LXR linux/drivers/acpi/acpi

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * ACPI support for platform bus type.
   4 *
   5 * Copyright (C) 2012, Intel Corporation
   6 * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
   7 *          Mathias Nyman <mathias.nyman@linux.intel.com>
   8 *          Rafael J. Wysocki <rafael.j.wysocki@intel.com>
   9 */
  10
  11#include <linux/acpi.h>
  12#include <linux/device.h>
  13#include <linux/err.h>
  14#include <linux/kernel.h>
  15#include <linux/module.h>
  16#include <linux/dma-mapping.h>
  17#include <linux/pci.h>
  18#include <linux/platform_device.h>
  19
  20#include "internal.h"
  21
  22ACPI_MODULE_NAME("platform");
  23
  24static const struct acpi_device_id forbidden_id_list[] = {
  25        {"PNP0000",  0},        /* PIC */
  26        {"PNP0100",  0},        /* Timer */
  27        {"PNP0200",  0},        /* AT DMA Controller */
  28        {"ACPI0009", 0},        /* IOxAPIC */
  29        {"ACPI000A", 0},        /* IOAPIC */
  30        {"SMB0001",  0},        /* ACPI SMBUS virtual device */
  31        {"", 0},
  32};
  33
  34static struct platform_device *acpi_platform_device_find_by_companion(struct acpi_device *adev)
  35{
  36        struct device *dev;
  37
  38        dev = bus_find_device_by_acpi_dev(&platform_bus_type, adev);
  39        return dev ? to_platform_device(dev) : NULL;
  40}
  41
  42static int acpi_platform_device_remove_notify(struct notifier_block *nb,
  43                                              unsigned long value, void *arg)
  44{
  45        struct acpi_device *adev = arg;
  46        struct platform_device *pdev;
  47
  48        switch (value) {
  49        case ACPI_RECONFIG_DEVICE_ADD:
  50                /* Nothing to do here */
  51                break;
  52        case ACPI_RECONFIG_DEVICE_REMOVE:
  53                if (!acpi_device_enumerated(adev))
  54                        break;
  55
  56                pdev = acpi_platform_device_find_by_companion(adev);
  57                if (!pdev)
  58                        break;
  59
  60                platform_device_unregister(pdev);
  61                put_device(&pdev->dev);
  62                break;
  63        }
  64
  65        return NOTIFY_OK;
  66}
  67
  68static struct notifier_block acpi_platform_notifier = {
  69        .notifier_call = acpi_platform_device_remove_notify,
  70};
  71
  72static void acpi_platform_fill_resource(struct acpi_device *adev,
  73        const struct resource *src, struct resource *dest)
  74{
  75        struct device *parent;
  76
  77        *dest = *src;
  78
  79        /*
  80         * If the device has parent we need to take its resources into
  81         * account as well because this device might consume part of those.
  82         */
  83        parent = acpi_get_first_physical_node(adev->parent);
  84        if (parent && dev_is_pci(parent))
  85                dest->parent = pci_find_resource(to_pci_dev(parent), dest);
  86}
  87
  88/**
  89 * acpi_create_platform_device - Create platform device for ACPI device node
  90 * @adev: ACPI device node to create a platform device for.
  91 * @properties: Optional collection of build-in properties.
  92 *
  93 * Check if the given @adev can be represented as a platform device and, if
  94 * that's the case, create and register a platform device, populate its common
  95 * resources and returns a pointer to it.  Otherwise, return %NULL.
  96 *
  97 * Name of the platform device will be the same as @adev's.
  98 */
  99struct platform_device *acpi_create_platform_device(struct acpi_device *adev,
 100                                        struct property_entry *properties)
 101{
 102        struct platform_device *pdev = NULL;
 103        struct platform_device_info pdevinfo;
 104        struct resource_entry *rentry;
 105        struct list_head resource_list;
 106        struct resource *resources = NULL;
 107        int count;
 108
 109        /* If the ACPI node already has a physical device attached, skip it. */
 110        if (adev->physical_node_count)
 111                return NULL;
 112
 113        if (!acpi_match_device_ids(adev, forbidden_id_list))
 114                return ERR_PTR(-EINVAL);
 115
 116        INIT_LIST_HEAD(&resource_list);
 117        count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
 118        if (count < 0) {
 119                return NULL;
 120        } else if (count > 0) {
 121                resources = kcalloc(count, sizeof(struct resource),
 122                                    GFP_KERNEL);
 123                if (!resources) {
 124                        dev_err(&adev->dev, "No memory for resources\n");
 125                        acpi_dev_free_resource_list(&resource_list);
 126                        return ERR_PTR(-ENOMEM);
 127                }
 128                count = 0;
 129                list_for_each_entry(rentry, &resource_list, node)
 130                        acpi_platform_fill_resource(adev, rentry->res,
 131                                                    &resources[count++]);
 132
 133                acpi_dev_free_resource_list(&resource_list);
 134        }
 135
 136        memset(&pdevinfo, 0, sizeof(pdevinfo));
 137        /*
 138         * If the ACPI node has a parent and that parent has a physical device
 139         * attached to it, that physical device should be the parent of the
 140         * platform device we are about to create.
 141         */
 142        pdevinfo.parent = adev->parent ?
 143                acpi_get_first_physical_node(adev->parent) : NULL;
 144        pdevinfo.name = dev_name(&adev->dev);
 145        pdevinfo.id = -1;
 146        pdevinfo.res = resources;
 147        pdevinfo.num_res = count;
 148        pdevinfo.fwnode = acpi_fwnode_handle(adev);
 149        pdevinfo.properties = properties;
 150
 151        if (acpi_dma_supported(adev))
 152                pdevinfo.dma_mask = DMA_BIT_MASK(32);
 153        else
 154                pdevinfo.dma_mask = 0;
 155
 156        pdev = platform_device_register_full(&pdevinfo);
 157        if (IS_ERR(pdev))
 158                dev_err(&adev->dev, "platform device creation failed: %ld\n",
 159                        PTR_ERR(pdev));
 160        else {
 161                set_dev_node(&pdev->dev, acpi_get_node(adev->handle));
 162                dev_dbg(&adev->dev, "created platform device %s\n",
 163                        dev_name(&pdev->dev));
 164        }
 165
 166        kfree(resources);
 167
 168        return pdev;
 169}
 170EXPORT_SYMBOL_GPL(acpi_create_platform_device);
 171
 172void __init acpi_platform_init(void)
 173{
 174        acpi_reconfig_notifier_register(&acpi_platform_notifier);
 175}
 176