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         size_t i;
  28         char buffer[count * 2 + 1];
  29
  30         for (i = 0; i < count; i++) {
  31                 sprintf(&buffer[2 * i], "%02X", buf[i]);
  32         }
  33
  34         buffer[count * 2] = 0;
  35
  36         sr_dbg("%s: %s [%zu bytes]", message, buffer, count);
  37 }
  38
  39 /* Send a command to the device. */
  40 static int send_cmd(struct sr_serial_dev_inst *serial, uint8_t buf[],
  41         size_t count)
  42 {
  43         int ret;
  44
  45         log_buf("Sending", buf, count);
  46         for (size_t byte = 0; byte < count; byte++) {
  47                 ret = serial_write_blocking(serial, &buf[byte], 1, 0);
  48                 if (ret < 0) {
  49                         sr_err("Error sending command: %d.", ret);
  50                         return ret;
  51                 }
  52                 /*
  53                  * Wait between bytes to prevent data loss at the receiving
  54                  * side.
  55                  */
  56                 g_usleep(10000);
  57         }
  58
  59         return (ret == (int)count) ? SR_OK : SR_ERR;
  60 }
  61
  62 /* Decode high byte and low byte into a float. */
  63 static float decode_value(uint8_t hi, uint8_t lo, float divisor)
  64 {
  65         return ((float)hi * 240.0 + (float)lo) / divisor;
  66 }
  67
  68 /* Encode a float into high byte and low byte. */
  69 static void encode_value(float current, uint8_t *hi, uint8_t *lo, float divisor)
  70 {
  71         int value;
  72
  73         value = (int)(current * divisor);
  74         sr_dbg("Value %d %d %d", value, value / 240, value % 240);
  75         *hi = value / 240;
  76         *lo = value % 240;
  77 }
  78
  79 /* Send updated configuration values to the load. */
  80 static int send_cfg(struct sr_serial_dev_inst *serial, struct dev_context *devc)
  81 {
  82         uint8_t send[] =
  83                 { 0xfa, 0x07, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf8 };
  84
  85         encode_value(devc->current_limit, &send[2], &send[3], 1000.0);
  86         encode_value(devc->uvc_threshold, &send[4], &send[5], 100.0);
  87
  88         send[8] = send[1] ^ send[2] ^ send[3] ^ send[4] ^ send[5]
  89                 ^ send[6] ^ send[7];
  90
  91         return send_cmd(serial, send, 10);
  92 }
  93
  94 /* Send the init/connect sequence; drive starts sending voltage and current. */
  95 SR_PRIV int ebd_init(struct sr_serial_dev_inst *serial, struct dev_context *devc)
  96 {
  97         uint8_t init[] =
  98                 { 0xfa, 0x05, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x05, 0xf8 };
  99
 100         (void)devc;
 101
 102         return send_cmd(serial, init, 10);
 103 }
 104
 105 /* Start the load functionality. */
 106 SR_PRIV int ebd_loadstart(struct sr_serial_dev_inst *serial,
 107         struct dev_context *devc)
 108 {
 109         int ret;
 110         uint8_t start[] =
 111                 { 0xfa, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0xf8 };
 112
 113         encode_value(devc->current_limit, &start[2], &start[3], 1000.0);
 114         encode_value(devc->uvc_threshold, &start[4], &start[5], 100.0);
 115
 116         start[8] = start[1] ^ start[2] ^ start[3] ^ start[4] ^ start[5]
 117                 ^ start[6] ^ start[7];
 118
 119         sr_info("Activating load");
 120         ret = send_cmd(serial, start, 10);
 121         if (ret)
 122                 return ret;
 123
 124         sr_dbg("current limit: %.03f", devc->current_limit);
 125         sr_dbg("under-voltage threshold: %.02f", devc->uvc_threshold);
 126         if (ebd_current_is0(devc))
 127                 return SR_OK;
 128
 129         return ret;
 130 }
 131
 132 /* Toggle the load functionality. */
 133 SR_PRIV int ebd_loadtoggle(struct sr_serial_dev_inst *serial,
 134         struct dev_context *devc)
 135 {
 136         uint8_t toggle[] =
 137                 { 0xfa, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xF8 };
 138
 139         (void) devc;
 140
 141         sr_info("Toggling load");
 142         return send_cmd(serial, toggle, 10);
 143 }
 144
 145 /* Stop the drive. */
 146 SR_PRIV int ebd_stop(struct sr_serial_dev_inst *serial, struct dev_context *devc)
 147 {
 148         uint8_t stop[] =
 149                 { 0xfa, 0x06, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0xF8 };
 150
 151         (void) devc;
 152
 153         return send_cmd(serial, stop, 10);
 154 }
 155
 156 /**
 157  * Receive a complete message.
 158  *
 159  * @param[in] serial Serial port from which to read the packet
 160  * @param[in] length Buffer length
 161  * @param[out] buf Buffer to write packet to
 162  *
 163  * @return packet length (0 = timeout, -1 = error)
 164  */
 165 SR_PRIV int ebd_read_message(struct sr_serial_dev_inst *serial, size_t length,
 166         uint8_t *buf)
 167 {
 168         int ret;
 169         gboolean message_complete;
 170         size_t turn, max_turns;
 171         size_t message_length;
 172
 173         /* Check parameters. */
 174         if (serial == NULL) {
 175                 sr_err("Serial device to receive packet missing.");
 176                 return -1;
 177         }
 178         if (length < 3) {
 179                 sr_err("Packet buffer not large enough.");
 180                 return -1;
 181         }
 182         if (buf == NULL) {
 183                 sr_err("Packet buffer missing.");
 184                 return -1;
 185         }
 186
 187         message_complete = FALSE;
 188         turn = 0;
 189         max_turns = 200;
 190         message_length = 0;
 191         buf[message_length] = 0;
 192
 193         /* Try to read data. */
 194         while (!message_complete && turn < max_turns) {
 195                 /* Wait for header byte. */
 196                 message_length = 0;
 197                 while (buf[0] != MSG_FRAME_BEGIN && turn < max_turns) {
 198                         ret = serial_read_blocking(serial, &buf[0], 1,
 199                                 serial_timeout(serial, 1));
 200                         if (ret < 0) {
 201                                 sr_err("Error %d reading byte.", ret);
 202                                 return ret;
 203                         } else if (ret == 1) {
 204                                 if (buf[message_length] != MSG_FRAME_BEGIN) {
 205                                         sr_warn("Not frame begin byte %02x received",
 206                                                 buf[message_length]);
 207                                 } else {
 208                                         sr_dbg("Message header received: %02x",
 209                                                 buf[message_length]);
 210                                         message_length += ret;
 211                                 }
 212                         }
 213                         turn++;
 214                 }
 215                 /* Read until end byte. */
 216                 while (buf[message_length - 1] != MSG_FRAME_END
 217                         && message_length < length && turn < max_turns) {
 218
 219                         ret = serial_read_blocking(serial, &buf[message_length],
 220                                 1, serial_timeout(serial, 1));
 221                         if (ret < 0) {
 222                                 sr_err("Error %d reading byte.", ret);
 223                                 return ret;
 224                         } else if (ret == 1) {
 225                                 if (buf[message_length] == MSG_FRAME_BEGIN) {
 226                                         sr_warn("Frame begin before end received");
 227                                         message_length = 1;
 228                                 } else {
 229                                         sr_dbg("Message data received: %02x",
 230                                                 buf[message_length]);
 231                                         message_length += ret;
 232                                 }
 233                         }
 234                         turn++;
 235                 }
 236                 /* Verify frame. */
 237                 if (turn < max_turns) {
 238                         if (buf[message_length - 1] == MSG_FRAME_END) {
 239                                 message_complete = TRUE;
 240                                 sr_dbg("Message end received");
 241                         } else {
 242                                 sr_warn("Frame end not received");
 243                         }
 244                 } else {
 245                         sr_warn("Invalid data and timeout");
 246                 }
 247         }
 248
 249         if (message_complete && message_length > 2) {
 250                 ret = message_length;
 251         } else if (turn >= max_turns) {
 252                 ret = 0;
 253         } else {
 254                 ret = -1;
 255         }
 256         return ret;
 257 }
 258
 259 static void ebd_send_value(const struct sr_dev_inst *sdi, struct sr_channel *ch,
 260         float value, enum sr_mq mq, enum sr_unit unit, int digits)
 261 {
 262         struct sr_datafeed_packet packet;
 263         struct sr_datafeed_analog analog;
 264         struct sr_analog_encoding encoding;
 265         struct sr_analog_meaning meaning;
 266         struct sr_analog_spec spec;
 267
 268         sr_analog_init(&analog, &encoding, &meaning, &spec, digits);
 269         analog.meaning->channels = g_slist_append(NULL, ch);
 270         analog.num_samples = 1;
 271         analog.data = &value;
 272         analog.meaning->mq = mq;
 273         analog.meaning->unit = unit;
 274         analog.meaning->mqflags = SR_MQFLAG_DC;
 275
 276         packet.type = SR_DF_ANALOG;
 277         packet.payload = &analog;
 278         sr_session_send(sdi, &packet);
 279         g_slist_free(analog.meaning->channels);
 280 }
 281
 282 SR_PRIV int ebd_receive_data(int fd, int revents, void *cb_data)
 283 {
 284         struct sr_dev_inst *sdi;
 285         struct dev_context *devc;
 286         struct sr_serial_dev_inst *serial;
 287         float current, current_limit;
 288         float voltage, voltage_dp, voltage_dm, uvc_threshold;
 289         uint8_t reply[MSG_MAX_LEN];
 290         int ret, i;
 291         uint8_t checksum;
 292
 293         (void)revents;
 294         (void)fd;
 295
 296         if (!(sdi = cb_data))
 297                 return FALSE;
 298
 299         if (!(devc = sdi->priv))
 300                 return FALSE;
 301
 302         serial = sdi->conn;
 303         current_limit = devc->current_limit;
 304         uvc_threshold = devc->uvc_threshold;
 305
 306         ret = ebd_read_message(serial, MSG_MAX_LEN, reply);
 307
 308         /* Tests for correct message. */
 309         if (ret == -1) {
 310                 sr_err("Can't receive messages");
 311                 return SR_ERR;
 312         } else if (ret == 0) {
 313                 sr_err("No messages received");
 314                 devc->running = FALSE;
 315                 return 0;
 316         } else if (ret != 19 ||
 317                 (reply[1] != 0x00 && reply[1] != 0x0a && reply[1] != 0x64 && reply[1] != 0x6e)) {
 318
 319                 sr_info("Not measurement message received");
 320                 return ret;
 321         }
 322
 323         /* Verify checksum */
 324         checksum = 0;
 325         for (i = 1; i < ret - 1; i++) {
 326                 checksum ^= reply[i];
 327         }
 328         if (checksum != 0) {
 329                 sr_warn("Invalid checksum");
 330                 /* Don't exit on wrong checksum, the device can recover */
 331                 return ret;
 332         }
 333
 334         devc->running = TRUE;
 335         if (reply[1] == 0x00 || reply[1] == 0x64)
 336                 devc->load_activated = FALSE;
 337         else if (reply[1] == 0x0a || reply[1] == 0x6e)
 338                 devc->load_activated = TRUE;
 339
 340         /* Calculate values. */
 341         current = decode_value(reply[2], reply[3], 10000.0);
 342         voltage = decode_value(reply[4], reply[5], 1000.0);
 343         voltage_dp = decode_value(reply[6], reply[7], 1000.0);
 344         voltage_dm = decode_value(reply[8], reply[9], 1000.0);
 345         if (reply[1] == 0x0a) {
 346                 current_limit = decode_value(reply[10], reply[11], 1000.0);
 347                 uvc_threshold = decode_value(reply[12], reply[13], 100.0);
 348         }
 349
 350         sr_dbg("VBUS current %.04f A", current);
 351         sr_dbg("VBUS voltage %.03f V", voltage);
 352         sr_dbg("D+ voltage %.03f V", voltage_dp);
 353         sr_dbg("D- voltage %.03f V", voltage_dm);
 354         if (reply[1] == 0x0a) {
 355                 sr_dbg("Current limit %.03f A", current_limit);
 356                 sr_dbg("UVC threshold %.03f V", uvc_threshold);
 357         }
 358
 359         /* Update load state. */
 360         if (devc->load_activated && ebd_current_is0(devc)) {
 361                 ebd_loadtoggle(serial, devc);
 362         } else if (!devc->load_activated && !ebd_current_is0(devc)) {
 363                 ebd_loadstart(serial, devc);
 364         } else if (devc->load_activated &&
 365                 (current_limit != devc->current_limit || uvc_threshold != devc->uvc_threshold)) {
 366
 367                 sr_dbg("Adjusting limit from %.03f A %.03f V to %.03f A %.03f V",
 368                         current_limit, uvc_threshold, devc->current_limit,
 369                         devc->uvc_threshold);
 370                 send_cfg(serial, devc);
 371         }
 372
 373         /* Begin frame. */
 374         std_session_send_df_frame_begin(sdi);
 375
 376         /* Values */
 377         ebd_send_value(sdi, sdi->channels->data, voltage,
 378                 SR_MQ_VOLTAGE, SR_UNIT_VOLT, 3);
 379         ebd_send_value(sdi, sdi->channels->next->data, current,
 380                 SR_MQ_CURRENT, SR_UNIT_AMPERE, 4);
 381         ebd_send_value(sdi, sdi->channels->next->next->data, voltage_dp,
 382                 SR_MQ_VOLTAGE, SR_UNIT_VOLT, 3);
 383         ebd_send_value(sdi, sdi->channels->next->next->next->data, voltage_dm,
 384                 SR_MQ_VOLTAGE, SR_UNIT_VOLT, 3);
 385
 386         /* End frame. */
 387         std_session_send_df_frame_end(sdi);
 388
 389         sr_sw_limits_update_samples_read(&devc->limits, 1);
 390         if (sr_sw_limits_check(&devc->limits))
 391                 sr_dev_acquisition_stop(sdi);
 392
 393         return TRUE;
 394 }
 395
 396 SR_PRIV int ebd_get_current_limit(const struct sr_dev_inst *sdi, float *current)
 397 {
 398         struct dev_context *devc;
 399
 400         if (!(devc = sdi->priv))
 401                 return SR_ERR;
 402
 403         g_mutex_lock(&devc->rw_mutex);
 404         *current = devc->current_limit;
 405         g_mutex_unlock(&devc->rw_mutex);
 406
 407         return SR_OK;
 408 }
 409
 410 SR_PRIV int ebd_set_current_limit(const struct sr_dev_inst *sdi, float current)
 411 {
 412         struct dev_context *devc;
 413         int ret;
 414
 415         if (!(devc = sdi->priv))
 416                 return SR_ERR;
 417
 418         g_mutex_lock(&devc->rw_mutex);
 419         devc->current_limit = current;
 420
 421         if (!devc->running) {
 422                 sr_dbg("Setting current limit later.");
 423                 g_mutex_unlock(&devc->rw_mutex);
 424                 return SR_OK;
 425         }
 426
 427         sr_dbg("Setting current limit to %fV.", current);
 428
 429         if (devc->load_activated) {
 430                 if (ebd_current_is0(devc)) {
 431                         /* Stop load. */
 432                         ret = ebd_loadtoggle(sdi->conn, devc);
 433                 } else {
 434                         /* Send new current. */
 435                         ret = send_cfg(sdi->conn, devc);
 436                 }
 437         } else {
 438                 if (ebd_current_is0(devc)) {
 439                         /* Nothing to do. */
 440                         ret = SR_OK;
 441                 } else {
 442                         /* Start load. */
 443                         ret = ebd_loadstart(sdi->conn, devc);
 444                 }
 445         }
 446
 447         g_mutex_unlock(&devc->rw_mutex);
 448
 449         return ret;
 450 }
 451
 452 SR_PRIV int ebd_get_uvc_threshold(const struct sr_dev_inst *sdi, float *voltage)
 453 {
 454         struct dev_context *devc;
 455
 456         if (!(devc = sdi->priv))
 457                 return SR_ERR;
 458
 459         g_mutex_lock(&devc->rw_mutex);
 460         *voltage = devc->uvc_threshold;
 461         g_mutex_unlock(&devc->rw_mutex);
 462
 463         return SR_OK;
 464 }
 465
 466 SR_PRIV int ebd_set_uvc_threshold(const struct sr_dev_inst *sdi, float voltage)
 467 {
 468         struct dev_context *devc;
 469         int ret;
 470
 471         if (!(devc = sdi->priv))
 472                 return SR_ERR;
 473
 474         g_mutex_lock(&devc->rw_mutex);
 475         devc->uvc_threshold = voltage;
 476
 477         if (!devc->running) {
 478                 sr_dbg("Setting uvc threshold later.");
 479                 g_mutex_unlock(&devc->rw_mutex);
 480                 return SR_OK;
 481         }
 482
 483         sr_dbg("Setting uvc threshold to %fV.", voltage);
 484
 485         if (devc->load_activated) {
 486                 if (ebd_current_is0(devc)) {
 487                         /* Stop load. */
 488                         ret = ebd_loadtoggle(sdi->conn, devc);
 489                 } else {
 490                         /* Send new current. */
 491                         ret = send_cfg(sdi->conn, devc);
 492                 }
 493         } else {
 494                 if (ebd_current_is0(devc)) {
 495                         /* Nothing to do. */
 496                         ret = SR_OK;
 497                 } else {
 498                         /* Start load. */
 499                         ret = ebd_loadstart(sdi->conn, devc);
 500                 }
 501         }
 502
 503         g_mutex_unlock(&devc->rw_mutex);
 504
 505         return ret;
 506 }
 507
 508 SR_PRIV gboolean ebd_current_is0(struct dev_context *devc)
 509 {
 510         return devc->current_limit < 0.001;
 511 }