1// SPDX-License-Identifier: GPL-2.0-only
  2
  3/*
  4 * ACPI support for platform bus type.
  5 *
  6 * Copyright (C) 2015, Linaro Ltd
  7 * Author: Graeme Gregory <graeme.gregory@linaro.org>
  8 */
  9
 10#include <linux/acpi.h>
 11#include <linux/amba/bus.h>
 12#include <linux/clkdev.h>
 13#include <linux/clk-provider.h>
 14#include <linux/device.h>
 15#include <linux/err.h>
 16#include <linux/ioport.h>
 17#include <linux/kernel.h>
 18#include <linux/module.h>
 19
 20#include "init.h"
 21
 22static const struct acpi_device_id amba_id_list[] = {
 23	{"ARMH0061", 0}, /* PL061 GPIO Device */
 24	{"ARMH0330", 0}, /* ARM DMA Controller DMA-330 */
 25	{"", 0},
 26};
 27
 28static void amba_register_dummy_clk(void)
 29{
 30	struct clk *amba_dummy_clk;
 31
 32	amba_dummy_clk = clk_register_fixed_rate(NULL, "apb_pclk", NULL, 0, 0);
 33	clk_register_clkdev(amba_dummy_clk, "apb_pclk", NULL);
 34}
 35
 36static int amba_handler_attach(struct acpi_device *adev,
 37				const struct acpi_device_id *id)
 38{
 39	struct acpi_device *parent = acpi_dev_parent(adev);
 40	struct amba_device *dev;
 41	struct resource_entry *rentry;
 42	struct list_head resource_list;
 43	bool address_found = false;
 44	int irq_no = 0;
 45	int ret;
 46
 47	/* If the ACPI node already has a physical device attached, skip it. */
 48	if (adev->physical_node_count)
 49		return 0;
 50
 51	dev = amba_device_alloc(dev_name(&adev->dev), 0, 0);
 52	if (!dev) {
 53		dev_err(&adev->dev, "%s(): amba_device_alloc() failed\n",
 54			__func__);
 55		return -ENOMEM;
 56	}
 57
 58	INIT_LIST_HEAD(&resource_list);
 59	ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
 60	if (ret < 0)
 61		goto err_free;
 62
 63	list_for_each_entry(rentry, &resource_list, node) {
 64		switch (resource_type(rentry->res)) {
 65		case IORESOURCE_MEM:
 66			if (!address_found) {
 67				dev->res = *rentry->res;
 68				dev->res.name = dev_name(&dev->dev);
 69				address_found = true;
 70			}
 71			break;
 72		case IORESOURCE_IRQ:
 73			if (irq_no < AMBA_NR_IRQS)
 74				dev->irq[irq_no++] = rentry->res->start;
 75			break;
 76		default:
 77			dev_warn(&adev->dev, "Invalid resource\n");
 78			break;
 79		}
 80	}
 81
 82	acpi_dev_free_resource_list(&resource_list);
 83
 84	/*
 85	 * If the ACPI node has a parent and that parent has a physical device
 86	 * attached to it, that physical device should be the parent of
 87	 * the amba device we are about to create.
 88	 */
 89	if (parent)
 90		dev->dev.parent = acpi_get_first_physical_node(parent);
 91
 92	device_set_node(&dev->dev, acpi_fwnode_handle(adev));
 93
 94	ret = amba_device_add(dev, &iomem_resource);
 95	if (ret) {
 96		dev_err(&adev->dev, "%s(): amba_device_add() failed (%d)\n",
 97		       __func__, ret);
 98		goto err_free;
 99	}
100
101	return 1;
102
103err_free:
104	amba_device_put(dev);
105	return ret;
106}
107
108static struct acpi_scan_handler amba_handler = {
109	.ids = amba_id_list,
110	.attach = amba_handler_attach,
111};
112
113void __init acpi_amba_init(void)
114{
115	amba_register_dummy_clk();
116	acpi_scan_add_handler(&amba_handler);
117}