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
49 FTDIStreamCallback *callback;
54 FTDIProgressInfo progress;
59 * With Exit request, free memory and release the transfer
61 * state->result is only set when some error happens
64 ftdi_readstream_cb(struct libusb_transfer *transfer)
66 FTDIStreamState *state = transfer->user_data;
67 int packet_size = state->packetsize;
70 if (transfer->status == LIBUSB_TRANSFER_COMPLETED)
73 uint8_t *ptr = transfer->buffer;
74 int length = transfer->actual_length;
75 int numPackets = (length + packet_size - 1) / packet_size;
78 for (i = 0; i < numPackets; i++)
81 int packetLen = length;
83 if (packetLen > packet_size)
84 packetLen = packet_size;
86 payloadLen = packetLen - 2;
87 state->progress.current.totalBytes += payloadLen;
89 res = state->callback(ptr + 2, payloadLen,
90 NULL, state->userdata);
97 free(transfer->buffer);
98 libusb_free_transfer(transfer);
102 transfer->status = -1;
103 state->result = libusb_submit_transfer(transfer);
108 fprintf(stderr, "unknown status %d\n",transfer->status);
109 state->result = LIBUSB_ERROR_IO;
114 Helper function to calculate (unix) time differences
120 TimevalDiff(const struct timeval *a, const struct timeval *b)
122 return (a->tv_sec - b->tv_sec) + 1e-6 * (a->tv_usec - b->tv_usec);
126 Streaming reading of data from the device
128 Use asynchronous transfers in libusb-1.0 for high-performance
129 streaming of data from a device interface back to the PC. This
130 function continuously transfers data until either an error occurs
131 or the callback returns a nonzero value. This function returns
132 a libusb error code or the callback's return value.
134 For every contiguous block of received data, the callback will
137 \param ftdi pointer to ftdi_context
138 \param callback to user supplied function for one block of data
140 \param packetsPerTransfer number of packets per transfer
141 \param numTransfers Number of transfers per callback
146 ftdi_readstream(struct ftdi_context *ftdi,
147 FTDIStreamCallback *callback, void *userdata,
148 int packetsPerTransfer, int numTransfers)
150 struct libusb_transfer **transfers;
151 FTDIStreamState state = { callback, userdata, ftdi->max_packet_size, 1 };
152 int bufferSize = packetsPerTransfer * ftdi->max_packet_size;
157 * Set up all transfers
160 transfers = calloc(numTransfers, sizeof *transfers);
162 err = LIBUSB_ERROR_NO_MEM;
166 for (xferIndex = 0; xferIndex < numTransfers; xferIndex++)
168 struct libusb_transfer *transfer;
170 transfer = libusb_alloc_transfer(0);
171 transfers[xferIndex] = transfer;
173 err = LIBUSB_ERROR_NO_MEM;
177 libusb_fill_bulk_transfer(transfer, ftdi->usb_dev, ftdi->out_ep,
178 malloc(bufferSize), bufferSize,
182 if (!transfer->buffer) {
183 err = LIBUSB_ERROR_NO_MEM;
187 transfer->status = -1;
188 err = libusb_submit_transfer(transfer);
193 /* Start the transfers only when everything has been set up.
194 * Otherwise the transfers start stuttering and the PC not
195 * fetching data for several to several ten milliseconds
198 if (ftdi_set_bitmode(ftdi, 0xff, BITMODE_SYNCFF) < 0)
200 fprintf(stderr,"Can't set synchronous fifo mode: %s\n",
201 ftdi_get_error_string(ftdi));
206 * Run the transfers, and periodically assess progress.
209 gettimeofday(&state.progress.first.time, NULL);
213 FTDIProgressInfo *progress = &state.progress;
214 const double progressInterval = 1.0;
215 struct timeval timeout = { 0, ftdi->usb_read_timeout };
218 int err = libusb_handle_events_timeout(ftdi->usb_ctx, &timeout);
219 if (err == LIBUSB_ERROR_INTERRUPTED)
220 /* restart interrupted events */
221 err = libusb_handle_events_timeout(ftdi->usb_ctx, &timeout);
226 if (state.activity == 0)
231 // If enough time has elapsed, update the progress
232 gettimeofday(&now, NULL);
233 if (TimevalDiff(&now, &progress->current.time) >= progressInterval)
235 progress->current.time = now;
236 progress->totalTime = TimevalDiff(&progress->current.time,
237 &progress->first.time);
239 if (progress->prev.totalBytes)
241 // We have enough information to calculate rates
245 currentTime = TimevalDiff(&progress->current.time,
246 &progress->prev.time);
248 progress->totalRate =
249 progress->current.totalBytes /progress->totalTime;
250 progress->currentRate =
251 (progress->current.totalBytes -
252 progress->prev.totalBytes) / currentTime;
255 state.callback(NULL, 0, progress, state.userdata);
256 progress->prev = progress->current;
259 } while (!state.result);
262 * Cancel any outstanding transfers, and free memory.
266 fprintf(stderr, "cleanup\n");