hardware/sysclk-lwla/protocol.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2014 Daniel Elstner <daniel.kitta@gmail.com>
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "protocol.h"
  21 #include <string.h>
  22
  23 /* Bit mask covering all 34 channels. */
  24 #define ALL_CHANNELS_MASK (((uint64_t)1 << NUM_PROBES) - 1)
  25
  26 /* Bit mask for the RLE repeat-count-follows flag. */
  27 #define RLE_FLAG_LEN_FOLLOWS ((uint64_t)1 << 35)
  28
  29 /* Start address of capture status memory area to read. */
  30 #define CAP_STAT_ADDR 5
  31
  32 /* Number of 64-bit words read from the capture status memory. */
  33 #define CAP_STAT_LEN 5
  34
  35 /* The bitstream filenames are indexed by the clock source enumeration.
  36  */
  37 static const char *const bitstream_map[] = {
  38         FIRMWARE_DIR "/sysclk-lwla1034-off.bitstream",
  39         FIRMWARE_DIR "/sysclk-lwla1034-int.bitstream",
  40         FIRMWARE_DIR "/sysclk-lwla1034-extpos.bitstream",
  41         FIRMWARE_DIR "/sysclk-lwla1034-extneg.bitstream",
  42 };
  43
  44 /* Submit an already filled-in USB transfer.
  45  */
  46 static int submit_transfer(struct dev_context *devc,
  47                            struct libusb_transfer *xfer)
  48 {
  49         int ret;
  50
  51         ret = libusb_submit_transfer(xfer);
  52
  53         if (ret != 0) {
  54                 sr_err("Submit transfer failed: %s.", libusb_error_name(ret));
  55                 devc->transfer_error = TRUE;
  56                 return SR_ERR;
  57         }
  58
  59         return SR_OK;
  60 }
  61
  62 /* Set up the LWLA in preparation for an acquisition session.
  63  */
  64 static int capture_setup(const struct sr_dev_inst *sdi)
  65 {
  66         struct dev_context *devc;
  67         struct acquisition_state *acq;
  68         uint64_t divider_count;
  69         uint64_t memory_limit;
  70         uint16_t command[3 + 10*4];
  71
  72         devc = sdi->priv;
  73         acq  = devc->acquisition;
  74
  75         command[0] = LWLA_WORD(CMD_CAP_SETUP);
  76         command[1] = LWLA_WORD(0); /* address */
  77         command[2] = LWLA_WORD(10); /* length */
  78
  79         command[3] = LWLA_WORD_0(devc->channel_mask);
  80         command[4] = LWLA_WORD_1(devc->channel_mask);
  81         command[5] = LWLA_WORD_2(devc->channel_mask);
  82         command[6] = LWLA_WORD_3(devc->channel_mask);
  83
  84         /* Set the clock divide counter maximum for samplerates of up to
  85          * 100 MHz. At the highest samplerate of 125 MHz the clock divider
  86          * is bypassed.
  87          */
  88         if (!acq->bypass_clockdiv && devc->samplerate > 0)
  89                 divider_count = SR_MHZ(100) / devc->samplerate - 1;
  90         else
  91                 divider_count = 0;
  92
  93         command[7]  = LWLA_WORD_0(divider_count);
  94         command[8]  = LWLA_WORD_1(divider_count);
  95         command[9]  = LWLA_WORD_2(divider_count);
  96         command[10] = LWLA_WORD_3(divider_count);
  97
  98         command[11] = LWLA_WORD_0(devc->trigger_values);
  99         command[12] = LWLA_WORD_1(devc->trigger_values);
 100         command[13] = LWLA_WORD_2(devc->trigger_values);
 101         command[14] = LWLA_WORD_3(devc->trigger_values);
 102
 103         command[15] = LWLA_WORD_0(devc->trigger_edge_mask);
 104         command[16] = LWLA_WORD_1(devc->trigger_edge_mask);
 105         command[17] = LWLA_WORD_2(devc->trigger_edge_mask);
 106         command[18] = LWLA_WORD_3(devc->trigger_edge_mask);
 107
 108         command[19] = LWLA_WORD_0(devc->trigger_mask);
 109         command[20] = LWLA_WORD_1(devc->trigger_mask);
 110         command[21] = LWLA_WORD_2(devc->trigger_mask);
 111         command[22] = LWLA_WORD_3(devc->trigger_mask);
 112
 113         /* Set the capture memory full threshold. This is slightly less
 114          * than the actual maximum, most likely in order to compensate for
 115          * pipeline latency.
 116          */
 117         memory_limit = MEMORY_DEPTH - 16;
 118
 119         command[23] = LWLA_WORD_0(memory_limit);
 120         command[24] = LWLA_WORD_1(memory_limit);
 121         command[25] = LWLA_WORD_2(memory_limit);
 122         command[26] = LWLA_WORD_3(memory_limit);
 123
 124         /* Fill remaining 64-bit words with zeroes. */
 125         memset(&command[27], 0, 16 * sizeof(uint16_t));
 126
 127         return lwla_send_command(sdi->conn, command, G_N_ELEMENTS(command));
 128 }
 129
 130 /* Issue a register write command as an asynchronous USB transfer.
 131  */
 132 static int issue_write_reg(const struct sr_dev_inst *sdi,
 133                            unsigned int reg, unsigned int value)
 134 {
 135         struct dev_context *devc;
 136         struct acquisition_state *acq;
 137
 138         devc = sdi->priv;
 139         acq  = devc->acquisition;
 140
 141         acq->xfer_buf_out[0] = LWLA_WORD(CMD_WRITE_REG);
 142         acq->xfer_buf_out[1] = LWLA_WORD(reg);
 143         acq->xfer_buf_out[2] = LWLA_WORD_0(value);
 144         acq->xfer_buf_out[3] = LWLA_WORD_1(value);
 145
 146         acq->xfer_out->length = 4 * sizeof(uint16_t);
 147
 148         return submit_transfer(devc, acq->xfer_out);
 149 }
 150
 151 /* Issue a register write command as an asynchronous USB transfer for the
 152  * next register/value pair of the currently active register write sequence.
 153  */
 154 static int issue_next_write_reg(const struct sr_dev_inst *sdi)
 155 {
 156         struct dev_context *devc;
 157         struct regval_pair *regval;
 158         int ret;
 159
 160         devc = sdi->priv;
 161
 162         if (devc->reg_write_pos >= devc->reg_write_len) {
 163                 sr_err("Already written all registers in sequence.");
 164                 return SR_ERR_BUG;
 165         }
 166         regval = &devc->reg_write_seq[devc->reg_write_pos];
 167
 168         ret = issue_write_reg(sdi, regval->reg, regval->val);
 169         if (ret != SR_OK)
 170                 return ret;
 171
 172         ++devc->reg_write_pos;
 173         return SR_OK;
 174 }
 175
 176 /* Issue a capture status request as an asynchronous USB transfer.
 177  */
 178 static void request_capture_status(const struct sr_dev_inst *sdi)
 179 {
 180         struct dev_context *devc;
 181         struct acquisition_state *acq;
 182
 183         devc = sdi->priv;
 184         acq  = devc->acquisition;
 185
 186         acq->xfer_buf_out[0] = LWLA_WORD(CMD_CAP_STATUS);
 187         acq->xfer_buf_out[1] = LWLA_WORD(CAP_STAT_ADDR);
 188         acq->xfer_buf_out[2] = LWLA_WORD(CAP_STAT_LEN);
 189
 190         acq->xfer_out->length = 3 * sizeof(uint16_t);
 191
 192         if (submit_transfer(devc, acq->xfer_out) == SR_OK)
 193                 devc->state = STATE_STATUS_REQUEST;
 194 }
 195
 196 /* Issue a request for the capture buffer fill level as
 197  * an asynchronous USB transfer.
 198  */
 199 static void request_capture_length(const struct sr_dev_inst *sdi)
 200 {
 201         struct dev_context *devc;
 202         struct acquisition_state *acq;
 203
 204         devc = sdi->priv;
 205         acq  = devc->acquisition;
 206
 207         acq->xfer_buf_out[0] = LWLA_WORD(CMD_READ_REG);
 208         acq->xfer_buf_out[1] = LWLA_WORD(REG_MEM_FILL);
 209
 210         acq->xfer_out->length = 2 * sizeof(uint16_t);
 211
 212         if (submit_transfer(devc, acq->xfer_out) == SR_OK)
 213                 devc->state = STATE_LENGTH_REQUEST;
 214 }
 215
 216 /* Initiate the capture memory read operation:  Reset the acquisition state
 217  * and start a sequence of register writes in order to set up the device for
 218  * reading from the capture buffer.
 219  */
 220 static void issue_read_start(const struct sr_dev_inst *sdi)
 221 {
 222         struct dev_context *devc;
 223         struct acquisition_state *acq;
 224         struct regval_pair *regvals;
 225
 226         devc = sdi->priv;
 227         acq  = devc->acquisition;
 228
 229         /* Reset RLE state. */
 230         acq->rle = RLE_STATE_DATA;
 231         acq->sample  = 0;
 232         acq->run_len = 0;
 233
 234         acq->samples_done = 0;
 235
 236         /* For some reason, the start address is 4 rather than 0. */
 237         acq->mem_addr_done = 4;
 238         acq->mem_addr_next = 4;
 239         acq->mem_addr_stop = acq->mem_addr_fill;
 240
 241         /* Sample position in the packet output buffer. */
 242         acq->out_index = 0;
 243
 244         regvals = devc->reg_write_seq;
 245
 246         regvals[0].reg = REG_DIV_BYPASS;
 247         regvals[0].val = 1;
 248
 249         regvals[1].reg = REG_MEM_CTRL2;
 250         regvals[1].val = 2;
 251
 252         regvals[2].reg = REG_MEM_CTRL4;
 253         regvals[2].val = 4;
 254
 255         devc->reg_write_pos = 0;
 256         devc->reg_write_len = 3;
 257
 258         if (issue_next_write_reg(sdi) == SR_OK)
 259                 devc->state = STATE_READ_PREPARE;
 260 }
 261
 262 /* Issue a command as an asynchronous USB transfer which returns the device
 263  * to normal state after a read operation.  Sets a new device context state
 264  * on success.
 265  */
 266 static void issue_read_end(const struct sr_dev_inst *sdi)
 267 {
 268         struct dev_context *devc;
 269
 270         devc = sdi->priv;
 271
 272         if (issue_write_reg(sdi, REG_DIV_BYPASS, 0) == SR_OK)
 273                 devc->state = STATE_READ_END;
 274 }
 275
 276 /* Decode an incoming reponse to a buffer fill level request and act on it
 277  * as appropriate.  Note that this function changes the device context state.
 278  */
 279 static void process_capture_length(const struct sr_dev_inst *sdi)
 280 {
 281         struct dev_context *devc;
 282         struct acquisition_state *acq;
 283
 284         devc = sdi->priv;
 285         acq  = devc->acquisition;
 286
 287         if (acq->xfer_in->actual_length != 4) {
 288                 sr_err("Received size %d doesn't match expected size 4.",
 289                        acq->xfer_in->actual_length);
 290                 devc->transfer_error = TRUE;
 291                 return;
 292         }
 293         acq->mem_addr_fill = LWLA_READ32(acq->xfer_buf_in);
 294
 295         sr_dbg("%lu words in capture buffer.",
 296                (unsigned long)acq->mem_addr_fill);
 297
 298         if (acq->mem_addr_fill > 0 && sdi->status == SR_ST_ACTIVE)
 299                 issue_read_start(sdi);
 300         else
 301                 issue_read_end(sdi);
 302 }
 303
 304 /* Initiate a sequence of register write commands with the effect of
 305  * cancelling a running capture operation.  This sets a new device state
 306  * if issuing the first command succeeds.
 307  */
 308 static void issue_stop_capture(const struct sr_dev_inst *sdi)
 309 {
 310         struct dev_context *devc;
 311         struct regval_pair *regvals;
 312
 313         devc = sdi->priv;
 314
 315         if (devc->stopping_in_progress)
 316                 return;
 317
 318         regvals = devc->reg_write_seq;
 319
 320         regvals[0].reg = REG_CMD_CTRL2;
 321         regvals[0].val = 10;
 322
 323         regvals[1].reg = REG_CMD_CTRL3;
 324         regvals[1].val = 0;
 325
 326         regvals[2].reg = REG_CMD_CTRL4;
 327         regvals[2].val = 0;
 328
 329         regvals[3].reg = REG_CMD_CTRL1;
 330         regvals[3].val = 0;
 331
 332         regvals[4].reg = REG_DIV_BYPASS;
 333         regvals[4].val = 0;
 334
 335         devc->reg_write_pos = 0;
 336         devc->reg_write_len = 5;
 337
 338         if (issue_next_write_reg(sdi) == SR_OK) {
 339                 devc->stopping_in_progress = TRUE;
 340                 devc->state = STATE_STOP_CAPTURE;
 341         }
 342 }
 343
 344 /* Decode an incoming capture status reponse and act on it as appropriate.
 345  * Note that this function changes the device state.
 346  */
 347 static void process_capture_status(const struct sr_dev_inst *sdi)
 348 {
 349         uint64_t duration;
 350         struct dev_context *devc;
 351         struct acquisition_state *acq;
 352
 353         devc = sdi->priv;
 354         acq  = devc->acquisition;
 355
 356         if (acq->xfer_in->actual_length != CAP_STAT_LEN * 8) {
 357                 sr_err("Received size %d doesn't match expected size %d.",
 358                        acq->xfer_in->actual_length, CAP_STAT_LEN * 8);
 359                 devc->transfer_error = TRUE;
 360                 return;
 361         }
 362
 363         /* TODO: Find out the actual bit width of these fields as stored
 364          * in the FPGA.  These fields are definitely less than 64 bit wide
 365          * internally, and the unused bits occasionally even contain garbage.
 366          */
 367         acq->mem_addr_fill = LWLA_READ32(&acq->xfer_buf_in[0]);
 368         duration           = LWLA_READ32(&acq->xfer_buf_in[8]);
 369         acq->capture_flags = LWLA_READ32(&acq->xfer_buf_in[16])
 370                                 & STATUS_FLAG_MASK;
 371
 372         /* The LWLA1034 runs at 125 MHz if the clock divider is bypassed.
 373          * However, the time base used for the duration is apparently not
 374          * adjusted for this "boost" mode.  Whereas normally the duration
 375          * unit is 1 ms, it is 0.8 ms when the clock divider is bypassed.
 376          * As 0.8 = 100 MHz / 125 MHz, it seems that the internal cycle
 377          * counter period is the same as at the 100 MHz setting.
 378          */
 379         if (acq->bypass_clockdiv)
 380                 acq->duration_now = duration * 4 / 5;
 381         else
 382                 acq->duration_now = duration;
 383
 384         sr_spew("Captured %zu words, %" PRIu64 " ms, flags 0x%02X",
 385                 acq->mem_addr_fill, acq->duration_now, acq->capture_flags);
 386
 387         if (acq->duration_now >= acq->duration_max) {
 388                 issue_stop_capture(sdi);
 389                 return;
 390         }
 391         devc->state = STATE_STATUS_WAIT;
 392
 393         if ((acq->capture_flags & STATUS_TRIGGERED) == 0) {
 394                 sr_spew("Waiting for trigger.");
 395         } else if ((acq->capture_flags & STATUS_MEM_AVAIL) == 0) {
 396                 sr_dbg("Capture memory filled.");
 397                 request_capture_length(sdi);
 398         } else if ((acq->capture_flags & STATUS_CAPTURING) != 0) {
 399                 sr_spew("Sampling in progress.");
 400         }
 401 }
 402
 403 /* Issue a capture buffer read request as an asynchronous USB transfer.
 404  * The address and size of the memory area to read are derived from the
 405  * current acquisition state.
 406  */
 407 static void request_read_mem(const struct sr_dev_inst *sdi)
 408 {
 409         struct dev_context *devc;
 410         struct acquisition_state *acq;
 411         size_t count;
 412
 413         devc = sdi->priv;
 414         acq  = devc->acquisition;
 415
 416         if (acq->mem_addr_next >= acq->mem_addr_stop)
 417                 return;
 418
 419         /* Always read a multiple of 8 device words. */
 420         count = (acq->mem_addr_stop - acq->mem_addr_next + 7) / 8 * 8;
 421         count = MIN(count, READ_CHUNK_LEN);
 422
 423         acq->xfer_buf_out[0] = LWLA_WORD(CMD_READ_MEM);
 424         acq->xfer_buf_out[1] = LWLA_WORD_0(acq->mem_addr_next);
 425         acq->xfer_buf_out[2] = LWLA_WORD_1(acq->mem_addr_next);
 426         acq->xfer_buf_out[3] = LWLA_WORD_0(count);
 427         acq->xfer_buf_out[4] = LWLA_WORD_1(count);
 428
 429         acq->xfer_out->length = 5 * sizeof(uint16_t);
 430
 431         if (submit_transfer(devc, acq->xfer_out) == SR_OK) {
 432                 acq->mem_addr_next += count;
 433                 devc->state = STATE_READ_REQUEST;
 434         }
 435 }
 436
 437 /* Demangle and decompress incoming sample data from the capture buffer.
 438  * The data chunk is taken from the acquisition state, and is expected to
 439  * contain a multiple of 8 device words.
 440  * All data currently in the acquisition buffer will be processed.  Packets
 441  * of decoded samples are sent off to the session bus whenever the output
 442  * buffer becomes full while decoding.
 443  */
 444 static int process_sample_data(const struct sr_dev_inst *sdi)
 445 {
 446         uint64_t sample;
 447         uint64_t high_nibbles;
 448         uint64_t word;
 449         struct dev_context *devc;
 450         struct acquisition_state *acq;
 451         uint8_t *out_p;
 452         uint16_t *slice;
 453         struct sr_datafeed_packet packet;
 454         struct sr_datafeed_logic logic;
 455         size_t expect_len;
 456         size_t actual_len;
 457         size_t out_max_samples;
 458         size_t out_run_samples;
 459         size_t ri;
 460         size_t in_words_left;
 461         size_t si;
 462
 463         devc = sdi->priv;
 464         acq  = devc->acquisition;
 465
 466         if (acq->mem_addr_done >= acq->mem_addr_stop
 467                         || acq->samples_done >= acq->samples_max)
 468                 return SR_OK;
 469
 470         in_words_left = MIN(acq->mem_addr_stop - acq->mem_addr_done,
 471                             READ_CHUNK_LEN);
 472         expect_len = LWLA1034_MEMBUF_LEN(in_words_left) * sizeof(uint16_t);
 473         actual_len = acq->xfer_in->actual_length;
 474
 475         if (actual_len != expect_len) {
 476                 sr_err("Received size %lu does not match expected size %lu.",
 477                        (unsigned long)actual_len, (unsigned long)expect_len);
 478                 devc->transfer_error = TRUE;
 479                 return SR_ERR;
 480         }
 481         acq->mem_addr_done += in_words_left;
 482
 483         /* Prepare session packet. */
 484         packet.type    = SR_DF_LOGIC;
 485         packet.payload = &logic;
 486         logic.unitsize = UNIT_SIZE;
 487         logic.data     = acq->out_packet;
 488
 489         slice = acq->xfer_buf_in;
 490         si = 0; /* word index within slice */
 491
 492         for (;;) {
 493                 /* Calculate number of samples to write into packet. */
 494                 out_max_samples = MIN(acq->samples_max - acq->samples_done,
 495                                       PACKET_LENGTH - acq->out_index);
 496                 out_run_samples = MIN(acq->run_len, out_max_samples);
 497
 498                 /* Expand run-length samples into session packet. */
 499                 sample = acq->sample;
 500                 out_p = &acq->out_packet[acq->out_index * UNIT_SIZE];
 501
 502                 for (ri = 0; ri < out_run_samples; ++ri) {
 503                         out_p[0] =  sample        & 0xFF;
 504                         out_p[1] = (sample >>  8) & 0xFF;
 505                         out_p[2] = (sample >> 16) & 0xFF;
 506                         out_p[3] = (sample >> 24) & 0xFF;
 507                         out_p[4] = (sample >> 32) & 0xFF;
 508                         out_p += UNIT_SIZE;
 509                 }
 510                 acq->run_len -= out_run_samples;
 511                 acq->out_index += out_run_samples;
 512                 acq->samples_done += out_run_samples;
 513
 514                 /* Packet full or sample count limit reached? */
 515                 if (out_run_samples == out_max_samples) {
 516                         logic.length = acq->out_index * UNIT_SIZE;
 517                         sr_session_send(sdi, &packet);
 518                         acq->out_index = 0;
 519
 520                         if (acq->samples_done >= acq->samples_max)
 521                                 return SR_OK; /* sample limit reached */
 522                         if (acq->run_len > 0)
 523                                 continue; /* need another packet */
 524                 }
 525
 526                 if (in_words_left == 0)
 527                         break; /* done with current chunk */
 528
 529                 /* Now work on the current slice. */
 530                 high_nibbles = LWLA_READ32(&slice[8 * 2]);
 531                 word = LWLA_READ32(&slice[si * 2]);
 532                 word |= (high_nibbles << (4 * si + 4)) & ((uint64_t)0xF << 32);
 533
 534                 if (acq->rle == RLE_STATE_DATA) {
 535                         acq->sample = word & ALL_CHANNELS_MASK;
 536                         acq->run_len = ((word >> NUM_PROBES) & 1) + 1;
 537                         if (word & RLE_FLAG_LEN_FOLLOWS)
 538                                 acq->rle = RLE_STATE_LEN;
 539                 } else {
 540                         acq->run_len += word << 1;
 541                         acq->rle = RLE_STATE_DATA;
 542                 }
 543
 544                 /* Move to next word. */
 545                 if (++si >= 8) {
 546                         si = 0;
 547                         slice += 9 * 2;
 548                 }
 549                 --in_words_left;
 550         }
 551
 552         /* Send out partially filled packet if this was the last chunk. */
 553         if (acq->mem_addr_done >= acq->mem_addr_stop && acq->out_index > 0) {
 554                 logic.length = acq->out_index * UNIT_SIZE;
 555                 sr_session_send(sdi, &packet);
 556                 acq->out_index = 0;
 557         }
 558         return SR_OK;
 559 }
 560
 561 /* Finish an acquisition session.  This sends the end packet to the session
 562  * bus and removes the listener for asynchronous USB transfers.
 563  */
 564 static void end_acquisition(struct sr_dev_inst *sdi)
 565 {
 566         struct drv_context *drvc;
 567         struct dev_context *devc;
 568         struct sr_datafeed_packet packet;
 569
 570         drvc = sdi->driver->priv;
 571         devc = sdi->priv;
 572
 573         if (devc->state == STATE_IDLE)
 574                 return;
 575
 576         devc->state = STATE_IDLE;
 577
 578         /* Remove USB file descriptors from polling. */
 579         usb_source_remove(drvc->sr_ctx);
 580
 581         packet.type = SR_DF_END;
 582         sr_session_send(sdi, &packet);
 583
 584         lwla_free_acquisition_state(devc->acquisition);
 585         devc->acquisition = NULL;
 586
 587         sdi->status = SR_ST_ACTIVE;
 588 }
 589
 590 /* USB output transfer completion callback.
 591  */
 592 static void receive_transfer_out(struct libusb_transfer *transfer)
 593 {
 594         struct sr_dev_inst *sdi;
 595         struct dev_context *devc;
 596
 597         sdi  = transfer->user_data;
 598         devc = sdi->priv;
 599
 600         if (transfer->status != LIBUSB_TRANSFER_COMPLETED) {
 601                 sr_err("Transfer to device failed: %d.", transfer->status);
 602                 devc->transfer_error = TRUE;
 603                 return;
 604         }
 605
 606         if (devc->reg_write_pos < devc->reg_write_len) {
 607                 issue_next_write_reg(sdi);
 608         } else {
 609                 switch (devc->state) {
 610                 case STATE_START_CAPTURE:
 611                         devc->state = STATE_STATUS_WAIT;
 612                         break;
 613                 case STATE_STATUS_REQUEST:
 614                         devc->state = STATE_STATUS_RESPONSE;
 615                         submit_transfer(devc, devc->acquisition->xfer_in);
 616                         break;
 617                 case STATE_STOP_CAPTURE:
 618                         if (sdi->status == SR_ST_ACTIVE)
 619                                 request_capture_length(sdi);
 620                         else
 621                                 end_acquisition(sdi);
 622                         break;
 623                 case STATE_LENGTH_REQUEST:
 624                         devc->state = STATE_LENGTH_RESPONSE;
 625                         submit_transfer(devc, devc->acquisition->xfer_in);
 626                         break;
 627                 case STATE_READ_PREPARE:
 628                         request_read_mem(sdi);
 629                         break;
 630                 case STATE_READ_REQUEST:
 631                         devc->state = STATE_READ_RESPONSE;
 632                         submit_transfer(devc, devc->acquisition->xfer_in);
 633                         break;
 634                 case STATE_READ_END:
 635                         end_acquisition(sdi);
 636                         break;
 637                 default:
 638                         sr_err("Unexpected device state %d.", devc->state);
 639                         break;
 640                 }
 641         }
 642 }
 643
 644 /* USB input transfer completion callback.
 645  */
 646 static void receive_transfer_in(struct libusb_transfer *transfer)
 647 {
 648         struct sr_dev_inst *sdi;
 649         struct dev_context *devc;
 650         struct acquisition_state *acq;
 651
 652         sdi  = transfer->user_data;
 653         devc = sdi->priv;
 654         acq  = devc->acquisition;
 655
 656         if (transfer->status != LIBUSB_TRANSFER_COMPLETED) {
 657                 sr_err("Transfer from device failed: %d.", transfer->status);
 658                 devc->transfer_error = TRUE;
 659                 return;
 660         }
 661
 662         switch (devc->state) {
 663         case STATE_STATUS_RESPONSE:
 664                 process_capture_status(sdi);
 665                 break;
 666         case STATE_LENGTH_RESPONSE:
 667                 process_capture_length(sdi);
 668                 break;
 669         case STATE_READ_RESPONSE:
 670                 if (process_sample_data(sdi) == SR_OK
 671                                 && acq->mem_addr_next < acq->mem_addr_stop
 672                                 && acq->samples_done < acq->samples_max)
 673                         request_read_mem(sdi);
 674                 else
 675                         issue_read_end(sdi);
 676                 break;
 677         default:
 678                 sr_err("Unexpected device state %d.", devc->state);
 679                 break;
 680         }
 681 }
 682
 683 /* Initialize the LWLA.  This downloads a bitstream into the FPGA
 684  * and executes a simple device test sequence.
 685  */
 686 SR_PRIV int lwla_init_device(const struct sr_dev_inst *sdi)
 687 {
 688         struct dev_context *devc;
 689         int ret;
 690         uint32_t value;
 691
 692         devc = sdi->priv;
 693
 694         /* Select internal clock if it hasn't been set yet */
 695         if (devc->selected_clock_source == CLOCK_SOURCE_NONE)
 696                 devc->selected_clock_source = CLOCK_SOURCE_INT;
 697
 698         /* Force reload of bitstream */
 699         devc->cur_clock_source = CLOCK_SOURCE_NONE;
 700
 701         ret = lwla_set_clock_source(sdi);
 702
 703         if (ret != SR_OK)
 704                 return ret;
 705
 706         ret = lwla_write_reg(sdi->conn, REG_CMD_CTRL2, 100);
 707         if (ret != SR_OK)
 708                 return ret;
 709
 710         ret = lwla_read_reg(sdi->conn, REG_CMD_CTRL1, &value);
 711         if (ret != SR_OK)
 712                 return ret;
 713         sr_info("Received test word 0x%08X back.", value);
 714         if (value != 0x12345678)
 715                 return SR_ERR;
 716
 717         ret = lwla_read_reg(sdi->conn, REG_CMD_CTRL4, &value);
 718         if (ret != SR_OK)
 719                 return ret;
 720         sr_info("Received test word 0x%08X back.", value);
 721         if (value != 0x12345678)
 722                 return SR_ERR;
 723
 724         ret = lwla_read_reg(sdi->conn, REG_CMD_CTRL3, &value);
 725         if (ret != SR_OK)
 726                 return ret;
 727         sr_info("Received test word 0x%08X back.", value);
 728         if (value != 0x87654321)
 729                 return SR_ERR;
 730
 731         return ret;
 732 }
 733
 734 /* Select the LWLA clock source.  If the clock source changed from the
 735  * previous setting, this will download a new bitstream to the FPGA.
 736  */
 737 SR_PRIV int lwla_set_clock_source(const struct sr_dev_inst *sdi)
 738 {
 739         struct dev_context *devc;
 740         int ret;
 741         enum clock_source selected;
 742         size_t idx;
 743
 744         devc = sdi->priv;
 745         selected = devc->selected_clock_source;
 746
 747         if (devc->cur_clock_source != selected) {
 748                 devc->cur_clock_source = CLOCK_SOURCE_NONE;
 749                 idx = selected;
 750                 if (idx >= G_N_ELEMENTS(bitstream_map)) {
 751                         sr_err("Clock source (%d) out of range", selected);
 752                         return SR_ERR_BUG;
 753                 }
 754                 ret = lwla_send_bitstream(sdi->conn, bitstream_map[idx]);
 755                 if (ret == SR_OK)
 756                         devc->cur_clock_source = selected;
 757                 return ret;
 758         }
 759         return SR_OK;
 760 }
 761
 762 /* Configure the LWLA in preparation for an acquisition session.
 763  */
 764 SR_PRIV int lwla_setup_acquisition(const struct sr_dev_inst *sdi)
 765 {
 766         struct dev_context *devc;
 767         struct sr_usb_dev_inst *usb;
 768         struct acquisition_state *acq;
 769         struct regval_pair regvals[7];
 770         int ret;
 771
 772         devc = sdi->priv;
 773         usb  = sdi->conn;
 774         acq  = devc->acquisition;
 775
 776         /* By default, run virtually unlimited. */
 777         acq->duration_max = (devc->limit_msec > 0)
 778                 ? devc->limit_msec : MAX_LIMIT_MSEC;
 779         acq->samples_max = (devc->limit_samples > 0)
 780                 ? devc->limit_samples : MAX_LIMIT_SAMPLES;
 781
 782         switch (devc->cur_clock_source) {
 783         case CLOCK_SOURCE_INT:
 784                 if (devc->samplerate == 0)
 785                         return SR_ERR_BUG;
 786                 /* At 125 MHz, the clock divider is bypassed. */
 787                 acq->bypass_clockdiv = (devc->samplerate > SR_MHZ(100));
 788
 789                 /* If only one of the limits is set, derive the other one. */
 790                 if (devc->limit_msec == 0 && devc->limit_samples > 0)
 791                         acq->duration_max = devc->limit_samples
 792                                         * 1000 / devc->samplerate + 1;
 793                 else if (devc->limit_samples == 0 && devc->limit_msec > 0)
 794                         acq->samples_max = devc->limit_msec
 795                                         * devc->samplerate / 1000;
 796                 break;
 797         case CLOCK_SOURCE_EXT_FALL:
 798         case CLOCK_SOURCE_EXT_RISE:
 799                 acq->bypass_clockdiv = TRUE;
 800                 break;
 801         default:
 802                 sr_err("No valid clock source has been configured.");
 803                 return SR_ERR;
 804         }
 805
 806         regvals[0].reg = REG_MEM_CTRL2;
 807         regvals[0].val = 2;
 808
 809         regvals[1].reg = REG_MEM_CTRL2;
 810         regvals[1].val = 1;
 811
 812         regvals[2].reg = REG_CMD_CTRL2;
 813         regvals[2].val = 10;
 814
 815         regvals[3].reg = REG_CMD_CTRL3;
 816         regvals[3].val = 0x74;
 817
 818         regvals[4].reg = REG_CMD_CTRL4;
 819         regvals[4].val = 0;
 820
 821         regvals[5].reg = REG_CMD_CTRL1;
 822         regvals[5].val = 0;
 823
 824         regvals[6].reg = REG_DIV_BYPASS;
 825         regvals[6].val = acq->bypass_clockdiv;
 826
 827         ret = lwla_write_regs(usb, regvals, G_N_ELEMENTS(regvals));
 828         if (ret != SR_OK)
 829                 return ret;
 830
 831         return capture_setup(sdi);
 832 }
 833
 834 /* Start the capture operation on the LWLA device.  Beginning with this
 835  * function, all USB transfers will be asynchronous until the end of the
 836  * acquisition session.
 837  */
 838 SR_PRIV int lwla_start_acquisition(const struct sr_dev_inst *sdi)
 839 {
 840         struct dev_context *devc;
 841         struct sr_usb_dev_inst *usb;
 842         struct acquisition_state *acq;
 843         struct regval_pair *regvals;
 844
 845         devc = sdi->priv;
 846         usb  = sdi->conn;
 847         acq  = devc->acquisition;
 848
 849         acq->duration_now = 0;
 850
 851         libusb_fill_bulk_transfer(acq->xfer_out, usb->devhdl, EP_COMMAND,
 852                                   (unsigned char *)acq->xfer_buf_out, 0,
 853                                   &receive_transfer_out,
 854                                   (struct sr_dev_inst *)sdi, USB_TIMEOUT);
 855
 856         libusb_fill_bulk_transfer(acq->xfer_in, usb->devhdl, EP_REPLY,
 857                                   (unsigned char *)acq->xfer_buf_in,
 858                                   sizeof acq->xfer_buf_in,
 859                                   &receive_transfer_in,
 860                                   (struct sr_dev_inst *)sdi, USB_TIMEOUT);
 861
 862         regvals = devc->reg_write_seq;
 863
 864         regvals[0].reg = REG_CMD_CTRL2;
 865         regvals[0].val = 10;
 866
 867         regvals[1].reg = REG_CMD_CTRL3;
 868         regvals[1].val = 1;
 869
 870         regvals[2].reg = REG_CMD_CTRL4;
 871         regvals[2].val = 0;
 872
 873         regvals[3].reg = REG_CMD_CTRL1;
 874         regvals[3].val = 0;
 875
 876         devc->reg_write_pos = 0;
 877         devc->reg_write_len = 4;
 878
 879         devc->state = STATE_START_CAPTURE;
 880
 881         return issue_next_write_reg(sdi);
 882 }
 883
 884 /* Allocate an acquisition state object.
 885  */
 886 SR_PRIV struct acquisition_state *lwla_alloc_acquisition_state(void)
 887 {
 888         struct acquisition_state *acq;
 889
 890         acq = g_try_new0(struct acquisition_state, 1);
 891         if (!acq) {
 892                 sr_err("Acquisition state malloc failed.");
 893                 return NULL;
 894         }
 895
 896         acq->xfer_in = libusb_alloc_transfer(0);
 897         if (!acq->xfer_in) {
 898                 sr_err("Transfer malloc failed.");
 899                 g_free(acq);
 900                 return NULL;
 901         }
 902
 903         acq->xfer_out = libusb_alloc_transfer(0);
 904         if (!acq->xfer_out) {
 905                 sr_err("Transfer malloc failed.");
 906                 libusb_free_transfer(acq->xfer_in);
 907                 g_free(acq);
 908                 return NULL;
 909         }
 910
 911         return acq;
 912 }
 913
 914 /* Deallocate an acquisition state object.
 915  */
 916 SR_PRIV void lwla_free_acquisition_state(struct acquisition_state *acq)
 917 {
 918         if (acq) {
 919                 libusb_free_transfer(acq->xfer_out);
 920                 libusb_free_transfer(acq->xfer_in);
 921                 g_free(acq);
 922         }
 923 }
 924
 925 /* USB I/O source callback.
 926  */
 927 SR_PRIV int lwla_receive_data(int fd, int revents, void *cb_data)
 928 {
 929         struct sr_dev_inst *sdi;
 930         struct dev_context *devc;
 931         struct drv_context *drvc;
 932         struct timeval tv;
 933         int ret;
 934
 935         (void)fd;
 936
 937         sdi  = cb_data;
 938         devc = sdi->priv;
 939         drvc = sdi->driver->priv;
 940
 941         if (!devc || !drvc)
 942                 return FALSE;
 943
 944         /* No timeout: return immediately. */
 945         tv.tv_sec  = 0;
 946         tv.tv_usec = 0;
 947
 948         ret = libusb_handle_events_timeout_completed(drvc->sr_ctx->libusb_ctx,
 949                                                      &tv, NULL);
 950         if (ret != 0)
 951                 sr_err("Event handling failed: %s.", libusb_error_name(ret));
 952
 953         /* If no event flags are set the timeout must have expired. */
 954         if (revents == 0 && devc->state == STATE_STATUS_WAIT) {
 955                 if (sdi->status == SR_ST_STOPPING)
 956                         issue_stop_capture(sdi);
 957                 else
 958                         request_capture_status(sdi);
 959         }
 960
 961         /* Check if an error occurred on a transfer. */
 962         if (devc->transfer_error)
 963                 end_acquisition(sdi);
 964
 965         return TRUE;
 966 }