linux/drivers/acpi/acpi_platform.c

105 lines
3.1 KiB
C

/*
* ACPI support for platform bus type.
*
* Copyright (C) 2012, Intel Corporation
* Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
* Mathias Nyman <mathias.nyman@linux.intel.com>
* Rafael J. Wysocki <rafael.j.wysocki@intel.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/acpi.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include "internal.h"
ACPI_MODULE_NAME("platform");
/**
* acpi_create_platform_device - Create platform device for ACPI device node
* @adev: ACPI device node to create a platform device for.
*
* Check if the given @adev can be represented as a platform device and, if
* that's the case, create and register a platform device, populate its common
* resources and returns a pointer to it. Otherwise, return %NULL.
*
* The platform device's name will be taken from the @adev's _HID and _UID.
*/
struct platform_device *acpi_create_platform_device(struct acpi_device *adev)
{
struct platform_device *pdev = NULL;
struct acpi_device *acpi_parent;
struct platform_device_info pdevinfo;
struct resource_list_entry *rentry;
struct list_head resource_list;
struct resource *resources;
int count;
/* If the ACPI node already has a physical device attached, skip it. */
if (adev->physical_node_count)
return NULL;
INIT_LIST_HEAD(&resource_list);
count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
if (count <= 0)
return NULL;
resources = kmalloc(count * sizeof(struct resource), GFP_KERNEL);
if (!resources) {
dev_err(&adev->dev, "No memory for resources\n");
acpi_dev_free_resource_list(&resource_list);
return NULL;
}
count = 0;
list_for_each_entry(rentry, &resource_list, node)
resources[count++] = rentry->res;
acpi_dev_free_resource_list(&resource_list);
memset(&pdevinfo, 0, sizeof(pdevinfo));
/*
* If the ACPI node has a parent and that parent has a physical device
* attached to it, that physical device should be the parent of the
* platform device we are about to create.
*/
pdevinfo.parent = NULL;
acpi_parent = adev->parent;
if (acpi_parent) {
struct acpi_device_physical_node *entry;
struct list_head *list;
mutex_lock(&acpi_parent->physical_node_lock);
list = &acpi_parent->physical_node_list;
if (!list_empty(list)) {
entry = list_first_entry(list,
struct acpi_device_physical_node,
node);
pdevinfo.parent = entry->dev;
}
mutex_unlock(&acpi_parent->physical_node_lock);
}
pdevinfo.name = dev_name(&adev->dev);
pdevinfo.id = -1;
pdevinfo.res = resources;
pdevinfo.num_res = count;
pdevinfo.acpi_node.handle = adev->handle;
pdev = platform_device_register_full(&pdevinfo);
if (IS_ERR(pdev)) {
dev_err(&adev->dev, "platform device creation failed: %ld\n",
PTR_ERR(pdev));
pdev = NULL;
} else {
dev_dbg(&adev->dev, "created platform device %s\n",
dev_name(&pdev->dev));
}
kfree(resources);
return pdev;
}