src/hardware/zketech-ebd-usb/protocol.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2018 Sven Bursch-Osewold <sb_git@bursch.com>
   5  * Copyright (C) 2019 King Kévin <kingkevin@cuvoodoo.info>
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation, either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <config.h>
  22 #include "protocol.h"
  23
  24 /* Log a byte-array as hex values. */
  25 static void log_buf(const char *message, uint8_t buf[], size_t count)
  26 {
  27         char buffer[count * 2 + 1];
  28
  29         for (size_t i = 0; i < count; i++) {
  30                 sprintf(&buffer[2 * i], "%02X", buf[i]);
  31         }
  32
  33         buffer[count * 2] = 0;
  34
  35         sr_dbg("%s: %s [%zu bytes]", message, buffer, count);
  36 }
  37
  38 /* Send a command to the device. */
  39 static int send_cmd(struct sr_serial_dev_inst *serial, uint8_t buf[],
  40         size_t count)
  41 {
  42         int ret;
  43
  44         log_buf("Sending", buf, count);
  45         for (size_t byte = 0; byte < count; byte++) {
  46                 ret = serial_write_blocking(serial, &buf[byte], 1, 0);
  47                 if (ret < 0) {
  48                         sr_err("Error sending command: %d.", ret);
  49                         return ret;
  50                 }
  51                 /*
  52                  * Wait between bytes to prevent data loss at the receiving
  53                  * side.
  54                  */
  55                 g_usleep(10000);
  56         }
  57
  58         return (ret == (int)count) ? SR_OK : SR_ERR;
  59 }
  60
  61 /* Decode high byte and low byte into a float. */
  62 static float decode_value(uint8_t hi, uint8_t lo, float divisor)
  63 {
  64         return ((float)hi * 240.0 + (float)lo) / divisor;
  65 }
  66
  67 /* Encode a float into high byte and low byte. */
  68 static void encode_value(float current, uint8_t *hi, uint8_t *lo, float divisor)
  69 {
  70         int value;
  71
  72         value = (int)(current * divisor);
  73         sr_dbg("Value %d %d %d", value, value / 240, value % 240);
  74         *hi = value / 240;
  75         *lo = value % 240;
  76 }
  77
  78 /* Send updated configuration values to the load. */
  79 static int send_cfg(struct sr_serial_dev_inst *serial, struct dev_context *devc)
  80 {
  81         uint8_t send[] = {0xfa, 0x07, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf8};
  82
  83         encode_value(devc->current_limit, &send[2], &send[3], 1000.0);
  84         encode_value(devc->uvc_threshold, &send[4], &send[5], 100.0);
  85
  86         send[8] = send[1] ^ send[2] ^ send[3] ^ send[4] ^ send[5] ^ send[6] ^ send[7];
  87
  88         return send_cmd(serial, send, 10);
  89 }
  90
  91 /* Send the init/connect sequence; drive starts sending voltage and current. */
  92 SR_PRIV int ebd_init(struct sr_serial_dev_inst *serial, struct dev_context *devc)
  93 {
  94         uint8_t init[] = { 0xfa, 0x05, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x05, 0xf8 };
  95
  96         (void)devc;
  97
  98         return send_cmd(serial, init, 10);
  99 }
 100
 101 /* Start the load functionality. */
 102 SR_PRIV int ebd_loadstart(struct sr_serial_dev_inst *serial,
 103         struct dev_context *devc)
 104 {
 105         int ret;
 106         uint8_t start[] = { 0xfa, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0xf8 };
 107
 108         encode_value(devc->current_limit, &start[2], &start[3], 1000.0);
 109         encode_value(devc->uvc_threshold, &start[4], &start[5], 100.0);
 110
 111         start[8] = start[1] ^ start[2] ^ start[3] ^ start[4] ^ start[5] ^ start[6] ^ start[7];
 112
 113         sr_info("Activating load");
 114         ret = send_cmd(serial, start, 10);
 115         if (ret)
 116                 return ret;
 117
 118         sr_dbg("current limit: %.03f", devc->current_limit);
 119         sr_dbg("under-voltage threshold: %.02f", devc->uvc_threshold);
 120         if (ebd_current_is0(devc))
 121                 return SR_OK;
 122
 123         return ret;
 124 }
 125
 126 /* Toggle the load functionality. */
 127 SR_PRIV int ebd_loadtoggle(struct sr_serial_dev_inst *serial,
 128         struct dev_context *devc)
 129 {
 130         uint8_t toggle[] = { 0xfa, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xF8 };
 131
 132         (void)devc;
 133
 134         sr_info("Toggling load");
 135         return send_cmd(serial, toggle, 10);
 136 }
 137
 138 /* Stop the drive. */
 139 SR_PRIV int ebd_stop(struct sr_serial_dev_inst *serial, struct dev_context *devc)
 140 {
 141         uint8_t stop[] = { 0xfa, 0x06, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0xF8 };
 142
 143         (void)devc;
 144
 145         return send_cmd(serial, stop, 10);
 146 }
 147
 148 /**
 149  * Receive a complete message.
 150  *
 151  * @param[in] serial Serial port from which to read the packet
 152  * @param[in] length Buffer length
 153  * @param[out] buf Buffer to write packet to
 154  *
 155  * @return packet length (0 = timeout, -1 = error)
 156  */
 157 SR_PRIV int ebd_read_message(struct sr_serial_dev_inst *serial, size_t length,
 158         uint8_t *buf)
 159 {
 160         int ret;
 161         gboolean message_complete;
 162         size_t turn, max_turns;
 163         size_t message_length;
 164
 165         /* Check parameters. */
 166         if (serial == NULL) {
 167                 sr_err("Serial device to receive packet missing.");
 168                 return -1;
 169         }
 170         if (length < 3) {
 171                 sr_err("Packet buffer not large enough.");
 172                 return -1;
 173         }
 174         if (buf == NULL) {
 175                 sr_err("Packet buffer missing.");
 176                 return -1;
 177         }
 178
 179         message_complete = FALSE;
 180         turn = 0;
 181         max_turns = 200;
 182         message_length = 0;
 183         buf[message_length] = 0;
 184
 185         /* Try to read data. */
 186         while (!message_complete && turn < max_turns) {
 187                 /* Wait for header byte. */
 188                 message_length = 0;
 189                 while ((buf[0] != MSG_FRAME_BEGIN) && (turn < max_turns)) {
 190                         ret = serial_read_blocking(serial, &buf[0], 1, serial_timeout(serial, 1));
 191                         if (ret < 0) {
 192                                 sr_err("Error %d reading byte.", ret);
 193                                 return ret;
 194                         } else if (ret == 1) {
 195                                 if (buf[message_length] != MSG_FRAME_BEGIN) {
 196                                         sr_warn("Not frame begin byte %02x received",
 197                                                 buf[message_length]);
 198                                 } else {
 199                                         sr_dbg("Message header received: %02x",
 200                                                 buf[message_length]);
 201                                         message_length += ret;
 202                                 }
 203                         }
 204                         turn++;
 205                 }
 206                 /* Read until end byte. */
 207                 while ((buf[message_length - 1] != MSG_FRAME_END)
 208                         && (message_length < length) && (turn < max_turns)) {
 209
 210                         ret = serial_read_blocking(serial, &buf[message_length], 1, serial_timeout(serial, 1));
 211                         if (ret < 0) {
 212                                 sr_err("Error %d reading byte.", ret);
 213                                 return ret;
 214                         } else if (ret == 1) {
 215                                 if (buf[message_length] == MSG_FRAME_BEGIN) {
 216                                         sr_warn("Frame begin before end received");
 217                                         message_length = 1;
 218                                 } else {
 219                                         sr_dbg("Message data received: %02x",
 220                                                 buf[message_length]);
 221                                         message_length += ret;
 222                                 }
 223                         }
 224                         turn++;
 225                 }
 226                 /* Verify frame. */
 227                 if (turn < max_turns) {
 228                         if (buf[message_length - 1] == MSG_FRAME_END) {
 229                                 message_complete = TRUE;
 230                                 sr_dbg("Message end received");
 231                         } else {
 232                                 sr_warn("Frame end not received");
 233                         }
 234                 } else {
 235                         sr_warn("Invalid data and timeout");
 236                 }
 237         }
 238
 239         if (message_complete && message_length > 2) {
 240                 ret = message_length;
 241         } else if (turn >= max_turns) {
 242                 ret = 0;
 243         } else {
 244                 ret = -1;
 245         }
 246         return ret;
 247 }
 248
 249 static void ebd_send_value(const struct sr_dev_inst *sdi, struct sr_channel *ch,
 250         float value, enum sr_mq mq, enum sr_unit unit, int digits)
 251 {
 252         struct sr_datafeed_packet packet;
 253         struct sr_datafeed_analog analog;
 254         struct sr_analog_encoding encoding;
 255         struct sr_analog_meaning meaning;
 256         struct sr_analog_spec spec;
 257
 258         sr_analog_init(&analog, &encoding, &meaning, &spec, digits);
 259         analog.meaning->channels = g_slist_append(NULL, ch);
 260         analog.num_samples = 1;
 261         analog.data = &value;
 262         analog.meaning->mq = mq;
 263         analog.meaning->unit = unit;
 264         analog.meaning->mqflags = SR_MQFLAG_DC;
 265
 266         packet.type = SR_DF_ANALOG;
 267         packet.payload = &analog;
 268         sr_session_send(sdi, &packet);
 269         g_slist_free(analog.meaning->channels);
 270 }
 271
 272 SR_PRIV int ebd_receive_data(int fd, int revents, void *cb_data)
 273 {
 274         struct sr_dev_inst *sdi;
 275         struct dev_context *devc;
 276         struct sr_serial_dev_inst *serial;
 277         float current, current_limit;
 278         float voltage, voltage_dp, voltage_dm, uvc_threshold;
 279         uint8_t reply[MSG_MAX_LEN];
 280         int ret, i;
 281         uint8_t checksum;
 282
 283         (void)revents;
 284         (void)fd;
 285
 286         if (!(sdi = cb_data))
 287                 return FALSE;
 288
 289         if (!(devc = sdi->priv))
 290                 return FALSE;
 291
 292         serial = sdi->conn;
 293         current_limit = devc->current_limit;
 294         uvc_threshold = devc->uvc_threshold;
 295
 296         ret = ebd_read_message(serial, MSG_MAX_LEN, reply);
 297
 298         /* Tests for correct message. */
 299         if (ret == -1) {
 300                 sr_err("Can't receive messages");
 301                 return SR_ERR;
 302         } else if (ret == 0) {
 303                 sr_err("No messages received");
 304                 devc->running = FALSE;
 305                 return 0;
 306         } else if ((ret != 19) ||
 307                 ((reply[1] != 0x00) && (reply[1] != 0x0a) && (reply[1] != 0x64) && (reply[1] != 0x6e))) {
 308
 309                 sr_info("Not measurement message received");
 310                 return ret;
 311         }
 312
 313         /* Verify checksum */
 314         checksum = 0;
 315         for (i = 1; i < ret - 1; i++) {
 316                 checksum ^= reply[i];
 317         }
 318         if (checksum != 0) {
 319                 sr_warn("Invalid checksum");
 320                 /* Don't exit on wrong checksum, the device can recover */
 321                 return ret;
 322         }
 323
 324         devc->running = TRUE;
 325         if ((reply[1] == 0x00) || (reply[1] == 0x64))
 326                 devc->load_activated = FALSE;
 327         else if ((reply[1] == 0x0a) || (reply[1] == 0x6e))
 328                 devc->load_activated = TRUE;
 329
 330         /* Calculate values. */
 331         current = decode_value(reply[2], reply[3], 10000.0);
 332         voltage = decode_value(reply[4], reply[5], 1000.0);
 333         voltage_dp = decode_value(reply[6], reply[7], 1000.0);
 334         voltage_dm = decode_value(reply[8], reply[9], 1000.0);
 335         if (reply[1] == 0x0a) {
 336                 current_limit = decode_value(reply[10], reply[11], 1000.0);
 337                 uvc_threshold = decode_value(reply[12], reply[13], 100.0);
 338         }
 339
 340         sr_dbg("VBUS current %.04f A", current);
 341         sr_dbg("VBUS voltage %.03f V", voltage);
 342         sr_dbg("D+ voltage %.03f V", voltage_dp);
 343         sr_dbg("D- voltage %.03f V", voltage_dm);
 344         if (reply[1] == 0x0a) {
 345                 sr_dbg("Current limit %.03f A", current_limit);
 346                 sr_dbg("UVC threshold %.03f V", uvc_threshold);
 347         }
 348
 349         /* Update load state. */
 350         if (devc->load_activated && ebd_current_is0(devc)) {
 351                 ebd_loadtoggle(serial, devc);
 352         } else if (!devc->load_activated && !ebd_current_is0(devc)) {
 353                 ebd_loadstart(serial, devc);
 354         } else if (devc->load_activated &&
 355                 ((current_limit != devc->current_limit) || (uvc_threshold != devc->uvc_threshold))) {
 356
 357                 sr_dbg("Adjusting limit from %.03f A %.03f V to %.03f A %.03f V",
 358                         current_limit, uvc_threshold, devc->current_limit,
 359                         devc->uvc_threshold);
 360                 send_cfg(serial, devc);
 361         }
 362
 363         /* Begin frame. */
 364         std_session_send_df_frame_begin(sdi);
 365
 366         /* Values */
 367         ebd_send_value(sdi, sdi->channels->data, voltage,
 368                 SR_MQ_VOLTAGE, SR_UNIT_VOLT, 3);
 369         ebd_send_value(sdi, sdi->channels->next->data, current,
 370                 SR_MQ_CURRENT, SR_UNIT_AMPERE, 4);
 371         ebd_send_value(sdi, sdi->channels->next->next->data, voltage_dp,
 372                 SR_MQ_VOLTAGE, SR_UNIT_VOLT, 3);
 373         ebd_send_value(sdi, sdi->channels->next->next->next->data, voltage_dm,
 374                 SR_MQ_VOLTAGE, SR_UNIT_VOLT, 3);
 375
 376         /* End frame. */
 377         std_session_send_df_frame_end(sdi);
 378
 379         sr_sw_limits_update_samples_read(&devc->limits, 1);
 380         if (sr_sw_limits_check(&devc->limits))
 381                 sr_dev_acquisition_stop(sdi);
 382
 383         return TRUE;
 384 }
 385
 386 SR_PRIV int ebd_get_current_limit(const struct sr_dev_inst *sdi, float *current)
 387 {
 388         struct dev_context *devc;
 389
 390         if (!(devc = sdi->priv))
 391                 return SR_ERR;
 392
 393         g_mutex_lock(&devc->rw_mutex);
 394         *current = devc->current_limit;
 395         g_mutex_unlock(&devc->rw_mutex);
 396
 397         return SR_OK;
 398 }
 399
 400 SR_PRIV int ebd_set_current_limit(const struct sr_dev_inst *sdi, float current)
 401 {
 402         struct dev_context *devc;
 403         int ret;
 404
 405         if (!(devc = sdi->priv))
 406                 return SR_ERR;
 407
 408         g_mutex_lock(&devc->rw_mutex);
 409         devc->current_limit = current;
 410
 411         if (!devc->running) {
 412                 sr_dbg("Setting current limit later.");
 413                 g_mutex_unlock(&devc->rw_mutex);
 414                 return SR_OK;
 415         }
 416
 417         sr_dbg("Setting current limit to %fV.", current);
 418
 419         if (devc->load_activated) {
 420                 if (ebd_current_is0(devc)) {
 421                         /* Stop load. */
 422                         ret = ebd_loadtoggle(sdi->conn, devc);
 423                 } else {
 424                         /* Send new current. */
 425                         ret = send_cfg(sdi->conn, devc);
 426                 }
 427         } else {
 428                 if (ebd_current_is0(devc)) {
 429                         /* Nothing to do. */
 430                         ret = SR_OK;
 431                 } else {
 432                         /* Start load. */
 433                         ret = ebd_loadstart(sdi->conn, devc);
 434                 }
 435         }
 436
 437         g_mutex_unlock(&devc->rw_mutex);
 438
 439         return ret;
 440 }
 441
 442 SR_PRIV int ebd_get_uvc_threshold(const struct sr_dev_inst *sdi, float *voltage)
 443 {
 444         struct dev_context *devc;
 445
 446         if (!(devc = sdi->priv))
 447                 return SR_ERR;
 448
 449         g_mutex_lock(&devc->rw_mutex);
 450         *voltage = devc->uvc_threshold;
 451         g_mutex_unlock(&devc->rw_mutex);
 452
 453         return SR_OK;
 454 }
 455
 456 SR_PRIV int ebd_set_uvc_threshold(const struct sr_dev_inst *sdi, float voltage)
 457 {
 458         struct dev_context *devc;
 459         int ret;
 460
 461         if (!(devc = sdi->priv))
 462                 return SR_ERR;
 463
 464         g_mutex_lock(&devc->rw_mutex);
 465         devc->uvc_threshold = voltage;
 466
 467         if (!devc->running) {
 468                 sr_dbg("Setting uvc threshold later.");
 469                 g_mutex_unlock(&devc->rw_mutex);
 470                 return SR_OK;
 471         }
 472
 473         sr_dbg("Setting uvc threshold to %fV.", voltage);
 474
 475         if (devc->load_activated) {
 476                 if (ebd_current_is0(devc)) {
 477                         /* Stop load. */
 478                         ret = ebd_loadtoggle(sdi->conn, devc);
 479                 } else {
 480                         /* Send new current. */
 481                         ret = send_cfg(sdi->conn, devc);
 482                 }
 483         } else {
 484                 if (ebd_current_is0(devc)) {
 485                         /* Nothing to do. */
 486                         ret = SR_OK;
 487                 } else {
 488                         /* Start load. */
 489                         ret = ebd_loadstart(sdi->conn, devc);
 490                 }
 491         }
 492
 493         g_mutex_unlock(&devc->rw_mutex);
 494
 495         return ret;
 496 }
 497
 498 SR_PRIV gboolean ebd_current_is0(struct dev_context *devc)
 499 {
 500         return devc->current_limit < 0.001;
 501 }