drivers/acpi/acpi_platform.c

   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
  22 ACPI_MODULE_NAME("platform");
  23
  24 static 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
  34 static 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
  42 static 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
  68 static struct notifier_block acpi_platform_notifier = {
  69         .notifier_call = acpi_platform_device_remove_notify,
  70 };
  71
  72 static 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  */
  99 struct 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 }
 170 EXPORT_SYMBOL_GPL(acpi_create_platform_device);
 171
 172 void __init acpi_platform_init(void)
 173 {
 174         acpi_reconfig_notifier_register(&acpi_platform_notifier);
 175 }