src/hardware/scpi-pps/protocol.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2014 Bert Vermeulen <bert@biot.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 <config.h>
  21 #include <string.h>
  22 #include <strings.h>
  23 #include <stdarg.h>
  24 #include "scpi.h"
  25 #include "protocol.h"
  26
  27 SR_PRIV int select_channel(const struct sr_dev_inst *sdi, struct sr_channel *ch)
  28 {
  29         struct dev_context *devc;
  30         struct pps_channel *cur_pch, *new_pch;
  31         int ret;
  32
  33         if (g_slist_length(sdi->channels) == 1)
  34                 return SR_OK;
  35
  36         devc = sdi->priv;
  37         if (ch == devc->cur_channel)
  38                 return SR_OK;
  39
  40         new_pch = ch->priv;
  41         if (devc->cur_channel) {
  42                 cur_pch = devc->cur_channel->priv;
  43                 if (cur_pch->hw_output_idx == new_pch->hw_output_idx) {
  44                         /* Same underlying output channel. */
  45                         devc->cur_channel = ch;
  46                         return SR_OK;
  47                 }
  48         }
  49
  50         if ((ret = scpi_cmd(sdi, devc->device->commands, SCPI_CMD_SELECT_CHANNEL,
  51                         new_pch->hwname)) >= 0)
  52                 devc->cur_channel = ch;
  53
  54         return ret;
  55 }
  56
  57 SR_PRIV int scpi_pps_receive_data(int fd, int revents, void *cb_data)
  58 {
  59         struct dev_context *devc;
  60         struct sr_datafeed_packet packet;
  61         struct sr_datafeed_analog analog;
  62         struct sr_analog_encoding encoding;
  63         struct sr_analog_meaning meaning;
  64         struct sr_analog_spec spec;
  65         const struct sr_dev_inst *sdi;
  66         struct sr_channel *next_channel;
  67         struct sr_scpi_dev_inst *scpi;
  68         struct pps_channel *pch;
  69         float f;
  70         int cmd;
  71
  72         (void)fd;
  73         (void)revents;
  74
  75         if (!(sdi = cb_data))
  76                 return TRUE;
  77
  78         if (!(devc = sdi->priv))
  79                 return TRUE;
  80
  81         scpi = sdi->conn;
  82
  83         /* Retrieve requested value for this state. */
  84         if (sr_scpi_get_float(scpi, NULL, &f) == SR_OK) {
  85                 pch = devc->cur_channel->priv;
  86                 packet.type = SR_DF_ANALOG;
  87                 packet.payload = &analog;
  88                 sr_analog_init(&analog, &encoding, &meaning, &spec, 0);
  89                 analog.meaning->channels = g_slist_append(NULL, devc->cur_channel);
  90                 analog.num_samples = 1;
  91                 analog.meaning->mq = pch->mq;
  92                 if (pch->mq == SR_MQ_VOLTAGE)
  93                         analog.meaning->unit = SR_UNIT_VOLT;
  94                 else if (pch->mq == SR_MQ_CURRENT)
  95                         analog.meaning->unit = SR_UNIT_AMPERE;
  96                 else if (pch->mq == SR_MQ_POWER)
  97                         analog.meaning->unit = SR_UNIT_WATT;
  98                 analog.meaning->mqflags = SR_MQFLAG_DC;
  99                 analog.data = &f;
 100                 sr_session_send(sdi, &packet);
 101                 g_slist_free(analog.meaning->channels);
 102         }
 103
 104         if (g_slist_length(sdi->channels) > 1) {
 105                 next_channel = sr_next_enabled_channel(sdi, devc->cur_channel);
 106                 if (select_channel(sdi, next_channel) != SR_OK) {
 107                         sr_err("Failed to select channel %s", next_channel->name);
 108                         return FALSE;
 109                 }
 110         }
 111
 112         pch = devc->cur_channel->priv;
 113         if (pch->mq == SR_MQ_VOLTAGE)
 114                 cmd = SCPI_CMD_GET_MEAS_VOLTAGE;
 115         else if (pch->mq == SR_MQ_FREQUENCY)
 116                 cmd = SCPI_CMD_GET_MEAS_FREQUENCY;
 117         else if (pch->mq == SR_MQ_CURRENT)
 118                 cmd = SCPI_CMD_GET_MEAS_CURRENT;
 119         else if (pch->mq == SR_MQ_POWER)
 120                 cmd = SCPI_CMD_GET_MEAS_POWER;
 121         else
 122                 return SR_ERR;
 123         scpi_cmd(sdi, devc->device->commands, cmd);
 124
 125         return TRUE;
 126 }