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 "libsigrok.h"
  22 #include "libsigrok-internal.h"
  23
  24 #include <glib.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27
  28 #define LOG_PREFIX "scpi_serial"
  29
  30 #define BUFFER_SIZE 1024
  31
  32 struct scpi_serial {
  33         struct sr_serial_dev_inst *serial;
  34         char buffer[BUFFER_SIZE];
  35         size_t count;
  36         size_t read;
  37 };
  38
  39 static struct {
  40         uint16_t vendor_id;
  41         uint16_t product_id;
  42         const char *serialcomm;
  43 } scpi_serial_usb_ids[] = {
  44         { 0x0403, 0xed72, "115200/8n1/flow=1" }, /* Hameg HO720 */
  45         { 0x0403, 0xed73, "115200/8n1/flow=1" }, /* Hameg HO730 */
  46 };
  47
  48 static GSList *scpi_serial_scan(struct drv_context *drvc)
  49 {
  50         GSList *l, *r, *resources = NULL;
  51         gchar *res;
  52         unsigned i;
  53
  54         (void)drvc;
  55
  56         for (i = 0; i < ARRAY_SIZE(scpi_serial_usb_ids); i++) {
  57                 if ((l = sr_serial_find_usb(scpi_serial_usb_ids[i].vendor_id,
  58                                             scpi_serial_usb_ids[i].product_id)) == NULL)
  59                         continue;
  60                 for (r = l; r; r = r->next) {
  61                         if (scpi_serial_usb_ids[i].serialcomm)
  62                                 res = g_strdup_printf("%s:%s", (char *) r->data,
  63                                                       scpi_serial_usb_ids[i].serialcomm);
  64                         else
  65                                 res = g_strdup(r->data);
  66                         resources = g_slist_append(resources, res);
  67                 }
  68                 g_slist_free_full(l, g_free);
  69         }
  70
  71         return resources;
  72 }
  73
  74 static int scpi_serial_dev_inst_new(void *priv, struct drv_context *drvc,
  75                 const char *resource, char **params, const char *serialcomm)
  76 {
  77         struct scpi_serial *sscpi = priv;
  78
  79         (void)drvc;
  80         (void)params;
  81
  82         if (!(sscpi->serial = sr_serial_dev_inst_new(resource, serialcomm)))
  83                 return SR_ERR;
  84
  85         return SR_OK;
  86 }
  87
  88 static int scpi_serial_open(void *priv)
  89 {
  90         struct scpi_serial *sscpi = priv;
  91         struct sr_serial_dev_inst *serial = sscpi->serial;
  92
  93         if (serial_open(serial, SERIAL_RDWR | SERIAL_NONBLOCK) != SR_OK)
  94                 return SR_ERR;
  95
  96         if (serial_flush(serial) != SR_OK)
  97                 return SR_ERR;
  98
  99         sscpi->count = 0;
 100         sscpi->read = 0;
 101
 102         return SR_OK;
 103 }
 104
 105 static int scpi_serial_source_add(struct sr_session *session, void *priv,
 106                 int events, int timeout, sr_receive_data_callback cb, void *cb_data)
 107 {
 108         struct scpi_serial *sscpi = priv;
 109         struct sr_serial_dev_inst *serial = sscpi->serial;
 110
 111         return serial_source_add(session, serial, events, timeout, cb, cb_data);
 112 }
 113
 114 static int scpi_serial_source_remove(struct sr_session *session, void *priv)
 115 {
 116         struct scpi_serial *sscpi = priv;
 117         struct sr_serial_dev_inst *serial = sscpi->serial;
 118
 119         return serial_source_remove(session, serial);
 120 }
 121
 122 static int scpi_serial_send(void *priv, const char *command)
 123 {
 124         int len, result, written;
 125         gchar *terminated_command;
 126         struct scpi_serial *sscpi = priv;
 127         struct sr_serial_dev_inst *serial = sscpi->serial;
 128
 129         terminated_command = g_strconcat(command, "\n", NULL);
 130         len = strlen(terminated_command);
 131         written = 0;
 132         while (written < len) {
 133                 result = serial_write(serial, terminated_command + written, len - written);
 134                 if (result < 0) {
 135                         sr_err("Error while sending SCPI command: '%s'.", command);
 136                         g_free(terminated_command);
 137                         return SR_ERR;
 138                 }
 139                 written += result;
 140         }
 141
 142         g_free(terminated_command);
 143
 144         sr_spew("Successfully sent SCPI command: '%s'.", command);
 145
 146         return SR_OK;
 147 }
 148
 149 static int scpi_serial_read_begin(void *priv)
 150 {
 151         (void) priv;
 152
 153         return SR_OK;
 154 }
 155
 156 static int scpi_serial_read_data(void *priv, char *buf, int maxlen)
 157 {
 158         struct scpi_serial *sscpi = priv;
 159         int len, ret;
 160
 161         len = BUFFER_SIZE - sscpi->count;
 162
 163         /* Try to read new data into the buffer if there is space. */
 164         if (len > 0) {
 165                 ret = serial_read(sscpi->serial, sscpi->buffer + sscpi->read,
 166                                 BUFFER_SIZE - sscpi->count);
 167
 168                 if (ret < 0)
 169                         return ret;
 170
 171                 sscpi->count += ret;
 172
 173                 if (ret > 0)
 174                         sr_spew("Read %d bytes into buffer.", ret);
 175         }
 176
 177         /* Return as many bytes as possible from buffer, excluding any trailing newline. */
 178         if (sscpi->read < sscpi->count) {
 179                 len = sscpi->count - sscpi->read;
 180                 if (len > maxlen)
 181                         len = maxlen;
 182                 if (sscpi->buffer[sscpi->read + len - 1] == '\n')
 183                         len--;
 184                 sr_spew("Returning %d bytes from buffer.", len);
 185                 memcpy(buf, sscpi->buffer + sscpi->read, len);
 186                 sscpi->read += len;
 187                 if (sscpi->read == BUFFER_SIZE) {
 188                         sr_spew("Resetting buffer.");
 189                         sscpi->count = 0;
 190                         sscpi->read = 0;
 191                 }
 192                 return len;
 193         }
 194
 195         return 0;
 196 }
 197
 198 static int scpi_serial_read_complete(void *priv)
 199 {
 200         struct scpi_serial *sscpi = priv;
 201
 202         /* If the next character is a newline, discard it and report complete. */
 203         if (sscpi->read < sscpi->count && sscpi->buffer[sscpi->read] == '\n') {
 204                 sscpi->read++;
 205                 return 1;
 206         } else {
 207                 return 0;
 208         }
 209 }
 210
 211 static int scpi_serial_close(void *priv)
 212 {
 213         struct scpi_serial *sscpi = priv;
 214
 215         return serial_close(sscpi->serial);
 216 }
 217
 218 static void scpi_serial_free(void *priv)
 219 {
 220         struct scpi_serial *sscpi = priv;
 221
 222         sr_serial_dev_inst_free(sscpi->serial);
 223 }
 224
 225 SR_PRIV const struct sr_scpi_dev_inst scpi_serial_dev = {
 226         .name          = "serial",
 227         .prefix        = "",
 228         .priv_size     = sizeof(struct scpi_serial),
 229         .scan          = scpi_serial_scan,
 230         .dev_inst_new  = scpi_serial_dev_inst_new,
 231         .open          = scpi_serial_open,
 232         .source_add    = scpi_serial_source_add,
 233         .source_remove = scpi_serial_source_remove,
 234         .send          = scpi_serial_send,
 235         .read_begin    = scpi_serial_read_begin,
 236         .read_data     = scpi_serial_read_data,
 237         .read_complete = scpi_serial_read_complete,
 238         .close         = scpi_serial_close,
 239         .free          = scpi_serial_free,
 240 };