src/hardware/brymen-bm86x/protocol.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2014 Aurelien Jacobs <aurel@gnuage.org>
   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 <math.h>
  23 #include "protocol.h"
  24
  25 #define USB_TIMEOUT 500
  26
  27 static const char char_map[128] = {
  28         [0x20] = '-',
  29         [0x5F] = '0',
  30         [0x50] = '1',
  31         [0x6D] = '2',
  32         [0x7C] = '3',
  33         [0x72] = '4',
  34         [0x3E] = '5',
  35         [0x3F] = '6',
  36         [0x54] = '7',
  37         [0x7F] = '8',
  38         [0x7E] = '9',
  39         [0x0F] = 'C',
  40         [0x27] = 'F',
  41         [0x0B] = 'L',
  42         [0x79] = 'd',
  43         [0x10] = 'i',
  44         [0x39] = 'o',
  45 };
  46
  47 static int brymen_bm86x_parse_digits(const unsigned char *buf, int length,
  48                                      char *str, float *floatval,
  49                                      char *temp_unit, int *digits, int flag)
  50 {
  51         char c, *p = str;
  52         int i, ret;
  53
  54         *digits = INT_MIN;
  55
  56         if (buf[0] & flag)
  57                 *p++ = '-';
  58         for (i = 0; i < length; i++) {
  59                 if (i && i < 5 && buf[i+1] & 0x01) {
  60                         *p++ = '.';
  61                         *digits = 0;
  62                 }
  63                 c = char_map[buf[i+1] >> 1];
  64                 if (i == 5 && (c == 'C' || c == 'F'))
  65                         *temp_unit = c;
  66                 else if (c) {
  67                         *p++ = c;
  68                         (*digits)++;
  69                 }
  70         }
  71         *p = 0;
  72
  73         if (*digits < 0)
  74                 *digits = 0;
  75
  76         if ((ret = sr_atof_ascii(str, floatval))) {
  77                 sr_dbg("invalid float string: '%s'", str);
  78                 return ret;
  79         }
  80
  81         return SR_OK;
  82 }
  83
  84 static void brymen_bm86x_parse(unsigned char *buf, float *floatval,
  85                                struct sr_datafeed_analog *analog)
  86 {
  87         char str[16], temp_unit;
  88         int ret1, ret2, digits[2], over_limit;
  89
  90         ret1 = brymen_bm86x_parse_digits(buf+2, 6, str, &floatval[0],
  91                                          &temp_unit, &digits[0], 0x80);
  92         over_limit = strstr(str, "0L") || strstr(str, "0.L");
  93         ret2 = brymen_bm86x_parse_digits(buf+9, 4, str, &floatval[1],
  94                                          &temp_unit, &digits[1], 0x10);
  95
  96         /* main display */
  97         if (ret1 == SR_OK || over_limit) {
  98                 /* SI unit */
  99                 if (buf[8] & 0x01) {
 100                         analog[0].meaning->mq = SR_MQ_VOLTAGE;
 101                         analog[0].meaning->unit = SR_UNIT_VOLT;
 102                         if (!strcmp(str, "diod"))
 103                                 analog[0].meaning->mqflags |= SR_MQFLAG_DIODE;
 104                 } else if (buf[14] & 0x80) {
 105                         analog[0].meaning->mq = SR_MQ_CURRENT;
 106                         analog[0].meaning->unit = SR_UNIT_AMPERE;
 107                 } else if (buf[14] & 0x20) {
 108                         analog[0].meaning->mq = SR_MQ_CAPACITANCE;
 109                         analog[0].meaning->unit = SR_UNIT_FARAD;
 110                 } else if (buf[14] & 0x10) {
 111                         analog[0].meaning->mq = SR_MQ_CONDUCTANCE;
 112                         analog[0].meaning->unit = SR_UNIT_SIEMENS;
 113                 } else if (buf[15] & 0x01) {
 114                         analog[0].meaning->mq = SR_MQ_FREQUENCY;
 115                         analog[0].meaning->unit = SR_UNIT_HERTZ;
 116                 } else if (buf[10] & 0x01) {
 117                         analog[0].meaning->mq = SR_MQ_CONTINUITY;
 118                         analog[0].meaning->unit = SR_UNIT_OHM;
 119                 } else if (buf[15] & 0x10) {
 120                         analog[0].meaning->mq = SR_MQ_RESISTANCE;
 121                         analog[0].meaning->unit = SR_UNIT_OHM;
 122                 } else if (buf[15] & 0x02) {
 123                         analog[0].meaning->mq = SR_MQ_POWER;
 124                         analog[0].meaning->unit = SR_UNIT_DECIBEL_MW;
 125                 } else if (buf[15] & 0x80) {
 126                         analog[0].meaning->mq = SR_MQ_DUTY_CYCLE;
 127                         analog[0].meaning->unit = SR_UNIT_PERCENTAGE;
 128                 } else if (buf[ 2] & 0x0A) {
 129                         analog[0].meaning->mq = SR_MQ_TEMPERATURE;
 130                         if (temp_unit == 'F')
 131                                 analog[0].meaning->unit = SR_UNIT_FAHRENHEIT;
 132                         else
 133                                 analog[0].meaning->unit = SR_UNIT_CELSIUS;
 134                 }
 135
 136                 /* when MIN MAX and AVG are displayed at the same time, remove them */
 137                 if ((buf[1] & 0xE0) == 0xE0)
 138                         buf[1] &= ~0xE0;
 139
 140                 /* AC/DC/Auto flags */
 141                 if (buf[1] & 0x10)  analog[0].meaning->mqflags |= SR_MQFLAG_DC;
 142                 if (buf[2] & 0x01)  analog[0].meaning->mqflags |= SR_MQFLAG_AC;
 143                 if (buf[1] & 0x01)  analog[0].meaning->mqflags |= SR_MQFLAG_AUTORANGE;
 144                 if (buf[1] & 0x08)  analog[0].meaning->mqflags |= SR_MQFLAG_HOLD;
 145                 if (buf[1] & 0x20)  analog[0].meaning->mqflags |= SR_MQFLAG_MAX;
 146                 if (buf[1] & 0x40)  analog[0].meaning->mqflags |= SR_MQFLAG_MIN;
 147                 if (buf[1] & 0x80)  analog[0].meaning->mqflags |= SR_MQFLAG_AVG;
 148                 if (buf[3] & 0x01)  analog[0].meaning->mqflags |= SR_MQFLAG_RELATIVE;
 149
 150                 /* when dBm is displayed, remove the m suffix so that it is
 151                    not considered as the 10e-3 SI prefix */
 152                 if (buf[15] & 0x02)
 153                         buf[15] &= ~0x04;
 154
 155                 /* SI prefix */
 156                 if (buf[14] & 0x40)  { floatval[0] *= 1e-9; digits[0] += 9; }  /* n */
 157                 if (buf[15] & 0x08)  { floatval[0] *= 1e-6; digits[0] += 6; }  /* µ */
 158                 if (buf[15] & 0x04)  { floatval[0] *= 1e-3; digits[0] += 3; }  /* m */
 159                 if (buf[15] & 0x40)  { floatval[0] *= 1e3;  digits[0] -= 3; }  /* k */
 160                 if (buf[15] & 0x20)  { floatval[0] *= 1e6;  digits[0] -= 6; }  /* M */
 161
 162                 if (over_limit)      floatval[0] = INFINITY;
 163
 164                 analog[0].encoding->digits  = digits[0];
 165                 analog[0].spec->spec_digits = digits[0];
 166         }
 167
 168         /* secondary display */
 169         if (ret2 == SR_OK) {
 170                 /* SI unit */
 171                 if (buf[14] & 0x08) {
 172                         analog[1].meaning->mq = SR_MQ_VOLTAGE;
 173                         analog[1].meaning->unit = SR_UNIT_VOLT;
 174                 } else if (buf[9] & 0x04) {
 175                         analog[1].meaning->mq = SR_MQ_CURRENT;
 176                         analog[1].meaning->unit = SR_UNIT_AMPERE;
 177                 } else if (buf[9] & 0x08) {
 178                         analog[1].meaning->mq = SR_MQ_CURRENT;
 179                         analog[1].meaning->unit = SR_UNIT_PERCENTAGE;
 180                 } else if (buf[14] & 0x04) {
 181                         analog[1].meaning->mq = SR_MQ_FREQUENCY;
 182                         analog[1].meaning->unit = SR_UNIT_HERTZ;
 183                 } else if (buf[9] & 0x40) {
 184                         analog[1].meaning->mq = SR_MQ_TEMPERATURE;
 185                         if (temp_unit == 'F')
 186                                 analog[1].meaning->unit = SR_UNIT_FAHRENHEIT;
 187                         else
 188                                 analog[1].meaning->unit = SR_UNIT_CELSIUS;
 189                 }
 190
 191                 /* AC flag */
 192                 if (buf[9] & 0x20)  analog[1].meaning->mqflags |= SR_MQFLAG_AC;
 193
 194                 /* SI prefix */
 195                 if (buf[ 9] & 0x01)  { floatval[1] *= 1e-6; digits[1] += 6; }  /* µ */
 196                 if (buf[ 9] & 0x02)  { floatval[1] *= 1e-3; digits[1] += 3; }  /* m */
 197                 if (buf[14] & 0x02)  { floatval[1] *= 1e3;  digits[1] -= 3; }  /* k */
 198                 if (buf[14] & 0x01)  { floatval[1] *= 1e6;  digits[1] -= 6; }  /* M */
 199
 200                 analog[1].encoding->digits  = digits[1];
 201                 analog[1].spec->spec_digits = digits[1];
 202         }
 203
 204         if (buf[9] & 0x80)
 205                 sr_spew("Battery is low.");
 206 }
 207
 208 static void brymen_bm86x_handle_packet(const struct sr_dev_inst *sdi,
 209                                        unsigned char *buf)
 210 {
 211         struct dev_context *devc;
 212         struct sr_datafeed_packet packet;
 213         struct sr_datafeed_analog analog[2];
 214         struct sr_analog_encoding encoding[2];
 215         struct sr_analog_meaning meaning[2];
 216         struct sr_analog_spec spec[2];
 217         float floatval[2];
 218
 219         devc = sdi->priv;
 220
 221         /* Note: digits/spec_digits will be overridden later. */
 222         sr_analog_init(&analog[0], &encoding[0], &meaning[0], &spec[0], 0);
 223         sr_analog_init(&analog[1], &encoding[1], &meaning[1], &spec[1], 0);
 224
 225         brymen_bm86x_parse(buf, floatval, analog);
 226
 227         if (analog[0].meaning->mq != 0) {
 228                 /* Got a measurement. */
 229                 analog[0].num_samples = 1;
 230                 analog[0].data = &floatval[0];
 231                 analog[0].meaning->channels = g_slist_append(NULL, sdi->channels->data);
 232                 packet.type = SR_DF_ANALOG;
 233                 packet.payload = &analog[0];
 234                 sr_session_send(sdi, &packet);
 235                 g_slist_free(analog[0].meaning->channels);
 236         }
 237
 238         if (analog[1].meaning->mq != 0) {
 239                 /* Got a measurement. */
 240                 analog[1].num_samples = 1;
 241                 analog[1].data = &floatval[1];
 242                 analog[1].meaning->channels = g_slist_append(NULL, sdi->channels->next->data);
 243                 packet.type = SR_DF_ANALOG;
 244                 packet.payload = &analog[1];
 245                 sr_session_send(sdi, &packet);
 246                 g_slist_free(analog[1].meaning->channels);
 247         }
 248
 249         if (analog[0].meaning->mq != 0 || analog[1].meaning->mq != 0)
 250                 sr_sw_limits_update_samples_read(&devc->sw_limits, 1);
 251 }
 252
 253 static int brymen_bm86x_send_command(const struct sr_dev_inst *sdi)
 254 {
 255         struct sr_usb_dev_inst *usb;
 256         unsigned char buf[] = { 0x00, 0x86, 0x66 };
 257         int ret;
 258
 259         usb = sdi->conn;
 260
 261         sr_dbg("Sending HID set report.");
 262         ret = libusb_control_transfer(usb->devhdl,
 263                                       LIBUSB_REQUEST_TYPE_CLASS  |
 264                                       LIBUSB_RECIPIENT_INTERFACE |
 265                                       LIBUSB_ENDPOINT_OUT,
 266                                       9,     /* bRequest: HID set_report */
 267                                       0x300, /* wValue: HID feature, report num 0 */
 268                                       0,     /* wIndex: interface 0 */
 269                                       buf, sizeof(buf), USB_TIMEOUT);
 270
 271         if (ret < 0) {
 272                 sr_err("HID feature report error: %s.", libusb_error_name(ret));
 273                 return SR_ERR;
 274         }
 275
 276         if (ret != sizeof(buf)) {
 277                 sr_err("Short packet: sent %d/%zu bytes.", ret, sizeof(buf));
 278                 return SR_ERR;
 279         }
 280
 281         return SR_OK;
 282 }
 283
 284 static int brymen_bm86x_read_interrupt(const struct sr_dev_inst *sdi)
 285 {
 286         struct dev_context *devc;
 287         struct sr_usb_dev_inst *usb;
 288         unsigned char buf[24];
 289         int ret, transferred;
 290
 291         devc = sdi->priv;
 292         usb = sdi->conn;
 293
 294         sr_dbg("Reading HID interrupt report.");
 295         /* Get data from EP1 using an interrupt transfer. */
 296         ret = libusb_interrupt_transfer(usb->devhdl,
 297                                         LIBUSB_ENDPOINT_IN | 1, /* EP1, IN */
 298                                         buf, sizeof(buf),
 299                                         &transferred, USB_TIMEOUT);
 300
 301         if (ret == LIBUSB_ERROR_TIMEOUT) {
 302                 if (++devc->interrupt_pending > 3)
 303                         devc->interrupt_pending = 0;
 304                 return SR_OK;
 305         }
 306
 307         if (ret < 0) {
 308                 sr_err("USB receive error: %s.", libusb_error_name(ret));
 309                 return SR_ERR;
 310         }
 311
 312         if (transferred != sizeof(buf)) {
 313                 sr_err("Short packet: received %d/%zu bytes.", transferred, sizeof(buf));
 314                 return SR_ERR;
 315         }
 316
 317         devc->interrupt_pending = 0;
 318         brymen_bm86x_handle_packet(sdi, buf);
 319
 320         return SR_OK;
 321 }
 322
 323 SR_PRIV int brymen_bm86x_receive_data(int fd, int revents, void *cb_data)
 324 {
 325         struct sr_dev_inst *sdi;
 326         struct dev_context *devc;
 327
 328         (void)fd;
 329         (void)revents;
 330
 331         if (!(sdi = cb_data))
 332                 return TRUE;
 333
 334         if (!(devc = sdi->priv))
 335                 return TRUE;
 336
 337         if (!devc->interrupt_pending) {
 338                 if (brymen_bm86x_send_command(sdi))
 339                         return FALSE;
 340                 devc->interrupt_pending = 1;
 341         }
 342
 343         if (brymen_bm86x_read_interrupt(sdi))
 344                 return FALSE;
 345
 346         if (sr_sw_limits_check(&devc->sw_limits))
 347                 sdi->driver->dev_acquisition_stop(sdi);
 348
 349         return TRUE;
 350 }