src/scpi/scpi_serial.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2013 poljar (Damir Jelić) <poljarinho@gmail.com>
   5  * Copyright (C) 2013 Martin Ling <martin-sigrok@earth.li>
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation, either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <glib.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <libsigrok/libsigrok.h>
  25 #include "libsigrok-internal.h"
  26
  27 #define LOG_PREFIX "scpi_serial"
  28
  29 #define BUFFER_SIZE 1024
  30
  31 struct scpi_serial {
  32         struct sr_serial_dev_inst *serial;
  33         char buffer[BUFFER_SIZE];
  34         size_t count;
  35         size_t read;
  36 };
  37
  38 static const struct {
  39         uint16_t vendor_id;
  40         uint16_t product_id;
  41         const char *serialcomm;
  42 } scpi_serial_usb_ids[] = {
  43         { 0x0403, 0xed72, "115200/8n1/flow=1" }, /* Hameg HO720 */
  44         { 0x0403, 0xed73, "115200/8n1/flow=1" }, /* Hameg HO730 */
  45 };
  46
  47 static GSList *scpi_serial_scan(struct drv_context *drvc)
  48 {
  49         GSList *l, *r, *resources = NULL;
  50         gchar *res;
  51         unsigned i;
  52
  53         (void)drvc;
  54
  55         for (i = 0; i < ARRAY_SIZE(scpi_serial_usb_ids); i++) {
  56                 if (!(l = sr_serial_find_usb(scpi_serial_usb_ids[i].vendor_id,
  57                                         scpi_serial_usb_ids[i].product_id)))
  58                         continue;
  59                 for (r = l; r; r = r->next) {
  60                         if (scpi_serial_usb_ids[i].serialcomm)
  61                                 res = g_strdup_printf("%s:%s", (char *) r->data,
  62                                                       scpi_serial_usb_ids[i].serialcomm);
  63                         else
  64                                 res = g_strdup(r->data);
  65                         resources = g_slist_append(resources, res);
  66                 }
  67                 g_slist_free_full(l, g_free);
  68         }
  69
  70         return resources;
  71 }
  72
  73 static int scpi_serial_dev_inst_new(void *priv, struct drv_context *drvc,
  74                 const char *resource, char **params, const char *serialcomm)
  75 {
  76         struct scpi_serial *sscpi = priv;
  77
  78         (void)drvc;
  79         (void)params;
  80
  81         sscpi->serial = sr_serial_dev_inst_new(resource, serialcomm);
  82
  83         return SR_OK;
  84 }
  85
  86 static int scpi_serial_open(void *priv)
  87 {
  88         struct scpi_serial *sscpi = priv;
  89         struct sr_serial_dev_inst *serial = sscpi->serial;
  90
  91         if (serial_open(serial, SERIAL_RDWR) != SR_OK)
  92                 return SR_ERR;
  93
  94         if (serial_flush(serial) != SR_OK)
  95                 return SR_ERR;
  96
  97         sscpi->count = 0;
  98         sscpi->read = 0;
  99
 100         return SR_OK;
 101 }
 102
 103 static int scpi_serial_source_add(struct sr_session *session, void *priv,
 104                 int events, int timeout, sr_receive_data_callback cb, void *cb_data)
 105 {
 106         struct scpi_serial *sscpi = priv;
 107         struct sr_serial_dev_inst *serial = sscpi->serial;
 108
 109         return serial_source_add(session, serial, events, timeout, cb, cb_data);
 110 }
 111
 112 static int scpi_serial_source_remove(struct sr_session *session, void *priv)
 113 {
 114         struct scpi_serial *sscpi = priv;
 115         struct sr_serial_dev_inst *serial = sscpi->serial;
 116
 117         return serial_source_remove(session, serial);
 118 }
 119
 120 static int scpi_serial_send(void *priv, const char *command)
 121 {
 122         int len, result, written;
 123         gchar *terminated_command;
 124         struct scpi_serial *sscpi = priv;
 125         struct sr_serial_dev_inst *serial = sscpi->serial;
 126
 127         terminated_command = g_strconcat(command, "\n", NULL);
 128         len = strlen(terminated_command);
 129         written = 0;
 130         while (written < len) {
 131                 result = serial_write_nonblocking(serial,
 132                                 terminated_command + written, len - written);
 133                 if (result < 0) {
 134                         sr_err("Error while sending SCPI command: '%s'.", command);
 135                         g_free(terminated_command);
 136                         return SR_ERR;
 137                 }
 138                 written += result;
 139         }
 140
 141         g_free(terminated_command);
 142
 143         sr_spew("Successfully sent SCPI command: '%s'.", command);
 144
 145         return SR_OK;
 146 }
 147
 148 static int scpi_serial_read_begin(void *priv)
 149 {
 150         (void) priv;
 151
 152         return SR_OK;
 153 }
 154
 155 static int scpi_serial_read_data(void *priv, char *buf, int maxlen)
 156 {
 157         struct scpi_serial *sscpi = priv;
 158         int len, ret;
 159
 160         len = BUFFER_SIZE - sscpi->count;
 161
 162         /* Try to read new data into the buffer if there is space. */
 163         if (len > 0) {
 164                 ret = serial_read_nonblocking(sscpi->serial, sscpi->buffer + sscpi->read,
 165                                 BUFFER_SIZE - sscpi->count);
 166
 167                 if (ret < 0)
 168                         return ret;
 169
 170                 sscpi->count += ret;
 171
 172                 if (ret > 0)
 173                         sr_spew("Read %d bytes into buffer.", ret);
 174         }
 175
 176         /* Return as many bytes as possible from buffer, excluding any trailing newline. */
 177         if (sscpi->read < sscpi->count) {
 178                 len = sscpi->count - sscpi->read;
 179                 if (len > maxlen)
 180                         len = maxlen;
 181                 if (sscpi->buffer[sscpi->read + len - 1] == '\n')
 182                         len--;
 183                 sr_spew("Returning %d bytes from buffer.", len);
 184                 memcpy(buf, sscpi->buffer + sscpi->read, len);
 185                 sscpi->read += len;
 186                 if (sscpi->read == BUFFER_SIZE) {
 187                         sr_spew("Resetting buffer.");
 188                         sscpi->count = 0;
 189                         sscpi->read = 0;
 190                 }
 191                 return len;
 192         }
 193
 194         return 0;
 195 }
 196
 197 static int scpi_serial_read_complete(void *priv)
 198 {
 199         struct scpi_serial *sscpi = priv;
 200
 201         /* If the next character is a newline, discard it and report complete. */
 202         if (sscpi->read < sscpi->count && sscpi->buffer[sscpi->read] == '\n') {
 203                 sscpi->read++;
 204                 return 1;
 205         } else {
 206                 return 0;
 207         }
 208 }
 209
 210 static int scpi_serial_close(void *priv)
 211 {
 212         struct scpi_serial *sscpi = priv;
 213
 214         return serial_close(sscpi->serial);
 215 }
 216
 217 static void scpi_serial_free(void *priv)
 218 {
 219         struct scpi_serial *sscpi = priv;
 220
 221         sr_serial_dev_inst_free(sscpi->serial);
 222 }
 223
 224 SR_PRIV const struct sr_scpi_dev_inst scpi_serial_dev = {
 225         .name          = "serial",
 226         .prefix        = "",
 227         .priv_size     = sizeof(struct scpi_serial),
 228         .scan          = scpi_serial_scan,
 229         .dev_inst_new  = scpi_serial_dev_inst_new,
 230         .open          = scpi_serial_open,
 231         .source_add    = scpi_serial_source_add,
 232         .source_remove = scpi_serial_source_remove,
 233         .send          = scpi_serial_send,
 234         .read_begin    = scpi_serial_read_begin,
 235         .read_data     = scpi_serial_read_data,
 236         .read_complete = scpi_serial_read_complete,
 237         .close         = scpi_serial_close,
 238         .free          = scpi_serial_free,
 239 };