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/>.
24 #include <libsigrok/libsigrok.h>
25 #include "libsigrok-internal.h"
27 #define LOG_PREFIX "modbus_serial"
29 #define BUFFER_SIZE 1024
31 struct modbus_serial_rtu {
32 struct sr_serial_dev_inst *serial;
37 static int modbus_serial_rtu_dev_inst_new(void *priv, const char *resource,
38 char **params, const char *serialcomm, int modbusaddr)
40 struct modbus_serial_rtu *modbus = priv;
44 modbus->serial = sr_serial_dev_inst_new(resource, serialcomm);
45 modbus->slave_addr = modbusaddr;
50 static int modbus_serial_rtu_open(void *priv)
52 struct modbus_serial_rtu *modbus = priv;
53 struct sr_serial_dev_inst *serial = modbus->serial;
55 if (serial_open(serial, SERIAL_RDWR) != SR_OK)
58 if (serial_flush(serial) != SR_OK)
64 static int modbus_serial_rtu_source_add(struct sr_session *session, void *priv,
65 int events, int timeout, sr_receive_data_callback cb, void *cb_data)
67 struct modbus_serial_rtu *modbus = priv;
68 struct sr_serial_dev_inst *serial = modbus->serial;
70 return serial_source_add(session, serial, events, timeout, cb, cb_data);
73 static int modbus_serial_rtu_source_remove(struct sr_session *session,
76 struct modbus_serial_rtu *modbus = priv;
77 struct sr_serial_dev_inst *serial = modbus->serial;
79 return serial_source_remove(session, serial);
82 static uint16_t modbus_serial_rtu_crc(uint16_t crc,
83 const uint8_t *buffer, int len)
87 if (!buffer || len < 0)
92 for (i = 0; i < 8; i++) {
103 static int modbus_serial_rtu_send(void *priv,
104 const uint8_t *buffer, int buffer_size)
107 struct modbus_serial_rtu *modbus = priv;
108 struct sr_serial_dev_inst *serial = modbus->serial;
109 uint8_t slave_addr = modbus->slave_addr;
112 result = serial_write_blocking(serial, &slave_addr, sizeof(slave_addr), 0);
116 result = serial_write_blocking(serial, buffer, buffer_size, 0);
120 crc = modbus_serial_rtu_crc(0xFFFF, &slave_addr, sizeof(slave_addr));
121 crc = modbus_serial_rtu_crc(crc, buffer, buffer_size);
123 result = serial_write_blocking(serial, &crc, sizeof(crc), 0);
130 static int modbus_serial_rtu_read_begin(void *priv, uint8_t *function_code)
132 struct modbus_serial_rtu *modbus = priv;
136 ret = serial_read_blocking(modbus->serial, &slave_addr, 1, 500);
137 if (ret != 1 || slave_addr != modbus->slave_addr)
140 ret = serial_read_blocking(modbus->serial, function_code, 1, 100);
144 modbus->crc = modbus_serial_rtu_crc(0xFFFF, &slave_addr, sizeof(slave_addr));
145 modbus->crc = modbus_serial_rtu_crc(modbus->crc, function_code, 1);
150 static int modbus_serial_rtu_read_data(void *priv, uint8_t *buf, int maxlen)
152 struct modbus_serial_rtu *modbus = priv;
155 ret = serial_read_nonblocking(modbus->serial, buf, maxlen);
158 modbus->crc = modbus_serial_rtu_crc(modbus->crc, buf, ret);
162 static int modbus_serial_rtu_read_end(void *priv)
164 struct modbus_serial_rtu *modbus = priv;
168 ret = serial_read_blocking(modbus->serial, &crc, sizeof(crc), 100);
172 if (crc != modbus->crc) {
173 sr_err("CRC error (0x%04X vs 0x%04X).", crc, modbus->crc);
180 static int modbus_serial_rtu_close(void *priv)
182 struct modbus_serial_rtu *modbus = priv;
184 return serial_close(modbus->serial);
187 static void modbus_serial_rtu_free(void *priv)
189 struct modbus_serial_rtu *modbus = priv;
191 sr_serial_dev_inst_free(modbus->serial);
194 SR_PRIV const struct sr_modbus_dev_inst modbus_serial_rtu_dev = {
195 .name = "serial_rtu",
197 .priv_size = sizeof(struct modbus_serial_rtu),
199 .dev_inst_new = modbus_serial_rtu_dev_inst_new,
200 .open = modbus_serial_rtu_open,
201 .source_add = modbus_serial_rtu_source_add,
202 .source_remove = modbus_serial_rtu_source_remove,
203 .send = modbus_serial_rtu_send,
204 .read_begin = modbus_serial_rtu_read_begin,
205 .read_data = modbus_serial_rtu_read_data,
206 .read_end = modbus_serial_rtu_read_end,
207 .close = modbus_serial_rtu_close,
208 .free = modbus_serial_rtu_free,