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/platform_device.h>
  21
  22 #include "internal.h"
  23
  24 ACPI_MODULE_NAME("platform");
  25
  26 static const struct acpi_device_id forbidden_id_list[] = {
  27         {"PNP0000", 0}, /* PIC */
  28         {"PNP0100", 0}, /* Timer */
  29         {"PNP0200", 0}, /* AT DMA Controller */
  30         {"", 0},
  31 };
  32
  33 /**
  34  * acpi_create_platform_device - Create platform device for ACPI device node
  35  * @adev: ACPI device node to create a platform device for.
  36  *
  37  * Check if the given @adev can be represented as a platform device and, if
  38  * that's the case, create and register a platform device, populate its common
  39  * resources and returns a pointer to it.  Otherwise, return %NULL.
  40  *
  41  * Name of the platform device will be the same as @adev's.
  42  */
  43 struct platform_device *acpi_create_platform_device(struct acpi_device *adev)
  44 {
  45         struct platform_device *pdev = NULL;
  46         struct acpi_device *acpi_parent;
  47         struct platform_device_info pdevinfo;
  48         struct resource_entry *rentry;
  49         struct list_head resource_list;
  50         struct resource *resources = NULL;
  51         int count;
  52
  53         /* If the ACPI node already has a physical device attached, skip it. */
  54         if (adev->physical_node_count)
  55                 return NULL;
  56
  57         if (!acpi_match_device_ids(adev, forbidden_id_list))
  58                 return ERR_PTR(-EINVAL);
  59
  60         INIT_LIST_HEAD(&resource_list);
  61         count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
  62         if (count < 0) {
  63                 return NULL;
  64         } else if (count > 0) {
  65                 resources = kmalloc(count * sizeof(struct resource),
  66                                     GFP_KERNEL);
  67                 if (!resources) {
  68                         dev_err(&adev->dev, "No memory for resources\n");
  69                         acpi_dev_free_resource_list(&resource_list);
  70                         return ERR_PTR(-ENOMEM);
  71                 }
  72                 count = 0;
  73                 list_for_each_entry(rentry, &resource_list, node)
  74                         resources[count++] = *rentry->res;
  75
  76                 acpi_dev_free_resource_list(&resource_list);
  77         }
  78
  79         memset(&pdevinfo, 0, sizeof(pdevinfo));
  80         /*
  81          * If the ACPI node has a parent and that parent has a physical device
  82          * attached to it, that physical device should be the parent of the
  83          * platform device we are about to create.
  84          */
  85         pdevinfo.parent = NULL;
  86         acpi_parent = adev->parent;
  87         if (acpi_parent) {
  88                 struct acpi_device_physical_node *entry;
  89                 struct list_head *list;
  90
  91                 mutex_lock(&acpi_parent->physical_node_lock);
  92                 list = &acpi_parent->physical_node_list;
  93                 if (!list_empty(list)) {
  94                         entry = list_first_entry(list,
  95                                         struct acpi_device_physical_node,
  96                                         node);
  97                         pdevinfo.parent = entry->dev;
  98                 }
  99                 mutex_unlock(&acpi_parent->physical_node_lock);
 100         }
 101         pdevinfo.name = dev_name(&adev->dev);
 102         pdevinfo.id = -1;
 103         pdevinfo.res = resources;
 104         pdevinfo.num_res = count;
 105         pdevinfo.fwnode = acpi_fwnode_handle(adev);
 106         pdevinfo.dma_mask = acpi_check_dma(adev, NULL) ? DMA_BIT_MASK(32) : 0;
 107         pdev = platform_device_register_full(&pdevinfo);
 108         if (IS_ERR(pdev))
 109                 dev_err(&adev->dev, "platform device creation failed: %ld\n",
 110                         PTR_ERR(pdev));
 111         else
 112                 dev_dbg(&adev->dev, "created platform device %s\n",
 113                         dev_name(&pdev->dev));
 114
 115         kfree(resources);
 116         return pdev;
 117 }
 118 EXPORT_SYMBOL_GPL(acpi_create_platform_device);