parallel.c

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/*
 * COPYRIGHT:        See COPYING in the top level directory
 * PROJECT:          ReactOS kernel
 * FILE:             services/parallel/parallel.c
 * PURPOSE:          Parallel port driver
 * PROGRAMMER:       David Welch (welch@mcmail.com)
 * UPDATE HISTORY:
 *              ??/??/??: Created
 *              18/06/98: Made more NT like
 */
 
/* FUNCTIONS **************************************************************/
 
#include <wdm.h>
 
#include "parallel.h"
 
#define NDEBUG
#include <debug.h>
 
 
#define LP_B (0x378)
#define LP_S (READ_PORT_UCHAR((PUCHAR)(LP_B+1)))
#define LP_C (LP_B+2)
 
NTSTATUS NTAPI
DriverEntry(PDRIVER_OBJECT DriverObject, PUNICODE_STRING RegistryPath);
 
static void Parallel_Reset(void)
/*
 * FUNCTION: Resets the device attached to the parallel port
 */
{
   int i;
 
   WRITE_PORT_UCHAR((PUCHAR)LP_C,0);
   for (i=0;i<LP_DELAY;i++);
   WRITE_PORT_UCHAR((PUCHAR)LP_C,LP_PSELECP | LP_PINITP);
}
 
static void Parallel_putchar(unsigned char ch)
/*
 * FUNCTION: Writes a character to the parallel port
 * ARGUMENTS:
 *          ch = character to write
 */
{
 
    int count=0;
    int status;
    int wait=0;
 
    do
      {
         status=LP_S;
         count++;
      }
    while ( count < 500000 && !(status & LP_PBUSY) );
 
    if (count==500000)
      {
         DPRINT("printer_putchar(): timed out\n");
         return;
      }
 
    WRITE_PORT_UCHAR((PUCHAR)LP_B,ch);
    while (wait != 10000) { wait++; }
    WRITE_PORT_UCHAR((PUCHAR)LP_C, (LP_PSELECP | LP_PINITP | LP_PSTROBE ));
    while (wait) { wait--; }
    WRITE_PORT_UCHAR((PUCHAR)LP_C, LP_PSELECP | LP_PINITP);
}
 
static DRIVER_DISPATCH Dispatch;
static NTSTATUS NTAPI
Dispatch(PDEVICE_OBJECT DeviceObject, PIRP Irp)
/*
 * FUNCTION: Handles user mode requests
 * ARGUMENTS:
 *           DeviceObject = Device for request
 *           Irp = I/O request packet describing request
 * RETURNS: Success or failure
 */
{
   PIO_STACK_LOCATION Stack = IoGetCurrentIrpStackLocation(Irp);
   NTSTATUS status;
   ULONG i;
 
   switch (Stack->MajorFunction)
     {
      case IRP_MJ_CREATE:
    DPRINT("(Parallel Port Driver) Creating\n");
    Parallel_Reset();
    status = STATUS_SUCCESS;
    break;
 
      case IRP_MJ_CLOSE:
    status = STATUS_SUCCESS;
    break;
 
      case IRP_MJ_WRITE:
    DPRINT("(Parallel Port Driver) Writing %d bytes\n",
           Stack->Parameters.Write.Length);
    for (i=0;i<Stack->Parameters.Write.Length;i++)
      {
         Parallel_putchar(((char *)Irp->UserBuffer)[i]);
      }
    status = STATUS_SUCCESS;
    break;
 
      default:
    status = STATUS_NOT_IMPLEMENTED;
    break;
     }
 
   Irp->IoStatus.Status = status;
   Irp->IoStatus.Information = 0;
 
   IoCompleteRequest(Irp, IO_NO_INCREMENT);
   return(status);
}
 
NTSTATUS NTAPI
DriverEntry(PDRIVER_OBJECT DriverObject, PUNICODE_STRING RegistryPath)
/*
 * FUNCTION: Called by the system to initialize the driver
 * ARGUMENTS:
 *           DriverObject = object describing this driver
 *           RegistryPath = path to our configuration entries
 * RETURNS: Success or failure
 */
{
   PDEVICE_OBJECT DeviceObject;
   UNICODE_STRING DeviceName = RTL_CONSTANT_STRING(L"\\Device\\Parallel");
   NTSTATUS Status;
 
   DPRINT("Parallel Port Driver 0.0.1\n");
 
   Status = IoCreateDevice(DriverObject,
               0,
               &DeviceName,
               FILE_DEVICE_PARALLEL_PORT,
               0,
               FALSE,
               &DeviceObject);
   if (!NT_SUCCESS(Status))
     {
    return(Status);
     }
 
   DeviceObject->Flags=0;
   DriverObject->MajorFunction[IRP_MJ_CLOSE] = Dispatch;
   DriverObject->MajorFunction[IRP_MJ_CREATE] = Dispatch;
   DriverObject->MajorFunction[IRP_MJ_WRITE] = Dispatch;
   DriverObject->DriverUnload = NULL;
 
   return(STATUS_SUCCESS);
}
 
/* EOF */