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/*++
Copyright (c) 1990-2000 Microsoft Corporation
Module Name:
device.c - Device handling events for example driver.
Abstract:
This is a C version of a very simple sample driver that illustrates
how to use the driver framework and demonstrates best practices.
--*/
#include "driver.h"
NTSTATUS
EchoDeviceCreate(
PWDFDEVICE_INIT DeviceInit
)
/*++
Routine Description:
Worker routine called to create a device and its software resources.
Arguments:
DeviceInit - Pointer to an opaque init structure. Memory for this
structure will be freed by the framework when the WdfDeviceCreate
succeeds. So don't access the structure after that point.
Return Value:
NTSTATUS
--*/
{
WDF_OBJECT_ATTRIBUTES deviceAttributes;
PDEVICE_CONTEXT deviceContext;
WDF_PNPPOWER_EVENT_CALLBACKS pnpPowerCallbacks;
WDFDEVICE device;
NTSTATUS status;
WDF_PNPPOWER_EVENT_CALLBACKS_INIT(&pnpPowerCallbacks);
//
// Register pnp/power callbacks so that we can start and stop the timer as the device
// gets started and stopped.
//
pnpPowerCallbacks.EvtDeviceSelfManagedIoInit = EchoEvtDeviceSelfManagedIoStart;
pnpPowerCallbacks.EvtDeviceSelfManagedIoSuspend = EchoEvtDeviceSelfManagedIoSuspend;
#pragma prefast(suppress: 28024, "Function used for both Init and Restart Callbacks")
pnpPowerCallbacks.EvtDeviceSelfManagedIoRestart = EchoEvtDeviceSelfManagedIoStart;
//
// Register the PnP and power callbacks. Power policy related callbacks will be registered
// later in SotwareInit.
//
WdfDeviceInitSetPnpPowerEventCallbacks(DeviceInit, &pnpPowerCallbacks);
WDF_OBJECT_ATTRIBUTES_INIT_CONTEXT_TYPE(&deviceAttributes, DEVICE_CONTEXT);
status = WdfDeviceCreate(&DeviceInit, &deviceAttributes, &device);
if (NT_SUCCESS(status)) {
//
// Get the device context and initialize it. WdfObjectGet_DEVICE_CONTEXT is an
// inline function generated by WDF_DECLARE_CONTEXT_TYPE macro in the
// device.h header file. This function will do the type checking and return
// the device context. If you pass a wrong object handle
// it will return NULL and assert if run under framework verifier mode.
//
deviceContext = WdfObjectGet_DEVICE_CONTEXT(device);
deviceContext->PrivateDeviceData = 0;
//
// Create a device interface so that application can find and talk
// to us.
//
status = WdfDeviceCreateDeviceInterface(
device,
&GUID_DEVINTERFACE_ECHO,
NULL // ReferenceString
);
if (NT_SUCCESS(status)) {
//
// Initialize the I/O Package and any Queues
//
status = EchoQueueInitialize(device);
}
}
return status;
}
NTSTATUS
EchoEvtDeviceSelfManagedIoStart(
IN WDFDEVICE Device
)
/*++
Routine Description:
This event is called by the Framework when the device is started
or restarted after a suspend operation.
This function is not marked pageable because this function is in the
device power up path. When a function is marked pagable and the code
section is paged out, it will generate a page fault which could impact
the fast resume behavior because the client driver will have to wait
until the system drivers can service this page fault.
Arguments:
Device - Handle to a framework device object.
Return Value:
NTSTATUS - Failures will result in the device stack being torn down.
--*/
{
PQUEUE_CONTEXT queueContext = QueueGetContext(WdfDeviceGetDefaultQueue(Device));
LARGE_INTEGER DueTime;
KdPrint(("--> EchoEvtDeviceSelfManagedIoInit\n"));
//
// Restart the queue and the periodic timer. We stopped them before going
// into low power state.
//
WdfIoQueueStart(WdfDeviceGetDefaultQueue(Device));
DueTime.QuadPart = WDF_REL_TIMEOUT_IN_MS(100);
WdfTimerStart(queueContext->Timer, DueTime.QuadPart);
KdPrint(( "<-- EchoEvtDeviceSelfManagedIoInit\n"));
return STATUS_SUCCESS;
}
NTSTATUS
EchoEvtDeviceSelfManagedIoSuspend(
IN WDFDEVICE Device
)
/*++
Routine Description:
This event is called by the Framework when the device is stopped
for resource rebalance or suspended when the system is entering
Sx state.
Arguments:
Device - Handle to a framework device object.
Return Value:
NTSTATUS - The driver is not allowed to fail this function. If it does, the
device stack will be torn down.
--*/
{
PQUEUE_CONTEXT queueContext = QueueGetContext(WdfDeviceGetDefaultQueue(Device));
PAGED_CODE();
KdPrint(("--> EchoEvtDeviceSelfManagedIoSuspend\n"));
//
// Before we stop the timer we should make sure there are no outstanding
// i/o. We need to do that because framework cannot suspend the device
// if there are requests owned by the driver. There are two ways to solve
// this issue: 1) We can wait for the outstanding I/O to be complete by the
// periodic timer 2) Register EvtIoStop callback on the queue and acknowledge
// the request to inform the framework that it's okay to suspend the device
// with outstanding I/O. In this sample we will use the 1st approach
// because it's pretty easy to do. We will restart the queue when the
// device is restarted.
//
WdfIoQueueStopSynchronously(WdfDeviceGetDefaultQueue(Device));
//
// Stop the watchdog timer and wait for DPC to run to completion if it's already fired.
//
WdfTimerStop(queueContext->Timer, TRUE);
KdPrint(( "<-- EchoEvtDeviceSelfManagedIoSuspend\n"));
return STATUS_SUCCESS;
}
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