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1 | /* | |
2 | * This file is part of the libsigrok project. | |
3 | * | |
4 | * Copyright (C) 2015 Aurelien Jacobs <aurel@gnuage.org> | |
5 | * | |
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. | |
10 | * | |
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. | |
15 | * | |
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/>. | |
18 | */ | |
19 | ||
20 | #include <config.h> | |
21 | #include <glib.h> | |
22 | #include <stdlib.h> | |
23 | #include <string.h> | |
24 | #include <libsigrok/libsigrok.h> | |
25 | #include "libsigrok-internal.h" | |
26 | ||
27 | #define LOG_PREFIX "modbus_serial" | |
28 | ||
29 | #define BUFFER_SIZE 1024 | |
30 | ||
31 | struct modbus_serial_rtu { | |
32 | struct sr_serial_dev_inst *serial; | |
33 | uint8_t slave_addr; | |
34 | uint16_t crc; | |
35 | }; | |
36 | ||
37 | static int modbus_serial_rtu_dev_inst_new(void *priv, const char *resource, | |
38 | char **params, const char *serialcomm, int modbusaddr) | |
39 | { | |
40 | struct modbus_serial_rtu *modbus = priv; | |
41 | ||
42 | (void)params; | |
43 | ||
44 | modbus->serial = sr_serial_dev_inst_new(resource, serialcomm); | |
45 | modbus->slave_addr = modbusaddr; | |
46 | ||
47 | return SR_OK; | |
48 | } | |
49 | ||
50 | static int modbus_serial_rtu_open(void *priv) | |
51 | { | |
52 | struct modbus_serial_rtu *modbus = priv; | |
53 | struct sr_serial_dev_inst *serial = modbus->serial; | |
54 | ||
55 | if (serial_open(serial, SERIAL_RDWR) != SR_OK) | |
56 | return SR_ERR; | |
57 | ||
58 | if (serial_flush(serial) != SR_OK) | |
59 | return SR_ERR; | |
60 | ||
61 | return SR_OK; | |
62 | } | |
63 | ||
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) | |
66 | { | |
67 | struct modbus_serial_rtu *modbus = priv; | |
68 | struct sr_serial_dev_inst *serial = modbus->serial; | |
69 | ||
70 | return serial_source_add(session, serial, events, timeout, cb, cb_data); | |
71 | } | |
72 | ||
73 | static int modbus_serial_rtu_source_remove(struct sr_session *session, | |
74 | void *priv) | |
75 | { | |
76 | struct modbus_serial_rtu *modbus = priv; | |
77 | struct sr_serial_dev_inst *serial = modbus->serial; | |
78 | ||
79 | return serial_source_remove(session, serial); | |
80 | } | |
81 | ||
82 | static uint16_t modbus_serial_rtu_crc(uint16_t crc, | |
83 | const uint8_t *buffer, int len) | |
84 | { | |
85 | int i; | |
86 | ||
87 | if (!buffer || len < 0) | |
88 | return crc; | |
89 | ||
90 | while (len--) { | |
91 | crc ^= *buffer++; | |
92 | for (i = 0; i < 8; i++) { | |
93 | int carry = crc & 1; | |
94 | crc >>= 1; | |
95 | if (carry) | |
96 | crc ^= 0xA001; | |
97 | } | |
98 | } | |
99 | ||
100 | return crc; | |
101 | } | |
102 | ||
103 | static int modbus_serial_rtu_send(void *priv, | |
104 | const uint8_t *buffer, int buffer_size) | |
105 | { | |
106 | int result; | |
107 | struct modbus_serial_rtu *modbus = priv; | |
108 | struct sr_serial_dev_inst *serial = modbus->serial; | |
109 | uint8_t slave_addr = modbus->slave_addr; | |
110 | uint16_t crc; | |
111 | ||
112 | result = serial_write_blocking(serial, &slave_addr, sizeof(slave_addr), 0); | |
113 | if (result < 0) | |
114 | return SR_ERR; | |
115 | ||
116 | result = serial_write_blocking(serial, buffer, buffer_size, 0); | |
117 | if (result < 0) | |
118 | return SR_ERR; | |
119 | ||
120 | crc = modbus_serial_rtu_crc(0xFFFF, &slave_addr, sizeof(slave_addr)); | |
121 | crc = modbus_serial_rtu_crc(crc, buffer, buffer_size); | |
122 | ||
123 | result = serial_write_blocking(serial, &crc, sizeof(crc), 0); | |
124 | if (result < 0) | |
125 | return SR_ERR; | |
126 | ||
127 | return SR_OK; | |
128 | } | |
129 | ||
130 | static int modbus_serial_rtu_read_begin(void *priv, uint8_t *function_code) | |
131 | { | |
132 | struct modbus_serial_rtu *modbus = priv; | |
133 | uint8_t slave_addr; | |
134 | int ret; | |
135 | ||
136 | ret = serial_read_blocking(modbus->serial, &slave_addr, 1, 500); | |
137 | if (ret != 1 || slave_addr != modbus->slave_addr) | |
138 | return SR_ERR; | |
139 | ||
140 | ret = serial_read_blocking(modbus->serial, function_code, 1, 100); | |
141 | if (ret != 1) | |
142 | return SR_ERR; | |
143 | ||
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); | |
146 | ||
147 | return SR_OK; | |
148 | } | |
149 | ||
150 | static int modbus_serial_rtu_read_data(void *priv, uint8_t *buf, int maxlen) | |
151 | { | |
152 | struct modbus_serial_rtu *modbus = priv; | |
153 | int ret; | |
154 | ||
155 | ret = serial_read_nonblocking(modbus->serial, buf, maxlen); | |
156 | if (ret < 0) | |
157 | return ret; | |
158 | modbus->crc = modbus_serial_rtu_crc(modbus->crc, buf, ret); | |
159 | return ret; | |
160 | } | |
161 | ||
162 | static int modbus_serial_rtu_read_end(void *priv) | |
163 | { | |
164 | struct modbus_serial_rtu *modbus = priv; | |
165 | uint16_t crc; | |
166 | int ret; | |
167 | ||
168 | ret = serial_read_blocking(modbus->serial, &crc, sizeof(crc), 100); | |
169 | if (ret != 2) | |
170 | return SR_ERR; | |
171 | ||
172 | if (crc != modbus->crc) { | |
173 | sr_err("CRC error (0x%04X vs 0x%04X).", crc, modbus->crc); | |
174 | return SR_ERR_DATA; | |
175 | } | |
176 | ||
177 | return SR_OK; | |
178 | } | |
179 | ||
180 | static int modbus_serial_rtu_close(void *priv) | |
181 | { | |
182 | struct modbus_serial_rtu *modbus = priv; | |
183 | ||
184 | return serial_close(modbus->serial); | |
185 | } | |
186 | ||
187 | static void modbus_serial_rtu_free(void *priv) | |
188 | { | |
189 | struct modbus_serial_rtu *modbus = priv; | |
190 | ||
191 | sr_serial_dev_inst_free(modbus->serial); | |
192 | } | |
193 | ||
194 | SR_PRIV const struct sr_modbus_dev_inst modbus_serial_rtu_dev = { | |
195 | .name = "serial_rtu", | |
196 | .prefix = "", | |
197 | .priv_size = sizeof(struct modbus_serial_rtu), | |
198 | .scan = NULL, | |
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, | |
209 | }; |