drivers/pci/pci-acpi.c - kernel/msm-4.9 - 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 <acpi/acpi.h>
 #include <acpi/acnamesp.h>
 #include <acpi/acresrc.h>
 #include <acpi/acpi_bus.h>

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

 static u32 ctrlset_buf[3] = {0, 0, 0};
 static u32 global_ctrlsets = 0;
 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_query_osc (
 	acpi_handle	handle,
 	u32		level,
 	void		*context,
 	void		**retval )
 {
 	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			osc_dw0;
 	acpi_status *ret_status = (acpi_status *)retval;


 	/* 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 *)context;

 	status = acpi_evaluate_object(handle, "_OSC", &input, &output);
 	if (ACPI_FAILURE (status)) {
 		*ret_status = status;
 		return status;
 	}
 	out_obj = output.pointer;

 	if (out_obj->type != ACPI_TYPE_BUFFER) {
 		printk(KERN_DEBUG
 			"Evaluate _OSC returns wrong type\n");
 		status = AE_TYPE;
 		goto query_osc_out;
 	}
 	osc_dw0 = *((u32 *) out_obj->buffer.pointer);
 	if (osc_dw0) {
 		if (osc_dw0 & OSC_REQUEST_ERROR)
 			printk(KERN_DEBUG "_OSC request fails\n");
 		if (osc_dw0 & OSC_INVALID_UUID_ERROR)
 			printk(KERN_DEBUG "_OSC invalid UUID\n");
 		if (osc_dw0 & OSC_INVALID_REVISION_ERROR)
 			printk(KERN_DEBUG "_OSC invalid revision\n");
 		if (osc_dw0 & OSC_CAPABILITIES_MASK_ERROR) {
 			/* Update Global Control Set */
 			global_ctrlsets = *((u32 *)(out_obj->buffer.pointer+8));
 			status = AE_OK;
 			goto query_osc_out;
 		}
 		status = AE_ERROR;
 		goto query_osc_out;
 	}

 	/* Update Global Control Set */
 	global_ctrlsets = *((u32 *)(out_obj->buffer.pointer + 8));
 	status = AE_OK;

 query_osc_out:
 	kfree(output.pointer);
 	*ret_status = status;
 	return status;
 }


 static acpi_status
 acpi_run_osc (
 	acpi_handle	handle,
 	void		*context)
 {
 	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			osc_dw0;

 	/* 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 *)context;

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

 	out_obj = output.pointer;
 	if (out_obj->type != ACPI_TYPE_BUFFER) {
 		printk(KERN_DEBUG
 			"Evaluate _OSC returns wrong type\n");
 		status = AE_TYPE;
 		goto run_osc_out;
 	}
 	osc_dw0 = *((u32 *) out_obj->buffer.pointer);
 	if (osc_dw0) {
 		if (osc_dw0 & OSC_REQUEST_ERROR)
 			printk(KERN_DEBUG "_OSC request fails\n");
 		if (osc_dw0 & OSC_INVALID_UUID_ERROR)
 			printk(KERN_DEBUG "_OSC invalid UUID\n");
 		if (osc_dw0 & OSC_INVALID_REVISION_ERROR)
 			printk(KERN_DEBUG "_OSC invalid revision\n");
 		if (osc_dw0 & OSC_CAPABILITIES_MASK_ERROR) {
 			printk(KERN_DEBUG "_OSC FW not grant req. control\n");
 			status = AE_SUPPORT;
 			goto run_osc_out;
 		}
 		status = AE_ERROR;
 		goto run_osc_out;
 	}
 	status = AE_OK;

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

 /**
  * __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)
 {
 	u32 temp;
 	acpi_status retval;

 	if (!(flags & OSC_SUPPORT_MASKS)) {
 		return AE_TYPE;
 	}
 	ctrlset_buf[OSC_SUPPORT_TYPE] |= (flags & OSC_SUPPORT_MASKS);

 	/* do _OSC query for all possible controls */
 	temp = ctrlset_buf[OSC_CONTROL_TYPE];
 	ctrlset_buf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
 	ctrlset_buf[OSC_CONTROL_TYPE] = OSC_CONTROL_MASKS;
 	acpi_get_devices(hid,
 			acpi_query_osc,
 			ctrlset_buf,
 			(void **) &retval );
 	ctrlset_buf[OSC_QUERY_TYPE] = !OSC_QUERY_ENABLE;
 	ctrlset_buf[OSC_CONTROL_TYPE] = temp;
 	if (ACPI_FAILURE(retval)) {
 		/* no osc support at all */
 		ctrlset_buf[OSC_SUPPORT_TYPE] = 0;
 	}
 	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;

 	ctrlset = (flags & OSC_CONTROL_MASKS);
 	if (!ctrlset) {
 		return AE_TYPE;
 	}
 	if (ctrlset_buf[OSC_SUPPORT_TYPE] &&
 	 	((global_ctrlsets & ctrlset) != ctrlset)) {
 		return AE_SUPPORT;
 	}
 	ctrlset_buf[OSC_CONTROL_TYPE] |= ctrlset;
 	status = acpi_run_osc(handle, ctrlset_buf);
 	if (ACPI_FAILURE (status)) {
 		ctrlset_buf[OSC_CONTROL_TYPE] &= ~ctrlset;
 	}

 	return status;
 }
 EXPORT_SYMBOL(pci_osc_control_set);

 #ifdef CONFIG_ACPI_SLEEP
 /*
  * _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,
 	pm_message_t state)
 {
 	int acpi_state;

 	acpi_state = acpi_pm_device_sleep_state(&pdev->dev,
 		device_may_wakeup(&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;
 }
 #endif

 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
 	};

 	if (!handle)
 		return -ENODEV;
 	/* If the ACPI device has _EJ0, ignore the device */
 	if (ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp)))
 		return 0;

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


 /* 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->bus_id, "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();
 	}
 	ret = register_acpi_bus_type(&acpi_pci_bus);
 	if (ret)
 		return 0;
 #ifdef	CONFIG_ACPI_SLEEP
 	platform_pci_choose_state = acpi_pci_choose_state;
 #endif
 	platform_pci_set_power_state = acpi_pci_set_power_state;
 	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 <acpi/acpi.h>
	#include <acpi/acnamesp.h>
	#include <acpi/acresrc.h>
	#include <acpi/acpi_bus.h>

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

	static u32 ctrlset_buf[3] = {0, 0, 0};
	static u32 global_ctrlsets = 0;
	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_query_osc (
	acpi_handle handle,
	u32 level,
	void *context,
	void **retval )
	{
	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 osc_dw0;
	acpi_status ret_status = (acpi_status )retval;


	/* 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 *)context;

	status = acpi_evaluate_object(handle, "_OSC", &input, &output);
	if (ACPI_FAILURE (status)) {
	*ret_status = status;
	return status;
	}
	out_obj = output.pointer;

	if (out_obj->type != ACPI_TYPE_BUFFER) {
	printk(KERN_DEBUG
	"Evaluate _OSC returns wrong type\n");
	status = AE_TYPE;
	goto query_osc_out;
	}
	osc_dw0 = ((u32 ) out_obj->buffer.pointer);
	if (osc_dw0) {
	if (osc_dw0 & OSC_REQUEST_ERROR)
	printk(KERN_DEBUG "_OSC request fails\n");
	if (osc_dw0 & OSC_INVALID_UUID_ERROR)
	printk(KERN_DEBUG "_OSC invalid UUID\n");
	if (osc_dw0 & OSC_INVALID_REVISION_ERROR)
	printk(KERN_DEBUG "_OSC invalid revision\n");
	if (osc_dw0 & OSC_CAPABILITIES_MASK_ERROR) {
	/* Update Global Control Set */
	global_ctrlsets = ((u32 )(out_obj->buffer.pointer+8));
	status = AE_OK;
	goto query_osc_out;
	}
	status = AE_ERROR;
	goto query_osc_out;
	}

	/* Update Global Control Set */
	global_ctrlsets = ((u32 )(out_obj->buffer.pointer + 8));
	status = AE_OK;

	query_osc_out:
	kfree(output.pointer);
	*ret_status = status;
	return status;
	}


	static acpi_status
	acpi_run_osc (
	acpi_handle handle,
	void *context)
	{
	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 osc_dw0;

	/* 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 *)context;

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

	out_obj = output.pointer;
	if (out_obj->type != ACPI_TYPE_BUFFER) {
	printk(KERN_DEBUG
	"Evaluate _OSC returns wrong type\n");
	status = AE_TYPE;
	goto run_osc_out;
	}
	osc_dw0 = ((u32 ) out_obj->buffer.pointer);
	if (osc_dw0) {
	if (osc_dw0 & OSC_REQUEST_ERROR)
	printk(KERN_DEBUG "_OSC request fails\n");
	if (osc_dw0 & OSC_INVALID_UUID_ERROR)
	printk(KERN_DEBUG "_OSC invalid UUID\n");
	if (osc_dw0 & OSC_INVALID_REVISION_ERROR)
	printk(KERN_DEBUG "_OSC invalid revision\n");
	if (osc_dw0 & OSC_CAPABILITIES_MASK_ERROR) {
	printk(KERN_DEBUG "_OSC FW not grant req. control\n");
	status = AE_SUPPORT;
	goto run_osc_out;
	}
	status = AE_ERROR;
	goto run_osc_out;
	}
	status = AE_OK;

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

	/**
	* __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)
	{
	u32 temp;
	acpi_status retval;

	if (!(flags & OSC_SUPPORT_MASKS)) {
	return AE_TYPE;
	}
	ctrlset_buf[OSC_SUPPORT_TYPE] \|= (flags & OSC_SUPPORT_MASKS);

	/* do _OSC query for all possible controls */
	temp = ctrlset_buf[OSC_CONTROL_TYPE];
	ctrlset_buf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
	ctrlset_buf[OSC_CONTROL_TYPE] = OSC_CONTROL_MASKS;
	acpi_get_devices(hid,
	acpi_query_osc,
	ctrlset_buf,
	(void **) &retval );
	ctrlset_buf[OSC_QUERY_TYPE] = !OSC_QUERY_ENABLE;
	ctrlset_buf[OSC_CONTROL_TYPE] = temp;
	if (ACPI_FAILURE(retval)) {
	/* no osc support at all */
	ctrlset_buf[OSC_SUPPORT_TYPE] = 0;
	}
	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;

	ctrlset = (flags & OSC_CONTROL_MASKS);
	if (!ctrlset) {
	return AE_TYPE;
	}
	if (ctrlset_buf[OSC_SUPPORT_TYPE] &&
	((global_ctrlsets & ctrlset) != ctrlset)) {
	return AE_SUPPORT;
	}
	ctrlset_buf[OSC_CONTROL_TYPE] \|= ctrlset;
	status = acpi_run_osc(handle, ctrlset_buf);
	if (ACPI_FAILURE (status)) {
	ctrlset_buf[OSC_CONTROL_TYPE] &= ~ctrlset;
	}

	return status;
	}
	EXPORT_SYMBOL(pci_osc_control_set);

	#ifdef CONFIG_ACPI_SLEEP
	/*
	* _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,
	pm_message_t state)
	{
	int acpi_state;

	acpi_state = acpi_pm_device_sleep_state(&pdev->dev,
	device_may_wakeup(&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;
	}
	#endif

	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
	};

	if (!handle)
	return -ENODEV;
	/* If the ACPI device has _EJ0, ignore the device */
	if (ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp)))
	return 0;

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


	/* 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->bus_id, "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();
	}
	ret = register_acpi_bus_type(&acpi_pci_bus);
	if (ret)
	return 0;
	#ifdef CONFIG_ACPI_SLEEP
	platform_pci_choose_state = acpi_pci_choose_state;
	#endif
	platform_pci_set_power_state = acpi_pci_set_power_state;
	return 0;
	}
	arch_initcall(acpi_pci_init);