--- /dev/null
+/*
+ * This file is part of the libsigrok project.
+ *
+ * Copyright (C) 2015 Aurelien Jacobs <aurel@gnuage.org>
+ *
+ * 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 <stdlib.h>
+#include <string.h>
+
+#define LOG_PREFIX "modbus_serial"
+
+#define BUFFER_SIZE 1024
+
+struct modbus_serial_rtu {
+ struct sr_serial_dev_inst *serial;
+ uint8_t slave_addr;
+ uint16_t crc;
+};
+
+static int modbus_serial_rtu_dev_inst_new(void *priv, const char *resource,
+ char **params, const char *serialcomm, int modbusaddr)
+{
+ struct modbus_serial_rtu *modbus = priv;
+
+ (void) params;
+
+ modbus->serial = sr_serial_dev_inst_new(resource, serialcomm);
+ modbus->slave_addr = modbusaddr;
+
+ return SR_OK;
+}
+
+static int modbus_serial_rtu_open(void *priv)
+{
+ struct modbus_serial_rtu *modbus = priv;
+ struct sr_serial_dev_inst *serial = modbus->serial;
+
+ if (serial_open(serial, SERIAL_RDWR) != SR_OK)
+ return SR_ERR;
+
+ if (serial_flush(serial) != SR_OK)
+ return SR_ERR;
+
+ return SR_OK;
+}
+
+static int modbus_serial_rtu_source_add(struct sr_session *session, void *priv,
+ int events, int timeout, sr_receive_data_callback cb, void *cb_data)
+{
+ struct modbus_serial_rtu *modbus = priv;
+ struct sr_serial_dev_inst *serial = modbus->serial;
+
+ return serial_source_add(session, serial, events, timeout, cb, cb_data);
+}
+
+static int modbus_serial_rtu_source_remove(struct sr_session *session,
+ void *priv)
+{
+ struct modbus_serial_rtu *modbus = priv;
+ struct sr_serial_dev_inst *serial = modbus->serial;
+
+ return serial_source_remove(session, serial);
+}
+
+static uint16_t modbus_serial_rtu_crc(uint16_t crc,
+ const uint8_t *buffer, int len)
+{
+ int i;
+
+ if (!buffer || len < 0)
+ return crc;
+
+ while (len--) {
+ crc ^= *buffer++;
+ for (i = 0; i < 8; i++) {
+ int carry = crc & 1;
+ crc >>= 1;
+ if (carry)
+ crc ^= 0xA001;
+ }
+ }
+ return crc;
+}
+
+static int modbus_serial_rtu_send(void *priv,
+ const uint8_t *buffer, int buffer_size)
+{
+ int result;
+ struct modbus_serial_rtu *modbus = priv;
+ struct sr_serial_dev_inst *serial = modbus->serial;
+ uint8_t slave_addr = modbus->slave_addr;
+ uint16_t crc;
+
+ result = serial_write_nonblocking(serial, &slave_addr, sizeof(slave_addr));
+ if (result < 0)
+ return result;
+
+ result = serial_write_nonblocking(serial, buffer, buffer_size);
+ if (result < 0)
+ return result;
+
+ crc = modbus_serial_rtu_crc(0xFFFF, &slave_addr, sizeof(slave_addr));
+ crc = modbus_serial_rtu_crc(crc, buffer, buffer_size);
+
+ result = serial_write_nonblocking(serial, &crc, sizeof(crc));
+ if (result < 0)
+ return result;
+
+ return SR_OK;
+}
+
+static int modbus_serial_rtu_read_begin(void *priv, uint8_t *function_code)
+{
+ struct modbus_serial_rtu *modbus = priv;
+ uint8_t slave_addr;
+ int ret;
+
+ ret = serial_read_blocking(modbus->serial, &slave_addr, 1, 100);
+ if (ret != 1 || slave_addr != modbus->slave_addr)
+ return ret;
+
+ ret = serial_read_blocking(modbus->serial, function_code, 1, 100);
+ if (ret != 1)
+ return ret;
+
+ modbus->crc = modbus_serial_rtu_crc(0xFFFF, &slave_addr, sizeof(slave_addr));
+ modbus->crc = modbus_serial_rtu_crc(modbus->crc, function_code, 1);
+
+ return SR_OK;
+}
+
+static int modbus_serial_rtu_read_data(void *priv, uint8_t *buf, int maxlen)
+{
+ struct modbus_serial_rtu *modbus = priv;
+ int ret;
+
+ ret = serial_read_nonblocking(modbus->serial, buf, maxlen);
+ if (ret < 0)
+ return ret;
+ modbus->crc = modbus_serial_rtu_crc(modbus->crc, buf, ret);
+ return ret;
+}
+
+static int modbus_serial_rtu_read_end(void *priv)
+{
+ struct modbus_serial_rtu *modbus = priv;
+ uint16_t crc;
+ int ret;
+
+ ret = serial_read_blocking(modbus->serial, &crc, sizeof(crc), 100);
+ if (ret != 2)
+ return ret;
+
+ if (crc != modbus->crc) {
+ sr_err("CRC error (0x%04X vs 0x%04X).", crc, modbus->crc);
+ return SR_ERR_DATA;
+ }
+
+ return SR_OK;
+}
+
+static int modbus_serial_rtu_close(void *priv)
+{
+ struct modbus_serial_rtu *modbus = priv;
+
+ return serial_close(modbus->serial);
+}
+
+static void modbus_serial_rtu_free(void *priv)
+{
+ struct modbus_serial_rtu *modbus = priv;
+
+ sr_serial_dev_inst_free(modbus->serial);
+}
+
+SR_PRIV const struct sr_modbus_dev_inst modbus_serial_rtu_dev = {
+ .name = "serial_rtu",
+ .prefix = "",
+ .priv_size = sizeof(struct modbus_serial_rtu),
+ .scan = NULL,
+ .dev_inst_new = modbus_serial_rtu_dev_inst_new,
+ .open = modbus_serial_rtu_open,
+ .source_add = modbus_serial_rtu_source_add,
+ .source_remove = modbus_serial_rtu_source_remove,
+ .send = modbus_serial_rtu_send,
+ .read_begin = modbus_serial_rtu_read_begin,
+ .read_data = modbus_serial_rtu_read_data,
+ .read_end = modbus_serial_rtu_read_end,
+ .close = modbus_serial_rtu_close,
+ .free = modbus_serial_rtu_free,
+};
projects / libsigrok.git / commitdiff