"ARMH0061", 0}, /* PL061 GPIO Device */
+ {"", 0},
+};
+
+static void amba_register_dummy_clk(void)
+{
+ static struct clk *amba_dummy_clk;
+
+ /* If clock already registered */
+ if (amba_dummy_clk)
+ return;
+
+ amba_dummy_clk = clk_register_fixed_rate(NULL, "apb_pclk", NULL, 0, 0);
+ clk_register_clkdev(amba_dummy_clk, "apb_pclk", NULL);
+}
+
+static int amba_handler_attach(struct acpi_device *adev,
+ const struct acpi_device_id *id)
+{
+ struct amba_device *dev;
+ struct resource_entry *rentry;
+ struct list_head resource_list;
+ bool address_found = false;
+ int irq_no = 0;
+ int ret;
+
+ /* If the ACPI node already has a physical device attached, skip it. */
+ if (adev->physical_node_count)
+ return 0;
+
+ dev = amba_device_alloc(dev_name(&adev->dev), 0, 0);
+ if (!dev) {
+ dev_err(&adev->dev, "%s(): amba_device_alloc() failed\n",
+ __func__);
+ return -ENOMEM;
+ }
+
+ INIT_LIST_HEAD(&resource_list);
+ ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
+ if (ret < 0)
+ goto err_free;
+
+ list_for_each_entry(rentry, &resource_list, node) {
+ switch (resource_type(rentry->res)) {
+ case IORESOURCE_MEM:
+ if (!address_found) {
+ dev->res = *rentry->res;
+ address_found = true;
+ }
+ break;
+ case IORESOURCE_IRQ:
+ if (irq_no < AMBA_NR_IRQS)
+ dev->irq[irq_no++] = rentry->res->start;
+ break;
+ default:
+ dev_warn(&adev->dev, "Invalid resource\n");
+ break;
+ }
+ }
+
+ acpi_dev_free_resource_list(&resource_list);
+
+ /*
+ * 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 amba device we are about to create.
+ */
+ if (adev->parent)
+ dev->dev.parent = acpi_get_first_physical_node(adev->parent);
+
+ ACPI_COMPANION_SET(&dev->dev, adev);
+
+ ret = amba_device_add(dev, &iomem_resource);
+ if (ret) {
+ dev_err(&adev->dev, "%s(): amba_device_add() failed (%d)\n",
+ __func__, ret);
+ goto err_free;
+ }
+
+ return 1;
+
+err_free:
+ amba_device_put(dev);
+ return ret;
+}
+
+static struct acpi_scan_handler amba_handler = {
+ .ids = amba_id_list,
+ .attach = amba_handler_attach,
+};
+
+void __init acpi_amba_init(void)
+{
+ amba_register_dummy_clk();
+ acpi_scan_add_handler(&amba_handler);
+}