LXR linux/drivers/acpi/acpi

   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
  23ACPI_MODULE_NAME("platform");
  24
  25/*
  26 * The following ACPI IDs are known to be suitable for representing as
  27 * platform devices.
  28 */
  29static const struct acpi_device_id acpi_platform_device_ids[] = {
  30
  31        { "PNP0D40" },
  32        { "ACPI0003" },
  33        { "VPC2004" },
  34        { "BCM4752" },
  35
  36        /* Intel Smart Sound Technology */
  37        { "INT33C8" },
  38        { "80860F28" },
  39
  40        { }
  41};
  42
  43/**
  44 * acpi_create_platform_device - Create platform device for ACPI device node
  45 * @adev: ACPI device node to create a platform device for.
  46 * @id: ACPI device ID used to match @adev.
  47 *
  48 * Check if the given @adev can be represented as a platform device and, if
  49 * that's the case, create and register a platform device, populate its common
  50 * resources and returns a pointer to it.  Otherwise, return %NULL.
  51 *
  52 * Name of the platform device will be the same as @adev's.
  53 */
  54int acpi_create_platform_device(struct acpi_device *adev,
  55                                const struct acpi_device_id *id)
  56{
  57        struct platform_device *pdev = NULL;
  58        struct acpi_device *acpi_parent;
  59        struct platform_device_info pdevinfo;
  60        struct resource_list_entry *rentry;
  61        struct list_head resource_list;
  62        struct resource *resources = NULL;
  63        int count;
  64
  65        /* If the ACPI node already has a physical device attached, skip it. */
  66        if (adev->physical_node_count)
  67                return 0;
  68
  69        INIT_LIST_HEAD(&resource_list);
  70        count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
  71        if (count < 0) {
  72                return 0;
  73        } else if (count > 0) {
  74                resources = kmalloc(count * sizeof(struct resource),
  75                                    GFP_KERNEL);
  76                if (!resources) {
  77                        dev_err(&adev->dev, "No memory for resources\n");
  78                        acpi_dev_free_resource_list(&resource_list);
  79                        return -ENOMEM;
  80                }
  81                count = 0;
  82                list_for_each_entry(rentry, &resource_list, node)
  83                        resources[count++] = rentry->res;
  84
  85                acpi_dev_free_resource_list(&resource_list);
  86        }
  87
  88        memset(&pdevinfo, 0, sizeof(pdevinfo));
  89        /*
  90         * If the ACPI node has a parent and that parent has a physical device
  91         * attached to it, that physical device should be the parent of the
  92         * platform device we are about to create.
  93         */
  94        pdevinfo.parent = NULL;
  95        acpi_parent = adev->parent;
  96        if (acpi_parent) {
  97                struct acpi_device_physical_node *entry;
  98                struct list_head *list;
  99
 100                mutex_lock(&acpi_parent->physical_node_lock);
 101                list = &acpi_parent->physical_node_list;
 102                if (!list_empty(list)) {
 103                        entry = list_first_entry(list,
 104                                        struct acpi_device_physical_node,
 105                                        node);
 106                        pdevinfo.parent = entry->dev;
 107                }
 108                mutex_unlock(&acpi_parent->physical_node_lock);
 109        }
 110        pdevinfo.name = dev_name(&adev->dev);
 111        pdevinfo.id = -1;
 112        pdevinfo.res = resources;
 113        pdevinfo.num_res = count;
 114        pdevinfo.acpi_node.companion = adev;
 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                pdev = NULL;
 120        } else {
 121                dev_dbg(&adev->dev, "created platform device %s\n",
 122                        dev_name(&pdev->dev));
 123        }
 124
 125        kfree(resources);
 126        return 1;
 127}
 128
 129static struct acpi_scan_handler platform_handler = {
 130        .ids = acpi_platform_device_ids,
 131        .attach = acpi_create_platform_device,
 132};
 133
 134void __init acpi_platform_init(void)
 135{
 136        acpi_scan_add_handler(&platform_handler);
 137}
 138