drivers/pci/pci-acpi.c - kernel/msm-4.19 - Gitiles

 /*
  * File:	pci-acpi.c
  * Purpose:	Provide PCI support in ACPI
  *
  * Copyright (C) 2005 David Shaohua Li <shaohua.li@intel.com>
  * Copyright (C) 2004 Tom Long Nguyen <tom.l.nguyen@intel.com>
  * Copyright (C) 2004 Intel Corp.
  */

 #include <linux/delay.h>
 #include <linux/init.h>
 #include <linux/pci.h>
 #include <linux/module.h>
 #include <linux/pci-aspm.h>
 #include <acpi/acpi.h>
 #include <acpi/acnamesp.h>
 #include <acpi/acresrc.h>
 #include <acpi/acpi_bus.h>

 #include <linux/pci-acpi.h>
 #include "pci.h"

 struct acpi_osc_data {
 	acpi_handle handle;
 	u32 support_set;
 	u32 control_set;
 	struct list_head sibiling;
 };
 static LIST_HEAD(acpi_osc_data_list);

 struct acpi_osc_args {
 	u32 capbuf[3];
 	u32 ctrl_result;
 };

 static DEFINE_MUTEX(pci_acpi_lock);

 static struct acpi_osc_data *acpi_get_osc_data(acpi_handle handle)
 {
 	struct acpi_osc_data *data;

 	list_for_each_entry(data, &acpi_osc_data_list, sibiling) {
 		if (data->handle == handle)
 			return data;
 	}
 	data = kzalloc(sizeof(*data), GFP_KERNEL);
 	if (!data)
 		return NULL;
 	INIT_LIST_HEAD(&data->sibiling);
 	data->handle = handle;
 	list_add_tail(&data->sibiling, &acpi_osc_data_list);
 	return data;
 }

 static u8 OSC_UUID[16] = {0x5B, 0x4D, 0xDB, 0x33, 0xF7, 0x1F, 0x1C, 0x40,
 			  0x96, 0x57, 0x74, 0x41, 0xC0, 0x3D, 0xD7, 0x66};

 static acpi_status acpi_run_osc(acpi_handle handle,
 				struct acpi_osc_args *osc_args)
 {
 	acpi_status status;
 	struct acpi_object_list input;
 	union acpi_object in_params[4];
 	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
 	union acpi_object *out_obj;
 	u32 errors, flags = osc_args->capbuf[OSC_QUERY_TYPE];

 	/* Setting up input parameters */
 	input.count = 4;
 	input.pointer = in_params;
 	in_params[0].type 		= ACPI_TYPE_BUFFER;
 	in_params[0].buffer.length 	= 16;
 	in_params[0].buffer.pointer	= OSC_UUID;
 	in_params[1].type 		= ACPI_TYPE_INTEGER;
 	in_params[1].integer.value 	= 1;
 	in_params[2].type 		= ACPI_TYPE_INTEGER;
 	in_params[2].integer.value	= 3;
 	in_params[3].type		= ACPI_TYPE_BUFFER;
 	in_params[3].buffer.length 	= 12;
 	in_params[3].buffer.pointer 	= (u8 *)osc_args->capbuf;

 	status = acpi_evaluate_object(handle, "_OSC", &input, &output);
 	if (ACPI_FAILURE(status))
 		return status;

 	if (!output.length)
 		return AE_NULL_OBJECT;

 	out_obj = output.pointer;
 	if (out_obj->type != ACPI_TYPE_BUFFER) {
 		printk(KERN_DEBUG "Evaluate _OSC returns wrong type\n");
 		status = AE_TYPE;
 		goto out_kfree;
 	}
 	/* Need to ignore the bit0 in result code */
 	errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
 	if (errors) {
 		if (errors & OSC_REQUEST_ERROR)
 			printk(KERN_DEBUG "_OSC request fails\n");
 		if (errors & OSC_INVALID_UUID_ERROR)
 			printk(KERN_DEBUG "_OSC invalid UUID\n");
 		if (errors & OSC_INVALID_REVISION_ERROR)
 			printk(KERN_DEBUG "_OSC invalid revision\n");
 		if (errors & OSC_CAPABILITIES_MASK_ERROR) {
 			if (flags & OSC_QUERY_ENABLE)
 				goto out_success;
 			printk(KERN_DEBUG "_OSC FW not grant req. control\n");
 			status = AE_SUPPORT;
 			goto out_kfree;
 		}
 		status = AE_ERROR;
 		goto out_kfree;
 	}
 out_success:
 	osc_args->ctrl_result =
 		*((u32 *)(out_obj->buffer.pointer + 8));
 	status = AE_OK;

 out_kfree:
 	kfree(output.pointer);
 	return status;
 }

 static acpi_status __acpi_query_osc(u32 flags, struct acpi_osc_data *osc_data,
 				    u32 *result)
 {
 	acpi_status status;
 	u32 support_set;
 	struct acpi_osc_args osc_args;

 	/* do _OSC query for all possible controls */
 	support_set = osc_data->support_set | (flags & OSC_SUPPORT_MASKS);
 	osc_args.capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
 	osc_args.capbuf[OSC_SUPPORT_TYPE] = support_set;
 	osc_args.capbuf[OSC_CONTROL_TYPE] = OSC_CONTROL_MASKS;

 	status = acpi_run_osc(osc_data->handle, &osc_args);
 	if (ACPI_SUCCESS(status)) {
 		osc_data->support_set = support_set;
 		*result = osc_args.ctrl_result;
 	}

 	return status;
 }

 static acpi_status acpi_query_osc(acpi_handle handle,
 				  u32 level, void *context, void **retval)
 {
 	acpi_status status;
 	struct acpi_osc_data *osc_data;
 	u32 flags = (unsigned long)context, dummy;
 	acpi_handle tmp;

 	status = acpi_get_handle(handle, "_OSC", &tmp);
 	if (ACPI_FAILURE(status))
 		return AE_OK;

 	mutex_lock(&pci_acpi_lock);
 	osc_data = acpi_get_osc_data(handle);
 	if (!osc_data) {
 		printk(KERN_ERR "acpi osc data array is full\n");
 		goto out;
 	}

 	__acpi_query_osc(flags, osc_data, &dummy);
 out:
 	mutex_unlock(&pci_acpi_lock);
 	return AE_OK;
 }

 /**
  * __pci_osc_support_set - register OS support to Firmware
  * @flags: OS support bits
  * @hid: hardware ID
  *
  * Update OS support fields and doing a _OSC Query to obtain an update
  * from Firmware on supported control bits.
  **/
 acpi_status __pci_osc_support_set(u32 flags, const char *hid)
 {
 	if (!(flags & OSC_SUPPORT_MASKS))
 		return AE_TYPE;

 	acpi_get_devices(hid, acpi_query_osc,
 			 (void *)(unsigned long)flags, NULL);
 	return AE_OK;
 }

 /**
  * pci_osc_control_set - commit requested control to Firmware
  * @handle: acpi_handle for the target ACPI object
  * @flags: driver's requested control bits
  *
  * Attempt to take control from Firmware on requested control bits.
  **/
 acpi_status pci_osc_control_set(acpi_handle handle, u32 flags)
 {
 	acpi_status status;
 	u32 ctrlset, control_set, result;
 	acpi_handle tmp;
 	struct acpi_osc_data *osc_data;
 	struct acpi_osc_args osc_args;

 	status = acpi_get_handle(handle, "_OSC", &tmp);
 	if (ACPI_FAILURE(status))
 		return status;

 	mutex_lock(&pci_acpi_lock);
 	osc_data = acpi_get_osc_data(handle);
 	if (!osc_data) {
 		printk(KERN_ERR "acpi osc data array is full\n");
 		status = AE_ERROR;
 		goto out;
 	}

 	ctrlset = (flags & OSC_CONTROL_MASKS);
 	if (!ctrlset) {
 		status = AE_TYPE;
 		goto out;
 	}

 	status = __acpi_query_osc(osc_data->support_set, osc_data, &result);
 	if (ACPI_FAILURE(status))
 		goto out;

 	if ((result & ctrlset) != ctrlset) {
 		status = AE_SUPPORT;
 		goto out;
 	}

 	control_set = osc_data->control_set | ctrlset;
 	osc_args.capbuf[OSC_QUERY_TYPE] = 0;
 	osc_args.capbuf[OSC_SUPPORT_TYPE] = osc_data->support_set;
 	osc_args.capbuf[OSC_CONTROL_TYPE] = control_set;
 	status = acpi_run_osc(handle, &osc_args);
 	if (ACPI_SUCCESS(status))
 		osc_data->control_set = control_set;
 out:
 	mutex_unlock(&pci_acpi_lock);
 	return status;
 }
 EXPORT_SYMBOL(pci_osc_control_set);

 /*
  * _SxD returns the D-state with the highest power
  * (lowest D-state number) supported in the S-state "x".
  *
  * If the devices does not have a _PRW
  * (Power Resources for Wake) supporting system wakeup from "x"
  * then the OS is free to choose a lower power (higher number
  * D-state) than the return value from _SxD.
  *
  * But if _PRW is enabled at S-state "x", the OS
  * must not choose a power lower than _SxD --
  * unless the device has an _SxW method specifying
  * the lowest power (highest D-state number) the device
  * may enter while still able to wake the system.
  *
  * ie. depending on global OS policy:
  *
  * if (_PRW at S-state x)
  *	choose from highest power _SxD to lowest power _SxW
  * else // no _PRW at S-state x
  * 	choose highest power _SxD or any lower power
  */

 static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
 {
 	int acpi_state;

 	acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL);
 	if (acpi_state < 0)
 		return PCI_POWER_ERROR;

 	switch (acpi_state) {
 	case ACPI_STATE_D0:
 		return PCI_D0;
 	case ACPI_STATE_D1:
 		return PCI_D1;
 	case ACPI_STATE_D2:
 		return PCI_D2;
 	case ACPI_STATE_D3:
 		return PCI_D3hot;
 	}
 	return PCI_POWER_ERROR;
 }

 static bool acpi_pci_power_manageable(struct pci_dev *dev)
 {
 	acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);

 	return handle ? acpi_bus_power_manageable(handle) : false;
 }

 static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
 {
 	acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
 	acpi_handle tmp;
 	static const u8 state_conv[] = {
 		[PCI_D0] = ACPI_STATE_D0,
 		[PCI_D1] = ACPI_STATE_D1,
 		[PCI_D2] = ACPI_STATE_D2,
 		[PCI_D3hot] = ACPI_STATE_D3,
 		[PCI_D3cold] = ACPI_STATE_D3
 	};
 	int error = -EINVAL;

 	/* If the ACPI device has _EJ0, ignore the device */
 	if (!handle || ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp)))
 		return -ENODEV;

 	switch (state) {
 	case PCI_D0:
 	case PCI_D1:
 	case PCI_D2:
 	case PCI_D3hot:
 	case PCI_D3cold:
 		error = acpi_bus_set_power(handle, state_conv[state]);
 	}

 	if (!error)
 		dev_printk(KERN_INFO, &dev->dev,
 				"power state changed by ACPI to D%d\n", state);

 	return error;
 }

 static bool acpi_pci_can_wakeup(struct pci_dev *dev)
 {
 	acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);

 	return handle ? acpi_bus_can_wakeup(handle) : false;
 }

 static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable)
 {
 	int error = acpi_pm_device_sleep_wake(&dev->dev, enable);

 	if (!error)
 		dev_printk(KERN_INFO, &dev->dev,
 				"wake-up capability %s by ACPI\n",
 				enable ? "enabled" : "disabled");
 	return error;
 }

 static struct pci_platform_pm_ops acpi_pci_platform_pm = {
 	.is_manageable = acpi_pci_power_manageable,
 	.set_state = acpi_pci_set_power_state,
 	.choose_state = acpi_pci_choose_state,
 	.can_wakeup = acpi_pci_can_wakeup,
 	.sleep_wake = acpi_pci_sleep_wake,
 };

 /* ACPI bus type */
 static int acpi_pci_find_device(struct device *dev, acpi_handle *handle)
 {
 	struct pci_dev * pci_dev;
 	acpi_integer	addr;

 	pci_dev = to_pci_dev(dev);
 	/* Please ref to ACPI spec for the syntax of _ADR */
 	addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
 	*handle = acpi_get_child(DEVICE_ACPI_HANDLE(dev->parent), addr);
 	if (!*handle)
 		return -ENODEV;
 	return 0;
 }

 static int acpi_pci_find_root_bridge(struct device *dev, acpi_handle *handle)
 {
 	int num;
 	unsigned int seg, bus;

 	/*
 	 * The string should be the same as root bridge's name
 	 * Please look at 'pci_scan_bus_parented'
 	 */
 	num = sscanf(dev_name(dev), "pci%04x:%02x", &seg, &bus);
 	if (num != 2)
 		return -ENODEV;
 	*handle = acpi_get_pci_rootbridge_handle(seg, bus);
 	if (!*handle)
 		return -ENODEV;
 	return 0;
 }

 static struct acpi_bus_type acpi_pci_bus = {
 	.bus = &pci_bus_type,
 	.find_device = acpi_pci_find_device,
 	.find_bridge = acpi_pci_find_root_bridge,
 };

 static int __init acpi_pci_init(void)
 {
 	int ret;

 	if (acpi_gbl_FADT.boot_flags & BAF_MSI_NOT_SUPPORTED) {
 		printk(KERN_INFO"ACPI FADT declares the system doesn't support MSI, so disable it\n");
 		pci_no_msi();
 	}

 	if (acpi_gbl_FADT.boot_flags & BAF_PCIE_ASPM_CONTROL) {
 		printk(KERN_INFO"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
 		pcie_no_aspm();
 	}

 	ret = register_acpi_bus_type(&acpi_pci_bus);
 	if (ret)
 		return 0;
 	pci_set_platform_pm(&acpi_pci_platform_pm);
 	return 0;
 }
 arch_initcall(acpi_pci_init);
	/*
	* File: pci-acpi.c
	* Purpose: Provide PCI support in ACPI
	*
	* Copyright (C) 2005 David Shaohua Li <shaohua.li@intel.com>
	* Copyright (C) 2004 Tom Long Nguyen <tom.l.nguyen@intel.com>
	* Copyright (C) 2004 Intel Corp.
	*/

	#include <linux/delay.h>
	#include <linux/init.h>
	#include <linux/pci.h>
	#include <linux/module.h>
	#include <linux/pci-aspm.h>
	#include <acpi/acpi.h>
	#include <acpi/acnamesp.h>
	#include <acpi/acresrc.h>
	#include <acpi/acpi_bus.h>

	#include <linux/pci-acpi.h>
	#include "pci.h"

	struct acpi_osc_data {
	acpi_handle handle;
	u32 support_set;
	u32 control_set;
	struct list_head sibiling;
	};
	static LIST_HEAD(acpi_osc_data_list);

	struct acpi_osc_args {
	u32 capbuf[3];
	u32 ctrl_result;
	};

	static DEFINE_MUTEX(pci_acpi_lock);

	static struct acpi_osc_data *acpi_get_osc_data(acpi_handle handle)
	{
	struct acpi_osc_data *data;

	list_for_each_entry(data, &acpi_osc_data_list, sibiling) {
	if (data->handle == handle)
	return data;
	}
	data = kzalloc(sizeof(*data), GFP_KERNEL);
	if (!data)
	return NULL;
	INIT_LIST_HEAD(&data->sibiling);
	data->handle = handle;
	list_add_tail(&data->sibiling, &acpi_osc_data_list);
	return data;
	}

	static u8 OSC_UUID[16] = {0x5B, 0x4D, 0xDB, 0x33, 0xF7, 0x1F, 0x1C, 0x40,
	0x96, 0x57, 0x74, 0x41, 0xC0, 0x3D, 0xD7, 0x66};

	static acpi_status acpi_run_osc(acpi_handle handle,
	struct acpi_osc_args *osc_args)
	{
	acpi_status status;
	struct acpi_object_list input;
	union acpi_object in_params[4];
	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
	union acpi_object *out_obj;
	u32 errors, flags = osc_args->capbuf[OSC_QUERY_TYPE];

	/* Setting up input parameters */
	input.count = 4;
	input.pointer = in_params;
	in_params[0].type = ACPI_TYPE_BUFFER;
	in_params[0].buffer.length = 16;
	in_params[0].buffer.pointer = OSC_UUID;
	in_params[1].type = ACPI_TYPE_INTEGER;
	in_params[1].integer.value = 1;
	in_params[2].type = ACPI_TYPE_INTEGER;
	in_params[2].integer.value = 3;
	in_params[3].type = ACPI_TYPE_BUFFER;
	in_params[3].buffer.length = 12;
	in_params[3].buffer.pointer = (u8 *)osc_args->capbuf;

	status = acpi_evaluate_object(handle, "_OSC", &input, &output);
	if (ACPI_FAILURE(status))
	return status;

	if (!output.length)
	return AE_NULL_OBJECT;

	out_obj = output.pointer;
	if (out_obj->type != ACPI_TYPE_BUFFER) {
	printk(KERN_DEBUG "Evaluate _OSC returns wrong type\n");
	status = AE_TYPE;
	goto out_kfree;
	}
	/* Need to ignore the bit0 in result code */
	errors = ((u32 )out_obj->buffer.pointer) & ~(1 << 0);
	if (errors) {
	if (errors & OSC_REQUEST_ERROR)
	printk(KERN_DEBUG "_OSC request fails\n");
	if (errors & OSC_INVALID_UUID_ERROR)
	printk(KERN_DEBUG "_OSC invalid UUID\n");
	if (errors & OSC_INVALID_REVISION_ERROR)
	printk(KERN_DEBUG "_OSC invalid revision\n");
	if (errors & OSC_CAPABILITIES_MASK_ERROR) {
	if (flags & OSC_QUERY_ENABLE)
	goto out_success;
	printk(KERN_DEBUG "_OSC FW not grant req. control\n");
	status = AE_SUPPORT;
	goto out_kfree;
	}
	status = AE_ERROR;
	goto out_kfree;
	}
	out_success:
	osc_args->ctrl_result =
	((u32 )(out_obj->buffer.pointer + 8));
	status = AE_OK;

	out_kfree:
	kfree(output.pointer);
	return status;
	}

	static acpi_status __acpi_query_osc(u32 flags, struct acpi_osc_data *osc_data,
	u32 *result)
	{
	acpi_status status;
	u32 support_set;
	struct acpi_osc_args osc_args;

	/* do _OSC query for all possible controls */
	support_set = osc_data->support_set \| (flags & OSC_SUPPORT_MASKS);
	osc_args.capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
	osc_args.capbuf[OSC_SUPPORT_TYPE] = support_set;
	osc_args.capbuf[OSC_CONTROL_TYPE] = OSC_CONTROL_MASKS;

	status = acpi_run_osc(osc_data->handle, &osc_args);
	if (ACPI_SUCCESS(status)) {
	osc_data->support_set = support_set;
	*result = osc_args.ctrl_result;
	}

	return status;
	}

	static acpi_status acpi_query_osc(acpi_handle handle,
	u32 level, void context, void *retval)
	{
	acpi_status status;
	struct acpi_osc_data *osc_data;
	u32 flags = (unsigned long)context, dummy;
	acpi_handle tmp;

	status = acpi_get_handle(handle, "_OSC", &tmp);
	if (ACPI_FAILURE(status))
	return AE_OK;

	mutex_lock(&pci_acpi_lock);
	osc_data = acpi_get_osc_data(handle);
	if (!osc_data) {
	printk(KERN_ERR "acpi osc data array is full\n");
	goto out;
	}

	__acpi_query_osc(flags, osc_data, &dummy);
	out:
	mutex_unlock(&pci_acpi_lock);
	return AE_OK;
	}

	/**
	* __pci_osc_support_set - register OS support to Firmware
	* @flags: OS support bits
	* @hid: hardware ID
	*
	* Update OS support fields and doing a _OSC Query to obtain an update
	* from Firmware on supported control bits.
	**/
	acpi_status __pci_osc_support_set(u32 flags, const char *hid)
	{
	if (!(flags & OSC_SUPPORT_MASKS))
	return AE_TYPE;

	acpi_get_devices(hid, acpi_query_osc,
	(void *)(unsigned long)flags, NULL);
	return AE_OK;
	}

	/**
	* pci_osc_control_set - commit requested control to Firmware
	* @handle: acpi_handle for the target ACPI object
	* @flags: driver's requested control bits
	*
	* Attempt to take control from Firmware on requested control bits.
	**/
	acpi_status pci_osc_control_set(acpi_handle handle, u32 flags)
	{
	acpi_status status;
	u32 ctrlset, control_set, result;
	acpi_handle tmp;
	struct acpi_osc_data *osc_data;
	struct acpi_osc_args osc_args;

	status = acpi_get_handle(handle, "_OSC", &tmp);
	if (ACPI_FAILURE(status))
	return status;

	mutex_lock(&pci_acpi_lock);
	osc_data = acpi_get_osc_data(handle);
	if (!osc_data) {
	printk(KERN_ERR "acpi osc data array is full\n");
	status = AE_ERROR;
	goto out;
	}

	ctrlset = (flags & OSC_CONTROL_MASKS);
	if (!ctrlset) {
	status = AE_TYPE;
	goto out;
	}

	status = __acpi_query_osc(osc_data->support_set, osc_data, &result);
	if (ACPI_FAILURE(status))
	goto out;

	if ((result & ctrlset) != ctrlset) {
	status = AE_SUPPORT;
	goto out;
	}

	control_set = osc_data->control_set \| ctrlset;
	osc_args.capbuf[OSC_QUERY_TYPE] = 0;
	osc_args.capbuf[OSC_SUPPORT_TYPE] = osc_data->support_set;
	osc_args.capbuf[OSC_CONTROL_TYPE] = control_set;
	status = acpi_run_osc(handle, &osc_args);
	if (ACPI_SUCCESS(status))
	osc_data->control_set = control_set;
	out:
	mutex_unlock(&pci_acpi_lock);
	return status;
	}
	EXPORT_SYMBOL(pci_osc_control_set);

	/*
	* _SxD returns the D-state with the highest power
	* (lowest D-state number) supported in the S-state "x".
	*
	* If the devices does not have a _PRW
	* (Power Resources for Wake) supporting system wakeup from "x"
	* then the OS is free to choose a lower power (higher number
	* D-state) than the return value from _SxD.
	*
	* But if _PRW is enabled at S-state "x", the OS
	* must not choose a power lower than _SxD --
	* unless the device has an _SxW method specifying
	* the lowest power (highest D-state number) the device
	* may enter while still able to wake the system.
	*
	* ie. depending on global OS policy:
	*
	* if (_PRW at S-state x)
	* choose from highest power _SxD to lowest power _SxW
	* else // no _PRW at S-state x
	* choose highest power _SxD or any lower power
	*/

	static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
	{
	int acpi_state;

	acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL);
	if (acpi_state < 0)
	return PCI_POWER_ERROR;

	switch (acpi_state) {
	case ACPI_STATE_D0:
	return PCI_D0;
	case ACPI_STATE_D1:
	return PCI_D1;
	case ACPI_STATE_D2:
	return PCI_D2;
	case ACPI_STATE_D3:
	return PCI_D3hot;
	}
	return PCI_POWER_ERROR;
	}

	static bool acpi_pci_power_manageable(struct pci_dev *dev)
	{
	acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);

	return handle ? acpi_bus_power_manageable(handle) : false;
	}

	static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
	{
	acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
	acpi_handle tmp;
	static const u8 state_conv[] = {
	[PCI_D0] = ACPI_STATE_D0,
	[PCI_D1] = ACPI_STATE_D1,
	[PCI_D2] = ACPI_STATE_D2,
	[PCI_D3hot] = ACPI_STATE_D3,
	[PCI_D3cold] = ACPI_STATE_D3
	};
	int error = -EINVAL;

	/* If the ACPI device has _EJ0, ignore the device */
	if (!handle \|\| ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp)))
	return -ENODEV;

	switch (state) {
	case PCI_D0:
	case PCI_D1:
	case PCI_D2:
	case PCI_D3hot:
	case PCI_D3cold:
	error = acpi_bus_set_power(handle, state_conv[state]);
	}

	if (!error)
	dev_printk(KERN_INFO, &dev->dev,
	"power state changed by ACPI to D%d\n", state);

	return error;
	}

	static bool acpi_pci_can_wakeup(struct pci_dev *dev)
	{
	acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);

	return handle ? acpi_bus_can_wakeup(handle) : false;
	}

	static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable)
	{
	int error = acpi_pm_device_sleep_wake(&dev->dev, enable);

	if (!error)
	dev_printk(KERN_INFO, &dev->dev,
	"wake-up capability %s by ACPI\n",
	enable ? "enabled" : "disabled");
	return error;
	}

	static struct pci_platform_pm_ops acpi_pci_platform_pm = {
	.is_manageable = acpi_pci_power_manageable,
	.set_state = acpi_pci_set_power_state,
	.choose_state = acpi_pci_choose_state,
	.can_wakeup = acpi_pci_can_wakeup,
	.sleep_wake = acpi_pci_sleep_wake,
	};

	/* ACPI bus type */
	static int acpi_pci_find_device(struct device dev, acpi_handle handle)
	{
	struct pci_dev * pci_dev;
	acpi_integer addr;

	pci_dev = to_pci_dev(dev);
	/* Please ref to ACPI spec for the syntax of _ADR */
	addr = (PCI_SLOT(pci_dev->devfn) << 16) \| PCI_FUNC(pci_dev->devfn);
	*handle = acpi_get_child(DEVICE_ACPI_HANDLE(dev->parent), addr);
	if (!*handle)
	return -ENODEV;
	return 0;
	}

	static int acpi_pci_find_root_bridge(struct device dev, acpi_handle handle)
	{
	int num;
	unsigned int seg, bus;

	/*
	* The string should be the same as root bridge's name
	* Please look at 'pci_scan_bus_parented'
	*/
	num = sscanf(dev_name(dev), "pci%04x:%02x", &seg, &bus);
	if (num != 2)
	return -ENODEV;
	*handle = acpi_get_pci_rootbridge_handle(seg, bus);
	if (!*handle)
	return -ENODEV;
	return 0;
	}

	static struct acpi_bus_type acpi_pci_bus = {
	.bus = &pci_bus_type,
	.find_device = acpi_pci_find_device,
	.find_bridge = acpi_pci_find_root_bridge,
	};

	static int __init acpi_pci_init(void)
	{
	int ret;

	if (acpi_gbl_FADT.boot_flags & BAF_MSI_NOT_SUPPORTED) {
	printk(KERN_INFO"ACPI FADT declares the system doesn't support MSI, so disable it\n");
	pci_no_msi();
	}

	if (acpi_gbl_FADT.boot_flags & BAF_PCIE_ASPM_CONTROL) {
	printk(KERN_INFO"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
	pcie_no_aspm();
	}

	ret = register_acpi_bus_type(&acpi_pci_bus);
	if (ret)
	return 0;
	pci_set_platform_pm(&acpi_pci_platform_pm);
	return 0;
	}
	arch_initcall(acpi_pci_init);