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