libsigrok/hardware/common/scpi_serial.c

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/*
* This file is part of the libsigrok project.
*
* Copyright (C) 2013 poljar (Damir Jelić) <poljarinho@gmail.com>
* Copyright (C) 2013 Martin Ling <martin-sigrok@earth.li>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "libsigrok.h"
#include "libsigrok-internal.h"
#include <glib.h>
#include <string.h>
/* Message logging helpers with subsystem-specific prefix string. */
#define LOG_PREFIX "scpi_serial: "
#define sr_log(l, s, args...) sr_log(l, LOG_PREFIX s, ## args)
#define sr_spew(s, args...) sr_spew(LOG_PREFIX s, ## args)
#define sr_dbg(s, args...) sr_dbg(LOG_PREFIX s, ## args)
#define sr_info(s, args...) sr_info(LOG_PREFIX s, ## args)
#define sr_warn(s, args...) sr_warn(LOG_PREFIX s, ## args)
#define SCPI_READ_RETRIES 100
#define SCPI_READ_RETRY_TIMEOUT 10000
SR_PRIV int scpi_serial_open(void *priv)
{
struct sr_serial_dev_inst *serial = priv;
if (serial_open(serial, SERIAL_RDWR | SERIAL_NONBLOCK) != SR_OK)
return SR_ERR;
if (serial_flush(serial) != SR_OK)
return SR_ERR;
return SR_OK;
}
SR_PRIV int scpi_serial_source_add(void *priv, int events, int timeout,
sr_receive_data_callback_t cb, void *cb_data)
{
struct sr_serial_dev_inst *serial = priv;
return serial_source_add(serial, events, timeout, cb, cb_data);
}
SR_PRIV int scpi_serial_source_remove(void *priv)
{
struct sr_serial_dev_inst *serial = priv;
return serial_source_remove(serial);
}
SR_PRIV int scpi_serial_send(void *priv, const char *command)
{
int len, result, written;
gchar *terminated_command;
struct sr_serial_dev_inst *serial = priv;
terminated_command = g_strconcat(command, "\n", NULL);
len = strlen(terminated_command);
written = 0;
while (written < len) {
result = serial_write(serial, terminated_command + written, len - written);
if (result < 0) {
sr_err("Error while sending SCPI command: '%s'.", command);
g_free(terminated_command);
return SR_ERR;
}
written += result;
}
g_free(terminated_command);
sr_spew("Successfully sent SCPI command: '%s'.", command);
return SR_OK;
}
SR_PRIV int scpi_serial_receive(void *priv, char **scpi_response)
{
int len, ret;
char buf[256];
unsigned int i;
GString *response;
struct sr_serial_dev_inst *serial = priv;
response = g_string_sized_new(1024);
for (i = 0; i <= SCPI_READ_RETRIES; i++) {
while ((len = serial_read(serial, buf, sizeof(buf))) > 0)
response = g_string_append_len(response, buf, len);
if (response->len > 0 &&
response->str[response->len-1] == '\n') {
sr_spew("Fetched full SCPI response.");
break;
}
g_usleep(SCPI_READ_RETRY_TIMEOUT);
}
if (response->len == 0) {
sr_dbg("No SCPI response received.");
g_string_free(response, TRUE);
*scpi_response = NULL;
return SR_ERR;
} else if (response->str[response->len - 1] == '\n') {
/*
* The SCPI response contains a LF ('\n') at the end and we
* don't need this so replace it with a '\0' and decrement
* the length.
*/
response->str[--response->len] = '\0';
ret = SR_OK;
} else {
sr_warn("Incomplete SCPI response received!");
ret = SR_ERR;
}
/* Minor optimization: steal the string instead of copying. */
*scpi_response = response->str;
/* A SCPI response can be quite large, print at most 50 characters. */
sr_dbg("SCPI response received (length %d): '%.50s'",
response->len, response->str);
g_string_free(response, FALSE);
return ret;
}
/* Some stubs to keep the compiler from whining. */
static int scpi_serial_read(void *priv, char *buf, int maxlen)
{
return serial_read(priv, buf, maxlen);
}
static int scpi_serial_close(void *priv)
{
return serial_close(priv);
}
static void scpi_serial_free(void *priv)
{
return sr_serial_dev_inst_free(priv);
}
SR_PRIV struct sr_scpi_dev_inst *scpi_serial_dev_inst_new(const char *port,
const char *serialcomm)
{
struct sr_scpi_dev_inst *scpi;
struct sr_serial_dev_inst *serial;
scpi = g_try_malloc(sizeof(struct sr_scpi_dev_inst));
if (!(serial = sr_serial_dev_inst_new(port, serialcomm)))
{
g_free(scpi);
return NULL;
}
scpi->open = scpi_serial_open;
scpi->source_add = scpi_serial_source_add;
scpi->source_remove = scpi_serial_source_remove;
scpi->send = scpi_serial_send;
scpi->receive = scpi_serial_receive;
scpi->read = scpi_serial_read;
scpi->close = scpi_serial_close;
scpi->free = scpi_serial_free;
scpi->priv = serial;
return scpi;
}