src/hardware/baylibre-acme/protocol.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2015 Bartosz Golaszewski <bgolaszewski@baylibre.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 <string.h>
  21 #include <stdlib.h>
  22 #include <errno.h>
  23 #include <fcntl.h>
  24 #include <glib/gstdio.h>
  25 #include "protocol.h"
  26 #include "gpio.h"
  27
  28 struct channel_group_priv {
  29         int hwmon_num;
  30         int probe_type;
  31         int index;
  32 };
  33
  34 struct channel_priv {
  35         int ch_type;
  36         int fd;
  37         struct channel_group_priv *probe;
  38 };
  39
  40 static const uint8_t enrg_i2c_addrs[] = {
  41         0x40, 0x41, 0x44, 0x45, 0x42, 0x43, 0x46, 0x47,
  42 };
  43
  44 static const uint8_t temp_i2c_addrs[] = {
  45         0x0, 0x0, 0x0, 0x0, 0x4c, 0x49, 0x4f, 0x4b,
  46 };
  47
  48 static const uint32_t pws_gpios[] = {
  49         486, 498, 502, 482, 478, 506, 510, 474,
  50 };
  51
  52 static const uint32_t pws_info_gpios[] = {
  53         487, 499, 503, 483, 479, 507, 511, 475,
  54 };
  55
  56 #define MOHM_TO_UOHM(x) ((x) * 1000)
  57 #define UOHM_TO_MOHM(x) ((x) / 1000)
  58
  59 SR_PRIV uint8_t bl_acme_get_enrg_addr(int index)
  60 {
  61         return enrg_i2c_addrs[index];
  62 }
  63
  64 SR_PRIV uint8_t bl_acme_get_temp_addr(int index)
  65 {
  66         return temp_i2c_addrs[index];
  67 }
  68
  69 SR_PRIV gboolean bl_acme_is_sane(void)
  70 {
  71         gboolean status;
  72
  73         /*
  74          * We expect sysfs to be present and mounted at /sys, ina226 and
  75          * tmp435 sensors detected by the system and their appropriate
  76          * drivers loaded and functional.
  77          */
  78         status = g_file_test("/sys", G_FILE_TEST_IS_DIR);
  79         if (!status) {
  80                 sr_err("/sys/ directory not found - sysfs not mounted?");
  81                 return FALSE;
  82         }
  83
  84         return TRUE;
  85 }
  86
  87 static void probe_name_path(unsigned int addr, GString *path)
  88 {
  89         g_string_printf(path,
  90                         "/sys/class/i2c-adapter/i2c-1/1-00%02x/name", addr);
  91 }
  92
  93 /*
  94  * For given address fill buf with the path to appropriate hwmon entry.
  95  */
  96 static void probe_hwmon_path(unsigned int addr, GString *path)
  97 {
  98         g_string_printf(path,
  99                         "/sys/class/i2c-adapter/i2c-1/1-00%02x/hwmon", addr);
 100 }
 101
 102 SR_PRIV gboolean bl_acme_detect_probe(unsigned int addr,
 103                                       int prb_num, const char *prb_name)
 104 {
 105         gboolean ret = FALSE, status;
 106         char *buf = NULL;
 107         GString *path = g_string_sized_new(64);
 108         GError *err = NULL;
 109         gsize size;
 110
 111         probe_name_path(addr, path);
 112         status = g_file_get_contents(path->str, &buf, &size, &err);
 113         if (!status) {
 114                 sr_dbg("Name for probe %d can't be read: %s",
 115                        prb_num, err->message);
 116                 g_string_free(path, TRUE);
 117                 return ret;
 118         }
 119
 120         if (!strncmp(buf, prb_name, strlen(prb_name))) {
 121                 /*
 122                  * Correct driver registered on this address - but is
 123                  * there an actual probe connected?
 124                  */
 125                 probe_hwmon_path(addr, path);
 126                 status = g_file_test(path->str, G_FILE_TEST_IS_DIR);
 127                 if (status) {
 128                         /* We have found an ACME probe. */
 129                         ret = TRUE;
 130                 }
 131         }
 132
 133         g_free(buf);
 134         g_string_free(path, TRUE);
 135
 136         return ret;
 137 }
 138
 139 static int get_hwmon_index(unsigned int addr)
 140 {
 141         int status, hwmon;
 142         GString *path = g_string_sized_new(64);
 143         GError *err = NULL;
 144         GDir *dir;
 145
 146         probe_hwmon_path(addr, path);
 147         dir = g_dir_open(path->str, 0, &err);
 148         if (!dir) {
 149                 sr_err("Error opening %s: %s", path->str, err->message);
 150                 g_string_free(path, TRUE);
 151                 return -1;
 152         }
 153
 154         g_string_free(path, TRUE);
 155
 156         /*
 157          * The directory should contain a single file named hwmonX where X
 158          * is the hwmon index.
 159          */
 160         status = sscanf(g_dir_read_name(dir), "hwmon%d", &hwmon);
 161         g_dir_close(dir);
 162         if (status != 1) {
 163                 sr_err("Unable to determine the hwmon entry");
 164                 return -1;
 165         }
 166
 167         return hwmon;
 168 }
 169
 170 static void append_channel(struct sr_dev_inst *sdi, struct sr_channel_group *cg,
 171                            int index, int type)
 172 {
 173         struct channel_priv *cp;
 174         struct dev_context *devc;
 175         struct sr_channel *ch;
 176         char *name;
 177
 178         devc = sdi->priv;
 179
 180         switch (type) {
 181         case ENRG_PWR:
 182                 name = g_strdup_printf("P%d_ENRG_PWR", index);
 183                 break;
 184         case ENRG_CURR:
 185                 name = g_strdup_printf("P%d_ENRG_CURR", index);
 186                 break;
 187         case ENRG_VOL:
 188                 name = g_strdup_printf("P%d_ENRG_VOL", index);
 189                 break;
 190         case TEMP_IN:
 191                 name = g_strdup_printf("P%d_TEMP_IN", index);
 192                 break;
 193         case TEMP_OUT:
 194                 name = g_strdup_printf("P%d_TEMP_OUT", index);
 195                 break;
 196         default:
 197                 sr_err("Invalid channel type: %d.", type);
 198                 return;
 199         }
 200
 201         cp = g_malloc0(sizeof(struct channel_priv));
 202         cp->ch_type = type;
 203         cp->probe = cg->priv;
 204
 205         ch = sr_channel_new(sdi, devc->num_channels++,
 206                             SR_CHANNEL_ANALOG, TRUE, name);
 207         g_free(name);
 208
 209         ch->priv = cp;
 210         cg->channels = g_slist_append(cg->channels, ch);
 211 }
 212
 213 SR_PRIV gboolean bl_acme_register_probe(struct sr_dev_inst *sdi, int type,
 214                                         unsigned int addr, int prb_num)
 215 {
 216         struct sr_channel_group *cg;
 217         struct channel_group_priv *cgp;
 218         int hwmon;
 219
 220         /* Obtain the hwmon index. */
 221         hwmon = get_hwmon_index(addr);
 222         if (hwmon < 0)
 223                 return FALSE;
 224
 225         cg = g_malloc0(sizeof(struct sr_channel_group));
 226         cgp = g_malloc0(sizeof(struct channel_group_priv));
 227         cgp->hwmon_num = hwmon;
 228         cgp->probe_type = type;
 229         cgp->index = prb_num - 1;
 230         cg->name = g_strdup_printf("Probe_%d", prb_num);
 231         cg->priv = cgp;
 232
 233         if (type == PROBE_ENRG) {
 234                 append_channel(sdi, cg, prb_num, ENRG_PWR);
 235                 append_channel(sdi, cg, prb_num, ENRG_CURR);
 236                 append_channel(sdi, cg, prb_num, ENRG_VOL);
 237         } else if (type == PROBE_TEMP) {
 238                 append_channel(sdi, cg, prb_num, TEMP_IN);
 239                 append_channel(sdi, cg, prb_num, TEMP_OUT);
 240         } else {
 241                 sr_err("Invalid probe type: %d.", type);
 242         }
 243
 244         sdi->channel_groups = g_slist_append(sdi->channel_groups, cg);
 245
 246         return TRUE;
 247 }
 248
 249 SR_PRIV int bl_acme_get_probe_type(const struct sr_channel_group *cg)
 250 {
 251         struct channel_group_priv *cgp = cg->priv;
 252
 253         return cgp->probe_type;
 254 }
 255
 256 SR_PRIV int bl_acme_probe_has_pws(const struct sr_channel_group *cg)
 257 {
 258         struct channel_group_priv *cgp = cg->priv;
 259
 260         return sr_gpio_getval_export(pws_info_gpios[cgp->index]);
 261 }
 262
 263 /*
 264  * Sets path to the hwmon attribute if this channel group
 265  * supports shunt resistance setting. The caller has to supply
 266  * a valid GString.
 267  */
 268 static int get_shunt_path(const struct sr_channel_group *cg, GString *path)
 269 {
 270         struct channel_group_priv *cgp;
 271         int ret = SR_OK, status;
 272
 273         cgp = cg->priv;
 274
 275         if (cgp->probe_type != PROBE_ENRG) {
 276                 sr_err("Probe doesn't support shunt resistance setting");
 277                 return SR_ERR_ARG;
 278         }
 279
 280         g_string_append_printf(path,
 281                                "/sys/class/hwmon/hwmon%d/shunt_resistor",
 282                                cgp->hwmon_num);
 283
 284         /*
 285          * The shunt_resistor sysfs attribute is available
 286          * in the Linux kernel since version 3.20. We have
 287          * to notify the user if this attribute is not present.
 288          */
 289         status = g_file_test(path->str, G_FILE_TEST_EXISTS);
 290         if (!status) {
 291                 sr_err("shunt_resistance attribute not present, please update "
 292                        "your kernel to version >=3.20");
 293                 return SR_ERR_NA;
 294         }
 295
 296         return ret;
 297 }
 298
 299 /*
 300  * Try setting the update_interval sysfs attribute for each probe according
 301  * to samplerate.
 302  */
 303 SR_PRIV void bl_acme_maybe_set_update_interval(const struct sr_dev_inst *sdi,
 304                                                uint64_t samplerate)
 305 {
 306         struct sr_channel_group *cg;
 307         struct channel_group_priv *cgp;
 308         GString *hwmon;
 309         GSList *l;
 310         FILE *fd;
 311
 312         for (l = sdi->channel_groups; l != NULL; l = l->next) {
 313                 cg = l->data;
 314                 cgp = cg->priv;
 315
 316                 hwmon = g_string_sized_new(64);
 317                 g_string_append_printf(hwmon,
 318                                 "/sys/class/hwmon/hwmon%d/update_interval",
 319                                 cgp->hwmon_num);
 320
 321                 if (g_file_test(hwmon->str, G_FILE_TEST_EXISTS)) {
 322                         fd = g_fopen(hwmon->str, "w");
 323                         if (!fd) {
 324                                 g_string_free(hwmon, TRUE);
 325                                 continue;
 326                         }
 327
 328                         g_fprintf(fd, "%" PRIu64 "\n", 1000 / samplerate);
 329                         fclose(fd);
 330                 }
 331
 332                 g_string_free(hwmon, TRUE);
 333         }
 334 }
 335
 336 SR_PRIV int bl_acme_get_shunt(const struct sr_channel_group *cg,
 337                               uint64_t *shunt)
 338 {
 339         GString *path = g_string_sized_new(64);
 340         gchar *contents;
 341         int status, ret = SR_OK;
 342         GError *err = NULL;
 343
 344         status = get_shunt_path(cg, path);
 345         if (status != SR_OK) {
 346                 ret = status;
 347                 goto out;
 348         }
 349
 350         status = g_file_get_contents(path->str, &contents, NULL, &err);
 351         if (!status) {
 352                 sr_err("Error reading shunt resistance: %s", err->message);
 353                 ret = SR_ERR_IO;
 354                 goto out;
 355         }
 356
 357         *shunt = UOHM_TO_MOHM(strtol(contents, NULL, 10));
 358
 359 out:
 360         g_string_free(path, TRUE);
 361         return ret;
 362 }
 363
 364 SR_PRIV int bl_acme_set_shunt(const struct sr_channel_group *cg, uint64_t shunt)
 365 {
 366         GString *path = g_string_sized_new(64);;
 367         int status, ret = SR_OK;
 368         FILE *fd;
 369
 370         status = get_shunt_path(cg, path);
 371         if (status != SR_OK) {
 372                 ret = status;
 373                 goto out;
 374         }
 375
 376         /*
 377          * Can't use g_file_set_contents() here, as it calls open() with
 378          * O_EXEC flag in a sysfs directory thus failing with EACCES.
 379          */
 380         fd = g_fopen(path->str, "w");
 381         if (!fd) {
 382                 sr_err("Error opening %s: %s", path->str, strerror(errno));
 383                 ret = SR_ERR_IO;
 384                 goto out;
 385         }
 386
 387         g_fprintf(fd, "%" PRIu64 "\n", MOHM_TO_UOHM(shunt));
 388         fclose(fd);
 389
 390 out:
 391         g_string_free(path, TRUE);
 392         return ret;
 393 }
 394
 395 SR_PRIV int bl_acme_read_power_state(const struct sr_channel_group *cg,
 396                                      gboolean *off)
 397 {
 398         struct channel_group_priv *cgp;
 399         int val;
 400
 401         cgp = cg->priv;
 402
 403         if (!bl_acme_probe_has_pws(cg)) {
 404                 sr_err("Probe has no power-switch");
 405                 return SR_ERR_ARG;
 406         }
 407
 408         val = sr_gpio_getval_export(pws_gpios[cgp->index]);
 409         *off = val ? FALSE : TRUE;
 410
 411         return SR_OK;
 412 }
 413
 414 SR_PRIV int bl_acme_set_power_off(const struct sr_channel_group *cg,
 415                                   gboolean off)
 416 {
 417         struct channel_group_priv *cgp;
 418         int val;
 419
 420         cgp = cg->priv;
 421
 422         if (!bl_acme_probe_has_pws(cg)) {
 423                 sr_err("Probe has no power-switch");
 424                 return SR_ERR_ARG;
 425         }
 426
 427         val = sr_gpio_setval_export(pws_gpios[cgp->index], off ? 0 : 1);
 428         if (val < 0) {
 429                 sr_err("Error setting power-off state: gpio: %d",
 430                        pws_gpios[cgp->index]);
 431                 return SR_ERR_IO;
 432         }
 433
 434         return SR_OK;
 435 }
 436
 437 static int channel_to_mq(struct sr_channel *ch)
 438 {
 439         struct channel_priv *chp;
 440
 441         chp = ch->priv;
 442
 443         switch (chp->ch_type) {
 444         case ENRG_PWR:
 445                 return SR_MQ_POWER;
 446         case ENRG_CURR:
 447                 return SR_MQ_CURRENT;
 448         case ENRG_VOL:
 449                 return SR_MQ_VOLTAGE;
 450         case TEMP_IN: /* Fallthrough */
 451         case TEMP_OUT:
 452                 return SR_MQ_TEMPERATURE;
 453         default:
 454                 return -1;
 455         }
 456 }
 457
 458 static int channel_to_unit(struct sr_channel *ch)
 459 {
 460         struct channel_priv *chp;
 461
 462         chp = ch->priv;
 463
 464         switch (chp->ch_type) {
 465         case ENRG_PWR:
 466                 return SR_UNIT_WATT;
 467         case ENRG_CURR:
 468                 return SR_UNIT_AMPERE;
 469         case ENRG_VOL:
 470                 return SR_UNIT_VOLT;
 471         case TEMP_IN: /* Fallthrough */
 472         case TEMP_OUT:
 473                 return SR_UNIT_CELSIUS;
 474         default:
 475                 return -1;
 476         }
 477 }
 478
 479 /* We need to scale measurements down from the units used by the drivers. */
 480 static float adjust_data(int val, int type)
 481 {
 482         switch (type) {
 483         case ENRG_PWR:
 484                 return ((float)val) / 1000000.0;
 485         case ENRG_CURR: /* Fallthrough */
 486         case ENRG_VOL: /* Fallthrough */
 487         case TEMP_IN: /* Fallthrough */
 488         case TEMP_OUT:
 489                 return ((float)val) / 1000.0;
 490         default:
 491                 return 0.0;
 492         }
 493 }
 494
 495 static float read_sample(struct sr_channel *ch)
 496 {
 497         struct channel_priv *chp;
 498         char buf[16];
 499         ssize_t len;
 500         int fd;
 501
 502         chp = ch->priv;
 503         fd = chp->fd;
 504
 505         lseek(fd, 0, SEEK_SET);
 506
 507         len = read(fd, buf, sizeof(buf));
 508         if (len < 0) {
 509                 sr_err("Error reading from channel %s (hwmon: %s): %s",
 510                         ch->name, chp->probe->hwmon_num, strerror(errno));
 511                 ch->enabled = FALSE;
 512                 return -1.0;
 513         }
 514
 515         return adjust_data(strtol(buf, NULL, 10), chp->ch_type);
 516 }
 517
 518 SR_PRIV int bl_acme_open_channel(struct sr_channel *ch)
 519 {
 520         struct channel_priv *chp;
 521         char path[64], *file;
 522         int fd;
 523
 524         chp = ch->priv;
 525
 526         switch (chp->ch_type) {
 527         case ENRG_PWR:  file = "power1_input";  break;
 528         case ENRG_CURR: file = "curr1_input";   break;
 529         case ENRG_VOL:  file = "in1_input";     break;
 530         case TEMP_IN:   file = "temp1_input";   break;
 531         case TEMP_OUT:  file = "temp2_input";   break;
 532         default:
 533                 sr_err("Invalid channel type: %d.", chp->ch_type);
 534                 return SR_ERR;
 535         }
 536
 537         snprintf(path, sizeof(path), "/sys/class/hwmon/hwmon%d/%s",
 538                  chp->probe->hwmon_num, file);
 539
 540         fd = open(path, O_RDONLY);
 541         if (fd < 0) {
 542                 sr_err("Error opening %s: %s", path, strerror(errno));
 543                 ch->enabled = FALSE;
 544                 return SR_ERR;
 545         }
 546
 547         chp->fd = fd;
 548
 549         return 0;
 550 }
 551
 552 SR_PRIV void bl_acme_close_channel(struct sr_channel *ch)
 553 {
 554         struct channel_priv *chp;
 555
 556         chp = ch->priv;
 557         close(chp->fd);
 558         chp->fd = -1;
 559 }
 560
 561 SR_PRIV int bl_acme_receive_data(int fd, int revents, void *cb_data)
 562 {
 563         uint32_t cur_time, elapsed_time;
 564         uint64_t nrexpiration;
 565         struct sr_datafeed_packet packet, framep;
 566         struct sr_datafeed_analog analog;
 567         struct sr_dev_inst *sdi;
 568         struct sr_channel *ch;
 569         struct dev_context *devc;
 570         GSList *chl, chonly;
 571         float valf;
 572
 573         (void)fd;
 574         (void)revents;
 575
 576         sdi = cb_data;
 577         if (!sdi)
 578                 return TRUE;
 579
 580         devc = sdi->priv;
 581         if (!devc)
 582                 return TRUE;
 583
 584         packet.type = SR_DF_ANALOG;
 585         packet.payload = &analog;
 586         memset(&analog, 0, sizeof(struct sr_datafeed_analog));
 587         analog.data = &valf;
 588
 589         if (read(devc->timer_fd, &nrexpiration, sizeof(nrexpiration)) < 0) {
 590                 sr_warn("Failed to read timer information");
 591                 return TRUE;
 592         }
 593
 594         /*
 595          * We were not able to process the previous timer expiration, we are
 596          * overloaded.
 597          */
 598         if (nrexpiration > 1)
 599                 devc->samples_missed += nrexpiration - 1;
 600
 601         framep.type = SR_DF_FRAME_BEGIN;
 602         sr_session_send(cb_data, &framep);
 603
 604         /*
 605          * Due to different units used in each channel we're sending
 606          * samples one-by-one.
 607          */
 608         for (chl = sdi->channels; chl; chl = chl->next) {
 609                 ch = chl->data;
 610                 if (!ch->enabled)
 611                         continue;
 612                 chonly.next = NULL;
 613                 chonly.data = ch;
 614                 analog.channels = &chonly;
 615                 analog.num_samples = 1;
 616                 analog.mq = channel_to_mq(chl->data);
 617                 analog.unit = channel_to_unit(ch);
 618
 619                 valf = read_sample(ch);
 620
 621                 sr_session_send(cb_data, &packet);
 622         }
 623
 624         framep.type = SR_DF_FRAME_END;
 625         sr_session_send(cb_data, &framep);
 626
 627         devc->samples_read++;
 628         if (devc->limit_samples > 0 &&
 629             devc->samples_read >= devc->limit_samples) {
 630                 sr_info("Requested number of samples reached.");
 631                 sdi->driver->dev_acquisition_stop(sdi, cb_data);
 632                 devc->last_sample_fin = g_get_monotonic_time();
 633                 return TRUE;
 634         } else if (devc->limit_msec > 0) {
 635                 cur_time = g_get_monotonic_time();
 636                 elapsed_time = cur_time - devc->start_time;
 637
 638                 if (elapsed_time >= devc->limit_msec) {
 639                         sr_info("Sampling time limit reached.");
 640                         sdi->driver->dev_acquisition_stop(sdi, cb_data);
 641                         devc->last_sample_fin = g_get_monotonic_time();
 642                         return TRUE;
 643                 }
 644         }
 645
 646         devc->last_sample_fin = g_get_monotonic_time();
 647         return TRUE;
 648 }