2 * This file is part of the libsigrok project.
4 * Copyright (C) 2015 Aurelien Jacobs <aurel@gnuage.org>
6 * This program is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 3 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
23 #include <libsigrok/libsigrok.h>
24 #include "libsigrok-internal.h"
26 #define LOG_PREFIX "modbus_serial"
28 #define BUFFER_SIZE 1024
30 struct modbus_serial_rtu {
31 struct sr_serial_dev_inst *serial;
36 static int modbus_serial_rtu_dev_inst_new(void *priv, const char *resource,
37 char **params, const char *serialcomm, int modbusaddr)
39 struct modbus_serial_rtu *modbus = priv;
43 modbus->serial = sr_serial_dev_inst_new(resource, serialcomm);
44 modbus->slave_addr = modbusaddr;
49 static int modbus_serial_rtu_open(void *priv)
51 struct modbus_serial_rtu *modbus = priv;
52 struct sr_serial_dev_inst *serial = modbus->serial;
54 if (serial_open(serial, SERIAL_RDWR) != SR_OK)
57 if (serial_flush(serial) != SR_OK)
63 static int modbus_serial_rtu_source_add(struct sr_session *session, void *priv,
64 int events, int timeout, sr_receive_data_callback cb, void *cb_data)
66 struct modbus_serial_rtu *modbus = priv;
67 struct sr_serial_dev_inst *serial = modbus->serial;
69 return serial_source_add(session, serial, events, timeout, cb, cb_data);
72 static int modbus_serial_rtu_source_remove(struct sr_session *session,
75 struct modbus_serial_rtu *modbus = priv;
76 struct sr_serial_dev_inst *serial = modbus->serial;
78 return serial_source_remove(session, serial);
81 static uint16_t modbus_serial_rtu_crc(uint16_t crc,
82 const uint8_t *buffer, int len)
86 if (!buffer || len < 0)
91 for (i = 0; i < 8; i++) {
102 static int modbus_serial_rtu_send(void *priv,
103 const uint8_t *buffer, int buffer_size)
106 struct modbus_serial_rtu *modbus = priv;
107 struct sr_serial_dev_inst *serial = modbus->serial;
108 uint8_t slave_addr = modbus->slave_addr;
111 result = serial_write_nonblocking(serial, &slave_addr, sizeof(slave_addr));
115 result = serial_write_nonblocking(serial, buffer, buffer_size);
119 crc = modbus_serial_rtu_crc(0xFFFF, &slave_addr, sizeof(slave_addr));
120 crc = modbus_serial_rtu_crc(crc, buffer, buffer_size);
122 result = serial_write_nonblocking(serial, &crc, sizeof(crc));
129 static int modbus_serial_rtu_read_begin(void *priv, uint8_t *function_code)
131 struct modbus_serial_rtu *modbus = priv;
135 ret = serial_read_blocking(modbus->serial, &slave_addr, 1, 100);
136 if (ret != 1 || slave_addr != modbus->slave_addr)
139 ret = serial_read_blocking(modbus->serial, function_code, 1, 100);
143 modbus->crc = modbus_serial_rtu_crc(0xFFFF, &slave_addr, sizeof(slave_addr));
144 modbus->crc = modbus_serial_rtu_crc(modbus->crc, function_code, 1);
149 static int modbus_serial_rtu_read_data(void *priv, uint8_t *buf, int maxlen)
151 struct modbus_serial_rtu *modbus = priv;
154 ret = serial_read_nonblocking(modbus->serial, buf, maxlen);
157 modbus->crc = modbus_serial_rtu_crc(modbus->crc, buf, ret);
161 static int modbus_serial_rtu_read_end(void *priv)
163 struct modbus_serial_rtu *modbus = priv;
167 ret = serial_read_blocking(modbus->serial, &crc, sizeof(crc), 100);
171 if (crc != modbus->crc) {
172 sr_err("CRC error (0x%04X vs 0x%04X).", crc, modbus->crc);
179 static int modbus_serial_rtu_close(void *priv)
181 struct modbus_serial_rtu *modbus = priv;
183 return serial_close(modbus->serial);
186 static void modbus_serial_rtu_free(void *priv)
188 struct modbus_serial_rtu *modbus = priv;
190 sr_serial_dev_inst_free(modbus->serial);
193 SR_PRIV const struct sr_modbus_dev_inst modbus_serial_rtu_dev = {
194 .name = "serial_rtu",
196 .priv_size = sizeof(struct modbus_serial_rtu),
198 .dev_inst_new = modbus_serial_rtu_dev_inst_new,
199 .open = modbus_serial_rtu_open,
200 .source_add = modbus_serial_rtu_source_add,
201 .source_remove = modbus_serial_rtu_source_remove,
202 .send = modbus_serial_rtu_send,
203 .read_begin = modbus_serial_rtu_read_begin,
204 .read_data = modbus_serial_rtu_read_data,
205 .read_end = modbus_serial_rtu_read_end,
206 .close = modbus_serial_rtu_close,
207 .free = modbus_serial_rtu_free,