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 <string.h>
  21 #include <math.h>
  22 #include "protocol.h"
  23
  24 #define USB_TIMEOUT 500
  25
  26 static char char_map[128] = {
  27         [0x20] = '-',
  28         [0x5F] = '0',
  29         [0x50] = '1',
  30         [0x6D] = '2',
  31         [0x7C] = '3',
  32         [0x72] = '4',
  33         [0x3E] = '5',
  34         [0x3F] = '6',
  35         [0x54] = '7',
  36         [0x7F] = '8',
  37         [0x7E] = '9',
  38         [0x0F] = 'C',
  39         [0x27] = 'F',
  40         [0x0B] = 'L',
  41         [0x79] = 'd',
  42         [0x10] = 'i',
  43         [0x39] = 'o',
  44 };
  45
  46 static int brymen_bm86x_parse_digits(const unsigned char *buf, int length,
  47                                      char *str, float *floatval,
  48                                      char *temp_unit, int flag)
  49 {
  50         char c, *p = str;
  51         int i, ret;
  52
  53         if (buf[0] & flag)
  54                 *p++ = '-';
  55         for (i = 0; i < length; i++) {
  56                 if (i && i < 5 && buf[i+1] & 0x01)
  57                         *p++ = '.';
  58                 c = char_map[buf[i+1] >> 1];
  59                 if (i == 5 && (c == 'C' || c == 'F'))
  60                         *temp_unit = c;
  61                 else if (c)
  62                         *p++ = c;
  63         }
  64         *p = 0;
  65
  66         if ((ret = sr_atof_ascii(str, floatval))) {
  67                 sr_dbg("invalid float string: '%s'", str);
  68                 return ret;
  69         }
  70
  71         return SR_OK;
  72 }
  73
  74 static void brymen_bm86x_parse(unsigned char *buf, float *floatval,
  75                                struct sr_datafeed_analog *analog)
  76 {
  77         char str[16], temp_unit;
  78         int ret1, ret2, over_limit;
  79
  80         ret1 = brymen_bm86x_parse_digits(buf+2, 6, str, &floatval[0],
  81                                          &temp_unit, 0x80);
  82         over_limit = strstr(str, "0L") || strstr(str, "0.L");
  83         ret2 = brymen_bm86x_parse_digits(buf+9, 4, str, &floatval[1],
  84                                          &temp_unit, 0x10);
  85
  86         /* main display */
  87         if (ret1 == SR_OK || over_limit) {
  88                 /* SI unit */
  89                 if (buf[8] & 0x01) {
  90                         analog[0].mq = SR_MQ_VOLTAGE;
  91                         analog[0].unit = SR_UNIT_VOLT;
  92                         if (!strcmp(str, "diod"))
  93                                 analog[0].mqflags |= SR_MQFLAG_DIODE;
  94                 } else if (buf[14] & 0x80) {
  95                         analog[0].mq = SR_MQ_CURRENT;
  96                         analog[0].unit = SR_UNIT_AMPERE;
  97                 } else if (buf[14] & 0x20) {
  98                         analog[0].mq = SR_MQ_CAPACITANCE;
  99                         analog[0].unit = SR_UNIT_FARAD;
 100                 } else if (buf[14] & 0x10) {
 101                         analog[0].mq = SR_MQ_CONDUCTANCE;
 102                         analog[0].unit = SR_UNIT_SIEMENS;
 103                 } else if (buf[15] & 0x01) {
 104                         analog[0].mq = SR_MQ_FREQUENCY;
 105                         analog[0].unit = SR_UNIT_HERTZ;
 106                 } else if (buf[10] & 0x01) {
 107                         analog[0].mq = SR_MQ_CONTINUITY;
 108                         analog[0].unit = SR_UNIT_OHM;
 109                 } else if (buf[15] & 0x10) {
 110                         analog[0].mq = SR_MQ_RESISTANCE;
 111                         analog[0].unit = SR_UNIT_OHM;
 112                 } else if (buf[15] & 0x02) {
 113                         analog[0].mq = SR_MQ_POWER;
 114                         analog[0].unit = SR_UNIT_DECIBEL_MW;
 115                 } else if (buf[15] & 0x80) {
 116                         analog[0].mq = SR_MQ_DUTY_CYCLE;
 117                         analog[0].unit = SR_UNIT_PERCENTAGE;
 118                 } else if (buf[ 2] & 0x0A) {
 119                         analog[0].mq = SR_MQ_TEMPERATURE;
 120                         if (temp_unit == 'F')
 121                                 analog[0].unit = SR_UNIT_FAHRENHEIT;
 122                         else
 123                                 analog[0].unit = SR_UNIT_CELSIUS;
 124                 }
 125
 126                 /* when MIN MAX and AVG are displayed at the same time, remove them */
 127                 if ((buf[1] & 0xE0) == 0xE0)
 128                         buf[1] &= ~0xE0;
 129
 130                 /* AC/DC/Auto flags */
 131                 if (buf[1] & 0x10)  analog[0].mqflags |= SR_MQFLAG_DC;
 132                 if (buf[2] & 0x01)  analog[0].mqflags |= SR_MQFLAG_AC;
 133                 if (buf[1] & 0x01)  analog[0].mqflags |= SR_MQFLAG_AUTORANGE;
 134                 if (buf[1] & 0x08)  analog[0].mqflags |= SR_MQFLAG_HOLD;
 135                 if (buf[1] & 0x20)  analog[0].mqflags |= SR_MQFLAG_MAX;
 136                 if (buf[1] & 0x40)  analog[0].mqflags |= SR_MQFLAG_MIN;
 137                 if (buf[1] & 0x80)  analog[0].mqflags |= SR_MQFLAG_AVG;
 138                 if (buf[3] & 0x01)  analog[0].mqflags |= SR_MQFLAG_RELATIVE;
 139
 140                 /* when dBm is displayed, remove the m suffix so that it is
 141                    not considered as the 10e-3 SI prefix */
 142                 if (buf[15] & 0x02)
 143                         buf[15] &= ~0x04;
 144
 145                 /* SI prefix */
 146                 if (buf[14] & 0x40)  floatval[0] *= 1e-9;  /* n */
 147                 if (buf[15] & 0x08)  floatval[0] *= 1e-6;  /* µ */
 148                 if (buf[15] & 0x04)  floatval[0] *= 1e-3;  /* m */
 149                 if (buf[15] & 0x40)  floatval[0] *= 1e3;   /* k */
 150                 if (buf[15] & 0x20)  floatval[0] *= 1e6;   /* M */
 151
 152                 if (over_limit)      floatval[0] = INFINITY;
 153         }
 154
 155         /* secondary display */
 156         if (ret2 == SR_OK) {
 157                 /* SI unit */
 158                 if (buf[14] & 0x08) {
 159                         analog[1].mq = SR_MQ_VOLTAGE;
 160                         analog[1].unit = SR_UNIT_VOLT;
 161                 } else if (buf[9] & 0x04) {
 162                         analog[1].mq = SR_MQ_CURRENT;
 163                         analog[1].unit = SR_UNIT_AMPERE;
 164                 } else if (buf[14] & 0x04) {
 165                         analog[1].mq = SR_MQ_FREQUENCY;
 166                         analog[1].unit = SR_UNIT_HERTZ;
 167                 } else if (buf[9] & 0x40) {
 168                         analog[1].mq = SR_MQ_TEMPERATURE;
 169                         if (temp_unit == 'F')
 170                                 analog[1].unit = SR_UNIT_FAHRENHEIT;
 171                         else
 172                                 analog[1].unit = SR_UNIT_CELSIUS;
 173                 }
 174
 175                 /* AC flag */
 176                 if (buf[9] & 0x20)  analog[1].mqflags |= SR_MQFLAG_AC;
 177
 178                 /* SI prefix */
 179                 if (buf[ 9] & 0x01)  floatval[1] *= 1e-6;  /* µ */
 180                 if (buf[ 9] & 0x02)  floatval[1] *= 1e-3;  /* m */
 181                 if (buf[14] & 0x02)  floatval[1] *= 1e3;   /* k */
 182                 if (buf[14] & 0x01)  floatval[1] *= 1e6;   /* M */
 183         }
 184
 185         if (buf[9] & 0x80)
 186                 sr_spew("Battery is low.");
 187 }
 188
 189 static void brymen_bm86x_handle_packet(const struct sr_dev_inst *sdi,
 190                                        unsigned char *buf)
 191 {
 192         struct dev_context *devc;
 193         struct sr_datafeed_packet packet;
 194         struct sr_datafeed_analog analog[2];
 195         float floatval[2];
 196
 197         devc = sdi->priv;
 198
 199         analog[0].mq = -1;
 200         analog[0].mqflags = 0;
 201
 202         analog[1].mq = -1;
 203         analog[1].mqflags = 0;
 204
 205         brymen_bm86x_parse(buf, floatval, analog);
 206
 207         if (analog[0].mq != -1) {
 208                 /* Got a measurement. */
 209                 analog[0].num_samples = 1;
 210                 analog[0].data = &floatval[0];
 211                 analog[0].channels = g_slist_append(NULL, sdi->channels->data);
 212                 packet.type = SR_DF_ANALOG;
 213                 packet.payload = &analog[0];
 214                 sr_session_send(sdi, &packet);
 215                 g_slist_free(analog[0].channels);
 216         }
 217
 218         if (analog[1].mq != -1) {
 219                 /* Got a measurement. */
 220                 analog[1].num_samples = 1;
 221                 analog[1].data = &floatval[1];
 222                 analog[1].channels = g_slist_append(NULL, sdi->channels->next->data);
 223                 packet.type = SR_DF_ANALOG;
 224                 packet.payload = &analog[1];
 225                 sr_session_send(sdi, &packet);
 226                 g_slist_free(analog[1].channels);
 227         }
 228
 229         if (analog[0].mq != -1 || analog[1].mq != -1)
 230                 devc->num_samples++;
 231 }
 232
 233 static int brymen_bm86x_send_command(const struct sr_dev_inst *sdi)
 234 {
 235         struct sr_usb_dev_inst *usb;
 236         unsigned char buf[] = { 0x00, 0x86, 0x66 };
 237         int ret;
 238
 239         usb = sdi->conn;
 240
 241         sr_dbg("Sending HID set report.");
 242         ret = libusb_control_transfer(usb->devhdl,
 243                                       LIBUSB_REQUEST_TYPE_CLASS  |
 244                                       LIBUSB_RECIPIENT_INTERFACE |
 245                                       LIBUSB_ENDPOINT_OUT,
 246                                       9,     /* bRequest: HID set_report */
 247                                       0x300, /* wValue: HID feature, report num 0 */
 248                                       0,     /* wIndex: interface 0 */
 249                                       buf, sizeof(buf), USB_TIMEOUT);
 250
 251         if (ret < 0) {
 252                 sr_err("HID feature report error: %s.", libusb_error_name(ret));
 253                 return SR_ERR;
 254         }
 255
 256         if (ret != sizeof(buf)) {
 257                 sr_err("Short packet: sent %d/%ld bytes.", ret, sizeof(buf));
 258                 return SR_ERR;
 259         }
 260
 261         return SR_OK;
 262 }
 263
 264 static int brymen_bm86x_read_interrupt(const struct sr_dev_inst *sdi)
 265 {
 266         struct dev_context *devc;
 267         struct sr_usb_dev_inst *usb;
 268         unsigned char buf[24];
 269         int ret, transferred;
 270
 271         devc = sdi->priv;
 272         usb = sdi->conn;
 273
 274         sr_dbg("Reading HID interrupt report.");
 275         /* Get data from EP1 using an interrupt transfer. */
 276         ret = libusb_interrupt_transfer(usb->devhdl,
 277                                         LIBUSB_ENDPOINT_IN | 1, /* EP1, IN */
 278                                         buf, sizeof(buf),
 279                                         &transferred, USB_TIMEOUT);
 280
 281         if (ret == LIBUSB_ERROR_TIMEOUT) {
 282                 if (++devc->interrupt_pending > 3)
 283                         devc->interrupt_pending = 0;
 284                 return SR_OK;
 285         }
 286
 287         if (ret < 0) {
 288                 sr_err("USB receive error: %s.", libusb_error_name(ret));
 289                 return SR_ERR;
 290         }
 291
 292         if (transferred != sizeof(buf)) {
 293                 sr_err("Short packet: received %d/%d bytes.", transferred, sizeof(buf));
 294                 return SR_ERR;
 295         }
 296
 297         devc->interrupt_pending = 0;
 298         brymen_bm86x_handle_packet(sdi, buf);
 299
 300         return SR_OK;
 301 }
 302
 303 SR_PRIV int brymen_bm86x_receive_data(int fd, int revents, void *cb_data)
 304 {
 305         struct sr_dev_inst *sdi;
 306         struct dev_context *devc;
 307         int64_t time;
 308
 309         (void)fd;
 310         (void)revents;
 311
 312         if (!(sdi = cb_data))
 313                 return TRUE;
 314
 315         if (!(devc = sdi->priv))
 316                 return TRUE;
 317
 318         if (!devc->interrupt_pending) {
 319                 if (brymen_bm86x_send_command(sdi))
 320                         return FALSE;
 321                 devc->interrupt_pending = 1;
 322         }
 323
 324         if (brymen_bm86x_read_interrupt(sdi))
 325                 return FALSE;
 326
 327         if (devc->limit_samples && devc->num_samples >= devc->limit_samples) {
 328                 sr_info("Requested number of samples reached, stopping.");
 329                 sdi->driver->dev_acquisition_stop(sdi, cb_data);
 330                 return TRUE;
 331         }
 332
 333         if (devc->limit_msec) {
 334                 time = (g_get_monotonic_time() - devc->start_time) / 1000;
 335                 if (time > (int64_t)devc->limit_msec) {
 336                         sr_info("Requested time limit reached, stopping.");
 337                         sdi->driver->dev_acquisition_stop(sdi, cb_data);
 338                         return TRUE;
 339                 }
 340         }
 341
 342         return TRUE;
 343 }