reactos/reactos/drivers/bus/acpi/cmbatt/cmbatt.c

/*
 * PROJECT:         ReactOS ACPI-Compliant Control Method Battery
 * LICENSE:         BSD - See COPYING.ARM in the top level directory
 * FILE:            boot/drivers/bus/acpi/cmbatt/cmbatt.c
 * PURPOSE:         Main Initialization Code and IRP Handling
 * PROGRAMMERS:     ReactOS Portable Systems Group
 */

/* INCLUDES *******************************************************************/

#include "cmbatt.h"

/* GLOBALS ********************************************************************/

ULONG CmBattDebug;
PCALLBACK_OBJECT CmBattPowerCallBackObject;
PVOID CmBattPowerCallBackRegistration;
UNICODE_STRING GlobalRegistryPath;
KTIMER CmBattWakeDpcTimerObject;
KDPC CmBattWakeDpcObject;
PDEVICE_OBJECT AcAdapterPdo;
 
/* FUNCTIONS ******************************************************************/

VOID
NTAPI
CmBattPowerCallBack(PCMBATT_DEVICE_EXTENSION DeviceExtension,
                    PVOID Argument1,
                    PVOID Argument2)
{
    UNIMPLEMENTED;
}

VOID
NTAPI
CmBattWakeDpc(PKDPC Dpc,
              PCMBATT_DEVICE_EXTENSION FdoExtension,
              PVOID SystemArgument1,
              PVOID SystemArgument2)
{

}

VOID
NTAPI
CmBattNotifyHandler(IN PCMBATT_DEVICE_EXTENSION DeviceExtension,
                    IN ULONG NotifyValue)
{
    ULONG ArFlag;
    PCMBATT_DEVICE_EXTENSION FdoExtension;
    PDEVICE_OBJECT DeviceObject;
    
    if (CmBattDebug & (CMBATT_ACPI_ASSERT | CMBATT_PNP_INFO))
        DbgPrint("CmBattNotifyHandler: CmBatt 0x%08x Type %d Number %d Notify Value: %x\n",
                 DeviceExtension,
                 DeviceExtension->FdoType,
                 DeviceExtension->DeviceId,
                 NotifyValue);
    
    /* Check what kind of notification was received */
    switch (NotifyValue)
    {
        /* ACPI Specification says is sends a "Bus Check" when power source changes */
        case ACPI_BUS_CHECK:
        
            /* We treat it as possible physical change */
            DeviceExtension->ArFlag |= (CMBATT_AR_NOTIFY | CMBATT_AR_INSERT);
            if ((DeviceExtension->Tag) &&
                (CmBattDebug & (CMBATT_ACPI_WARNING | CMBATT_GENERIC_WARNING)))
                DbgPrint("CmBattNotifyHandler: Received battery #%x insertion, but tag was not invalid.\n",
                         DeviceExtension->DeviceId);
            break;
        
        /* Status of the battery has changed */
        case ACPI_BATT_NOTIFY_STATUS:
        
            /* All we'll do is notify the class driver */
            DeviceExtension->ArFlag |= CMBATT_AR_NOTIFY;
            break;
        
        /* Information on the battery has changed, such as physical presence */
        case ACPI_DEVICE_CHECK:
        case ACPI_BATT_NOTIFY_INFO:
        
            /* Reset all state and let the class driver re-evaluate it all */
            DeviceExtension->ArFlag |= (CMBATT_AR_NOTIFY |
                                        CMBATT_AR_INSERT |
                                        CMBATT_AR_REMOVE);
            break;
            
        default:
        
            if (CmBattDebug & CMBATT_PNP_INFO)
                DbgPrint("CmBattNotifyHandler: Unknown Notify Value: %x\n", NotifyValue);
    }

    /* Check if we're supposed to delay the notification till later */
    if (DeviceExtension->DelayNotification)
    {
        /* We'll handle this when we get a status query later on */
        if (CmBattDebug & CMBATT_PNP_INFO)
            DbgPrint("CmBattNotifyHandler: Notification delayed: ARs = %01x\n",
                      DeviceExtension->ArFlag);
        return;
    }

    /* We're going to handle this now */
    if (CmBattDebug & CMBATT_PNP_INFO) 
        DbgPrint("CmBattNotifyHandler: Performing ARs: %01x\n", DeviceExtension->ArFlag);

    /* Check if this is a battery or AC adapter notification */
    if (DeviceExtension->FdoType == CmBattBattery)
    {
        /* Reset the current trip point */
        DeviceExtension->TripPointValue = 0xFFFFFFFF;
        
        /* Check what ARs have to be done */
        ArFlag = DeviceExtension->ArFlag;
        
        /* New battery inserted, reset lock value */
        if (ArFlag & CMBATT_AR_INSERT) InterlockedExchange(&DeviceExtension->ArLockValue, 0);

        /* Check if the battery may have been removed */
        if (ArFlag & CMBATT_AR_REMOVE) DeviceExtension->Tag = 0;
        
        /* Check if there's been any sort of change to the battery */
        if (ArFlag & CMBATT_AR_NOTIFY)
        {
            /* We'll probably end up re-evaluating _BIF and _BST */
            DeviceExtension->NotifySent = TRUE;
            BatteryClassStatusNotify(DeviceExtension->ClassData);
        }
    }
    else
    {
        /* The only known notification is AC/DC change */
        if (DeviceExtension->ArFlag & CMBATT_AR_NOTIFY)
        {
            for (DeviceObject = DeviceExtension->FdoDeviceObject->DriverObject->DeviceObject;
                 DeviceObject;
                 DeviceObject = DeviceObject->NextDevice)
            {
                /* Is this a battery? */
                FdoExtension = DeviceObject->DeviceExtension;
                if (FdoExtension->FdoType == CmBattBattery)
                {
                    /* Send a notification to the class driver */
                    FdoExtension->NotifySent = TRUE;
                    BatteryClassStatusNotify(FdoExtension->ClassData);
                }
            }
        }
    }
    
    /* ARs have been processed */
    DeviceExtension->ArFlag = 0;
}

VOID
NTAPI
CmBattUnload(IN PDRIVER_OBJECT DriverObject)
{
    if (CmBattDebug & CMBATT_GENERIC_INFO) DPRINT("CmBattUnload: \n");
    
    /* Check if we have a registered power callback */
    if (CmBattPowerCallBackObject)
    {
        /* Get rid of it */
        ExUnregisterCallback(CmBattPowerCallBackRegistration);
        ObfDereferenceObject(CmBattPowerCallBackObject);
    }
    
    /* Free the registry buffer if it exists */
    if (GlobalRegistryPath.Buffer) ExFreePool(GlobalRegistryPath.Buffer);

    /* Make sure we don't still have references to the DO */
    if ((DriverObject->DeviceObject) && (CmBattDebug & CMBATT_GENERIC_WARNING))
    {
        DbgPrint("Unload called before all devices removed.\n");
    }
}

NTSTATUS
NTAPI
CmBattVerifyStaticInfo(PCMBATT_DEVICE_EXTENSION DeviceExtension,
                       ULONG BatteryTag)
{
    UNIMPLEMENTED;
    return STATUS_NOT_IMPLEMENTED;   
}

NTSTATUS
NTAPI
CmBattOpenClose(IN PDEVICE_OBJECT DeviceObject,
                IN PIRP Irp)
{
    NTSTATUS Status = STATUS_SUCCESS;
    PIO_STACK_LOCATION IoStackLocation;
    UCHAR Major;
    ULONG Count;
    PCMBATT_DEVICE_EXTENSION DeviceExtension;
    PAGED_CODE();
    if (CmBattDebug & CMBATT_GENERIC_INFO) DPRINT("CmBattOpenClose\n");

    /* Grab the device extension and lock it */
    DeviceExtension = DeviceObject->DeviceExtension;
    ExAcquireFastMutex(&DeviceExtension->FastMutex);
    
    /* Check if someone is trying to open a device that doesn't exist yet */
    Count = DeviceExtension->HandleCount;
    if (Count == 0xFFFFFFFF)
    {
        /* Fail the request */
        Status = STATUS_NO_SUCH_DEVICE;
        if (CmBattDebug & CMBATT_PNP_INFO)
        {
            DbgPrint("CmBattOpenClose: Failed (UID = %x)(device being removed).\n",
                     DeviceExtension->Tag);
        }
        goto Complete;
    }
    
    /* Check if this is an open or close */
    IoStackLocation = IoGetCurrentIrpStackLocation(Irp);
    Major = IoStackLocation->MajorFunction;
    if (Major == IRP_MJ_CREATE)
    {
        /* Increment the open count */
        DeviceExtension->HandleCount = Count + 1;  
        if (CmBattDebug & CMBATT_PNP_INFO)
        {
            DbgPrint("CmBattOpenClose: Open (DeviceNumber = %x)(count = %x).\n",
                     DeviceExtension->DeviceId, Count + 1);
        }
    }
    else if (Major == IRP_MJ_CLOSE)
    {
        /* Decrement the open count */
        DeviceExtension->HandleCount = Count - 1;
        if (CmBattDebug & CMBATT_PNP_INFO)
        {
            DbgPrint("CmBattOpenClose: Close (DeviceNumber = %x)(count = %x).\n",
                     DeviceExtension->DeviceId, Count + 1);
        }
    }

Complete:
    /* Release lock and complete request */
    ExReleaseFastMutex(&DeviceExtension->FastMutex);
    Irp->IoStatus.Status = Status;
    IofCompleteRequest(Irp, IO_NO_INCREMENT);
    return Status;  
}

NTSTATUS
NTAPI
CmBattIoctl(PDEVICE_OBJECT DeviceObject,
            PIRP Irp)
{
    UNIMPLEMENTED;
    return STATUS_NOT_IMPLEMENTED;
}

NTSTATUS
NTAPI
CmBattQueryTag(IN PCMBATT_DEVICE_EXTENSION DeviceExtension,
               OUT PULONG Tag)
{
    PDEVICE_OBJECT PdoDevice;
    ULONG StaData;
    ULONG NewTag;
    NTSTATUS Status;
    PAGED_CODE();
    if (CmBattDebug & (CMBATT_ACPI_WARNING | CMBATT_GENERIC_INFO))
      DbgPrint("CmBattQueryTag - Tag (%d), Battery %x, Device %d\n",
                *Tag, DeviceExtension, DeviceExtension->DeviceId);
    
    /* Get PDO and clear notification flag */  
    PdoDevice = DeviceExtension->PdoDeviceObject;
    DeviceExtension->NotifySent = 0;
    
    /* Get _STA from PDO (we need the machine status, not the battery status) */
    Status = CmBattGetStaData(PdoDevice, &StaData);
    if (NT_SUCCESS(Status))
    {
        /* Is a battery present? */
        if (StaData & ACPI_STA_BATTERY_PRESENT)
        {
            /* Do we not have a tag yet? */
            if (!DeviceExtension->Tag)
            {
                /* Set the new tag value, reset tags if we reached the maximum */
                NewTag = DeviceExtension->TagData;
                if (DeviceExtension->TagData++ == 0xFFFFFFFF) NewTag = 1;
                DeviceExtension->Tag = NewTag;
                if (CmBattDebug & CMBATT_GENERIC_INFO)
                    DbgPrint("CmBattQueryTag - New Tag: (%d)\n", DeviceExtension->Tag);
                
                /* Reset trip point data */
                DeviceExtension->TripPointOld = 0;
                DeviceExtension->TripPointValue = 0xFFFFFFFF;
                                
                /* Clear AR lock and set new interrupt time */
                InterlockedExchange(&DeviceExtension->ArLockValue, 0);
                DeviceExtension->InterruptTime = KeQueryInterruptTime();
            }
        }
        else
        {
            /* No battery, so no tag */
            DeviceExtension->Tag = 0;
            Status = STATUS_NO_SUCH_DEVICE;
        }
    }
    
    /* Return the tag and status result */
    *Tag = DeviceExtension->Tag;
    if (CmBattDebug & CMBATT_ACPI_WARNING)
      DbgPrint("CmBattQueryTag: Returning Tag: 0x%x, status 0x%x\n", *Tag, Status);
    return Status;
}

NTSTATUS
NTAPI
CmBattDisableStatusNotify(PCMBATT_DEVICE_EXTENSION DeviceExtension)
{
    UNIMPLEMENTED;
    return STATUS_NOT_IMPLEMENTED;
}

NTSTATUS
NTAPI
CmBattSetStatusNotify(PCMBATT_DEVICE_EXTENSION DeviceExtension,
                      ULONG BatteryTag,
                      PBATTERY_NOTIFY BatteryNotify)
{
    UNIMPLEMENTED;
    return STATUS_NOT_IMPLEMENTED;
}

NTSTATUS
NTAPI
CmBattGetBatteryStatus(IN PCMBATT_DEVICE_EXTENSION DeviceExtension,
                       IN ULONG Tag)
{
    ULONG PsrData = 0;
    NTSTATUS Status;
    ULONG BstState;
    ULONG DesignVoltage, PresentRate, RemainingCapacity;
    PAGED_CODE();
    if (CmBattDebug & CMBATT_GENERIC_INFO)
        DbgPrint("CmBattGetBatteryStatus - CmBatt (%08x) Tag (%d)\n", DeviceExtension, Tag);
    
    /* Validate ACPI data */    
    Status = CmBattVerifyStaticInfo(DeviceExtension, Tag);
    if (!NT_SUCCESS(Status)) return Status;

    /* Check for delayed status notifications */
    if (DeviceExtension->DelayNotification)
    {
        /* Process them now and don't do any other work */
        CmBattNotifyHandler(DeviceExtension, ACPI_BATT_NOTIFY_STATUS);
        return Status;
    }

    /* Get _BST from ACPI */
    Status = CmBattGetBstData(DeviceExtension, &DeviceExtension->BstData);
    if (!NT_SUCCESS(Status))
    {
        /* Fail */
        InterlockedExchange(&DeviceExtension->ArLockValue, 0);
        return Status;
    }
    
    /* Clear current BST information */ 
    DeviceExtension->State = 0;
    DeviceExtension->RemainingCapacity = 0;
    DeviceExtension->PresentVoltage = 0;
    DeviceExtension->Rate = 0;

    /* Get battery state */
    BstState = DeviceExtension->BstData.State;
    
    /* Is the battery both charging and discharging? */
    if ((BstState & ACPI_BATT_STAT_DISCHARG) && (BstState & ACPI_BATT_STAT_CHARGING) &&
        (CmBattDebug & (CMBATT_ACPI_WARNING | CMBATT_GENERIC_WARNING)))
            DbgPrint("************************ ACPI BIOS BUG ********************\n* "
                     "CmBattGetBatteryStatus: Invalid state: _BST method returned 0x%08x for Battery State.\n"
                     "* One battery cannot be charging and discharging at the same time.\n",
                     BstState);
    
    /* Is the battery discharging? */   
    if (BstState & ACPI_BATT_STAT_DISCHARG)
    {
        /* Set power state and check if it just started discharging now */
        DeviceExtension->State |= BATTERY_DISCHARGING;
        if (!(DeviceExtension->State & ACPI_BATT_STAT_DISCHARG))
        {
            /* Remember the time when the state changed */
            DeviceExtension->InterruptTime = KeQueryInterruptTime();
        }
    }
    else if (BstState & ACPI_BATT_STAT_CHARGING)
    {
        /* Battery is charging, update power state */
        DeviceExtension->State |= (BATTERY_CHARGING | BATTERY_POWER_ON_LINE);
    }
    
    /* Is the battery in a critical state? */
    if (BstState & ACPI_BATT_STAT_CRITICAL) DeviceExtension->State |= BATTERY_CRITICAL;
    
    /* Read the voltage data */  
    DeviceExtension->PresentVoltage = DeviceExtension->BstData.PresentVoltage;
    
    /* Check if we have an A/C adapter */
    if (AcAdapterPdo)
    {
        /* Query information on it */
        CmBattGetPsrData(AcAdapterPdo, &PsrData);
    }
    else
    {
        /* Otherwise, check if the battery is charging */
        if (BstState & ACPI_BATT_STAT_CHARGING)
        {
            /* Then we'll assume there's a charger */
            PsrData = 1;
        }
        else
        {
            /* Assume no charger */
            PsrData = 0;        
        }
    }
    
    /* Is there a charger? */
    if (PsrData)
    {
        /* Set the power state flag to reflect this */
        DeviceExtension->State |= BATTERY_POWER_ON_LINE;
        if (CmBattDebug & (CMBATT_GENERIC_INFO | CMBATT_GENERIC_STATUS))
            DbgPrint("CmBattGetBatteryStatus: AC adapter is connected\n");
    }
    else if (CmBattDebug & (CMBATT_GENERIC_INFO | CMBATT_GENERIC_STATUS))
    {
        DbgPrint("CmBattGetBatteryStatus: AC adapter is NOT connected\n");        
    }
    
    /* Get some data we'll need */
    DesignVoltage = DeviceExtension->BifData.DesignVoltage;
    PresentRate = DeviceExtension->BstData.PresentRate;
    RemainingCapacity = DeviceExtension->BstData.RemainingCapacity;
    
    /* Check if we have battery data in Watts instead of Amps */
    if (DeviceExtension->BifData.PowerUnit == ACPI_BATT_POWER_UNIT_WATTS)
    {
        /* Get the data from the BST */
        DeviceExtension->RemainingCapacity = RemainingCapacity;
        DeviceExtension->Rate = PresentRate;
        
        /* Check if the rate is invalid */
        if (PresentRate > CM_MAX_VALUE)
        {
            /* Set an unknown rate and don't touch the old value */
            DeviceExtension->Rate = BATTERY_UNKNOWN_RATE;
            if ((PresentRate != CM_UNKNOWN_VALUE) && (CmBattDebug & CMBATT_ACPI_WARNING))
            {
                DbgPrint("CmBattGetBatteryStatus - Rate is greater than CM_MAX_VALUE\n");
                DbgPrint("----------------------   PresentRate = 0x%08x\n", PresentRate);
            }
        }
    }
    else if ((DesignVoltage != CM_UNKNOWN_VALUE) && (DesignVoltage))
    {
        /* We have voltage data, what about capacity? */
        if (RemainingCapacity == CM_UNKNOWN_VALUE)
        {
            /* Unable to calculate it */
            DeviceExtension->RemainingCapacity = BATTERY_UNKNOWN_CAPACITY;
            if (CmBattDebug & CMBATT_ACPI_WARNING)
            {
                DbgPrint("CmBattGetBatteryStatus - Can't calculate RemainingCapacity \n");
                DbgPrint("----------------------   RemainingCapacity = CM_UNKNOWN_VALUE\n");
            }
        }
        else
        {
            /* Compute the capacity with the information we have */
            DeviceExtension->RemainingCapacity = (DesignVoltage * RemainingCapacity + 500) / 1000;
        }
        
        /* Check if we have a rate */
        if (PresentRate != CM_UNKNOWN_VALUE)
        {
            /* Make sure the rate isn't too large */
            if (PresentRate > (-500 / DesignVoltage))
            {
                /* It is, so set unknown state */
                DeviceExtension->Rate = BATTERY_UNKNOWN_RATE;
                if (CmBattDebug & CMBATT_ACPI_WARNING)
                {
                    DbgPrint("CmBattGetBatteryStatus - Can't calculate Rate \n");
                    DbgPrint("----------------------   Overflow: PresentRate = 0x%08x\n", PresentRate);
                }
            }
            
            /* Compute the rate */
            DeviceExtension->Rate = (PresentRate * DesignVoltage + 500) / 1000;
        }
        else
        {
            /* We don't have a rate, so set unknown value */
            DeviceExtension->Rate = BATTERY_UNKNOWN_RATE;        
            if (CmBattDebug & CMBATT_ACPI_WARNING)
            {
                DbgPrint("CmBattGetBatteryStatus - Can't calculate Rate \n");
                DbgPrint("----------------------   Present Rate = CM_UNKNOWN_VALUE\n");
            }
        }
    }
    else
    {
        /* We have no rate, and no capacity, set unknown values */
        DeviceExtension->Rate = BATTERY_UNKNOWN_RATE;
        DeviceExtension->RemainingCapacity = BATTERY_UNKNOWN_CAPACITY;
        if (CmBattDebug & CMBATT_ACPI_WARNING)
        {
            DbgPrint("CmBattGetBatteryStatus - Can't calculate RemainingCapacity and Rate \n");
            DbgPrint("----------------------   DesignVoltage = 0x%08x\n", DesignVoltage);
        }
    }
    
    /* Check if we have an unknown rate */
    if (DeviceExtension->Rate == BATTERY_UNKNOWN_RATE)
    {
        /* The battery is discharging but we don't know by how much... this is bad! */
        if ((BstState & ACPI_BATT_STAT_DISCHARG) &&
            (CmBattDebug & (CMBATT_ACPI_WARNING | CMBATT_GENERIC_WARNING)))
            DbgPrint("CmBattGetBatteryStatus: battery rate is unkown when battery is not charging!\n");
    }
    else if (DeviceExtension->State & BATTERY_DISCHARGING)
    {
        /* The battery is discharging, so treat the rate as a negative rate */
        DeviceExtension->Rate = -DeviceExtension->Rate;
    }
    else if (!(DeviceExtension->State & BATTERY_CHARGING) && (DeviceExtension->Rate))
    {
        /* We are not charging, not discharging, but have a rate? Ignore it! */
        if (CmBattDebug & CMBATT_GENERIC_WARNING)
            DbgPrint("CmBattGetBatteryStatus: battery is not charging or discharging, but rate = %x\n",
                     DeviceExtension->Rate);
        DeviceExtension->Rate = 0;
    }
     
    /* Done */
    return STATUS_SUCCESS;
}

NTSTATUS
NTAPI
CmBattQueryInformation(IN PCMBATT_DEVICE_EXTENSION FdoExtension,
                       IN ULONG Tag,
                       IN BATTERY_QUERY_INFORMATION_LEVEL InfoLevel,
                       IN OPTIONAL LONG AtRate,
                       IN PVOID Buffer,
                       IN ULONG BufferLength,
                       OUT PULONG ReturnedLength)
{
    NTSTATUS Status;
    PVOID QueryData = NULL;
    ULONG QueryLength = 0;
    ULONG RemainingTime = 0;
    ANSI_STRING TempString;
    UNICODE_STRING TempString2;
    WCHAR InfoBuffer[256];
    WCHAR TempBuffer[256];
    UNICODE_STRING InfoString;
    ULONG RemainingCapacity;
    BATTERY_REPORTING_SCALE BatteryReportingScale[2];
    LONG Rate;
    PAGED_CODE();
    if (CmBattDebug & (CMBATT_ACPI_WARNING | CMBATT_GENERIC_INFO))
        DbgPrint("CmBattQueryInformation - Tag (%d) Device %d, Informationlevel %d\n",
                 Tag,
                 FdoExtension->DeviceId,
                 InfoLevel);

    /* Check ACPI Data */
    Status = CmBattVerifyStaticInfo(FdoExtension, Tag);
    if (!NT_SUCCESS(Status)) return Status;

    /* Check what caller wants */
    switch (InfoLevel)
    {
        case BatteryInformation:
            /* Just return our static information */
            QueryData = &FdoExtension->BatteryInformation;
            QueryLength = sizeof(BATTERY_INFORMATION);
            break;
        
        case BatteryGranularityInformation:
        
            /* Return our static information, we have two scales */
            BatteryReportingScale[0].Granularity = FdoExtension->BatteryCapacityGranularity1;
            BatteryReportingScale[0].Capacity = FdoExtension->BatteryInformation.DefaultAlert1;
            BatteryReportingScale[1].Granularity = FdoExtension->BatteryCapacityGranularity2;
            BatteryReportingScale[1].Capacity = FdoExtension->BatteryInformation.DesignedCapacity;
            QueryData = BatteryReportingScale;
            QueryLength = sizeof(BATTERY_REPORTING_SCALE) * 2;
            break;
            
        case BatteryEstimatedTime:
        
            /* Check if it's been more than 2 1/2 minutes since the last change */
            if ((KeQueryInterruptTime() - 150000000) > (FdoExtension->InterruptTime))
            {
                /* Get new battery status */
                CmBattGetBatteryStatus(FdoExtension, FdoExtension->Tag);
                
                /* If the caller didn't specify a rate, use our static one */
                Rate = AtRate;
                if (!Rate) Rate = FdoExtension->Rate;
                
                /* If we don't have a valid negative rate, use unknown value */
                if (Rate >= 0) Rate = BATTERY_UNKNOWN_RATE;
                
                /* Grab the remaining capacity */
                RemainingCapacity = FdoExtension->RemainingCapacity;
                
                /* See if we don't know one or the other */
                if ((Rate == BATTERY_UNKNOWN_RATE) ||
                    (RemainingCapacity == BATTERY_UNKNOWN_CAPACITY))
                {
                    /* If the battery is discharging, we can't give out a time */
                    if ((FdoExtension->BstData.State & ACPI_BATT_STAT_DISCHARG) &&
                        (CmBattDebug & CMBATT_GENERIC_WARNING))
                            DbgPrint("CmBattQueryInformation: Can't calculate EstimatedTime.\n");
                    
                    /* Check if we don't have a rate and capacity is going down */
                    if ((FdoExtension->Rate == BATTERY_UNKNOWN_RATE) &&
                        (FdoExtension->BstData.State & ACPI_BATT_STAT_DISCHARG))
                    {
                        /* We have to fail, since we lack data */
                        Status = STATUS_INVALID_DEVICE_REQUEST;
                        if (CmBattDebug & CMBATT_GENERIC_WARNING)
                            DbgPrint("----------------------   PresentRate = BATTERY_UNKNOWN_RATE\n");
                    }
                    
                    /* If we don't have capacity, the rate is useless */
                    if (RemainingCapacity == BATTERY_UNKNOWN_CAPACITY)
                    {
                        /* We have to fail the request */
                        Status = STATUS_INVALID_DEVICE_REQUEST;
                        if (CmBattDebug & CMBATT_GENERIC_WARNING)
                            DbgPrint("----------------------   RemainingCapacity = BATTERY_UNKNOWN_CAPACITY\n");
                    }
                }
                else
                {
                    /* We have data, but is it valid? */
                    if (RemainingCapacity > 0x123456)
                    {
                        /* The capacity seems bogus, so don't use it */
                        if (CmBattDebug & CMBATT_ACPI_WARNING)
                            DbgPrint("CmBattQueryInformation: Data Overflow in calculating Remaining Capacity.\n");
                    }
                    else
                    {
                        /* Compute the remaining time in seconds, based on rate */
                        RemainingTime = (RemainingCapacity * 3600) / -Rate;
                    }
                }
            }
            
            /* Return the remaining time */
            QueryData = &RemainingTime;
            QueryLength = sizeof(ULONG);
            break;
            
        case BatteryDeviceName:
        
            /* Build the model number string */
            RtlInitAnsiString(&TempString, FdoExtension->ModelNumber);

            /* Convert it to Unicode */
            InfoString.Buffer = InfoBuffer;
            InfoString.MaximumLength = sizeof(InfoBuffer);            
            Status = RtlAnsiStringToUnicodeString(&InfoString, &TempString, 0);
            
            /* Return the unicode buffer */
            QueryData = InfoString.Buffer;
            QueryLength = InfoString.Length;
            break;
            
        case BatteryTemperature:
        case BatteryManufactureDate:
        
            /* We don't support these */
            Status = STATUS_INVALID_DEVICE_REQUEST;
            break;
            
        case BatteryManufactureName:
            
            /* Build the OEM info string */
            RtlInitAnsiString(&TempString, FdoExtension->OemInfo);
            
            /* Convert it to Unicode */
            InfoString.Buffer = InfoBuffer;
            InfoString.MaximumLength = sizeof(InfoBuffer);
            Status = RtlAnsiStringToUnicodeString(&InfoString, &TempString, 0);
            
            /* Return the unicode buffer */
            QueryData = InfoString.Buffer;
            QueryLength = InfoString.Length;
            break;
            
        case BatteryUniqueID:

            /* Build the serial number string */
            RtlInitAnsiString(&TempString, FdoExtension->SerialNumber);

            /* Convert it to Unicode */
            InfoString.Buffer = InfoBuffer;
            InfoString.MaximumLength = sizeof(InfoBuffer);
            RtlAnsiStringToUnicodeString(&InfoString, &TempString, 0);

            /* Setup a temporary string for concatenation */
            TempString2.Buffer = TempBuffer;
            TempString2.MaximumLength = sizeof(TempBuffer);
            
            /* Check if there's an OEM string */
            if (FdoExtension->OemInfo[0])
            {
                /* Build the OEM info string */
                RtlInitAnsiString(&TempString, FdoExtension->OemInfo);
              
                /* Convert it to Unicode and append it */
                RtlAnsiStringToUnicodeString(&TempString2, &TempString, 0);
                RtlAppendUnicodeStringToString(&InfoString, &TempString2);
            }
            
            /* Build the model number string */
            RtlInitAnsiString(&TempString, FdoExtension->ModelNumber);
            
            /* Convert it to Unicode and append it */
            RtlAnsiStringToUnicodeString(&TempString2, &TempString, 0);
            RtlAppendUnicodeStringToString(&InfoString, &TempString2);
            
            /* Return the final appended string */
            QueryData = InfoString.Buffer;
            QueryLength = InfoString.Length;
            break;
            
        default:
        
            /* Everything else is unknown */
            Status = STATUS_INVALID_PARAMETER;
            break;
    }

    /* Return the required length and check if the caller supplied enough */
    *ReturnedLength = QueryLength;
    if (BufferLength < QueryLength) Status = STATUS_BUFFER_TOO_SMALL;

    /* Copy the data if there's enough space and it exists */
    if ((NT_SUCCESS(Status)) && (QueryData)) RtlCopyMemory(Buffer, QueryData, QueryLength);
      
    /* Return function result */
    return Status;
}

NTSTATUS
NTAPI
CmBattQueryStatus(IN PCMBATT_DEVICE_EXTENSION DeviceExtension,
                  IN ULONG Tag,
                  IN PBATTERY_STATUS BatteryStatus)
{
    NTSTATUS Status;
    PAGED_CODE();
    if (CmBattDebug & (CMBATT_ACPI_WARNING | CMBATT_GENERIC_INFO))
        DbgPrint("CmBattQueryStatus - Tag (%d) Device %x\n", Tag, DeviceExtension->DeviceId);
    
    /* Query ACPI information */
    Status = CmBattGetBatteryStatus(DeviceExtension, Tag);
    if (NT_SUCCESS(Status))
    {
        BatteryStatus->PowerState = DeviceExtension->State;
        BatteryStatus->Capacity = DeviceExtension->RemainingCapacity;
        BatteryStatus->Voltage = DeviceExtension->PresentVoltage;
        BatteryStatus->Rate = DeviceExtension->Rate;
    }
    
    /* Return status */
    if (CmBattDebug & (CMBATT_GENERIC_INFO))
        DbgPrint("CmBattQueryStatus: Returning [%#08lx][%#08lx][%#08lx][%#08lx]\n",
                 BatteryStatus->PowerState,
                 BatteryStatus->Capacity,
                 BatteryStatus->Voltage,
                 BatteryStatus->Rate);
    return Status;
}

NTSTATUS
NTAPI
DriverEntry(IN PDRIVER_OBJECT DriverObject,
            IN PUNICODE_STRING RegistryPath)
{
    NTSTATUS Status;
    PDRIVER_EXTENSION DriverExtension;
    OBJECT_ATTRIBUTES ObjectAttributes;
    UNICODE_STRING CallbackName;

    /* Allocate registry path */
    GlobalRegistryPath.MaximumLength = RegistryPath->Length + sizeof(UNICODE_NULL);
    GlobalRegistryPath.Length = RegistryPath->Length;
    GlobalRegistryPath.Buffer = ExAllocatePoolWithTag(PagedPool,
                                                      GlobalRegistryPath.MaximumLength,
                                                      'MtaB');
    if (!GlobalRegistryPath.Buffer)
    {
        /* Fail if we're out of memory this early */
        if (CmBattDebug & CMBATT_GENERIC_WARNING)
            DbgPrint("CmBatt: Couldn't allocate pool for registry path.");
        return STATUS_INSUFFICIENT_RESOURCES;
    }
    
    /* Buffer allocated, copy the string */
    RtlCopyUnicodeString(&GlobalRegistryPath, RegistryPath);
    if (CmBattDebug & CMBATT_GENERIC_INFO)
        DbgPrint("CmBatt DriverEntry - Obj (%08x) Path \"%ws\"\n",
                 DriverObject,
                 RegistryPath->Buffer);
    
    /* Setup the major dispatchers */
    DriverObject->MajorFunction[0] = CmBattOpenClose;
    DriverObject->MajorFunction[2] = CmBattOpenClose;
    DriverObject->MajorFunction[14] = CmBattIoctl;
    DriverObject->MajorFunction[22] = CmBattPowerDispatch;
    DriverObject->MajorFunction[27] = CmBattPnpDispatch;
    DriverObject->MajorFunction[23] = CmBattSystemControl;

    /* And the unload routine */
    DriverObject->DriverUnload = CmBattUnload;
    
    /* And the add device routine */
    DriverExtension = DriverObject->DriverExtension;
    DriverExtension->AddDevice = CmBattAddDevice;

    /* Create a power callback */    
    RtlInitUnicodeString(&CallbackName, L"\\Callback\\PowerState");
    InitializeObjectAttributes(&ObjectAttributes,
                               &CallbackName,
                               OBJ_KERNEL_HANDLE,
                               NULL,
                               NULL);
    Status = ExCreateCallback(&CmBattPowerCallBackObject, &ObjectAttributes, 0, TRUE);
    if (!NT_SUCCESS(Status))
    {
        /* No callback, fail */
        CmBattPowerCallBackObject = 0;
        if (CmBattDebug & CMBATT_GENERIC_WARNING)
            DbgPrint("CmBattRegisterPowerCallBack: failed status=0x%08x\n", Status);
    }
    else
    {
        /* Register the power callback now */
        CmBattPowerCallBackRegistration = ExRegisterCallback(CmBattPowerCallBackObject,
                                                             (PVOID)CmBattPowerCallBack,
                                                             DriverObject);
        if (CmBattPowerCallBackRegistration)
        {
            /* Last thing: setup our DPC and timer for battery wake */
            KeInitializeDpc(&CmBattWakeDpcObject, (PVOID)CmBattWakeDpc, DriverObject);
            KeInitializeTimer(&CmBattWakeDpcTimerObject);
        }
        else
        {
            ObfDereferenceObject(CmBattPowerCallBackObject);
            if (CmBattDebug & CMBATT_GENERIC_WARNING)
                DbgPrint("CmBattRegisterPowerCallBack: ExRegisterCallback failed.\n");
        }
        
        /* All good */
        Status = STATUS_SUCCESS;
    }

    /* Return failure or success */
    return Status;
}

/* EOF */