src/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 <config.h>
  21 #include <string.h>
  22 #include "protocol.h"
  23 #include "lwla.h"
  24
  25 /* Submit an already filled-in USB transfer.
  26  */
  27 static int submit_transfer(struct dev_context *devc,
  28                            struct libusb_transfer *xfer)
  29 {
  30         int ret;
  31
  32         ret = libusb_submit_transfer(xfer);
  33
  34         if (ret != 0) {
  35                 sr_err("Submit transfer failed: %s.", libusb_error_name(ret));
  36                 devc->transfer_error = TRUE;
  37                 return SR_ERR;
  38         }
  39
  40         return SR_OK;
  41 }
  42
  43 /* Set up transfer for the next register in a write sequence.
  44  */
  45 static void next_reg_write(struct acquisition_state *acq)
  46 {
  47         struct regval *regval;
  48
  49         regval = &acq->reg_sequence[acq->reg_seq_pos];
  50
  51         acq->xfer_buf_out[0] = LWLA_WORD(CMD_WRITE_REG);
  52         acq->xfer_buf_out[1] = LWLA_WORD(regval->reg);
  53         acq->xfer_buf_out[2] = LWLA_WORD_0(regval->val);
  54         acq->xfer_buf_out[3] = LWLA_WORD_1(regval->val);
  55
  56         acq->xfer_out->length = 4 * sizeof(acq->xfer_buf_out[0]);
  57 }
  58
  59 /* Set up transfer for the next register in a read sequence.
  60  */
  61 static void next_reg_read(struct acquisition_state *acq)
  62 {
  63         unsigned int addr;
  64
  65         addr = acq->reg_sequence[acq->reg_seq_pos].reg;
  66
  67         acq->xfer_buf_out[0] = LWLA_WORD(CMD_READ_REG);
  68         acq->xfer_buf_out[1] = LWLA_WORD(addr);
  69
  70         acq->xfer_out->length = 2 * sizeof(acq->xfer_buf_out[0]);
  71 }
  72
  73 /* Decode the response to a register read request.
  74  */
  75 static int read_reg_response(struct acquisition_state *acq)
  76 {
  77         uint32_t value;
  78
  79         if (acq->xfer_in->actual_length != 4) {
  80                 sr_err("Received size %d doesn't match expected size 4.",
  81                        acq->xfer_in->actual_length);
  82                 return SR_ERR;
  83         }
  84         value = LWLA_TO_UINT32(acq->xfer_buf_in[0]);
  85         acq->reg_sequence[acq->reg_seq_pos].val = value;
  86
  87         return SR_OK;
  88 }
  89
  90 /* Enter a new state and submit the corresponding request to the device.
  91  */
  92 static int submit_request(const struct sr_dev_inst *sdi,
  93                           enum protocol_state state)
  94 {
  95         struct dev_context *devc;
  96         struct acquisition_state *acq;
  97         int ret;
  98
  99         devc = sdi->priv;
 100         acq  = devc->acquisition;
 101
 102         devc->state = state;
 103
 104         acq->xfer_out->length = 0;
 105         acq->reg_seq_pos = 0;
 106         acq->reg_seq_len = 0;
 107
 108         /* Perform the model-specific action for the new state. */
 109         ret = (*devc->model->prepare_request)(sdi);
 110
 111         if (ret != SR_OK) {
 112                 devc->transfer_error = TRUE;
 113                 return ret;
 114         }
 115
 116         if (acq->reg_seq_pos < acq->reg_seq_len) {
 117                 if ((state & STATE_EXPECT_RESPONSE) != 0)
 118                         next_reg_read(acq);
 119                 else
 120                         next_reg_write(acq);
 121         }
 122
 123         return submit_transfer(devc, acq->xfer_out);
 124 }
 125
 126 /* Evaluate and act on the response to a capture status request.
 127  */
 128 static void handle_status_response(const struct sr_dev_inst *sdi)
 129 {
 130         struct dev_context *devc;
 131         struct acquisition_state *acq;
 132         unsigned int old_status;
 133
 134         devc = sdi->priv;
 135         acq  = devc->acquisition;
 136         old_status = acq->status;
 137
 138         if ((*devc->model->handle_response)(sdi) != SR_OK) {
 139                 devc->transfer_error = TRUE;
 140                 return;
 141         }
 142         devc->state = STATE_STATUS_WAIT;
 143
 144         sr_spew("Captured %u words, %" PRIu64 " ms, status 0x%02X.",
 145                 acq->mem_addr_fill, acq->duration_now, acq->status);
 146
 147         if ((~old_status & acq->status & STATUS_TRIGGERED) != 0)
 148                 sr_info("Capture triggered.");
 149
 150         if (acq->duration_now >= acq->duration_max) {
 151                 sr_dbg("Time limit reached, stopping capture.");
 152                 submit_request(sdi, STATE_STOP_CAPTURE);
 153         } else if ((acq->status & STATUS_TRIGGERED) == 0) {
 154                 sr_spew("Waiting for trigger.");
 155         } else if ((acq->status & STATUS_MEM_AVAIL) == 0) {
 156                 sr_dbg("Capture memory filled.");
 157                 submit_request(sdi, STATE_LENGTH_REQUEST);
 158         } else if ((acq->status & STATUS_CAPTURING) != 0) {
 159                 sr_spew("Sampling in progress.");
 160         }
 161 }
 162
 163 /* Evaluate and act on the response to a capture length request.
 164  */
 165 static void handle_length_response(const struct sr_dev_inst *sdi)
 166 {
 167         struct dev_context *devc;
 168         struct acquisition_state *acq;
 169
 170         devc = sdi->priv;
 171         acq  = devc->acquisition;
 172
 173         if ((*devc->model->handle_response)(sdi) != SR_OK) {
 174                 devc->transfer_error = TRUE;
 175                 return;
 176         }
 177         acq->rle = RLE_STATE_DATA;
 178         acq->sample = 0;
 179         acq->run_len = 0;
 180         acq->samples_done = 0;
 181         acq->mem_addr_done = acq->mem_addr_next;
 182         acq->out_index = 0;
 183
 184         if (acq->mem_addr_next >= acq->mem_addr_stop) {
 185                 submit_request(sdi, STATE_READ_FINISH);
 186                 return;
 187         }
 188         sr_dbg("%u words in capture buffer.",
 189                acq->mem_addr_stop - acq->mem_addr_next);
 190
 191         submit_request(sdi, STATE_READ_PREPARE);
 192 }
 193
 194 /* Evaluate and act on the response to a capture memory read request.
 195  */
 196 static void handle_read_response(const struct sr_dev_inst *sdi)
 197 {
 198         struct dev_context *devc;
 199         struct acquisition_state *acq;
 200         struct sr_datafeed_packet packet;
 201         struct sr_datafeed_logic logic;
 202         unsigned int end_addr;
 203
 204         devc = sdi->priv;
 205         acq  = devc->acquisition;
 206
 207         /* Prepare session packet. */
 208         packet.type    = SR_DF_LOGIC;
 209         packet.payload = &logic;
 210         logic.unitsize = (devc->model->num_channels + 7) / 8;
 211         logic.data     = acq->out_packet;
 212
 213         end_addr = MIN(acq->mem_addr_next, acq->mem_addr_stop);
 214         acq->in_index = 0;
 215         /*
 216          * Repeatedly call the model-specific read response handler until
 217          * all data received in the transfer has been accounted for.
 218          */
 219         while (!devc->cancel_requested
 220                         && (acq->run_len > 0 || acq->mem_addr_done < end_addr)
 221                         && acq->samples_done < acq->samples_max) {
 222
 223                 if ((*devc->model->handle_response)(sdi) != SR_OK) {
 224                         devc->transfer_error = TRUE;
 225                         return;
 226                 }
 227                 if (acq->out_index * logic.unitsize >= PACKET_SIZE) {
 228                         /* Send off full logic packet. */
 229                         logic.length = acq->out_index * logic.unitsize;
 230                         sr_session_send(sdi, &packet);
 231                         acq->out_index = 0;
 232                 }
 233         }
 234
 235         if (!devc->cancel_requested
 236                         && acq->samples_done < acq->samples_max
 237                         && acq->mem_addr_next < acq->mem_addr_stop) {
 238                 /* Request the next block. */
 239                 submit_request(sdi, STATE_READ_REQUEST);
 240                 return;
 241         }
 242
 243         /* Send partially filled packet as it is the last one. */
 244         if (!devc->cancel_requested && acq->out_index > 0) {
 245                 logic.length = acq->out_index * logic.unitsize;
 246                 sr_session_send(sdi, &packet);
 247                 acq->out_index = 0;
 248         }
 249         submit_request(sdi, STATE_READ_FINISH);
 250 }
 251
 252 /* Destroy and unset the acquisition state record.
 253  */
 254 static void clear_acquisition_state(const struct sr_dev_inst *sdi)
 255 {
 256         struct dev_context *devc;
 257         struct acquisition_state *acq;
 258
 259         devc = sdi->priv;
 260         acq  = devc->acquisition;
 261
 262         devc->acquisition = NULL;
 263
 264         if (acq) {
 265                 libusb_free_transfer(acq->xfer_out);
 266                 libusb_free_transfer(acq->xfer_in);
 267                 g_free(acq);
 268         }
 269 }
 270
 271 /* USB I/O source callback.
 272  */
 273 static int transfer_event(int fd, int revents, void *cb_data)
 274 {
 275         const struct sr_dev_inst *sdi;
 276         struct dev_context *devc;
 277         struct drv_context *drvc;
 278         struct timeval tv;
 279         struct sr_datafeed_packet packet;
 280         int ret;
 281
 282         (void)fd;
 283
 284         sdi  = cb_data;
 285         devc = sdi->priv;
 286         drvc = sdi->driver->context;
 287
 288         if (!devc || !drvc)
 289                 return G_SOURCE_REMOVE;
 290
 291         /* Handle pending USB events without blocking. */
 292         tv.tv_sec  = 0;
 293         tv.tv_usec = 0;
 294         ret = libusb_handle_events_timeout_completed(drvc->sr_ctx->libusb_ctx,
 295                                                      &tv, NULL);
 296         if (ret != 0) {
 297                 sr_err("Event handling failed: %s.", libusb_error_name(ret));
 298                 devc->transfer_error = TRUE;
 299         }
 300
 301         if (!devc->transfer_error && devc->state == STATE_STATUS_WAIT) {
 302                 if (devc->cancel_requested)
 303                         submit_request(sdi, STATE_STOP_CAPTURE);
 304                 else if (revents == 0) /* status poll timeout */
 305                         submit_request(sdi, STATE_STATUS_REQUEST);
 306         }
 307
 308         /* Stop processing events if an error occurred on a transfer. */
 309         if (devc->transfer_error)
 310                 devc->state = STATE_IDLE;
 311
 312         if (devc->state != STATE_IDLE)
 313                 return G_SOURCE_CONTINUE;
 314
 315         sr_info("Acquisition stopped.");
 316
 317         /* We are done, clean up and send end packet to session bus. */
 318         clear_acquisition_state(sdi);
 319
 320         packet.type = SR_DF_END;
 321         packet.payload = NULL;
 322         sr_session_send(sdi, &packet);
 323
 324         return G_SOURCE_REMOVE;
 325 }
 326
 327 /* USB output transfer completion callback.
 328  */
 329 static void LIBUSB_CALL transfer_out_completed(struct libusb_transfer *transfer)
 330 {
 331         const struct sr_dev_inst *sdi;
 332         struct dev_context *devc;
 333         struct acquisition_state *acq;
 334
 335         sdi  = transfer->user_data;
 336         devc = sdi->priv;
 337         acq  = devc->acquisition;
 338
 339         if (transfer->status != LIBUSB_TRANSFER_COMPLETED) {
 340                 sr_err("Transfer to device failed (state %d): %s.",
 341                        devc->state, libusb_error_name(transfer->status));
 342                 devc->transfer_error = TRUE;
 343                 return;
 344         }
 345
 346         /* If this was a read request, wait for the response. */
 347         if ((devc->state & STATE_EXPECT_RESPONSE) != 0) {
 348                 submit_transfer(devc, acq->xfer_in);
 349                 return;
 350         }
 351         if (acq->reg_seq_pos < acq->reg_seq_len)
 352                 acq->reg_seq_pos++; /* register write completed */
 353
 354         /* Repeat until all queued registers have been written. */
 355         if (acq->reg_seq_pos < acq->reg_seq_len && !devc->cancel_requested) {
 356                 next_reg_write(acq);
 357                 submit_transfer(devc, acq->xfer_out);
 358                 return;
 359         }
 360
 361         switch (devc->state) {
 362         case STATE_START_CAPTURE:
 363                 sr_info("Acquisition started.");
 364
 365                 if (!devc->cancel_requested)
 366                         devc->state = STATE_STATUS_WAIT;
 367                 else
 368                         submit_request(sdi, STATE_STOP_CAPTURE);
 369                 break;
 370         case STATE_STOP_CAPTURE:
 371                 if (!devc->cancel_requested)
 372                         submit_request(sdi, STATE_LENGTH_REQUEST);
 373                 else
 374                         devc->state = STATE_IDLE;
 375                 break;
 376         case STATE_READ_PREPARE:
 377                 if (acq->mem_addr_next < acq->mem_addr_stop && !devc->cancel_requested)
 378                         submit_request(sdi, STATE_READ_REQUEST);
 379                 else
 380                         submit_request(sdi, STATE_READ_FINISH);
 381                 break;
 382         case STATE_READ_FINISH:
 383                 devc->state = STATE_IDLE;
 384                 break;
 385         default:
 386                 sr_err("Unexpected device state %d.", devc->state);
 387                 devc->transfer_error = TRUE;
 388                 break;
 389         }
 390 }
 391
 392 /* USB input transfer completion callback.
 393  */
 394 static void LIBUSB_CALL transfer_in_completed(struct libusb_transfer *transfer)
 395 {
 396         const struct sr_dev_inst *sdi;
 397         struct dev_context *devc;
 398         struct acquisition_state *acq;
 399
 400         sdi  = transfer->user_data;
 401         devc = sdi->priv;
 402         acq  = devc->acquisition;
 403
 404         if (transfer->status != LIBUSB_TRANSFER_COMPLETED) {
 405                 sr_err("Transfer from device failed (state %d): %s.",
 406                        devc->state, libusb_error_name(transfer->status));
 407                 devc->transfer_error = TRUE;
 408                 return;
 409         }
 410         if ((devc->state & STATE_EXPECT_RESPONSE) == 0) {
 411                 sr_err("Unexpected completion of input transfer (state %d).",
 412                        devc->state);
 413                 devc->transfer_error = TRUE;
 414                 return;
 415         }
 416
 417         if (acq->reg_seq_pos < acq->reg_seq_len && !devc->cancel_requested) {
 418                 /* Complete register read sequence. */
 419                 if (read_reg_response(acq) != SR_OK) {
 420                         devc->transfer_error = TRUE;
 421                         return;
 422                 }
 423                 /* Repeat until all queued registers have been read. */
 424                 if (++acq->reg_seq_pos < acq->reg_seq_len) {
 425                         next_reg_read(acq);
 426                         submit_transfer(devc, acq->xfer_out);
 427                         return;
 428                 }
 429         }
 430
 431         switch (devc->state) {
 432         case STATE_STATUS_REQUEST:
 433                 if (devc->cancel_requested)
 434                         submit_request(sdi, STATE_STOP_CAPTURE);
 435                 else
 436                         handle_status_response(sdi);
 437                 break;
 438         case STATE_LENGTH_REQUEST:
 439                 if (devc->cancel_requested)
 440                         submit_request(sdi, STATE_READ_FINISH);
 441                 else
 442                         handle_length_response(sdi);
 443                 break;
 444         case STATE_READ_REQUEST:
 445                 handle_read_response(sdi);
 446                 break;
 447         default:
 448                 sr_err("Unexpected device state %d.", devc->state);
 449                 devc->transfer_error = TRUE;
 450                 break;
 451         }
 452 }
 453
 454 /* Set up the acquisition state record.
 455  */
 456 static int init_acquisition_state(const struct sr_dev_inst *sdi)
 457 {
 458         struct dev_context *devc;
 459         struct sr_usb_dev_inst *usb;
 460         struct acquisition_state *acq;
 461
 462         devc = sdi->priv;
 463         usb  = sdi->conn;
 464
 465         if (devc->acquisition) {
 466                 sr_err("Acquisition still in progress?");
 467                 return SR_ERR;
 468         }
 469         if (devc->cfg_clock_source == CLOCK_INTERNAL && devc->samplerate == 0) {
 470                 sr_err("Samplerate not set.");
 471                 return SR_ERR;
 472         }
 473
 474         acq = g_try_malloc0(sizeof(struct acquisition_state));
 475         if (!acq)
 476                 return SR_ERR_MALLOC;
 477
 478         acq->xfer_in = libusb_alloc_transfer(0);
 479         if (!acq->xfer_in) {
 480                 g_free(acq);
 481                 return SR_ERR_MALLOC;
 482         }
 483         acq->xfer_out = libusb_alloc_transfer(0);
 484         if (!acq->xfer_out) {
 485                 libusb_free_transfer(acq->xfer_in);
 486                 g_free(acq);
 487                 return SR_ERR_MALLOC;
 488         }
 489
 490         libusb_fill_bulk_transfer(acq->xfer_out, usb->devhdl, EP_COMMAND,
 491                                   (unsigned char *)acq->xfer_buf_out, 0,
 492                                   &transfer_out_completed,
 493                                   (struct sr_dev_inst *)sdi, USB_TIMEOUT_MS);
 494
 495         libusb_fill_bulk_transfer(acq->xfer_in, usb->devhdl, EP_REPLY,
 496                                   (unsigned char *)acq->xfer_buf_in,
 497                                   sizeof(acq->xfer_buf_in),
 498                                   &transfer_in_completed,
 499                                   (struct sr_dev_inst *)sdi, USB_TIMEOUT_MS);
 500
 501         if (devc->limit_msec > 0) {
 502                 acq->duration_max = devc->limit_msec;
 503                 sr_info("Acquisition time limit %" PRIu64 " ms.",
 504                         devc->limit_msec);
 505         } else
 506                 acq->duration_max = MAX_LIMIT_MSEC;
 507
 508         if (devc->limit_samples > 0) {
 509                 acq->samples_max = devc->limit_samples;
 510                 sr_info("Acquisition sample count limit %" PRIu64 ".",
 511                         devc->limit_samples);
 512         } else
 513                 acq->samples_max = MAX_LIMIT_SAMPLES;
 514
 515         if (devc->cfg_clock_source == CLOCK_INTERNAL) {
 516                 sr_info("Internal clock, samplerate %" PRIu64 ".",
 517                         devc->samplerate);
 518                 /* Ramp up clock speed to enable samplerates above 100 MS/s. */
 519                 acq->clock_boost = (devc->samplerate > SR_MHZ(100));
 520
 521                 /* If only one of the limits is set, derive the other one. */
 522                 if (devc->limit_msec == 0 && devc->limit_samples > 0)
 523                         acq->duration_max = devc->limit_samples
 524                                         * 1000 / devc->samplerate + 1;
 525                 else if (devc->limit_samples == 0 && devc->limit_msec > 0)
 526                         acq->samples_max = devc->limit_msec
 527                                         * devc->samplerate / 1000;
 528         } else {
 529                 acq->clock_boost = TRUE;
 530
 531                 if (devc->cfg_clock_edge == EDGE_POSITIVE)
 532                         sr_info("External clock, rising edge.");
 533                 else
 534                         sr_info("External clock, falling edge.");
 535         }
 536
 537         acq->rle_enabled = devc->cfg_rle;
 538         devc->acquisition = acq;
 539
 540         return SR_OK;
 541 }
 542
 543 SR_PRIV int lwla_start_acquisition(const struct sr_dev_inst *sdi)
 544 {
 545         struct drv_context *drvc;
 546         struct dev_context *devc;
 547         int ret;
 548
 549         const int poll_interval_ms = 100;
 550
 551         drvc = sdi->driver->context;
 552         devc = sdi->priv;
 553
 554         if (devc->state != STATE_IDLE) {
 555                 sr_err("Not in idle state, cannot start acquisition.");
 556                 return SR_ERR;
 557         }
 558         devc->cancel_requested = FALSE;
 559         devc->transfer_error = FALSE;
 560
 561         ret = init_acquisition_state(sdi);
 562         if (ret != SR_OK)
 563                 return ret;
 564
 565         ret = (*devc->model->setup_acquisition)(sdi);
 566         if (ret != SR_OK) {
 567                 sr_err("Failed to set up device for acquisition.");
 568                 clear_acquisition_state(sdi);
 569                 return ret;
 570         }
 571         /* Register event source for asynchronous USB I/O. */
 572         ret = usb_source_add(sdi->session, drvc->sr_ctx, poll_interval_ms,
 573                              &transfer_event, (struct sr_dev_inst *)sdi);
 574         if (ret != SR_OK) {
 575                 clear_acquisition_state(sdi);
 576                 return ret;
 577         }
 578         ret = submit_request(sdi, STATE_START_CAPTURE);
 579
 580         if (ret == SR_OK) {
 581                 /* Send header packet to the session bus. */
 582                 ret = std_session_send_df_header(sdi, LOG_PREFIX);
 583         }
 584         if (ret != SR_OK) {
 585                 usb_source_remove(sdi->session, drvc->sr_ctx);
 586                 clear_acquisition_state(sdi);
 587         }
 588         return ret;
 589 }