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 /*
  26  * The following ACPI IDs are known to be suitable for representing as
  27  * platform devices.
  28  */
  29 static const struct acpi_device_id acpi_platform_device_ids[] = {
  30
  31         { "PNP0D40" },
  32         { "VPC2004" },
  33         { "BCM4752" },
  34
  35         /* Intel Smart Sound Technology */
  36         { "INT33C8" },
  37         { "80860F28" },
  38
  39         { }
  40 };
  41
  42 /**
  43  * acpi_create_platform_device - Create platform device for ACPI device node
  44  * @adev: ACPI device node to create a platform device for.
  45  * @id: ACPI device ID used to match @adev.
  46  *
  47  * Check if the given @adev can be represented as a platform device and, if
  48  * that's the case, create and register a platform device, populate its common
  49  * resources and returns a pointer to it.  Otherwise, return %NULL.
  50  *
  51  * Name of the platform device will be the same as @adev's.
  52  */
  53 int acpi_create_platform_device(struct acpi_device *adev,
  54                                 const struct acpi_device_id *id)
  55 {
  56         struct platform_device *pdev = NULL;
  57         struct acpi_device *acpi_parent;
  58         struct platform_device_info pdevinfo;
  59         struct resource_list_entry *rentry;
  60         struct list_head resource_list;
  61         struct resource *resources = NULL;
  62         int count;
  63
  64         /* If the ACPI node already has a physical device attached, skip it. */
  65         if (adev->physical_node_count)
  66                 return 0;
  67
  68         INIT_LIST_HEAD(&resource_list);
  69         count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
  70         if (count < 0) {
  71                 return 0;
  72         } else if (count > 0) {
  73                 resources = kmalloc(count * sizeof(struct resource),
  74                                     GFP_KERNEL);
  75                 if (!resources) {
  76                         dev_err(&adev->dev, "No memory for resources\n");
  77                         acpi_dev_free_resource_list(&resource_list);
  78                         return -ENOMEM;
  79                 }
  80                 count = 0;
  81                 list_for_each_entry(rentry, &resource_list, node)
  82                         resources[count++] = rentry->res;
  83
  84                 acpi_dev_free_resource_list(&resource_list);
  85         }
  86
  87         memset(&pdevinfo, 0, sizeof(pdevinfo));
  88         /*
  89          * If the ACPI node has a parent and that parent has a physical device
  90          * attached to it, that physical device should be the parent of the
  91          * platform device we are about to create.
  92          */
  93         pdevinfo.parent = NULL;
  94         acpi_parent = adev->parent;
  95         if (acpi_parent) {
  96                 struct acpi_device_physical_node *entry;
  97                 struct list_head *list;
  98
  99                 mutex_lock(&acpi_parent->physical_node_lock);
 100                 list = &acpi_parent->physical_node_list;
 101                 if (!list_empty(list)) {
 102                         entry = list_first_entry(list,
 103                                         struct acpi_device_physical_node,
 104                                         node);
 105                         pdevinfo.parent = entry->dev;
 106                 }
 107                 mutex_unlock(&acpi_parent->physical_node_lock);
 108         }
 109         pdevinfo.name = dev_name(&adev->dev);
 110         pdevinfo.id = -1;
 111         pdevinfo.res = resources;
 112         pdevinfo.num_res = count;
 113         pdevinfo.acpi_node.companion = adev;
 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                 pdev = NULL;
 119         } else {
 120                 dev_dbg(&adev->dev, "created platform device %s\n",
 121                         dev_name(&pdev->dev));
 122         }
 123
 124         kfree(resources);
 125         return 1;
 126 }
 127
 128 static struct acpi_scan_handler platform_handler = {
 129         .ids = acpi_platform_device_ids,
 130         .attach = acpi_create_platform_device,
 131 };
 132
 133 void __init acpi_platform_init(void)
 134 {
 135         acpi_scan_add_handler(&platform_handler);
 136 }