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
50 FTDIStreamCallback *callback;
55 FTDIProgressInfo progress;
60 * With Exit request, free memory and release the transfer
62 * state->result is only set when some error happens
65 ftdi_readstream_cb(struct libusb_transfer *transfer)
67 FTDIStreamState *state = transfer->user_data;
68 int packet_size = state->packetsize;
71 if (transfer->status == LIBUSB_TRANSFER_COMPLETED)
74 uint8_t *ptr = transfer->buffer;
75 int length = transfer->actual_length;
76 int numPackets = (length + packet_size - 1) / packet_size;
79 for (i = 0; i < numPackets; i++)
82 int packetLen = length;
84 if (packetLen > packet_size)
85 packetLen = packet_size;
87 payloadLen = packetLen - 2;
88 state->progress.current.totalBytes += payloadLen;
90 res = state->callback(ptr + 2, payloadLen,
91 NULL, state->userdata);
98 free(transfer->buffer);
99 libusb_free_transfer(transfer);
103 transfer->status = -1;
104 state->result = libusb_submit_transfer(transfer);
109 fprintf(stderr, "unknown status %d\n",transfer->status);
110 state->result = LIBUSB_ERROR_IO;
115 Helper function to calculate (unix) time differences
121 TimevalDiff(const struct timeval *a, const struct timeval *b)
123 return (a->tv_sec - b->tv_sec) + 1e-6 * (a->tv_usec - b->tv_usec);
127 Streaming reading of data from the device
129 Use asynchronous transfers in libusb-1.0 for high-performance
130 streaming of data from a device interface back to the PC. This
131 function continuously transfers data until either an error occurs
132 or the callback returns a nonzero value. This function returns
133 a libusb error code or the callback's return value.
135 For every contiguous block of received data, the callback will
138 \param ftdi pointer to ftdi_context
139 \param callback to user supplied function for one block of data
141 \param packetsPerTransfer number of packets per transfer
142 \param numTransfers Number of transfers per callback
147 ftdi_readstream(struct ftdi_context *ftdi,
148 FTDIStreamCallback *callback, void *userdata,
149 int packetsPerTransfer, int numTransfers)
151 struct libusb_transfer **transfers;
152 FTDIStreamState state = { callback, userdata, ftdi->max_packet_size, 1 };
153 int bufferSize = packetsPerTransfer * ftdi->max_packet_size;
157 /* Only FT2232H and FT232H know about the synchronous FIFO Mode*/
158 if ((ftdi->type != TYPE_2232H) && (ftdi->type != TYPE_232H))
160 fprintf(stderr,"Device doesn't support synchronous FIFO mode\n");
164 /* We don't know in what state we are, switch to reset*/
165 if (ftdi_set_bitmode(ftdi, 0xff, BITMODE_RESET) < 0)
167 fprintf(stderr,"Can't reset mode\n");
171 /* Purge anything remaining in the buffers*/
172 if (ftdi_usb_purge_buffers(ftdi) < 0)
174 fprintf(stderr,"Can't Purge\n");
179 * Set up all transfers
182 transfers = calloc(numTransfers, sizeof *transfers);
184 err = LIBUSB_ERROR_NO_MEM;
188 for (xferIndex = 0; xferIndex < numTransfers; xferIndex++)
190 struct libusb_transfer *transfer;
192 transfer = libusb_alloc_transfer(0);
193 transfers[xferIndex] = transfer;
195 err = LIBUSB_ERROR_NO_MEM;
199 libusb_fill_bulk_transfer(transfer, ftdi->usb_dev, ftdi->out_ep,
200 malloc(bufferSize), bufferSize,
204 if (!transfer->buffer) {
205 err = LIBUSB_ERROR_NO_MEM;
209 transfer->status = -1;
210 err = libusb_submit_transfer(transfer);
215 /* Start the transfers only when everything has been set up.
216 * Otherwise the transfers start stuttering and the PC not
217 * fetching data for several to several ten milliseconds
220 if (ftdi_set_bitmode(ftdi, 0xff, BITMODE_SYNCFF) < 0)
222 fprintf(stderr,"Can't set synchronous fifo mode: %s\n",
223 ftdi_get_error_string(ftdi));
228 * Run the transfers, and periodically assess progress.
231 gettimeofday(&state.progress.first.time, NULL);
235 FTDIProgressInfo *progress = &state.progress;
236 const double progressInterval = 1.0;
237 struct timeval timeout = { 0, ftdi->usb_read_timeout };
240 int err = libusb_handle_events_timeout(ftdi->usb_ctx, &timeout);
241 if (err == LIBUSB_ERROR_INTERRUPTED)
242 /* restart interrupted events */
243 err = libusb_handle_events_timeout(ftdi->usb_ctx, &timeout);
248 if (state.activity == 0)
253 // If enough time has elapsed, update the progress
254 gettimeofday(&now, NULL);
255 if (TimevalDiff(&now, &progress->current.time) >= progressInterval)
257 progress->current.time = now;
258 progress->totalTime = TimevalDiff(&progress->current.time,
259 &progress->first.time);
261 if (progress->prev.totalBytes)
263 // We have enough information to calculate rates
267 currentTime = TimevalDiff(&progress->current.time,
268 &progress->prev.time);
270 progress->totalRate =
271 progress->current.totalBytes /progress->totalTime;
272 progress->currentRate =
273 (progress->current.totalBytes -
274 progress->prev.totalBytes) / currentTime;
277 state.callback(NULL, 0, progress, state.userdata);
278 progress->prev = progress->current;
281 } while (!state.result);
284 * Cancel any outstanding transfers, and free memory.
288 fprintf(stderr, "cleanup\n");