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         {"SMB0001",  0},        /* ACPI SMBUS virtual device */
  33         {"", 0},
  34 };
  35
  36 /**
  37  * acpi_create_platform_device - Create platform device for ACPI device node
  38  * @adev: ACPI device node to create a platform device for.
  39  *
  40  * Check if the given @adev can be represented as a platform device and, if
  41  * that's the case, create and register a platform device, populate its common
  42  * resources and returns a pointer to it.  Otherwise, return %NULL.
  43  *
  44  * Name of the platform device will be the same as @adev's.
  45  */
  46 struct platform_device *acpi_create_platform_device(struct acpi_device *adev)
  47 {
  48         struct platform_device *pdev = NULL;
  49         struct acpi_device *acpi_parent;
  50         struct platform_device_info pdevinfo;
  51         struct resource_entry *rentry;
  52         struct list_head resource_list;
  53         struct resource *resources = NULL;
  54         int count;
  55
  56         /* If the ACPI node already has a physical device attached, skip it. */
  57         if (adev->physical_node_count)
  58                 return NULL;
  59
  60         if (!acpi_match_device_ids(adev, forbidden_id_list))
  61                 return ERR_PTR(-EINVAL);
  62
  63         INIT_LIST_HEAD(&resource_list);
  64         count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
  65         if (count < 0) {
  66                 return NULL;
  67         } else if (count > 0) {
  68                 resources = kmalloc(count * sizeof(struct resource),
  69                                     GFP_KERNEL);
  70                 if (!resources) {
  71                         dev_err(&adev->dev, "No memory for resources\n");
  72                         acpi_dev_free_resource_list(&resource_list);
  73                         return ERR_PTR(-ENOMEM);
  74                 }
  75                 count = 0;
  76                 list_for_each_entry(rentry, &resource_list, node)
  77                         resources[count++] = *rentry->res;
  78
  79                 acpi_dev_free_resource_list(&resource_list);
  80         }
  81
  82         memset(&pdevinfo, 0, sizeof(pdevinfo));
  83         /*
  84          * If the ACPI node has a parent and that parent has a physical device
  85          * attached to it, that physical device should be the parent of the
  86          * platform device we are about to create.
  87          */
  88         pdevinfo.parent = NULL;
  89         acpi_parent = adev->parent;
  90         if (acpi_parent) {
  91                 struct acpi_device_physical_node *entry;
  92                 struct list_head *list;
  93
  94                 mutex_lock(&acpi_parent->physical_node_lock);
  95                 list = &acpi_parent->physical_node_list;
  96                 if (!list_empty(list)) {
  97                         entry = list_first_entry(list,
  98                                         struct acpi_device_physical_node,
  99                                         node);
 100                         pdevinfo.parent = entry->dev;
 101                 }
 102                 mutex_unlock(&acpi_parent->physical_node_lock);
 103         }
 104         pdevinfo.name = dev_name(&adev->dev);
 105         pdevinfo.id = -1;
 106         pdevinfo.res = resources;
 107         pdevinfo.num_res = count;
 108         pdevinfo.fwnode = acpi_fwnode_handle(adev);
 109
 110         if (acpi_dma_supported(adev))
 111                 pdevinfo.dma_mask = DMA_BIT_MASK(32);
 112         else
 113                 pdevinfo.dma_mask = 0;
 114
 115         pdev = platform_device_register_full(&pdevinfo);
 116         if (IS_ERR(pdev))
 117                 dev_err(&adev->dev, "platform device creation failed: %ld\n",
 118                         PTR_ERR(pdev));
 119         else
 120                 dev_dbg(&adev->dev, "created platform device %s\n",
 121                         dev_name(&pdev->dev));
 122
 123         kfree(resources);
 124         return pdev;
 125 }
 126 EXPORT_SYMBOL_GPL(acpi_create_platform_device);