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/platform_device.h>
  20
  21 #include "internal.h"
  22
  23 ACPI_MODULE_NAME("platform");
  24
  25 static const struct acpi_device_id forbidden_id_list[] = {
  26         {"PNP0000", 0}, /* PIC */
  27         {"PNP0100", 0}, /* Timer */
  28         {"PNP0200", 0}, /* AT DMA Controller */
  29         {"", 0},
  30 };
  31
  32 /**
  33  * acpi_create_platform_device - Create platform device for ACPI device node
  34  * @adev: ACPI device node to create a platform device for.
  35  *
  36  * Check if the given @adev can be represented as a platform device and, if
  37  * that's the case, create and register a platform device, populate its common
  38  * resources and returns a pointer to it.  Otherwise, return %NULL.
  39  *
  40  * Name of the platform device will be the same as @adev's.
  41  */
  42 struct platform_device *acpi_create_platform_device(struct acpi_device *adev)
  43 {
  44         struct platform_device *pdev = NULL;
  45         struct acpi_device *acpi_parent;
  46         struct platform_device_info pdevinfo;
  47         struct resource_list_entry *rentry;
  48         struct list_head resource_list;
  49         struct resource *resources = NULL;
  50         int count;
  51
  52         /* If the ACPI node already has a physical device attached, skip it. */
  53         if (adev->physical_node_count)
  54                 return NULL;
  55
  56         if (!acpi_match_device_ids(adev, forbidden_id_list))
  57                 return ERR_PTR(-EINVAL);
  58
  59         INIT_LIST_HEAD(&resource_list);
  60         count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
  61         if (count < 0) {
  62                 return NULL;
  63         } else if (count > 0) {
  64                 resources = kmalloc(count * sizeof(struct resource),
  65                                     GFP_KERNEL);
  66                 if (!resources) {
  67                         dev_err(&adev->dev, "No memory for resources\n");
  68                         acpi_dev_free_resource_list(&resource_list);
  69                         return ERR_PTR(-ENOMEM);
  70                 }
  71                 count = 0;
  72                 list_for_each_entry(rentry, &resource_list, node)
  73                         resources[count++] = rentry->res;
  74
  75                 acpi_dev_free_resource_list(&resource_list);
  76         }
  77
  78         memset(&pdevinfo, 0, sizeof(pdevinfo));
  79         /*
  80          * If the ACPI node has a parent and that parent has a physical device
  81          * attached to it, that physical device should be the parent of the
  82          * platform device we are about to create.
  83          */
  84         pdevinfo.parent = NULL;
  85         acpi_parent = adev->parent;
  86         if (acpi_parent) {
  87                 struct acpi_device_physical_node *entry;
  88                 struct list_head *list;
  89
  90                 mutex_lock(&acpi_parent->physical_node_lock);
  91                 list = &acpi_parent->physical_node_list;
  92                 if (!list_empty(list)) {
  93                         entry = list_first_entry(list,
  94                                         struct acpi_device_physical_node,
  95                                         node);
  96                         pdevinfo.parent = entry->dev;
  97                 }
  98                 mutex_unlock(&acpi_parent->physical_node_lock);
  99         }
 100         pdevinfo.name = dev_name(&adev->dev);
 101         pdevinfo.id = -1;
 102         pdevinfo.res = resources;
 103         pdevinfo.num_res = count;
 104         pdevinfo.acpi_node.companion = adev;
 105         pdev = platform_device_register_full(&pdevinfo);
 106         if (IS_ERR(pdev))
 107                 dev_err(&adev->dev, "platform device creation failed: %ld\n",
 108                         PTR_ERR(pdev));
 109         else
 110                 dev_dbg(&adev->dev, "created platform device %s\n",
 111                         dev_name(&pdev->dev));
 112
 113         kfree(resources);
 114         return pdev;
 115 }