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/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/platform_device.h>
  19
  20 #include "internal.h"
  21
  22 ACPI_MODULE_NAME("platform");
  23
  24 /**
  25  * acpi_create_platform_device - Create platform device for ACPI device node
  26  * @adev: ACPI device node to create a platform device for.
  27  *
  28  * Check if the given @adev can be represented as a platform device and, if
  29  * that's the case, create and register a platform device, populate its common
  30  * resources and returns a pointer to it.  Otherwise, return %NULL.
  31  *
  32  * The platform device's name will be taken from the @adev's _HID and _UID.
  33  */
  34 struct platform_device *acpi_create_platform_device(struct acpi_device *adev)
  35 {
  36         struct platform_device *pdev = NULL;
  37         struct acpi_device *acpi_parent;
  38         struct platform_device_info pdevinfo;
  39         struct resource_list_entry *rentry;
  40         struct list_head resource_list;
  41         struct resource *resources;
  42         int count;
  43
  44         /* If the ACPI node already has a physical device attached, skip it. */
  45         if (adev->physical_node_count)
  46                 return NULL;
  47
  48         INIT_LIST_HEAD(&resource_list);
  49         count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
  50         if (count <= 0)
  51                 return NULL;
  52
  53         resources = kmalloc(count * sizeof(struct resource), GFP_KERNEL);
  54         if (!resources) {
  55                 dev_err(&adev->dev, "No memory for resources\n");
  56                 acpi_dev_free_resource_list(&resource_list);
  57                 return NULL;
  58         }
  59         count = 0;
  60         list_for_each_entry(rentry, &resource_list, node)
  61                 resources[count++] = rentry->res;
  62
  63         acpi_dev_free_resource_list(&resource_list);
  64
  65         memset(&pdevinfo, 0, sizeof(pdevinfo));
  66         /*
  67          * If the ACPI node has a parent and that parent has a physical device
  68          * attached to it, that physical device should be the parent of the
  69          * platform device we are about to create.
  70          */
  71         pdevinfo.parent = NULL;
  72         acpi_parent = adev->parent;
  73         if (acpi_parent) {
  74                 struct acpi_device_physical_node *entry;
  75                 struct list_head *list;
  76
  77                 mutex_lock(&acpi_parent->physical_node_lock);
  78                 list = &acpi_parent->physical_node_list;
  79                 if (!list_empty(list)) {
  80                         entry = list_first_entry(list,
  81                                         struct acpi_device_physical_node,
  82                                         node);
  83                         pdevinfo.parent = entry->dev;
  84                 }
  85                 mutex_unlock(&acpi_parent->physical_node_lock);
  86         }
  87         pdevinfo.name = dev_name(&adev->dev);
  88         pdevinfo.id = -1;
  89         pdevinfo.res = resources;
  90         pdevinfo.num_res = count;
  91         pdevinfo.acpi_node.handle = adev->handle;
  92         pdev = platform_device_register_full(&pdevinfo);
  93         if (IS_ERR(pdev)) {
  94                 dev_err(&adev->dev, "platform device creation failed: %ld\n",
  95                         PTR_ERR(pdev));
  96                 pdev = NULL;
  97         } else {
  98                 dev_dbg(&adev->dev, "created platform device %s\n",
  99                         dev_name(&pdev->dev));
 100         }
 101
 102         kfree(resources);
 103         return pdev;
 104 }