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 static 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
  32 static 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
  40 static 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
  66 static struct notifier_block acpi_platform_notifier = {
  67         .notifier_call = acpi_platform_device_remove_notify,
  68 };
  69
  70 static 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  */
  97 struct 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 }
 168 EXPORT_SYMBOL_GPL(acpi_create_platform_device);
 169
 170 void __init acpi_platform_init(void)
 171 {
 172         acpi_reconfig_notifier_register(&acpi_platform_notifier);
 173 }