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

#include <linux/acpi.h>
#include <linux/bits.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"

/* Exclude devices that have no _CRS resources provided */
#define ACPI_ALLOW_WO_RESOURCES         BIT(0)

static const struct acpi_device_id forbidden_id_list[] = {
        {"ACPI0009", 0},        /* IOxAPIC */
        {"ACPI000A", 0},        /* IOAPIC */
        {"PNP0000",  0},        /* PIC */
        {"PNP0100",  0},        /* Timer */
        {"PNP0200",  0},        /* AT DMA Controller */
        {ACPI_SMBUS_MS_HID,  ACPI_ALLOW_WO_RESOURCES},  /* ACPI SMBUS virtual device */
        { }
};

static struct platform_device *acpi_platform_device_find_by_companion(struct acpi_device *adev)
{
        struct device *dev;

        dev = bus_find_device_by_acpi_dev(&platform_bus_type, adev);
        return dev ? to_platform_device(dev) : NULL;
}

static int acpi_platform_device_remove_notify(struct notifier_block *nb,
                                              unsigned long value, void *arg)
{
        struct acpi_device *adev = arg;
        struct platform_device *pdev;

        switch (value) {
        case ACPI_RECONFIG_DEVICE_ADD:
                /* Nothing to do here */
                break;
        case ACPI_RECONFIG_DEVICE_REMOVE:
                if (!acpi_device_enumerated(adev))
                        break;

                pdev = acpi_platform_device_find_by_companion(adev);
                if (!pdev)
                        break;

                platform_device_unregister(pdev);
                put_device(&pdev->dev);
                break;
        }

        return NOTIFY_OK;
}

static struct notifier_block acpi_platform_notifier = {
        .notifier_call = acpi_platform_device_remove_notify,
};

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(acpi_dev_parent(adev));
        if (parent && dev_is_pci(parent))
                dest->parent = pci_find_resource(to_pci_dev(parent), dest);
}

static unsigned int acpi_platform_resource_count(struct acpi_resource *ares, void *data)
{
        bool *has_resources = data;

        *has_resources = true;

        return AE_CTRL_TERMINATE;
}

/**
 * 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,
                                                    const struct property_entry *properties)
{
        struct acpi_device *parent = acpi_dev_parent(adev);
        struct platform_device *pdev = NULL;
        struct platform_device_info pdevinfo;
        const struct acpi_device_id *match;
        struct resource *resources = NULL;
        int count = 0;

        /* If the ACPI node already has a physical device attached, skip it. */
        if (adev->physical_node_count && !adev->pnp.type.backlight)
                return NULL;

        match = acpi_match_acpi_device(forbidden_id_list, adev);
        if (match) {
                if (match->driver_data & ACPI_ALLOW_WO_RESOURCES) {
                        bool has_resources = false;

                        acpi_walk_resources(adev->handle, METHOD_NAME__CRS,
                                            acpi_platform_resource_count, &has_resources);
                        if (has_resources)
                                return ERR_PTR(-EINVAL);
                } else {
                        return ERR_PTR(-EINVAL);
                }
        }

        if (adev->device_type == ACPI_BUS_TYPE_DEVICE) {
                LIST_HEAD(resource_list);

                count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
                if (count < 0)
                        return ERR_PTR(-ENODATA);

                if (count > 0) {
                        struct resource_entry *rentry;

                        resources = kzalloc_objs(*resources, count);
                        if (!resources) {
                                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 = parent ? acpi_get_first_physical_node(parent) : NULL;
        pdevinfo.name = dev_name(&adev->dev);
        pdevinfo.id = PLATFORM_DEVID_NONE;
        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);

void __init acpi_platform_init(void)
{
        acpi_reconfig_notifier_register(&acpi_platform_notifier);
}