/* * @APPLE_LICENSE_HEADER_START@ * * Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved. * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this * file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_LICENSE_HEADER_END@ */ /* File: HIDPutData.c Contains: xxx put contents here xxx Version: xxx put version here xxx Copyright: © 1999-2000 by Apple Computer, Inc., all rights reserved. File Ownership: DRI: xxx put dri here xxx Other Contact: xxx put other contact here xxx Technology: xxx put technology here xxx Writers: (BWS) Brent Schorsch (KH) Keithen Hayenga Change History (most recent first): <USB3> 12/12/00 KH Correcct cast of void * <USB2> 11/11/99 KH Use shifted value when HIDSetUsageValue fills data into a report field that spans multiple bytes. <USB2> 11/10/99 KH Data that overflowed byte bounderies was lost because we shifted initial value instead of value corrected for starting bit location. <USB1> 3/5/99 BWS first checked in */ #include "HIDLib.h" //#include <stdio.h> /* *------------------------------------------------------------------------------ * * HIDPutData - Put a single data item to a report * * Input: * psReport - The report * iReportLength - The length of the report * iStart - Start Bit in report * iSize - Number of Bits * iValue - The data * Output: * Returns: * kHidP_Success - Success * kHidP_NullPointer - Argument, Pointer was Null * *------------------------------------------------------------------------------ */ OSStatus HIDPutData (void * report, ByteCount reportLength, UInt32 start, UInt32 size, SInt32 value) { Byte * psReport = (Byte *)report; SInt32 data, iShiftedData; UInt32 iStartByte, startBit; UInt32 iLastByte, iLastBit; UInt32 iStartMask, iLastMask; UInt32 iDataMask; /* * Report * Bit 28 27 26 25 24 | 23 22 21 20 19 18 17 16 | 15 14 13 12 11 10 09 ... * Last Byte (3) | | Byte 2 | | Start Byte (1) * Data x x x d d | d d d d d d d d | d d y y y y y * Last Bit (1) / | | \ Start Bit (6) * ... 1 1 1 0 0 | Intermediate | 0 0 1 1 1 1 1 ... * Last Mask | Byte(s) | StartMask */ iLastByte = (start + size - 1)/8; /* * Check the parameters */ if ((size == 0) || (iLastByte >= reportLength)) return kHIDBadParameterErr; iLastBit = (start + size - 1)&7; iLastMask = ~((1<<(iLastBit+1)) - 1); iStartByte = start/8; startBit = start&7; iStartMask = (1<<startBit) - 1; /* * If the data is contained in one byte then * handle it differently * Mask off just the area where the new data goes * Shift the data over to its new location * Mask the data for its new location * Or in the data */ if (iStartByte == iLastByte) { data = psReport[iStartByte]; iDataMask = iStartMask | iLastMask; data &= iDataMask; iShiftedData = value << startBit; iShiftedData &= ~iDataMask; data |= iShiftedData; } /* * If the data is in more than one byte then * Do the start byte first * Mask off the bits where the new data goes * Shift the new data over to the start of field * Or the two together and store back out */ else { data = psReport[iStartByte]; data &= iStartMask; iShiftedData = value << startBit; data |= iShiftedData; psReport[iStartByte] = (Byte) data; iShiftedData >>= 8; /* * Store out an intermediate bytes */ while (++iStartByte < iLastByte) { psReport[iStartByte] = (Byte) iShiftedData; iShiftedData >>= 8; } /* * Mask off the bits where the new data goes * Mask off the bits in the new data where the old goes * Or the two together and store back out */ data = psReport[iLastByte]; data &= iLastMask; iShiftedData &= ~iLastMask; data |= iShiftedData; } /* * Store out the last or only Byte */ psReport[iStartByte] = (Byte) data; return kHIDSuccess; }