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;
156 fprintf(stderr, "ftdi_readstream\n");
158 * Set up all transfers
161 transfers = calloc(numTransfers, sizeof *transfers);
163 err = LIBUSB_ERROR_NO_MEM;
167 for (xferIndex = 0; xferIndex < numTransfers; xferIndex++)
169 struct libusb_transfer *transfer;
171 transfer = libusb_alloc_transfer(0);
172 transfers[xferIndex] = transfer;
174 err = LIBUSB_ERROR_NO_MEM;
178 libusb_fill_bulk_transfer(transfer, ftdi->usb_dev, ftdi->out_ep,
179 malloc(bufferSize), bufferSize,
183 if (!transfer->buffer) {
184 err = LIBUSB_ERROR_NO_MEM;
188 transfer->status = -1;
189 err = libusb_submit_transfer(transfer);
194 /* Start the transfers only when everything has been set up.
195 * Otherwise the transfers start stuttering and the PC not
196 * fetching data for several to several ten milliseconds
199 if (ftdi_set_bitmode(ftdi, 0xff, BITMODE_SYNCFF) < 0)
201 fprintf(stderr,"Can't set synchronous fifo mode\n",
202 ftdi_get_error_string(ftdi));
207 * Run the transfers, and periodically assess progress.
210 gettimeofday(&state.progress.first.time, NULL);
214 FTDIProgressInfo *progress = &state.progress;
215 const double progressInterval = 1.0;
216 struct timeval timeout = { 0, ftdi->usb_read_timeout };
219 int err = libusb_handle_events_timeout(ftdi->usb_ctx, &timeout);
220 if (err == LIBUSB_ERROR_INTERRUPTED)
221 /* restart interrupted events */
222 err = libusb_handle_events_timeout(ftdi->usb_ctx, &timeout);
227 if (state.activity == 0)
232 // If enough time has elapsed, update the progress
233 gettimeofday(&now, NULL);
234 if (TimevalDiff(&now, &progress->current.time) >= progressInterval)
236 progress->current.time = now;
237 progress->totalTime = TimevalDiff(&progress->current.time,
238 &progress->first.time);
240 if (progress->prev.totalBytes)
242 // We have enough information to calculate rates
246 currentTime = TimevalDiff(&progress->current.time,
247 &progress->prev.time);
249 progress->totalRate =
250 progress->current.totalBytes /progress->totalTime;
251 progress->currentRate =
252 (progress->current.totalBytes -
253 progress->prev.totalBytes) / currentTime;
256 state.callback(NULL, 0, progress, state.userdata);
257 progress->prev = progress->current;
260 } while (!state.result);
263 * Cancel any outstanding transfers, and free memory.
267 fprintf(stderr, "cleanup\n");