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 /* Flags for acpi_create_platform_device */
  26 #define ACPI_PLATFORM_CLK       BIT(0)
  27
  28 /*
  29  * The following ACPI IDs are known to be suitable for representing as
  30  * platform devices.
  31  */
  32 static const struct acpi_device_id acpi_platform_device_ids[] = {
  33
  34         { "PNP0D40" },
  35
  36         /* Haswell LPSS devices */
  37         { "INT33C0", ACPI_PLATFORM_CLK },
  38         { "INT33C1", ACPI_PLATFORM_CLK },
  39         { "INT33C2", ACPI_PLATFORM_CLK },
  40         { "INT33C3", ACPI_PLATFORM_CLK },
  41         { "INT33C4", ACPI_PLATFORM_CLK },
  42         { "INT33C5", ACPI_PLATFORM_CLK },
  43         { "INT33C6", ACPI_PLATFORM_CLK },
  44         { "INT33C7", ACPI_PLATFORM_CLK },
  45
  46         { }
  47 };
  48
  49 static int acpi_create_platform_clks(struct acpi_device *adev)
  50 {
  51         static struct platform_device *pdev;
  52
  53         /* Create Lynxpoint LPSS clocks */
  54         if (!pdev && !strncmp(acpi_device_hid(adev), "INT33C", 6)) {
  55                 pdev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
  56                 if (IS_ERR(pdev))
  57                         return PTR_ERR(pdev);
  58         }
  59
  60         return 0;
  61 }
  62
  63 /**
  64  * acpi_create_platform_device - Create platform device for ACPI device node
  65  * @adev: ACPI device node to create a platform device for.
  66  * @id: ACPI device ID used to match @adev.
  67  *
  68  * Check if the given @adev can be represented as a platform device and, if
  69  * that's the case, create and register a platform device, populate its common
  70  * resources and returns a pointer to it.  Otherwise, return %NULL.
  71  *
  72  * Name of the platform device will be the same as @adev's.
  73  */
  74 static int acpi_create_platform_device(struct acpi_device *adev,
  75                                        const struct acpi_device_id *id)
  76 {
  77         unsigned long flags = id->driver_data;
  78         struct platform_device *pdev = NULL;
  79         struct acpi_device *acpi_parent;
  80         struct platform_device_info pdevinfo;
  81         struct resource_list_entry *rentry;
  82         struct list_head resource_list;
  83         struct resource *resources;
  84         int count;
  85
  86         if (flags & ACPI_PLATFORM_CLK) {
  87                 int ret = acpi_create_platform_clks(adev);
  88                 if (ret) {
  89                         dev_err(&adev->dev, "failed to create clocks\n");
  90                         return ret;
  91                 }
  92         }
  93
  94         /* If the ACPI node already has a physical device attached, skip it. */
  95         if (adev->physical_node_count)
  96                 return 0;
  97
  98         INIT_LIST_HEAD(&resource_list);
  99         count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
 100         if (count <= 0)
 101                 return 0;
 102
 103         resources = kmalloc(count * sizeof(struct resource), GFP_KERNEL);
 104         if (!resources) {
 105                 dev_err(&adev->dev, "No memory for resources\n");
 106                 acpi_dev_free_resource_list(&resource_list);
 107                 return -ENOMEM;
 108         }
 109         count = 0;
 110         list_for_each_entry(rentry, &resource_list, node)
 111                 resources[count++] = rentry->res;
 112
 113         acpi_dev_free_resource_list(&resource_list);
 114
 115         memset(&pdevinfo, 0, sizeof(pdevinfo));
 116         /*
 117          * If the ACPI node has a parent and that parent has a physical device
 118          * attached to it, that physical device should be the parent of the
 119          * platform device we are about to create.
 120          */
 121         pdevinfo.parent = NULL;
 122         acpi_parent = adev->parent;
 123         if (acpi_parent) {
 124                 struct acpi_device_physical_node *entry;
 125                 struct list_head *list;
 126
 127                 mutex_lock(&acpi_parent->physical_node_lock);
 128                 list = &acpi_parent->physical_node_list;
 129                 if (!list_empty(list)) {
 130                         entry = list_first_entry(list,
 131                                         struct acpi_device_physical_node,
 132                                         node);
 133                         pdevinfo.parent = entry->dev;
 134                 }
 135                 mutex_unlock(&acpi_parent->physical_node_lock);
 136         }
 137         pdevinfo.name = dev_name(&adev->dev);
 138         pdevinfo.id = -1;
 139         pdevinfo.res = resources;
 140         pdevinfo.num_res = count;
 141         pdevinfo.acpi_node.handle = adev->handle;
 142         pdev = platform_device_register_full(&pdevinfo);
 143         if (IS_ERR(pdev)) {
 144                 dev_err(&adev->dev, "platform device creation failed: %ld\n",
 145                         PTR_ERR(pdev));
 146                 pdev = NULL;
 147         } else {
 148                 dev_dbg(&adev->dev, "created platform device %s\n",
 149                         dev_name(&pdev->dev));
 150         }
 151
 152         kfree(resources);
 153         return 1;
 154 }
 155
 156 static struct acpi_scan_handler platform_handler = {
 157         .ids = acpi_platform_device_ids,
 158         .attach = acpi_create_platform_device,
 159 };
 160
 161 void __init acpi_platform_init(void)
 162 {
 163         acpi_scan_add_handler(&platform_handler);
 164 }