libsigrok/hardware/common/scpi_serial.c

203 lines
4.9 KiB
C

/*
* 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>
#define LOG_PREFIX "scpi_serial"
#define BUFFER_SIZE 1024
struct scpi_serial {
struct sr_serial_dev_inst *serial;
char buffer[BUFFER_SIZE];
size_t count;
size_t read;
};
static int scpi_serial_dev_inst_new(void *priv, const char *resource,
char **params, const char *serialcomm)
{
struct scpi_serial *sscpi = priv;
(void)params;
if (!(sscpi->serial = sr_serial_dev_inst_new(resource, serialcomm)))
return SR_ERR;
return SR_OK;
}
static int scpi_serial_open(void *priv)
{
struct scpi_serial *sscpi = priv;
struct sr_serial_dev_inst *serial = sscpi->serial;
if (serial_open(serial, SERIAL_RDWR | SERIAL_NONBLOCK) != SR_OK)
return SR_ERR;
if (serial_flush(serial) != SR_OK)
return SR_ERR;
sscpi->count = 0;
sscpi->read = 0;
return SR_OK;
}
static int scpi_serial_source_add(void *priv, int events, int timeout,
sr_receive_data_callback_t cb, void *cb_data)
{
struct scpi_serial *sscpi = priv;
struct sr_serial_dev_inst *serial = sscpi->serial;
return serial_source_add(serial, events, timeout, cb, cb_data);
}
static int scpi_serial_source_remove(void *priv)
{
struct scpi_serial *sscpi = priv;
struct sr_serial_dev_inst *serial = sscpi->serial;
return serial_source_remove(serial);
}
static int scpi_serial_send(void *priv, const char *command)
{
int len, result, written;
gchar *terminated_command;
struct scpi_serial *sscpi = priv;
struct sr_serial_dev_inst *serial = sscpi->serial;
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;
}
static int scpi_serial_read_begin(void *priv)
{
(void) priv;
return SR_OK;
}
static int scpi_serial_read_data(void *priv, char *buf, int maxlen)
{
struct scpi_serial *sscpi = priv;
int len, ret;
len = BUFFER_SIZE - sscpi->count;
/* Try to read new data into the buffer if there is space. */
if (len > 0) {
ret = serial_read(sscpi->serial, sscpi->buffer + sscpi->read,
BUFFER_SIZE - sscpi->count);
if (ret < 0)
return ret;
sscpi->count += ret;
if (ret > 0)
sr_spew("Read %d bytes into buffer.", ret);
}
/* Return as many bytes as possible from buffer, excluding any trailing newline. */
if (sscpi->read < sscpi->count) {
len = sscpi->count - sscpi->read;
if (len > maxlen)
len = maxlen;
if (sscpi->buffer[sscpi->read + len - 1] == '\n')
len--;
sr_spew("Returning %d bytes from buffer.", len);
memcpy(buf, sscpi->buffer + sscpi->read, len);
sscpi->read += len;
if (sscpi->read == BUFFER_SIZE) {
sr_spew("Resetting buffer.");
sscpi->count = 0;
sscpi->read = 0;
}
return len;
}
return 0;
}
static int scpi_serial_read_complete(void *priv)
{
struct scpi_serial *sscpi = priv;
/* If the next character is a newline, discard it and report complete. */
if (sscpi->read < sscpi->count && sscpi->buffer[sscpi->read] == '\n') {
sscpi->read++;
return 1;
} else {
return 0;
}
}
static int scpi_serial_close(void *priv)
{
struct scpi_serial *sscpi = priv;
return serial_close(sscpi->serial);
}
static void scpi_serial_free(void *priv)
{
struct scpi_serial *sscpi = priv;
sr_serial_dev_inst_free(sscpi->serial);
}
SR_PRIV const struct sr_scpi_dev_inst scpi_serial_dev = {
.name = "serial",
.prefix = "",
.priv_size = sizeof(struct scpi_serial),
.dev_inst_new = scpi_serial_dev_inst_new,
.open = scpi_serial_open,
.source_add = scpi_serial_source_add,
.source_remove = scpi_serial_source_remove,
.send = scpi_serial_send,
.read_begin = scpi_serial_read_begin,
.read_data = scpi_serial_read_data,
.read_complete = scpi_serial_read_complete,
.close = scpi_serial_close,
.free = scpi_serial_free,
};