hid.cpp

这是一个Keil MCB2148开发板上针对LPC2148的HID项目程序

#include "stdafx.h"

extern "C" 
{
#include "setupapi.h" 
#include "hidsdi.h"
}

#include "HID.h"


#define DEV_NUM  10

int                                DevCount;
PSP_DEVICE_INTERFACE_DETAIL_DATA   DevDetailData[DEV_NUM];
HANDLE                             DevHandle;


/*
 *  HID Initialization
 *    Parameters:      None
 *    Return Value:    None
 */

void HID_Init() {
  int  i;

  DevCount = 0;

  for (i = 0; i < DEV_NUM; i++) {
    DevDetailData[i] = NULL;
  }
}


/*
 *  HID Uninitialization
 *    Parameters:      None
 *    Return Value:    None
 */

void HID_UnInit() {
  int  i;

  for (i = 0; i < DEV_NUM; i++) {
    if (DevDetailData[i]) free(DevDetailData[i]);
  }
}


/*
 *  HID Find Devices
 *    Parameters:      None
 *    Return Value:    Number of Devices found
 */

int HID_FindDevices() {
  GUID                             HidGuid;
  HDEVINFO                         DevInfo;
	SP_DEVICE_INTERFACE_DATA         DevData;
  PSP_DEVICE_INTERFACE_DETAIL_DATA DevDetail;
	PHIDP_PREPARSED_DATA	           PreparsedData;
	HIDP_CAPS		                     Capabilities;
  ULONG                            Length;
  int                              Index;
  BOOL                             ok;

  /* Get GUID for all System HIDs */
  HidD_GetHidGuid(&HidGuid);

  /* Get Device Information for all present devices */
  DevInfo = SetupDiGetClassDevs(&HidGuid, 
                                NULL, 
                                NULL, 
                                (DIGCF_PRESENT | DIGCF_DEVICEINTERFACE)
                                );

  DevData.cbSize = sizeof(DevData);

  DevDetail = NULL;

  Index = -1;

  /* Scan all Devices */
  do {

    Index++;

    /* Device Interface Element of a Device Information set */
		ok = SetupDiEnumDeviceInterfaces(DevInfo, 
                                     0, 
                                     &HidGuid, 
                                     Index, 
                                     &DevData
                                     );
    if (!ok) break;

    /* Get Device Interface Details - Get Length */
	  ok = SetupDiGetDeviceInterfaceDetail(DevInfo, 
                                         &DevData, 
                                         NULL, 
                                         0, 
                                         &Length, 
                                         NULL
                                         );

		/* Allocate memory for Device Detailed Data */
		DevDetail = (PSP_DEVICE_INTERFACE_DETAIL_DATA) malloc(Length);
			
		/* Set cbSize in the DevDetail structure */
		DevDetail->cbSize = sizeof(SP_DEVICE_INTERFACE_DETAIL_DATA);

		/* Get Device Interface Details */
		ok = SetupDiGetDeviceInterfaceDetail(DevInfo, 
			                                   &DevData, 
			                                   DevDetail, 
			                                   Length, 
			                                   NULL, 
			                                   NULL
                                         );
    if (!ok) continue;

    /* Create File for Device Read/Write */
		DevHandle = CreateFile(DevDetail->DevicePath, 
			                     GENERIC_READ | GENERIC_WRITE, 
			                     FILE_SHARE_READ | FILE_SHARE_WRITE, 
			                     (LPSECURITY_ATTRIBUTES)NULL,
			                     OPEN_EXISTING, 
			                     0, 
			                     NULL
                           );

    if (DevHandle == INVALID_HANDLE_VALUE) continue;

    /* Get Preparsed Data */
	  ok = HidD_GetPreparsedData(DevHandle, &PreparsedData);
    if (!ok) continue;

    /* Get Device's Capabilities */
	  HidP_GetCaps(PreparsedData, &Capabilities);

    /* Remember Device Interface Detail Data for acceptable Devices */
    if ((Capabilities.UsagePage == 0xFF00) && (Capabilities.Usage == 0x0001)) {
      DevDetailData[DevCount++] = DevDetail;
      DevDetail = NULL;
    }

    CloseHandle (DevHandle);

  } while (DevCount < DEV_NUM);

  if (DevDetail) free(DevDetail);

  SetupDiDestroyDeviceInfoList (DevInfo);

  return (DevCount);
}


/*
 *  HID Get Name (Product String)
 *    Parameters:      num:   Device number
 *                     buf:   Pointer to buffer that receives data
 *                     sz:    Number of bytes to read
 *    Return Value:    TRUE - Success, FALSE - Error
 */

BOOL HID_GetName(int num, char *buf, int sz) {
  HANDLE DevHandle;
  WCHAR  wbuf[128];
  int    i;
  BOOL   ok;

  if (DevDetailData[num] == NULL) return (FALSE);

  /* Create File for Device Read/Write */
  DevHandle = CreateFile(DevDetailData[num]->DevicePath, 
		                     GENERIC_READ | GENERIC_WRITE, 
		                     FILE_SHARE_READ | FILE_SHARE_WRITE, 
		                     (LPSECURITY_ATTRIBUTES)NULL,
		                     OPEN_EXISTING, 
		                     0, 
		                     NULL
                         );

  if (DevHandle == INVALID_HANDLE_VALUE) return (FALSE);

  ok = HidD_GetProductString(DevHandle, wbuf, sizeof(wbuf));

  if (ok) {
    for (i = 0; i < sz; i++) {
      *buf++ = (char)wbuf[i];
    }
  }

  CloseHandle (DevHandle);

  return (ok);
}


/*
 *  HID Open
 *    Parameters:      num:   Device number
 *    Return Value:    TRUE - Success, FALSE - Error
 */

BOOL HID_Open(int num) {

  if (DevDetailData[num] == NULL) return (FALSE);

  /* Create File for Device Read/Write */
  DevHandle = CreateFile(DevDetailData[num]->DevicePath, 
		                     GENERIC_READ | GENERIC_WRITE, 
		                     FILE_SHARE_READ | FILE_SHARE_WRITE, 
		                     (LPSECURITY_ATTRIBUTES)NULL,
		                     OPEN_EXISTING, 
		                     0, 
		                     NULL
                         );

  if (DevHandle == INVALID_HANDLE_VALUE) return (FALSE);

  return (TRUE);
}


/*
 *  HID Open
 *    Parameters:      None
 *    Return Value:    None
 */

void HID_Close() {

  if (DevHandle != INVALID_HANDLE_VALUE) CloseHandle(DevHandle);
}


/*
 *  HID Read
 *    Parameters:      buf:   Pointer to buffer that receives data
 *                     sz:    Number of bytes to read
 *                     cnt:   Pointer to number of bytes read
 *    Return Value:    TRUE - Success, FALSE - Error
 */

BOOL HID_Read(BYTE *buf, DWORD sz, DWORD *cnt) {
  BOOL  ok;

  /* Read from Device */
	ok = ReadFile(DevHandle, buf, sz, cnt, NULL);

  return (ok);
}


/*
 *  HID Write
 *    Parameters:      buf:   Pointer to buffer with data to write
 *                     sz:    Number of bytes to write
 *                     cnt:   Pointer to number of bytes written
 *    Return Value:    TRUE - Success, FALSE - Error
 */

BOOL HID_Write(BYTE *buf, DWORD sz, DWORD *cnt) {
  BOOL  ok;

	/* Write to Device */
  ok = WriteFile(DevHandle, buf, sz, cnt, NULL);

  return (ok);
}