2 LPCUSB, an USB device driver for LPC microcontrollers
3 Copyright (C) 2006 Bertrik Sikken (bertrik@sikken.nl)
5 Redistribution and use in source and binary forms, with or without
6 modification, are permitted provided that the following conditions are met:
8 1. Redistributions of source code must retain the above copyright
9 notice, this list of conditions and the following disclaimer.
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11 notice, this list of conditions and the following disclaimer in the
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14 derived from this software without specific prior written permission.
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30 Control transfer handler.
32 This module handles control transfers and is normally installed on the
35 Control transfers can be of the following type:
41 A callback can be installed for each of these control transfers using
42 USBRegisterRequestHandler.
43 When an OUT request arrives, data is collected in the data store provided
44 with the USBRegisterRequestHandler call. When the transfer is done, the
46 When an IN request arrives, the callback is called immediately to either
47 put the control transfer data in the data store, or to get a pointer to
48 control transfer data. The data is then packetised and sent to the host.
53 #include "usbstruct.h"
58 #define MAX_CONTROL_SIZE 128 /**< maximum total size of control transfer data */
59 #define MAX_REQ_HANDLERS 4 /**< standard, class, vendor, reserved */
61 static TSetupPacket Setup; /**< setup packet */
63 static unsigned char *pbData; /**< pointer to data buffer */
64 static int iResidue; /**< remaining bytes in buffer */
65 static int iLen; /**< total length of control transfer */
67 /** Array of installed request handler callbacks */
68 static TFnHandleRequest *apfnReqHandlers[4] = {NULL, NULL, NULL, NULL};
69 /** Array of installed request data pointers */
70 static unsigned char *apbDataStore[4] = {NULL, NULL, NULL, NULL};
73 Local function to handle a request by calling one of the installed
76 In case of data going from host to device, the data is at *ppbData.
77 In case of data going from device to host, the handler can either
78 choose to write its data at *ppbData or update the data pointer.
80 @param [in] pSetup The setup packet
81 @param [in,out] *piLen Pointer to data length
82 @param [in,out] ppbData Data buffer.
84 @return TRUE if the request was handles successfully
86 static BOOL _HandleRequest(TSetupPacket *pSetup, int *piLen, unsigned char **ppbData)
88 TFnHandleRequest *pfnHandler;
91 iType = REQTYPE_GET_TYPE(pSetup->bmRequestType);
92 pfnHandler = apfnReqHandlers[iType];
93 if (pfnHandler == NULL) {
94 DBG("No handler for reqtype %d\n", iType);
98 return pfnHandler(pSetup, piLen, ppbData);
103 Local function to stall the control endpoint
105 @param [in] bEPStat Endpoint status
107 static void StallControlPipe(unsigned char bEPStat)
113 USBHwEPStall(0x80, TRUE);
117 pb = (unsigned char *)&Setup;
118 for (i = 0; i < 8; i++) {
121 DBG("] stat=%x\n", bEPStat);
126 Sends next chunk of data (possibly 0 bytes) to host
128 static void DataIn(void)
132 if( MAX_PACKET_SIZE0 < iResidue )
134 iChunk = MAX_PACKET_SIZE0;
141 USBHwEPWrite(0x80, pbData, iChunk);
148 * Handles IN/OUT transfers on EP0
150 * @param [in] bEP Endpoint address
151 * @param [in] bEPStat Endpoint status
153 void USBHandleControlTransfer(unsigned char bEP, unsigned char bEPStat)
159 if (bEPStat & EP_STATUS_SETUP) {
160 // setup packet, reset request message state machine
161 USBHwEPRead(0x00, (unsigned char *)&Setup, sizeof(Setup));
162 DBG("S%x", Setup.bRequest);
164 // defaults for data pointer and residue
165 iType = REQTYPE_GET_TYPE(Setup.bmRequestType);
166 pbData = apbDataStore[iType];
167 iResidue = Setup.wLength;
168 iLen = Setup.wLength;
170 if ((Setup.wLength == 0) ||
171 (REQTYPE_GET_DIR(Setup.bmRequestType) == REQTYPE_DIR_TO_HOST)) {
172 // ask installed handler to process request
173 if (!_HandleRequest(&Setup, &iLen, &pbData)) {
174 DBG("_HandleRequest1 failed\n");
175 StallControlPipe(bEPStat);
178 // send smallest of requested and offered length
179 if( iLen < Setup.wLength )
185 iResidue = Setup.wLength;
188 // send first part (possibly a zero-length status message)
195 iChunk = USBHwEPRead(0x00, pbData, iResidue);
197 StallControlPipe(bEPStat);
203 // received all, send data to handler
204 iType = REQTYPE_GET_TYPE(Setup.bmRequestType);
205 pbData = apbDataStore[iType];
206 if (!_HandleRequest(&Setup, &iLen, &pbData)) {
207 DBG("_HandleRequest2 failed\n");
208 StallControlPipe(bEPStat);
211 // send status to host
216 // absorb zero-length status message
217 iChunk = USBHwEPRead(0x00, NULL, 0);
218 DBG(iChunk > 0 ? "?" : "");
222 else if (bEP == 0x80) {
224 // send more data if available (possibly a 0-length packet)
234 Registers a callback for handling requests
236 @param [in] iType Type of request, e.g. REQTYPE_TYPE_STANDARD
237 @param [in] *pfnHandler Callback function pointer
238 @param [in] *pbDataStore Data storage area for this type of request
240 void USBRegisterRequestHandler(int iType, TFnHandleRequest *pfnHandler, unsigned char *pbDataStore)
244 apfnReqHandlers[iType] = pfnHandler;
245 apbDataStore[iType] = pbDataStore;