hardware/tekpower-dmm/api.c

   1 /*
   2  * This file is part of the sigrok project.
   3  *
   4  * Copyright (C) 2012 Bert Vermeulen <bert@biot.com>
   5  * Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.com>
   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 <glib.h>
  22 #include <sys/types.h>
  23 #include <sys/stat.h>
  24 #include <fcntl.h>
  25 #include <string.h>
  26 #include <errno.h>
  27 #include "libsigrok.h"
  28 #include "libsigrok-internal.h"
  29 #include "protocol.h"
  30
  31 static const int hwopts[] = {
  32         SR_HWOPT_CONN,
  33         SR_HWOPT_SERIALCOMM,
  34         0,
  35 };
  36
  37 static const int hwcaps[] = {
  38         SR_HWCAP_MULTIMETER,
  39         SR_HWCAP_LIMIT_SAMPLES,
  40         SR_HWCAP_CONTINUOUS,
  41         0,
  42 };
  43
  44 static const char *probe_names[] = {
  45         "Probe",
  46         NULL,
  47 };
  48
  49 SR_PRIV struct sr_dev_driver tekpower_dmm_driver_info;
  50 static struct sr_dev_driver *di = &tekpower_dmm_driver_info;
  51
  52 /* Properly close and free all devices. */
  53 static int clear_instances(void)
  54 {
  55         struct sr_dev_inst *sdi;
  56         struct drv_context *drvc;
  57         struct dev_context *devc;
  58         GSList *l;
  59
  60         if (!(drvc = di->priv))
  61                 return SR_OK;
  62
  63         drvc = di->priv;
  64         for (l = drvc->instances; l; l = l->next) {
  65                 if (!(sdi = l->data))
  66                         continue;
  67                 if (!(devc = sdi->priv))
  68                         continue;
  69                 sr_serial_dev_inst_free(devc->serial);
  70                 sr_dev_inst_free(sdi);
  71         }
  72         g_slist_free(drvc->instances);
  73         drvc->instances = NULL;
  74
  75         return SR_OK;
  76 }
  77
  78 static int hw_init(void)
  79 {
  80         struct drv_context *drvc;
  81
  82         if (!(drvc = g_try_malloc0(sizeof(struct drv_context)))) {
  83                 sr_err("Driver context malloc failed.");
  84                 return SR_ERR_MALLOC;
  85         }
  86
  87         di->priv = drvc;
  88
  89         return SR_OK;
  90 }
  91
  92 static int serial_readline(int fd, char **buf, int *buflen,
  93                            uint64_t timeout_ms)
  94 {
  95         uint64_t start;
  96         int maxlen, len;
  97
  98         timeout_ms *= 1000;
  99         start = g_get_monotonic_time();
 100
 101         maxlen = *buflen;
 102         *buflen = len = 0;
 103         while (1) {
 104                 len = maxlen - *buflen - 1;
 105                 if (len < 1)
 106                         break;
 107                 len = serial_read(fd, *buf + *buflen, 1);
 108                 if (len > 0) {
 109                         *buflen += len;
 110                         *(*buf + *buflen) = '\0';
 111                         if (*buflen > 0 && *(*buf + *buflen - 1) == '\r') {
 112                                 /* Strip LF and terminate. */
 113                                 *(*buf + --*buflen) = '\0';
 114                                 break;
 115                         }
 116                 }
 117                 if (g_get_monotonic_time() - start > timeout_ms)
 118                         /* Timeout */
 119                         break;
 120                 g_usleep(2000);
 121         }
 122
 123         return SR_OK;
 124 }
 125
 126 static GSList *lcd14_scan(const char *conn, const char *serialcomm)
 127 {
 128         struct sr_dev_inst *sdi;
 129         struct drv_context *drvc;
 130         struct dev_context *devc;
 131         struct sr_probe *probe;
 132         struct lcd14_packet *packet;
 133         GSList *devices;
 134         int i, len, fd, retry, good_packets = 0, dropped, ret;
 135         char buf[128], *b;
 136
 137         if ((fd = serial_open(conn, O_RDONLY | O_NONBLOCK)) == -1) {
 138                 sr_err("Unable to open %s: %s.", conn, strerror(errno));
 139                 return NULL;
 140         }
 141         if ((ret = serial_set_paramstr(fd, serialcomm)) != SR_OK) {
 142                 sr_err("Unable to set serial parameters: %d", ret);
 143                 return NULL;
 144         }
 145
 146         sr_info("Probing port %s readonly.", conn);
 147
 148         drvc = di->priv;
 149         b = buf;
 150         retry = 0;
 151         devices = NULL;
 152         serial_flush(fd);
 153
 154         /*
 155          * There's no way to get an ID from the multimeter. It just sends data
 156          * periodically, so the best we can do is check if the packets match
 157          * the expected format.
 158          */
 159         while (!devices && retry < 3) {
 160                 retry++;
 161
 162                 /* Let's get a bit of data and see if we can find a packet. */
 163                 len = sizeof(buf);
 164                 serial_readline(fd, &b, &len, 500);
 165                 if ((len == 0) || (len < LCD14_PACKET_SIZE)) {
 166                         /* Not enough data received, is the DMM connected? */
 167                         continue;
 168                 }
 169
 170                 /* Let's treat our buffer like a stream, and find any
 171                  * valid packets */
 172                 for (i = 0; i < len - LCD14_PACKET_SIZE + 1;) {
 173                         packet = (void *)(&buf[i]);
 174                         if (!lcd14_is_packet_valid(packet, NULL)) {
 175                                 i++;
 176                                 continue;
 177                         }
 178                         good_packets++;
 179                         i += LCD14_PACKET_SIZE;
 180                 }
 181
 182                 /*
 183                  * If we dropped more than two packets worth of data,
 184                  * something is wrong.
 185                  */
 186                 dropped = len - (good_packets * LCD14_PACKET_SIZE);
 187                 if (dropped > 2 * LCD14_PACKET_SIZE)
 188                         continue;
 189
 190                 /* Let's see if we have anything good. */
 191                 if (good_packets == 0)
 192                         continue;
 193
 194                 sr_info("Found device on port %s.", conn);
 195
 196                 if (!(sdi = sr_dev_inst_new(0, SR_ST_INACTIVE, "TekPower",
 197                                             "TP4000ZC", "")))
 198                         return NULL;
 199                 if (!(devc = g_try_malloc0(sizeof(struct dev_context)))) {
 200                         sr_err("Device context malloc failed.");
 201                         return NULL;
 202                 }
 203
 204                 devc->serial = sr_serial_dev_inst_new(conn, -1);
 205                 devc->serialcomm = g_strdup(serialcomm);
 206
 207                 sdi->priv = devc;
 208                 sdi->driver = di;
 209                 if (!(probe = sr_probe_new(0, SR_PROBE_ANALOG, TRUE, "P1")))
 210                         return NULL;
 211                 sdi->probes = g_slist_append(sdi->probes, probe);
 212                 drvc->instances = g_slist_append(drvc->instances, sdi);
 213                 devices = g_slist_append(devices, sdi);
 214                 break;
 215         }
 216
 217         serial_close(fd);
 218         return devices;
 219 }
 220
 221 static GSList *hw_scan(GSList *options)
 222 {
 223         struct sr_hwopt *opt;
 224         GSList *l, *devices;
 225         const char *conn, *serialcomm;
 226
 227         conn = serialcomm = NULL;
 228         for (l = options; l; l = l->next) {
 229                 opt = l->data;
 230                 switch (opt->hwopt) {
 231                 case SR_HWOPT_CONN:
 232                         conn = opt->value;
 233                         break;
 234                 case SR_HWOPT_SERIALCOMM:
 235                         serialcomm = opt->value;
 236                         break;
 237                 }
 238         }
 239         if (!conn)
 240                 return NULL;
 241
 242         if (serialcomm) {
 243                 /* Use the provided comm specs. */
 244                 devices = lcd14_scan(conn, serialcomm);
 245         } else {
 246                 /* Try the default 2400/8n1. */
 247                 devices = lcd14_scan(conn, "2400/8n1");
 248         }
 249
 250         return devices;
 251 }
 252
 253 static GSList *hw_dev_list(void)
 254 {
 255         struct drv_context *drvc;
 256
 257         drvc = di->priv;
 258
 259         return drvc->instances;
 260 }
 261
 262 static int hw_dev_open(struct sr_dev_inst *sdi)
 263 {
 264         int ret;
 265         struct dev_context *devc;
 266
 267         if (!(devc = sdi->priv)) {
 268                 sr_err("sdi->priv was NULL.");
 269                 return SR_ERR_BUG;
 270         }
 271
 272         devc->serial->fd = serial_open(devc->serial->port, O_RDONLY);
 273         if (devc->serial->fd == -1) {
 274                 sr_err("Couldn't open serial port '%s'.", devc->serial->port);
 275                 return SR_ERR;
 276         }
 277
 278         ret = serial_set_paramstr(devc->serial->fd, devc->serialcomm);
 279         if (ret != SR_OK) {
 280                 sr_err("Unable to set serial parameters: %d.", ret);
 281                 return SR_ERR;
 282         }
 283         sdi->status = SR_ST_ACTIVE;
 284
 285         return SR_OK;
 286 }
 287
 288 static int hw_dev_close(struct sr_dev_inst *sdi)
 289 {
 290         struct dev_context *devc;
 291
 292         if (!(devc = sdi->priv)) {
 293                 sr_err("sdi->priv was NULL.");
 294                 return SR_ERR_BUG;
 295         }
 296
 297         if (devc->serial && devc->serial->fd != -1) {
 298                 serial_close(devc->serial->fd);
 299                 devc->serial->fd = -1;
 300                 sdi->status = SR_ST_INACTIVE;
 301         }
 302
 303         return SR_OK;
 304 }
 305
 306 static int hw_cleanup(void)
 307 {
 308         clear_instances();
 309
 310         return SR_OK;
 311 }
 312
 313 static int hw_info_get(int info_id, const void **data,
 314                        const struct sr_dev_inst *sdi)
 315 {
 316         (void)sdi;
 317
 318         switch (info_id) {
 319         case SR_DI_HWOPTS:
 320                 *data = hwopts;
 321                 break;
 322         case SR_DI_HWCAPS:
 323                 *data = hwcaps;
 324                 break;
 325         case SR_DI_NUM_PROBES:
 326                 *data = GINT_TO_POINTER(1);
 327                 break;
 328         case SR_DI_PROBE_NAMES:
 329                 *data = probe_names;
 330                 break;
 331         default:
 332                 return SR_ERR_ARG;
 333         }
 334
 335         return SR_OK;
 336 }
 337
 338 static int hw_dev_config_set(const struct sr_dev_inst *sdi, int hwcap,
 339                              const void *value)
 340 {
 341         struct dev_context *devc;
 342
 343         if (sdi->status != SR_ST_ACTIVE)
 344                 return SR_ERR;
 345
 346         if (!(devc = sdi->priv)) {
 347                 sr_err("sdi->priv was NULL.");
 348                 return SR_ERR_BUG;
 349         }
 350
 351         switch (hwcap) {
 352         case SR_HWCAP_LIMIT_SAMPLES:
 353                 devc->limit_samples = *(const uint64_t *)value;
 354                 sr_dbg("Setting sample limit to %" PRIu64 ".",
 355                        devc->limit_samples);
 356                 break;
 357         default:
 358                 sr_err("Unknown capability: %d.", hwcap);
 359                 return SR_ERR;
 360                 break;
 361         }
 362
 363         return SR_OK;
 364 }
 365
 366 static int hw_dev_acquisition_start(const struct sr_dev_inst *sdi,
 367                                     void *cb_data)
 368 {
 369         struct sr_datafeed_packet packet;
 370         struct sr_datafeed_header header;
 371         struct sr_datafeed_meta_analog meta;
 372         struct dev_context *devc;
 373
 374         if (!(devc = sdi->priv)) {
 375                 sr_err("sdi->priv was NULL.");
 376                 return SR_ERR_BUG;
 377         }
 378
 379         sr_dbg("Starting acquisition.");
 380
 381         devc->cb_data = cb_data;
 382
 383         /*
 384          * Reset the number of samples to take. If we've already collected our
 385          * quota, but we start a new session, and don't reset this, we'll just
 386          * quit without acquiring any new samples.
 387          */
 388         devc->num_samples = 0;
 389
 390         /* Send header packet to the session bus. */
 391         sr_dbg("Sending SR_DF_HEADER.");
 392         packet.type = SR_DF_HEADER;
 393         packet.payload = (uint8_t *)&header;
 394         header.feed_version = 1;
 395         gettimeofday(&header.starttime, NULL);
 396         sr_session_send(devc->cb_data, &packet);
 397
 398         /* Send metadata about the SR_DF_ANALOG packets to come. */
 399         sr_dbg("Sending SR_DF_META_ANALOG.");
 400         packet.type = SR_DF_META_ANALOG;
 401         packet.payload = &meta;
 402         meta.num_probes = 1;
 403         sr_session_send(devc->cb_data, &packet);
 404
 405         /* Poll every 50ms, or whenever some data comes in. */
 406         sr_source_add(devc->serial->fd, G_IO_IN, 50,
 407                       tekpower_dmm_receive_data, (void *)sdi);
 408
 409         return SR_OK;
 410 }
 411
 412 static int hw_dev_acquisition_stop(const struct sr_dev_inst *sdi,
 413                                    void *cb_data)
 414 {
 415         struct sr_datafeed_packet packet;
 416         struct dev_context *devc;
 417
 418         if (sdi->status != SR_ST_ACTIVE)
 419                 return SR_ERR;
 420
 421         if (!(devc = sdi->priv)) {
 422                 sr_err("sdi->priv was NULL.");
 423                 return SR_ERR_BUG;
 424         }
 425
 426         sr_dbg("Stopping acquisition.");
 427
 428         sr_source_remove(devc->serial->fd);
 429         hw_dev_close((struct sr_dev_inst *)sdi);
 430
 431         /* Send end packet to the session bus. */
 432         sr_dbg("Sending SR_DF_END.");
 433         packet.type = SR_DF_END;
 434         sr_session_send(cb_data, &packet);
 435
 436         return SR_OK;
 437 }
 438
 439 SR_PRIV struct sr_dev_driver tekpower_dmm_driver_info = {
 440         .name = "tekpower-dmm",
 441         .longname = "TekPower/Digitek TP4000ZC/DT4000ZC DMM",
 442         .api_version = 1,
 443         .init = hw_init,
 444         .cleanup = hw_cleanup,
 445         .scan = hw_scan,
 446         .dev_list = hw_dev_list,
 447         .dev_clear = clear_instances,
 448         .dev_open = hw_dev_open,
 449         .dev_close = hw_dev_close,
 450         .info_get = hw_info_get,
 451         .dev_config_set = hw_dev_config_set,
 452         .dev_acquisition_start = hw_dev_acquisition_start,
 453         .dev_acquisition_stop = hw_dev_acquisition_stop,
 454         .priv = NULL,
 455 };