linux/drivers/acpi/acpi_platform.c
Mika Westerberg e375325ce5 ACPI / platform: create LPSS clocks if Lynxpoint devices are found during scan
Intel Lynxpoint LPSS peripheral drivers depend on LPSS clock tree being
created in order to function properly. The clock tree is exposed as a
platform driver that binds to a device named 'clk-lpt'.

To support this we modify the acpi_create_platform_device() to take one
additional parameter called flags. This is passed from
acpi_platform_device_ids[] array when acpi_create_platform_device() is
called.

We then introduce a new flag ACPI_PLATFORM_CLK which is used to tell
acpi_create_platform_device() to create the platform clocks as well.

Finally we set the ACPI_PLATFORM_CLK flags for all the Lynxpoint LPSS
devices and make sure that when this flag is set we create the
corresponding clock tree platform device.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-01-23 21:14:22 +01:00

128 lines
3.6 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/err.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include "internal.h"
ACPI_MODULE_NAME("platform");
static int acpi_create_platform_clks(struct acpi_device *adev)
{
static struct platform_device *pdev;
/* Create Lynxpoint LPSS clocks */
if (!pdev && !strncmp(acpi_device_hid(adev), "INT33C", 6)) {
pdev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
if (IS_ERR(pdev))
return PTR_ERR(pdev);
}
return 0;
}
/**
* acpi_create_platform_device - Create platform device for ACPI device node
* @adev: ACPI device node to create a platform device for.
* @flags: ACPI_PLATFORM_* flags that affect the creation of the platform
* devices.
*
* 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.
*
* Name of the platform device will be the same as @adev's.
*/
struct platform_device *acpi_create_platform_device(struct acpi_device *adev,
unsigned long flags)
{
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 ((flags & ACPI_PLATFORM_CLK) && acpi_create_platform_clks(adev)) {
dev_err(&adev->dev, "failed to create clocks\n");
return NULL;
}
/* 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;
}