//
// Driver.c - Chapter 9 - Minimal PnP Parallel Port Driver
//
// Copyright (C) 2000 by Jerry Lozano
//

#include "Driver.h"

// Forward declarations
//
NTSTATUS AddDevice (
			IN PDRIVER_OBJECT pDriverObject,
			IN PDEVICE_OBJECT pdo	);

NTSTATUS DispPnp(	IN PDEVICE_OBJECT pDO,
					IN PIRP pIrp );

NTSTATUS PassDownPnP( IN PDEVICE_OBJECT pDO,
					IN PIRP pIrp );

NTSTATUS HandleStartDevice(	IN PDEVICE_OBJECT pDO,
							IN PIRP pIrp );
NTSTATUS HandleStopDevice(	IN PDEVICE_OBJECT pDO,
							IN PIRP pIrp );

NTSTATUS HandleRemoveDevice(IN PDEVICE_OBJECT pDO,
							IN PIRP pIrp );

static VOID DriverUnload (
		IN PDRIVER_OBJECT	pDriverObject	);

static NTSTATUS DispatchCreate (
		IN PDEVICE_OBJECT	pDevObj,
		IN PIRP				pIrp			);

static NTSTATUS DispatchClose (
		IN PDEVICE_OBJECT	pDevObj,
		IN PIRP				pIrp			);

static NTSTATUS DispatchWrite (
		IN PDEVICE_OBJECT	pDevObj,
		IN PIRP				pIrp			);

static NTSTATUS DispatchRead (
		IN PDEVICE_OBJECT	pDevObj,
		IN PIRP				pIrp			);

BOOLEAN Isr (
			IN PKINTERRUPT pIntObj,
			IN PVOID pServiceContext		);

static BOOLEAN TransmitByte( 
		IN PVOID pArg );

VOID StartIo(
	IN PDEVICE_OBJECT pDevObj,
	IN PIRP pIrp
	);

VOID DpcForIsr(
	IN PKDPC pDpc,
	IN PDEVICE_OBJECT pDevObj,
	IN PIRP pIrp,
	IN PVOID pContext
	);

//++
// Function:	DriverEntry
//
// Description:
//		Initializes the driver.
//
// Arguments:
//		pDriverObject - Passed from I/O Manager
//		pRegistryPath - UNICODE_STRING pointer to
//						registry info (service key)
//						for this driver
//
// Return value:
//		NTSTATUS signaling success or failure
//--
extern "C" NTSTATUS DriverEntry (
			IN PDRIVER_OBJECT pDriverObject,
			IN PUNICODE_STRING pRegistryPath	) {
#if DBG>=2
	DbgPrint("MINPNP: DriverEntry\n");
#endif
	ULONG ulDeviceNumber = 0;
	NTSTATUS status = STATUS_SUCCESS;

	// Announce other driver entry points
	pDriverObject->DriverUnload = DriverUnload;

	// Announce the PNP AddDevice entry point
	pDriverObject->DriverExtension->AddDevice =
				AddDevice;

	// Announce the PNP Major Function entry point
	pDriverObject->MajorFunction[IRP_MJ_PNP] =
				DispPnp;

	// This includes Dispatch routines for Create, Write & Read
	pDriverObject->MajorFunction[IRP_MJ_CREATE] =
				DispatchCreate;
	pDriverObject->MajorFunction[IRP_MJ_CLOSE] =
				DispatchClose;
	pDriverObject->MajorFunction[IRP_MJ_WRITE] =
				DispatchWrite;
	pDriverObject->MajorFunction[IRP_MJ_READ] =
				DispatchRead;
	pDriverObject->DriverStartIo = StartIo;
	
	// Notice that no device objects are created by DriverEntry.
	// Instead, we await the PnP call to AddDevice

	return status;
}

//++
// Function:	AddDevice
//
// Description:
//	Called by the PNP Manager when a new device is
//	detected on a bus.  The responsibilities include
//	creating an FDO, device name, and symbolic link.
//
// Arguments:
//	pDriverObject - Passed from PNP Manager
//	pdo		    - pointer to Physcial Device Object
//				 passed from PNP Manager
//
// Return value:
//	NTSTATUS signaling success or failure
//--
NTSTATUS AddDevice (
			IN PDRIVER_OBJECT pDriverObject,
			IN PDEVICE_OBJECT pdo	) {
	NTSTATUS status;
	PDEVICE_OBJECT pfdo;
	PDEVICE_EXTENSION pDevExt;
	static int ulDeviceNumber = 0;
#if DBG>=2
	DbgPrint("MINPNP: AddDevice; current DeviceNumber = %d\n",
				ulDeviceNumber);
#endif
	
	// Form the internal Device Name
	CUString devName("\\Device\\MINPNP"); // for "minimal" dev
	devName += CUString(ulDeviceNumber);

	// Now create the device
	status =
		IoCreateDevice( pDriverObject,
						sizeof(DEVICE_EXTENSION),
						&(UNICODE_STRING)devName,
						FILE_DEVICE_UNKNOWN,
						0, FALSE,
						&pfdo );
	if (!NT_SUCCESS(status))
		return status;

	// Choose to use BUFFERED_IO
	pfdo->Flags |= DO_BUFFERED_IO;

	// Initialize the Device Extension
	pDevExt = (PDEVICE_EXTENSION)pfdo->DeviceExtension;
	pDevExt->pDevice = pfdo;	// back pointer
	pDevExt->DeviceNumber = ulDeviceNumber;
	pDevExt->ustrDeviceName = devName;
	pDevExt->pIntObj = NULL;
	pDevExt->bInterruptExpected = FALSE;
	pDevExt->state = Stopped;

	// Pile this new fdo on top of the existing lower stack
	pDevExt->pLowerDevice =		// downward pointer
		IoAttachDeviceToDeviceStack( pfdo, pdo);

	// This is where the upper pointer would be initialized.
	// Notice how the cast of the lower device's extension
	// must be known in order to find the offset pUpperDevice.
	// PLOWER_DEVEXT pLowerDevExt = (PLOWER_DEVEXT)
	//		pDevExt->pLowerDevice->DeviceExtension;
	// pLowerDevExt->pUpperDevice = pfdo;

	// Form the symbolic link name
	CUString symLinkName("\\??\\MPNP");
	symLinkName += CUString(ulDeviceNumber+1);	// 1 based
	pDevExt->ustrSymLinkName = symLinkName;

	// Now create the link name
	status = 
		IoCreateSymbolicLink( &(UNICODE_STRING)symLinkName,
						  &(UNICODE_STRING)devName );
	if (!NT_SUCCESS(status)) {
		// if it fails now, must delete Device object
		IoDeleteDevice( pfdo );
		return status;
	}

	// We need a DpcForIsr registration
	IoInitializeDpcRequest( 
		pfdo, 
		DpcForIsr );

    //  Clear the Device Initializing bit since the FDO was created
    //  outside of DriverEntry.
    pfdo->Flags &= ~DO_DEVICE_INITIALIZING;

	// Made it
	ulDeviceNumber++;
	return STATUS_SUCCESS;
}


NTSTATUS DispPnp(	IN PDEVICE_OBJECT pDO,
					IN PIRP pIrp ) {
	// obtain current IRP stack location
	PIO_STACK_LOCATION pIrpStack;
	pIrpStack = IoGetCurrentIrpStackLocation( pIrp );
#if DBG>=2
	DbgPrint("MINPNP: Received PNP IRP: %d\n",
				pIrpStack->MinorFunction);
#endif

	switch (pIrpStack->MinorFunction) {
	case IRP_MN_START_DEVICE:
		return HandleStartDevice(pDO, pIrp );
	case IRP_MN_STOP_DEVICE:
		return HandleStopDevice( pDO, pIrp );
	case IRP_MN_REMOVE_DEVICE:
		return HandleRemoveDevice( pDO, pIrp );
	default:
		// if not supported here, just pass it down
		return PassDownPnP(pDO, pIrp);
	}

	// all paths from the switch statement will "return"
	// the results of the handler invoked
}

NTSTATUS PassDownPnP( IN PDEVICE_OBJECT pDO,
					IN PIRP pIrp ) {
	IoSkipCurrentIrpStackLocation( pIrp );
	PDEVICE_EXTENSION pDevExt = (PDEVICE_EXTENSION)
		pDO->DeviceExtension;
	return IoCallDriver(pDevExt->pLowerDevice, pIrp);
}

NTSTATUS HandleStartDevice(	IN PDEVICE_OBJECT pDO,
							IN PIRP pIrp ) {
	// The stack location contains the Parameter info
	PIO_STACK_LOCATION pIrpStack =
		IoGetCurrentIrpStackLocation( pIrp );
	PDEVICE_EXTENSION pDevExt = (PDEVICE_EXTENSION)
		pDO->DeviceExtension;
#if DBG>=2
	DbgPrint("MINPNP: StartDevice, Symbolic device #%d\n",
				pDevExt->DeviceNumber+1);
#endif

	PCM_RESOURCE_LIST pResourceList;
	PCM_FULL_RESOURCE_DESCRIPTOR pFullDescriptor;
	PCM_PARTIAL_RESOURCE_LIST pPartialList;
	PCM_PARTIAL_RESOURCE_DESCRIPTOR pPartialDescriptor;
	int i;
	NTSTATUS status;

	pResourceList =	pIrpStack->Parameters.StartDevice.AllocatedResourcesTranslated;
	pFullDescriptor =
		pResourceList->List;
	pPartialList =
		&pFullDescriptor->PartialResourceList;
	for (i=0; i<(int)pPartialList->Count; i++) {
		pPartialDescriptor =
			&pPartialList->PartialDescriptors[i];
		switch (pPartialDescriptor->Type) {
		case CmResourceTypeInterrupt:
			pDevExt->IRQL = (KIRQL)
				pPartialDescriptor->u.Interrupt.Level;
			pDevExt->Vector = 
				pPartialDescriptor->u.Interrupt.Vector;
			pDevExt->Affinity = 
				pPartialDescriptor->u.Interrupt.Affinity;
#if DBG>=2
	DbgPrint("MINPNP: Claiming Interrupt Resources: "
			 "IRQ=%d Vector=0x%03X Affinity=%X\n",
			 pDevExt->IRQL, pDevExt->Vector, pDevExt->Affinity);
#endif
			break;
		case CmResourceTypeDma:
			// We don't do DMA - ignore
			break;
		case CmResourceTypePort:
			pDevExt->portBase = (PUCHAR)
				pPartialDescriptor->u.Port.Start.LowPart;
			pDevExt->portLength =
				pPartialDescriptor->u.Port.Length;
#if DBG>=2
	DbgPrint("MINPNP: Claiming Port Resources: Base=%X Len=%d\n",
				pDevExt->portBase, pDevExt->portLength);
#endif
			break;
		case CmResourceTypeMemory:
			// We don't do memory usage
			break;
		}
	}

	// Make sure we got our interrupt (and port) resources
	// Fail this IRP if we didn't.
	// Most likely cause for no interrupt:
	//   Failure to request an interrupt resource for the
	//	 printer port from the Device Manager.
	// Be SURE to use Control Panel...
	//				  Administrative Tools...
	//				  Computer Management...
	//				  Device Manager...
	// Then select Ports...Printer Port (LPT1)
	// From the Port Settings tab,
	// select "Use any interrupt assigned to the port"
	if (pDevExt->IRQL == 0 ||
		pDevExt->portBase == 0)
		return STATUS_BIOS_FAILED_TO_CONNECT_INTERRUPT;

	// Create & connect to an Interrupt object
	status =
		IoConnectInterrupt(
			&pDevExt->pIntObj,	// the Interrupt object
			Isr,			// our ISR
			pDevExt,		// Service Context
			NULL,			// no spin lock
			pDevExt->Vector,			// vector
			pDevExt->IRQL,		// DIRQL
			pDevExt->IRQL,		// DIRQL
			Latched,	// Latched or LevelSensitive
			TRUE,			// Shared?
			pDevExt->Affinity,		// processors in an MP set
			FALSE );		// save FP registers?
	if (!NT_SUCCESS(status)) {
	#if DBG>=2
		DbgPrint("MINPNP: Interrupt connection failure: %X\n", status);
	#endif
		return status;
	}
	
	#if DBG>=2
		DbgPrint("MINPNP: Interrupt successfully connected\n");
	#endif

	pDevExt->state = Started;

	return PassDownPnP(pDO, pIrp);

}

NTSTATUS HandleStopDevice(	IN PDEVICE_OBJECT pDO,
							IN PIRP pIrp ) {
#if DBG>=1
	DbgPrint("MINPNP: StopDevice Handler\n");
#endif
	PDEVICE_EXTENSION pDevExt = (PDEVICE_EXTENSION)
		pDO->DeviceExtension;

	// Delete our Interrupt object
	if (pDevExt->pIntObj)
		IoDisconnectInterrupt( pDevExt->pIntObj );

	pDevExt->state = Stopped;

	return PassDownPnP(pDO, pIrp);
}

NTSTATUS HandleRemoveDevice(IN PDEVICE_OBJECT pDO,
							IN PIRP pIrp ) {
#if DBG>=1
	DbgPrint("MINPNP: RemoveDevice Handler\n");
#endif
	PDEVICE_EXTENSION pDevExt = (PDEVICE_EXTENSION)
		pDO->DeviceExtension;

	if (pDevExt->state == Started) {
		// Woah!  we still have an interrupt object out there!
		// Delete our Interrupt object
		if (pDevExt->pIntObj)
			IoDisconnectInterrupt( pDevExt->pIntObj );
	}

	// This will yield the symbolic link name
	UNICODE_STRING pLinkName =
		pDevExt->ustrSymLinkName;
	// ... which can now be deleted
	IoDeleteSymbolicLink(&pLinkName);
#if DBG>=1
	DbgPrint("PPORT: Symbolic Link MPMP%d Deleted\n",
				pDevExt->DeviceNumber+1);
#endif
	
	// Delete the device
	IoDeleteDevice( pDO );

	pDevExt->state = Removed;
	return PassDownPnP( pDO, pIrp );
}

//++
// Function:	DriverUnload
//
// Description:
//		Stops & Deletes devices controlled by this driver.
//		Stops interrupt processing (if any)
//		Releases kernel resources consumed by driver
//
// Arguments:
//		pDriverObject - Passed from I/O Manager
//
// Return value:
//		None
//--

VOID DriverUnload (
		IN PDRIVER_OBJECT	pDriverObject	) {
#if DBG>=1
	DbgPrint("MINPNP: DriverUnload\n");
#endif

}

//++
// Function:	DispatchCreate
//
// Description:
//		Handles call from Win32 CreateFile request
//		Does nothing
//
// Arguments:
//		pDevObj - Passed from I/O Manager
//		pIrp - Passed from I/O Manager
//
// Return value:
//		NTSTATUS - success or failure code
//--

NTSTATUS DispatchCreate (
		IN PDEVICE_OBJECT	pDevObj,
		IN PIRP				pIrp			) {
#if DBG>=1