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/bits.h>
  13 #include <linux/device.h>
  14 #include <linux/err.h>
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/dma-mapping.h>
  18 #include <linux/pci.h>
  19 #include <linux/platform_device.h>
  20
  21 #include "internal.h"
  22
  23 /* Exclude devices that have no _CRS resources provided */
  24 #define ACPI_ALLOW_WO_RESOURCES         BIT(0)
  25
  26 static const struct acpi_device_id forbidden_id_list[] = {
  27         {"ACPI0009", 0},        /* IOxAPIC */
  28         {"ACPI000A", 0},        /* IOAPIC */
  29         {"PNP0000",  0},        /* PIC */
  30         {"PNP0100",  0},        /* Timer */
  31         {"PNP0200",  0},        /* AT DMA Controller */
  32         {ACPI_SMBUS_MS_HID,  ACPI_ALLOW_WO_RESOURCES},  /* ACPI SMBUS virtual device */
  33         { }
  34 };
  35
  36 static struct platform_device *acpi_platform_device_find_by_companion(struct acpi_device *adev)
  37 {
  38         struct device *dev;
  39
  40         dev = bus_find_device_by_acpi_dev(&platform_bus_type, adev);
  41         return dev ? to_platform_device(dev) : NULL;
  42 }
  43
  44 static int acpi_platform_device_remove_notify(struct notifier_block *nb,
  45                                               unsigned long value, void *arg)
  46 {
  47         struct acpi_device *adev = arg;
  48         struct platform_device *pdev;
  49
  50         switch (value) {
  51         case ACPI_RECONFIG_DEVICE_ADD:
  52                 /* Nothing to do here */
  53                 break;
  54         case ACPI_RECONFIG_DEVICE_REMOVE:
  55                 if (!acpi_device_enumerated(adev))
  56                         break;
  57
  58                 pdev = acpi_platform_device_find_by_companion(adev);
  59                 if (!pdev)
  60                         break;
  61
  62                 platform_device_unregister(pdev);
  63                 put_device(&pdev->dev);
  64                 break;
  65         }
  66
  67         return NOTIFY_OK;
  68 }
  69
  70 static struct notifier_block acpi_platform_notifier = {
  71         .notifier_call = acpi_platform_device_remove_notify,
  72 };
  73
  74 static void acpi_platform_fill_resource(struct acpi_device *adev,
  75         const struct resource *src, struct resource *dest)
  76 {
  77         struct device *parent;
  78
  79         *dest = *src;
  80
  81         /*
  82          * If the device has parent we need to take its resources into
  83          * account as well because this device might consume part of those.
  84          */
  85         parent = acpi_get_first_physical_node(acpi_dev_parent(adev));
  86         if (parent && dev_is_pci(parent))
  87                 dest->parent = pci_find_resource(to_pci_dev(parent), dest);
  88 }
  89
  90 static unsigned int acpi_platform_resource_count(struct acpi_resource *ares, void *data)
  91 {
  92         bool *has_resources = data;
  93
  94         *has_resources = true;
  95
  96         return AE_CTRL_TERMINATE;
  97 }
  98
  99 /**
 100  * acpi_create_platform_device - Create platform device for ACPI device node
 101  * @adev: ACPI device node to create a platform device for.
 102  * @properties: Optional collection of build-in properties.
 103  *
 104  * Check if the given @adev can be represented as a platform device and, if
 105  * that's the case, create and register a platform device, populate its common
 106  * resources and returns a pointer to it.  Otherwise, return %NULL.
 107  *
 108  * Name of the platform device will be the same as @adev's.
 109  */
 110 struct platform_device *acpi_create_platform_device(struct acpi_device *adev,
 111                                                     const struct property_entry *properties)
 112 {
 113         struct acpi_device *parent = acpi_dev_parent(adev);
 114         struct platform_device *pdev = NULL;
 115         struct platform_device_info pdevinfo;
 116         const struct acpi_device_id *match;
 117         struct resource_entry *rentry;
 118         struct list_head resource_list;
 119         struct resource *resources = NULL;
 120         int count;
 121
 122         /* If the ACPI node already has a physical device attached, skip it. */
 123         if (adev->physical_node_count)
 124                 return NULL;
 125
 126         match = acpi_match_acpi_device(forbidden_id_list, adev);
 127         if (match) {
 128                 if (match->driver_data & ACPI_ALLOW_WO_RESOURCES) {
 129                         bool has_resources = false;
 130
 131                         acpi_walk_resources(adev->handle, METHOD_NAME__CRS,
 132                                             acpi_platform_resource_count, &has_resources);
 133                         if (has_resources)
 134                                 return ERR_PTR(-EINVAL);
 135                 } else {
 136                         return ERR_PTR(-EINVAL);
 137                 }
 138         }
 139
 140         INIT_LIST_HEAD(&resource_list);
 141         count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
 142         if (count < 0)
 143                 return NULL;
 144         if (count > 0) {
 145                 resources = kcalloc(count, sizeof(*resources), GFP_KERNEL);
 146                 if (!resources) {
 147                         acpi_dev_free_resource_list(&resource_list);
 148                         return ERR_PTR(-ENOMEM);
 149                 }
 150                 count = 0;
 151                 list_for_each_entry(rentry, &resource_list, node)
 152                         acpi_platform_fill_resource(adev, rentry->res,
 153                                                     &resources[count++]);
 154
 155                 acpi_dev_free_resource_list(&resource_list);
 156         }
 157
 158         memset(&pdevinfo, 0, sizeof(pdevinfo));
 159         /*
 160          * If the ACPI node has a parent and that parent has a physical device
 161          * attached to it, that physical device should be the parent of the
 162          * platform device we are about to create.
 163          */
 164         pdevinfo.parent = parent ? acpi_get_first_physical_node(parent) : NULL;
 165         pdevinfo.name = dev_name(&adev->dev);
 166         pdevinfo.id = PLATFORM_DEVID_NONE;
 167         pdevinfo.res = resources;
 168         pdevinfo.num_res = count;
 169         pdevinfo.fwnode = acpi_fwnode_handle(adev);
 170         pdevinfo.properties = properties;
 171
 172         if (acpi_dma_supported(adev))
 173                 pdevinfo.dma_mask = DMA_BIT_MASK(32);
 174         else
 175                 pdevinfo.dma_mask = 0;
 176
 177         pdev = platform_device_register_full(&pdevinfo);
 178         if (IS_ERR(pdev))
 179                 dev_err(&adev->dev, "platform device creation failed: %ld\n",
 180                         PTR_ERR(pdev));
 181         else {
 182                 set_dev_node(&pdev->dev, acpi_get_node(adev->handle));
 183                 dev_dbg(&adev->dev, "created platform device %s\n",
 184                         dev_name(&pdev->dev));
 185         }
 186
 187         kfree(resources);
 188
 189         return pdev;
 190 }
 191 EXPORT_SYMBOL_GPL(acpi_create_platform_device);
 192
 193 void __init acpi_platform_init(void)
 194 {
 195         acpi_reconfig_notifier_register(&acpi_platform_notifier);
 196 }