drivers/acpi/acpi_platform.c

   1 /*
   2  * ACPI support for platform bus type.
   3  *
   4  * Copyright (C) 2012, Intel Corporation
   5  * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
   6  *          Mathias Nyman <mathias.nyman@linux.intel.com>
   7  *          Rafael J. Wysocki <rafael.j.wysocki@intel.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #include <linux/acpi.h>
  15 #include <linux/device.h>
  16 #include <linux/err.h>
  17 #include <linux/kernel.h>
  18 #include <linux/module.h>
  19 #include <linux/dma-mapping.h>
  20 #include <linux/platform_device.h>
  21
  22 #include "internal.h"
  23
  24 ACPI_MODULE_NAME("platform");
  25
  26 static const struct acpi_device_id forbidden_id_list[] = {
  27         {"PNP0000",  0},        /* PIC */
  28         {"PNP0100",  0},        /* Timer */
  29         {"PNP0200",  0},        /* AT DMA Controller */
  30         {"ACPI0009", 0},        /* IOxAPIC */
  31         {"ACPI000A", 0},        /* IOAPIC */
  32         {"", 0},
  33 };
  34
  35 /**
  36  * acpi_create_platform_device - Create platform device for ACPI device node
  37  * @adev: ACPI device node to create a platform device for.
  38  *
  39  * Check if the given @adev can be represented as a platform device and, if
  40  * that's the case, create and register a platform device, populate its common
  41  * resources and returns a pointer to it.  Otherwise, return %NULL.
  42  *
  43  * Name of the platform device will be the same as @adev's.
  44  */
  45 struct platform_device *acpi_create_platform_device(struct acpi_device *adev)
  46 {
  47         struct platform_device *pdev = NULL;
  48         struct acpi_device *acpi_parent;
  49         struct platform_device_info pdevinfo;
  50         struct resource_entry *rentry;
  51         struct list_head resource_list;
  52         struct resource *resources = NULL;
  53         int count;
  54
  55         /* If the ACPI node already has a physical device attached, skip it. */
  56         if (adev->physical_node_count)
  57                 return NULL;
  58
  59         if (!acpi_match_device_ids(adev, forbidden_id_list))
  60                 return ERR_PTR(-EINVAL);
  61
  62         INIT_LIST_HEAD(&resource_list);
  63         count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
  64         if (count < 0) {
  65                 return NULL;
  66         } else if (count > 0) {
  67                 resources = kmalloc(count * sizeof(struct resource),
  68                                     GFP_KERNEL);
  69                 if (!resources) {
  70                         dev_err(&adev->dev, "No memory for resources\n");
  71                         acpi_dev_free_resource_list(&resource_list);
  72                         return ERR_PTR(-ENOMEM);
  73                 }
  74                 count = 0;
  75                 list_for_each_entry(rentry, &resource_list, node)
  76                         resources[count++] = *rentry->res;
  77
  78                 acpi_dev_free_resource_list(&resource_list);
  79         }
  80
  81         memset(&pdevinfo, 0, sizeof(pdevinfo));
  82         /*
  83          * If the ACPI node has a parent and that parent has a physical device
  84          * attached to it, that physical device should be the parent of the
  85          * platform device we are about to create.
  86          */
  87         pdevinfo.parent = NULL;
  88         acpi_parent = adev->parent;
  89         if (acpi_parent) {
  90                 struct acpi_device_physical_node *entry;
  91                 struct list_head *list;
  92
  93                 mutex_lock(&acpi_parent->physical_node_lock);
  94                 list = &acpi_parent->physical_node_list;
  95                 if (!list_empty(list)) {
  96                         entry = list_first_entry(list,
  97                                         struct acpi_device_physical_node,
  98                                         node);
  99                         pdevinfo.parent = entry->dev;
 100                 }
 101                 mutex_unlock(&acpi_parent->physical_node_lock);
 102         }
 103         pdevinfo.name = dev_name(&adev->dev);
 104         pdevinfo.id = -1;
 105         pdevinfo.res = resources;
 106         pdevinfo.num_res = count;
 107         pdevinfo.fwnode = acpi_fwnode_handle(adev);
 108
 109         if (acpi_dma_supported(adev))
 110                 pdevinfo.dma_mask = DMA_BIT_MASK(32);
 111         else
 112                 pdevinfo.dma_mask = 0;
 113
 114         pdev = platform_device_register_full(&pdevinfo);
 115         if (IS_ERR(pdev))
 116                 dev_err(&adev->dev, "platform device creation failed: %ld\n",
 117                         PTR_ERR(pdev));
 118         else
 119                 dev_dbg(&adev->dev, "created platform device %s\n",
 120                         dev_name(&pdev->dev));
 121
 122         kfree(resources);
 123         return pdev;
 124 }
 125 EXPORT_SYMBOL_GPL(acpi_create_platform_device);