// SPDX-License-Identifier: GPL-2.0-only

/*
 * ACPI support for platform bus type.
 *
 * Copyright (C) 2015, Linaro Ltd
 * Author: Graeme Gregory <graeme.gregory@linaro.org>
 */

#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 "init.h"

static const struct acpi_device_id amba_id_list[] = {
        {"ARMH0061", 0}, /* PL061 GPIO Device */
        {"ARMH0330", 0}, /* ARM DMA Controller DMA-330 */
        {"", 0},
};

static void amba_register_dummy_clk(void)
{
        struct clk *amba_dummy_clk;

        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 acpi_device *parent = acpi_dev_parent(adev);
        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;
                                dev->res.name = dev_name(&dev->dev);
                                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 (parent)
                dev->dev.parent = acpi_get_first_physical_node(parent);

        device_set_node(&dev->dev, acpi_fwnode_handle(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);
}