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/pci.h>
  21 #include <linux/platform_device.h>
  22
  23 #include "internal.h"
  24
  25 ACPI_MODULE_NAME("platform");
  26
  27 static const struct acpi_device_id forbidden_id_list[] = {
  28         {"PNP0000", 0}, /* PIC */
  29         {"PNP0100", 0}, /* Timer */
  30         {"PNP0200", 0}, /* AT DMA Controller */
  31         {"", 0},
  32 };
  33
  34 static void acpi_platform_fill_resource(struct acpi_device *adev,
  35         const struct resource *src, struct resource *dest)
  36 {
  37         struct device *parent;
  38
  39         *dest = *src;
  40
  41         /*
  42          * If the device has parent we need to take its resources into
  43          * account as well because this device might consume part of those.
  44          */
  45         parent = acpi_get_first_physical_node(adev->parent);
  46         if (parent && dev_is_pci(parent))
  47                 dest->parent = pci_find_resource(to_pci_dev(parent), dest);
  48 }
  49
  50 /**
  51  * acpi_create_platform_device - Create platform device for ACPI device node
  52  * @adev: ACPI device node to create a platform device for.
  53  *
  54  * Check if the given @adev can be represented as a platform device and, if
  55  * that's the case, create and register a platform device, populate its common
  56  * resources and returns a pointer to it.  Otherwise, return %NULL.
  57  *
  58  * Name of the platform device will be the same as @adev's.
  59  */
  60 struct platform_device *acpi_create_platform_device(struct acpi_device *adev)
  61 {
  62         struct platform_device *pdev = NULL;
  63         struct platform_device_info pdevinfo;
  64         struct resource_entry *rentry;
  65         struct list_head resource_list;
  66         struct resource *resources = NULL;
  67         int count;
  68
  69         /* If the ACPI node already has a physical device attached, skip it. */
  70         if (adev->physical_node_count)
  71                 return NULL;
  72
  73         if (!acpi_match_device_ids(adev, forbidden_id_list))
  74                 return ERR_PTR(-EINVAL);
  75
  76         INIT_LIST_HEAD(&resource_list);
  77         count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
  78         if (count < 0) {
  79                 return NULL;
  80         } else if (count > 0) {
  81                 resources = kzalloc(count * sizeof(struct resource),
  82                                     GFP_KERNEL);
  83                 if (!resources) {
  84                         dev_err(&adev->dev, "No memory for resources\n");
  85                         acpi_dev_free_resource_list(&resource_list);
  86                         return ERR_PTR(-ENOMEM);
  87                 }
  88                 count = 0;
  89                 list_for_each_entry(rentry, &resource_list, node)
  90                         acpi_platform_fill_resource(adev, rentry->res,
  91                                                     &resources[count++]);
  92
  93                 acpi_dev_free_resource_list(&resource_list);
  94         }
  95
  96         memset(&pdevinfo, 0, sizeof(pdevinfo));
  97         /*
  98          * If the ACPI node has a parent and that parent has a physical device
  99          * attached to it, that physical device should be the parent of the
 100          * platform device we are about to create.
 101          */
 102         pdevinfo.parent = adev->parent ?
 103                 acpi_get_first_physical_node(adev->parent) : NULL;
 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);