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 <string.h>
  21 #include <strings.h>
  22 #include <stdarg.h>
  23 #include "scpi.h"
  24 #include "protocol.h"
  25
  26 SR_PRIV int select_channel(const struct sr_dev_inst *sdi, struct sr_channel *ch)
  27 {
  28         struct dev_context *devc;
  29         struct pps_channel *cur_pch, *new_pch;
  30         int ret;
  31
  32         if (g_slist_length(sdi->channels) == 1)
  33                 return SR_OK;
  34
  35         devc = sdi->priv;
  36         if (ch == devc->cur_channel)
  37                 return SR_OK;
  38
  39         new_pch = ch->priv;
  40         if (devc->cur_channel) {
  41                 cur_pch = devc->cur_channel->priv;
  42                 if (cur_pch->hw_output_idx == new_pch->hw_output_idx) {
  43                         /* Same underlying output channel. */
  44                         devc->cur_channel = ch;
  45                         return SR_OK;
  46                 }
  47         }
  48
  49         if ((ret = scpi_cmd(sdi, devc->device->commands, SCPI_CMD_SELECT_CHANNEL,
  50                         new_pch->hwname)) >= 0)
  51                 devc->cur_channel = ch;
  52
  53         return ret;
  54 }
  55
  56 SR_PRIV struct sr_channel *next_enabled_channel(const struct sr_dev_inst *sdi,
  57                 struct sr_channel *cur_channel)
  58 {
  59         struct sr_channel *next_channel;
  60         GSList *l;
  61
  62         next_channel = cur_channel;
  63         do {
  64                 l = g_slist_find(sdi->channels, next_channel);
  65                 if (l && l->next)
  66                         next_channel = l->next->data;
  67                 else
  68                         next_channel = sdi->channels->data;
  69         } while (!next_channel->enabled);
  70
  71         return next_channel;
  72 }
  73
  74 SR_PRIV int scpi_pps_receive_data(int fd, int revents, void *cb_data)
  75 {
  76         struct dev_context *devc;
  77         struct sr_datafeed_packet packet;
  78         struct sr_datafeed_analog analog;
  79         const struct sr_dev_inst *sdi;
  80         struct sr_channel *next_channel;
  81         struct sr_scpi_dev_inst *scpi;
  82         struct pps_channel *pch;
  83         float f;
  84         int cmd;
  85
  86         (void)fd;
  87         (void)revents;
  88
  89         if (!(sdi = cb_data))
  90                 return TRUE;
  91
  92         if (!(devc = sdi->priv))
  93                 return TRUE;
  94
  95         scpi = sdi->conn;
  96
  97         /* Retrieve requested value for this state. */
  98         if (sr_scpi_get_float(scpi, NULL, &f) == SR_OK) {
  99                 pch = devc->cur_channel->priv;
 100                 packet.type = SR_DF_ANALOG;
 101                 packet.payload = &analog;
 102                 analog.channels = g_slist_append(NULL, devc->cur_channel);
 103                 analog.num_samples = 1;
 104                 analog.mq = pch->mq;
 105                 if (pch->mq == SR_MQ_VOLTAGE)
 106                         analog.unit = SR_UNIT_VOLT;
 107                 else if (pch->mq == SR_MQ_CURRENT)
 108                         analog.unit = SR_UNIT_AMPERE;
 109                 else if (pch->mq == SR_MQ_POWER)
 110                         analog.unit = SR_UNIT_WATT;
 111                 analog.mqflags = SR_MQFLAG_DC;
 112                 analog.data = &f;
 113                 sr_session_send(sdi, &packet);
 114                 g_slist_free(analog.channels);
 115         }
 116
 117         if (g_slist_length(sdi->channels) > 1) {
 118                 next_channel = next_enabled_channel(sdi, devc->cur_channel);
 119                 if (select_channel(sdi, next_channel) != SR_OK) {
 120                         sr_err("Failed to select channel %s", next_channel->name);
 121                         return FALSE;
 122                 }
 123         }
 124
 125         pch = devc->cur_channel->priv;
 126         if (pch->mq == SR_MQ_VOLTAGE)
 127                 cmd = SCPI_CMD_GET_MEAS_VOLTAGE;
 128         else if (pch->mq == SR_MQ_FREQUENCY)
 129                 cmd = SCPI_CMD_GET_MEAS_FREQUENCY;
 130         else if (pch->mq == SR_MQ_CURRENT)
 131                 cmd = SCPI_CMD_GET_MEAS_CURRENT;
 132         else if (pch->mq == SR_MQ_POWER)
 133                 cmd = SCPI_CMD_GET_MEAS_POWER;
 134         else
 135                 return SR_ERR;
 136         scpi_cmd(sdi, devc->device->commands, cmd);
 137
 138         return TRUE;
 139 }