1 /***************************************************************************
2 ftdi_stream.c - description
4 copyright : (C) 2009 Micah Dowty 2010 Uwe Bonnes
5 email : opensource@intra2net.com
6 ***************************************************************************/
8 /***************************************************************************
10 * This program is free software; you can redistribute it and/or modify *
11 * it under the terms of the GNU Lesser General Public License *
12 * version 2.1 as published by the Free Software Foundation; *
14 ***************************************************************************/
17 * fastftdi.c - A minimal FTDI FT232H interface for which supports bit-bang
18 * mode, but focuses on very high-performance support for
19 * synchronous FIFO mode. Requires libusb-1.0
21 * Copyright (C) 2009 Micah Dowty
23 * Permission is hereby granted, free of charge, to any person obtaining a copy
24 * of this software and associated documentation files (the "Software"), to deal
25 * in the Software without restriction, including without limitation the rights
26 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
27 * copies of the Software, and to permit persons to whom the Software is
28 * furnished to do so, subject to the following conditions:
30 * The above copyright notice and this permission notice shall be included in
31 * all copies or substantial portions of the Software.
33 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
34 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
35 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
36 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
37 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
38 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
51 FTDIStreamCallback *callback;
56 FTDIProgressInfo progress;
61 * With Exit request, free memory and release the transfer
63 * state->result is only set when some error happens
65 static void LIBUSB_CALL
66 ftdi_readstream_cb(struct libusb_transfer *transfer)
68 FTDIStreamState *state = transfer->user_data;
69 int packet_size = state->packetsize;
72 if (transfer->status == LIBUSB_TRANSFER_COMPLETED)
75 uint8_t *ptr = transfer->buffer;
76 int length = transfer->actual_length;
77 int numPackets = (length + packet_size - 1) / packet_size;
80 for (i = 0; i < numPackets; i++)
83 int packetLen = length;
85 if (packetLen > packet_size)
86 packetLen = packet_size;
88 payloadLen = packetLen - 2;
89 state->progress.current.totalBytes += payloadLen;
91 res = state->callback(ptr + 2, payloadLen,
92 NULL, state->userdata);
99 free(transfer->buffer);
100 libusb_free_transfer(transfer);
104 transfer->status = -1;
105 state->result = libusb_submit_transfer(transfer);
110 fprintf(stderr, "unknown status %d\n",transfer->status);
111 state->result = LIBUSB_ERROR_IO;
116 Helper function to calculate (unix) time differences
122 TimevalDiff(const struct timeval *a, const struct timeval *b)
124 return (a->tv_sec - b->tv_sec) + 1e-6 * (a->tv_usec - b->tv_usec);
128 Streaming reading of data from the device
130 Use asynchronous transfers in libusb-1.0 for high-performance
131 streaming of data from a device interface back to the PC. This
132 function continuously transfers data until either an error occurs
133 or the callback returns a nonzero value. This function returns
134 a libusb error code or the callback's return value.
136 For every contiguous block of received data, the callback will
139 \param ftdi pointer to ftdi_context
140 \param callback to user supplied function for one block of data
142 \param packetsPerTransfer number of packets per transfer
143 \param numTransfers Number of transfers per callback
148 ftdi_readstream(struct ftdi_context *ftdi,
149 FTDIStreamCallback *callback, void *userdata,
150 int packetsPerTransfer, int numTransfers)
152 struct libusb_transfer **transfers;
153 FTDIStreamState state = { callback, userdata, ftdi->max_packet_size, 1 };
154 int bufferSize = packetsPerTransfer * ftdi->max_packet_size;
158 /* Only FT2232H and FT232H know about the synchronous FIFO Mode*/
159 if ((ftdi->type != TYPE_2232H) && (ftdi->type != TYPE_232H))
161 fprintf(stderr,"Device doesn't support synchronous FIFO mode\n");
165 /* We don't know in what state we are, switch to reset*/
166 if (ftdi_set_bitmode(ftdi, 0xff, BITMODE_RESET) < 0)
168 fprintf(stderr,"Can't reset mode\n");
172 /* Purge anything remaining in the buffers*/
173 if (ftdi_usb_purge_buffers(ftdi) < 0)
175 fprintf(stderr,"Can't Purge\n");
180 * Set up all transfers
183 transfers = calloc(numTransfers, sizeof *transfers);
186 err = LIBUSB_ERROR_NO_MEM;
190 for (xferIndex = 0; xferIndex < numTransfers; xferIndex++)
192 struct libusb_transfer *transfer;
194 transfer = libusb_alloc_transfer(0);
195 transfers[xferIndex] = transfer;
198 err = LIBUSB_ERROR_NO_MEM;
202 libusb_fill_bulk_transfer(transfer, ftdi->usb_dev, ftdi->out_ep,
203 malloc(bufferSize), bufferSize,
207 if (!transfer->buffer)
209 err = LIBUSB_ERROR_NO_MEM;
213 transfer->status = -1;
214 err = libusb_submit_transfer(transfer);
219 /* Start the transfers only when everything has been set up.
220 * Otherwise the transfers start stuttering and the PC not
221 * fetching data for several to several ten milliseconds
224 if (ftdi_set_bitmode(ftdi, 0xff, BITMODE_SYNCFF) < 0)
226 fprintf(stderr,"Can't set synchronous fifo mode: %s\n",
227 ftdi_get_error_string(ftdi));
232 * Run the transfers, and periodically assess progress.
235 gettimeofday(&state.progress.first.time, NULL);
239 FTDIProgressInfo *progress = &state.progress;
240 const double progressInterval = 1.0;
241 struct timeval timeout = { 0, ftdi->usb_read_timeout * 1000};
244 int err = libusb_handle_events_timeout(ftdi->usb_ctx, &timeout);
245 if (err == LIBUSB_ERROR_INTERRUPTED)
246 /* restart interrupted events */
247 err = libusb_handle_events_timeout(ftdi->usb_ctx, &timeout);
252 if (state.activity == 0)
257 // If enough time has elapsed, update the progress
258 gettimeofday(&now, NULL);
259 if (TimevalDiff(&now, &progress->current.time) >= progressInterval)
261 progress->current.time = now;
262 progress->totalTime = TimevalDiff(&progress->current.time,
263 &progress->first.time);
265 if (progress->prev.totalBytes)
267 // We have enough information to calculate rates
271 currentTime = TimevalDiff(&progress->current.time,
272 &progress->prev.time);
274 progress->totalRate =
275 progress->current.totalBytes /progress->totalTime;
276 progress->currentRate =
277 (progress->current.totalBytes -
278 progress->prev.totalBytes) / currentTime;
281 state.callback(NULL, 0, progress, state.userdata);
282 progress->prev = progress->current;
285 } while (!state.result);
288 * Cancel any outstanding transfers, and free memory.
292 fprintf(stderr, "cleanup\n");