2 LPCUSB, an USB device driver for LPC microcontrollers
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3 Copyright (C) 2006 Bertrik Sikken (bertrik@sikken.nl)
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5 Redistribution and use in source and binary forms, with or without
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6 modification, are permitted provided that the following conditions are met:
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8 1. Redistributions of source code must retain the above copyright
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9 notice, this list of conditions and the following disclaimer.
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10 2. Redistributions in binary form must reproduce the above copyright
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11 notice, this list of conditions and the following disclaimer in the
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12 documentation and/or other materials provided with the distribution.
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13 3. The name of the author may not be used to endorse or promote products
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14 derived from this software without specific prior written permission.
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16 THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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17 IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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18 OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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19 IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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20 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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21 NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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22 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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23 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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24 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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25 THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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30 Control transfer handler.
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32 This module handles control transfers and is normally installed on the
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33 endpoint 0 callback.
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35 Control transfers can be of the following type:
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41 A callback can be installed for each of these control transfers using
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42 USBRegisterRequestHandler.
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43 When an OUT request arrives, data is collected in the data store provided
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44 with the USBRegisterRequestHandler call. When the transfer is done, the
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46 When an IN request arrives, the callback is called immediately to either
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47 put the control transfer data in the data store, or to get a pointer to
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48 control transfer data. The data is then packetised and sent to the host.
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51 #include "usbdebug.h"
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53 #include "usbstruct.h"
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58 #define MAX_CONTROL_SIZE 128 /**< maximum total size of control transfer data */
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59 #define MAX_REQ_HANDLERS 4 /**< standard, class, vendor, reserved */
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61 static TSetupPacket Setup; /**< setup packet */
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63 static unsigned char *pbData; /**< pointer to data buffer */
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64 static int iResidue; /**< remaining bytes in buffer */
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65 static int iLen; /**< total length of control transfer */
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67 /** Array of installed request handler callbacks */
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68 static TFnHandleRequest *apfnReqHandlers[4] = {NULL, NULL, NULL, NULL};
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69 /** Array of installed request data pointers */
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70 static unsigned char *apbDataStore[4] = {NULL, NULL, NULL, NULL};
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73 Local function to handle a request by calling one of the installed
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76 In case of data going from host to device, the data is at *ppbData.
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77 In case of data going from device to host, the handler can either
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78 choose to write its data at *ppbData or update the data pointer.
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80 @param [in] pSetup The setup packet
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81 @param [in,out] *piLen Pointer to data length
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82 @param [in,out] ppbData Data buffer.
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84 @return TRUE if the request was handles successfully
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86 static BOOL _HandleRequest(TSetupPacket *pSetup, int *piLen, unsigned char **ppbData)
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88 TFnHandleRequest *pfnHandler;
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91 iType = REQTYPE_GET_TYPE(pSetup->bmRequestType);
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92 pfnHandler = apfnReqHandlers[iType];
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93 if (pfnHandler == NULL) {
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94 DBG("No handler for reqtype %d\n", iType);
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98 return pfnHandler(pSetup, piLen, ppbData);
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103 Local function to stall the control endpoint
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105 @param [in] bEPStat Endpoint status
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107 static void StallControlPipe(unsigned char bEPStat)
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112 USBHwEPStall(0x80, TRUE);
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114 // dump setup packet
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116 pb = (unsigned char *)&Setup;
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117 for (i = 0; i < 8; i++) {
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118 DBG(" %02x", *pb++);
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120 DBG("] stat=%x\n", bEPStat);
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125 Sends next chunk of data (possibly 0 bytes) to host
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127 static void DataIn(void)
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131 if( MAX_PACKET_SIZE0 < iResidue )
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133 iChunk = MAX_PACKET_SIZE0;
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140 USBHwEPWrite(0x80, pbData, iChunk);
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142 iResidue -= iChunk;
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147 * Handles IN/OUT transfers on EP0
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149 * @param [in] bEP Endpoint address
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150 * @param [in] bEPStat Endpoint status
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152 void USBHandleControlTransfer(unsigned char bEP, unsigned char bEPStat)
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158 if (bEPStat & EP_STATUS_SETUP) {
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159 // setup packet, reset request message state machine
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160 USBHwEPRead(0x00, (unsigned char *)&Setup, sizeof(Setup));
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161 DBG("S%x", Setup.bRequest);
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163 // defaults for data pointer and residue
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164 iType = REQTYPE_GET_TYPE(Setup.bmRequestType);
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165 pbData = apbDataStore[iType];
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166 iResidue = Setup.wLength;
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167 iLen = Setup.wLength;
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169 if ((Setup.wLength == 0) ||
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170 (REQTYPE_GET_DIR(Setup.bmRequestType) == REQTYPE_DIR_TO_HOST)) {
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171 // ask installed handler to process request
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172 if (!_HandleRequest(&Setup, &iLen, &pbData)) {
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173 DBG("_HandleRequest1 failed\n");
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174 StallControlPipe(bEPStat);
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177 // send smallest of requested and offered length
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178 if( iLen < Setup.wLength )
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184 iResidue = Setup.wLength;
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187 // send first part (possibly a zero-length status message)
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192 if (iResidue > 0) {
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194 iChunk = USBHwEPRead(0x00, pbData, iResidue);
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196 StallControlPipe(bEPStat);
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200 iResidue -= iChunk;
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201 if (iResidue == 0) {
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202 // received all, send data to handler
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203 iType = REQTYPE_GET_TYPE(Setup.bmRequestType);
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204 pbData = apbDataStore[iType];
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205 if (!_HandleRequest(&Setup, &iLen, &pbData)) {
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206 DBG("_HandleRequest2 failed\n");
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207 StallControlPipe(bEPStat);
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210 // send status to host
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215 // absorb zero-length status message
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216 iChunk = USBHwEPRead(0x00, NULL, 0);
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217 DBG(iChunk > 0 ? "?" : "");
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221 else if (bEP == 0x80) {
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223 // send more data if available (possibly a 0-length packet)
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233 Registers a callback for handling requests
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235 @param [in] iType Type of request, e.g. REQTYPE_TYPE_STANDARD
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236 @param [in] *pfnHandler Callback function pointer
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237 @param [in] *pbDataStore Data storage area for this type of request
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239 void USBRegisterRequestHandler(int iType, TFnHandleRequest *pfnHandler, unsigned char *pbDataStore)
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241 ASSERT(iType >= 0);
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243 apfnReqHandlers[iType] = pfnHandler;
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244 apbDataStore[iType] = pbDataStore;
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